Journal articles: 'State and transformer matrix'

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Zainuddin, Zafirah, Rahimi Baharom, Ihsan Mohd Yassin, and Khairul Safuan Muhammad. "Solid-State Transformer (S2T) of Single Phase Matrix Converter." International Journal of Power Electronics and Drive Systems (IJPEDS) 9, no. 3 (September 1, 2018): 997. http://dx.doi.org/10.11591/ijpeds.v9.i3.pp997-1005.

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<span lang="EN-US">Solid-State Transformer (S2T) also known as Power Electronic Transformer (PET) is applied in various industrial fields compared to the conventional transformer due to it flexible voltage transfer ratio, high power density, and low harmonic distortion. This paper presents the S2T of Single Phase Matrix Converter (SPMC) that acts as cyclo-converter. A 1kHz frequency was synthesized on the primary side of the transformer using Pulse Width Modulation (PWM) technique, whilst, the output converted by the SPMC that produces the 50Hz frequency. A part of AC to AC operation, the switching algorithm for safe-commutation technique is also presented to solve the commutation problem caused by the usage of inductive load. Minimization of size, losses and optimal efficiency are the advantages of this approach. The proposed model was simulated by using MATLAB/Simulink (MLS).</span>

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Pinto, S. F., P. V. Mendes, and J. Fernando Silva. "Modular Matrix Converter Based Solid State Transformer for smart grids." Electric Power Systems Research 136 (July 2016): 189–200. http://dx.doi.org/10.1016/j.epsr.2016.02.020.

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Sun, Chengyu, and XiaoGuang Yue. "Method Based on Rough Set and Improved Petri Net for Transformer Faults Diagnosis." International Journal of Online Engineering (iJOE) 11, no. 8 (October 26, 2015): 25. http://dx.doi.org/10.3991/ijoe.v11i8.4879.

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Oil chromatographic analysis is widely used in transformer fault diagnosis, but it is difficult to establish accurate maping relationship between the parameter space and the state space, and there is information complexity. This paper adopts the combined diagnostic model of rough sets and petri nets, firstlysimplifies the complex system which contains complicated discrete information by rough set to solve the state space limitations of Petri network; and improves petri network based on mining association rules, adopts the correlation matrix and state equation method to improve the reasoning speed, at the same time turns the diagnosis into matrix operations to change complex calculations to simple math which has certain applicability. Finally the algorithm is applied to gas chromatographic analysis in transformer oil, the calculation results is the same with IEC three ratio method, which proves that this method can quickly and accurately to judge the running state of transformer, so as to improve the safety, stability and economic operation of the flat water transformer.

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Wang, Hui, Yichun Zhang, Yao Sun, Minghui Zheng, Xiao Liang, Guanguan Zhang, Kaiyuan Tan, and Jianghua Feng. "Topology and Control Method of a Single-Cell Matrix-Type Solid-State Transformer." IEEE Journal of Emerging and Selected Topics in Power Electronics 8, no. 3 (September 2020): 2302–12. http://dx.doi.org/10.1109/jestpe.2019.2940514.

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Meng, Xiang Ping, Lin Li, Hui Wang, and Xiu Ji. "The Condition Assessment of Distribution Transformer Based on Improved Analytic Hierarchy Process." Applied Mechanics and Materials 644-650 (September 2014): 3463–67. http://dx.doi.org/10.4028/www.scientific.net/amm.644-650.3463.

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It is very vital for the distribution transformer in the distribution system, crucially ensuring its reliable operation is, therefore, timely and accurately grasping the state of the transformer is very meaningful for guiding the condition maintenance of transformer and improving the operation reliability of distribution system. It is very difficult for AHP to inspect and adjust the consistency of judgment matrix, and its inspection standard lacks of scientific basis, so we put forward a fuzzy comprehensive evaluation method which uses five-demarcation method to establish the fuzzy complementary matrix on the condition assessment of distribution transformer. Through an example analysis, which proposed method is proved to be rationality and validity.

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Lai, R. S., K. D. T. Ngo, and J. K. Watson. "Steady-state analysis of the symmetrical push-pull power converter employing a matrix transformer." IEEE Transactions on Power Electronics 7, no. 1 (January 1992): 44–53. http://dx.doi.org/10.1109/63.124576.

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González A, G., and R. Galindo. "Steady state determination using bond graphs for systems with singular state matrix." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 225, no. 7 (August 26, 2011): 887–901. http://dx.doi.org/10.1177/2041304110394552.

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A bond graph procedure to get the steady state value for linear time-invariant systems is presented. The general case of a singular state matrix is considered. The procedure is based on a junction structure configuration with derivative causality assignment, and on relationships of the bond graphs with integral and derivative causality assignments. It is shown that the structurally null modes, i.e. the poles at the origin, are cancelled for steady state. The key to cancel the poles at the origin is that the adjugate matrix of sIn − Ap multiplies Bp yielding the zeros at the origin with the same order that the structurally null modes, where ( Ap, Bp, Cp, Dp) is a state space realization of a linear time-invariant system, s is the Laplace operator and In, is an n × n identity matrix. Hence, this unstable part of the system is cancelled and the steady state can be obtained. Thus, the singularity of the state space matrix is avoided, and the steady state is obtained from the bond graph with derivative causality assignment. Since the singular state matrix is considered, it is shown that by using the bond graph with derivative causality assignment, an equivalent system with linearly independent state variables can be obtained. An example of an electrical system with an electrical transformer modelled by an I-field whose state matrix is singular is presented. Also, the proposed methodology for a load driven by two DC motors is applied.

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Liu, Jian, Shixin Yue, Wenxi Yao, Wuhua Li, and Zhengyu Lu. "DC Voltage Ripple Optimization of a Single-Stage Solid-State Transformer Based on the Modular Multilevel Matrix Converter." IEEE Transactions on Power Electronics 35, no. 12 (December 2020): 12801–15. http://dx.doi.org/10.1109/tpel.2020.2992707.

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Liu, Yupeng, Yushan Liu, Baoming Ge, and Haitham Abu-Rub. "Interactive Grid Interfacing System by Matrix-Converter-Based Solid State Transformer With Model Predictive Control." IEEE Transactions on Industrial Informatics 16, no. 4 (April 2020): 2533–41. http://dx.doi.org/10.1109/tii.2017.2679137.

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Banaei, M. R., and E. Salary. "Mitigation of voltage sag, swell and power factor correction using solid-state transformer based matrix converter in output stage." Alexandria Engineering Journal 53, no. 3 (September 2014): 563–72. http://dx.doi.org/10.1016/j.aej.2014.06.003.

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Jiang, Ting, Jian Feng Jiang, and Xi Jun Yang. "Research on Multi-Stage Series-Connection High-Voltage High-Power Matrix Converter." Advanced Materials Research 347-353 (October 2011): 843–47. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.843.

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Charge storage is an important research topic in smart grid and distributed generation system, pumped storage as one of the most popular large-scale charge storage methods has attracted increasing attention. However, the motor generator of the pumped charge station has high input voltage and heavy load, so in order to get grid connected safely, being soft started by a high voltage converter is necessary. In the view of the existing high voltage high power converters, only the voltage source inverter Multi-stage Series-connection high voltage frequency converters are suitable for this application, and this paper gives analysis of such converters. Based on Carrier Wave Phase-Shifted modulation, this paper proposes a multi-stage Series-connection high voltage frequency converter with balanced output power of the step-down transformer’s secondary windings, in which a winding burdens three symmetry three-phase to single-phase MC outputs, and the same phase outputs of the MC are cascaded at the secondary side of the transformers, letting out one phase of high-voltage AC output. The circuit is consisted of a step-down industry frequency transformer at the network side, three-phase to single-phase MC arrays, a step-up high frequency transformer at the load side and filter components. The simulation result based on MATLAB/SIMULINK shows that the proposed multi-stage Series-connection high voltage frequency converter is feasible and low-cost.

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Abdulahovic, Tarik, and Torbjörn Thiringer. "Improvement of admittance measurements for modeling of an ungrounded reactor/transformer winding." International Journal of Modeling, Simulation, and Scientific Computing 07, no. 03 (August 23, 2016): 1640002. http://dx.doi.org/10.1142/s179396231640002x.

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In this paper, a model of an ungrounded reactor winding is developed for transient voltage studies. The developed model is a black box model where the state-space model is developed using the directly measured admittance matrix of the reactor winding. Furthermore, an improved model is developed, where the accuracy of the admittance matrix measurement set in the low frequency band is obtained indirectly using an additional set of voltage ratio measurements. When the measured admittances are low, the accuracy of the diagonal admittance vectors in the low frequency band is low as well. However, the accuracy at low frequencies obtained using the indirect measurements is improved at nodes with the lowest admittances. In this paper, different approaches for indirect measurements are studied and the most accurate method is identified considering the physical structure of windings.

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Trkulja, Bojan, Ana Drandić, Viktor Milardić, and Igor Žiger. "Evaluation of Methodology for Lightning Impulse Voltage Distribution over High-Voltage Windings of Inductive Voltage Transformers." Energies 14, no. 16 (August 20, 2021): 5144. http://dx.doi.org/10.3390/en14165144.

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Knowledge of lightning impulse (LI) voltage distribution over transformer windings during the design stage of the transformer is very important. Specific design differences in inductive voltage transformers make the transient analysis approach different to the approach to the power transformers. In this paper, a methodology for acquiring lightning impulse voltage distribution over high-voltage (HV) winding of inductive voltage transformers is presented and evaluated. Resistance, inductance, and capacitance matrices are calculated using the integral and boundary element methods (BEM) approach. Additionally, in order to improve the capacitance matrix solver, adaptive cross approximation (ACA) is applied. These parameters are then used to solve the equivalent circuit model in time domain. In order to evaluate the methodology, an experimental and numerical investigation of the layer discretisation, iron core influence, and accuracy of the proposed methodology is performed. The comparison of numerical results with measurements confirms the validity of the methodology.

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Liu, Yupeng, Wencheng Wang, Yushan Liu, and Sertac Bayhan. "Real-time implementation of finite control set model predictive control for matrix converter based solid state transformer." International Journal of Hydrogen Energy 42, no. 28 (July 2017): 17976–83. http://dx.doi.org/10.1016/j.ijhydene.2017.04.293.

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Bortis, Dominik, Juergen Biela, and Johann W. Kolar. "Transient Behavior of Solid-State Modulators With Matrix Transformers." IEEE Transactions on Plasma Science 38, no. 10 (October 2010): 2785–92. http://dx.doi.org/10.1109/tps.2010.2065243.

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Suo, Chunguang, Yanan Ren, Wenbin Zhang, Yincheng Li, Yanyun Wang, and Yi Ke. "Evaluation Method for Winding Performance of Distribution Transformer." Energies 14, no. 18 (September 15, 2021): 5832. http://dx.doi.org/10.3390/en14185832.

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In order to ensure the safe and stable operation of a power system, the performance evaluation of transformer windings after a short-circuit test can predict whether the windings are deformed in order to provide a useful reference for the operation and maintenance of the power sector. This paper proposes a method for evaluating the performance of transformer windings in order to improve the overall effectiveness of a winding evaluation. The index data obtained based on a short-circuit impedance method, frequency response method, and oscillation wave method are used in the algorithm proposed in this paper. First, the transformer winding performance evaluation index system is constructed. Second, the weight of each index is determined by analytic hierarchy process, and then the fuzzy comprehensive assessment method is introduced, and the fuzzy evaluation matrix is established, the evaluation results are calculated using the evaluation formula. Finally, the maximum membership principle is used to determine the performance level of the transformer winding on the evaluation results, and the evaluation results of the transformer winding state are obtained. The example shows that the evaluation level of the measured transformer winding performance can be obtained by this method as “good”. Compared with the traditional method, this method can simplify the evaluation while maintaining higher accuracy.

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Yan, Yu Heng, and Yan Song Li. "OCT Signal Processing Method Based on Sequential Kalman Filtering." Advanced Materials Research 1092-1093 (March 2015): 300–303. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.300.

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Optical current transformer (OCT) measured current signal which is mixed with strong random noise. The measured readings can’t accurately reflect the value of the measured current. Since the optical current transformer noise inside the band is basically where the measured current signal overlap,we can not use the traditional method to filter it out. This paper describes the measurement principle based on the Faraday effect of optical current transformer and signal to noise characteristics. Considering optical current transformer for low SNR characteristics, and embedded systems do not have the characteristics of a matrix library, we proposed using sequential Kalman filter to improve the real-time output signal to noise ratio. In the measured current for DC and AC conditions,we established an appropriate state space model Kalman filter.,and conduct simulation on matlab. Practice shows that the sequential Kalman filter algorithm can effectively improve the output signal to noise ratio and accuracy.

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Tikhonov, A. I., A. V. Stulov, A. A. Karzhevin, and A. V. Podobny. "Development of a nonlinear model of a three-phase transformer to study the effect of asymmetry of the magnetic system on the operation of the device in arbitrary modes." Vestnik IGEU, no. 1 (2020): 22–31. http://dx.doi.org/10.17588/2072-2672.2020.1.022-031.

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Currently, when designing power transformers in order to take into account the influence of the asymmetry of the magnetic system on the operation of the device, especially in transition modes, engineering analysis packages based on field models are increasingly being used. However, such models are slow. At the same time, dynamic transformer models based on the magnetic circuit model are not inferior in accuracy to field models. Existing chain models of a three-phase transformer either do not take into account the asymmetry of the magnetic system or poorly integrate with simulation packages. The purpose of this article is to develop a dynamic model of a three-phase transformer which would allow considering the design features at the design stage, in particular, the asymmetry of the magnetic system and the influence of these features on arbitrary modes of the device operation. A contour current method was used to calculate a non-linear magnetic circuit of a three-rod transformer, and a single-step method based on a modified 2nd order Rosenbrock formula was used to calculate the electrical circuit. A nonlinear dynamic model of a three-phase three-core transformer based on the use of controlled current sources and EMF has been developed. This model is able to integrate with simulation packages including MatLab Simulink SimPowerSystem. The model allows taking into account the influence of the asymmetry of the magnetic system on the transformer operation in various operating modes including emergency and asymmetric ones. The novelty of the developed model can be seen in the approach to constructing a nonlinear matrix of magnetic resistances without explicitly using inductance matrices, which increases the accuracy and stability of the model considering the asymmetry of the magnetic system. The curves of transients in the characteristic operating modes of the transformer are given. The developed models can be used in the design of power transformers, including specific ones. They enable to increase the accuracy of the verification calculation and bring it to the level of simulation modelling. These models can also be applied for constructing digital twins of power transformers taking into account the influence of the design features of transformer equipment on the operation of power grids.

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Gu, Da-Ke, Da-Wei Zhang, and Yin-Dong Liu. "Robust Parametric Control of Lorenz System via State Feedback." Complexity 2020 (November 23, 2020): 1–10. http://dx.doi.org/10.1155/2020/6548142.

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This paper considers the parametric control to the Lorenz system by state feedback. Based on the solutions of the generalized Sylvester matrix equation (GSE), the unified explicit parametric expression of the state feedback gain matrix is proposed. The closed loop of the Lorenz system can be transformed into an arbitrary constant matrix with the desired eigenstructure (eigenvalues and eigenvectors). The freedom provided by the parametric control can be fully used to find a controller to satisfy the robustness criteria. A numerical simulation is developed to illustrate the effectiveness of the proposed approach.

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Zhou, Qiang, and Xin Li. "STN-Homography: Direct Estimation of Homography Parameters for Image Pairs." Applied Sciences 9, no. 23 (November 29, 2019): 5187. http://dx.doi.org/10.3390/app9235187.

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Estimating a 2D homography from a pair of images is a fundamental task in computer vision. Contrary to most convolutional neural network-based homography estimation methods that use alternative four-point homography parameterization schemes, in this study, we directly estimate the 3 × 3 homography matrix value. We show that after coordinate normalization, the magnitude difference and variance of the elements of the normalized 3 × 3 homography matrix is very small. Accordingly, we present STN-Homography, a neural network based on spatial transformer network (STN), to directly estimate the normalized homography matrix of an image pair. To decrease the homography estimation error, we propose hierarchical STN-Homography and sequence STN-homography models in which the sequence STN-Homography can be trained in an end-to-end manner. The effectiveness of the proposed methods is demonstrated based on experiments on the Microsoft common objects in context (MSCOCO) dataset, and it is shown that they significantly outperform the current state-of-the-art. The average processing time of the three-stage hierarchical STN-Homography and the three-stage sequence STN-Homography models on a GPU are 17.85 ms and 13.85 ms, respectively. Both models satisfy the real-time processing requirements of most potential applications.

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Wang, Yongqiang, Changhui Feng, Ruoyu Fei, and Yu Luo. "Thermal-ageing characteristics of dry-type transformer epoxy composite insulation." High Performance Polymers 32, no. 7 (February 26, 2020): 741–52. http://dx.doi.org/10.1177/0954008320906439.

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To study the ageing characteristics of epoxy resin composite insulation in dry-type transformers in high-temperature environments, glass fibre-reinforced epoxy resin samples were placed in a hot air ageing environment at 130°C for testing. Dielectric properties, partial discharge (PD), microscopic morphology, three-dimensional morphology and Fourier transform infrared spectroscopy of aged samples were periodically tested. The results show that during the ageing process, the change in the surface morphology of the sample leads to an overall upward trend in surface roughness, and the older the sample, the faster the surface roughness increases; changes in the surface morphology and three-dimensional morphology of the material constitute the basis for judging the condition of the insulating surface and the state of ageing development. Microcracks are the direct cause of debonding of glass fibres and epoxy matrix. Degradation of the sample during the ageing process generates many free radicals, which enhances the polarisation ability of the sample and increases both the dielectric constant and the dielectric loss factor. The real part of the complex dielectric constant is more sensitive to the ageing response of the sample. The older the sample, the greater the effect on the results of the dielectric spectrum test. Since the aged sample generates more hot electrons during the PD process and makes it easier to inject electrons into the material, the PD of the sample is rendered more intense by thermal ageing. There is a significant difference between the degradation mechanism of the thermal ageing and PD. The samples subjected to PD after thermal ageing produce new groups, and the degradation of the samples is more severe than that caused by thermal ageing, or PD, alone.

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Wick, Markus, Matthias Jüttner, and Wolfgang M. Rucker. "Harmonic balanced Jiles-Atherton hysteresis implementation for finite element simulation." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 36, no. 5 (September 4, 2017): 1386–95. http://dx.doi.org/10.1108/compel-02-2017-0098.

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Purpose The high calculation effort for accurate material loss simulation prevents its observation in most magnetic devices. This paper aims at reducing this effort for time periodic applications and so for the steady state of such devices. Design/methodology/approach The vectorized Jiles-Atherton hysteresis model is chosen for the accurate material losses calculation. It is transformed in the frequency domain and coupled with a harmonic balanced finite element solver. The beneficial Jacobian matrix of the material model in the frequency domain is assembled based on Fourier transforms of the Jacobian matrix in the time domain. A three-phase transformer is simulated to verify this method and to examine the multi-harmonic coupling. Findings A fast method to calculate the linearization of non-trivial material models in the frequency domain is shown. The inter-harmonic coupling is moderate, and so, a separated harmonic balanced solver is favored. The additional calculation effort compared to a saturation material model without losses is low. The overall calculation time is much lower than a time-dependent simulation. Research limitations/implications A moderate working point is chosen, so highly saturated materials may lead to a worse coupling. A single material model is evaluated. Researchers are encouraged to evaluate the suggested method on different material models. Frequency domain approaches should be in favor for all kinds of periodic steady-state applications. Practical implications Because of the reduced calculation effort, the simulation of accurate material losses becomes reasonable. This leads to a more accurate development of magnetic devices. Originality/value This paper proposes a new efficient method to calculate complex material models like the Jiles-Atherton hysteresis and their Jacobian matrices in the frequency domain.

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Fan, Hong-Yi, and Yue Fan. "Coherent State Representation for Generalized Bosonic Bogolyubov Transformation." Modern Physics Letters B 11, no. 26n27 (November 20, 1997): 1157–60. http://dx.doi.org/10.1142/s0217984997001377.

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We show that the generalized bosonic Bogolyubov transformation generator [Formula: see text] where G is a n×n matrix, has the manifest coherent state representation [Formula: see text] This expression has the advantage of exhibiting the transition from classical transformation to its quantum mechanical correspondence apparent and providing us with a convenient approach for calculating some Bogolyubov transformed states.

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Prikhna, Tatiana, Vladimir Sokolovsky, Victor Meerovich, Michael Eisterer, Athanasios G. Mamalis, Artem Kozyrev, Wolfgang Gawalek, et al. "Processing of Bulk MgB₂ Superconductors for Application in Fault Current Limiters." Materials Science Forum 856 (May 2016): 32–37. http://dx.doi.org/10.4028/www.scientific.net/msf.856.32.

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Fault current limiters (FCL) require superconducting (SC) materials which can provide a definite rate of response to a fault event resulting in the SC – normal state reversible transition. The main characteristics determined the material suitability are the critical current density, jc, thermal conductivity and capacity which are strongly determined by manufacturing technology, in particular, of MgB2. In the paper we estimate the jc of bulk MgB2 samples by the vibrating magnetometer and inductive, contactless transformer, method using ring samples. The bulk MgB2 samples were produced under 30 MPa (hot pressing) and 2 GPa (quasihydrostatic pressing) at 800-1050 оС from different initial ingredients (Mg and B or MgB2 with and without additions). It is shown that the technology process and initial ingredients strongly influence the distribution of boron-and oxygen-enriched nanosized inhomogenities in MgB2 matrix, connectivity between SC grains, material porosity and, as result, the SC properties. The transformer method gives the jc in the range from 1.6·104 up to 6.3·104 A/cm2 at about 4 K while using magnetometer measurements the jc is estimated from 2.24·105 up to 5.1·105 A/cm2 at 10 K in self-magnetic fields. The contradictions in the jc estimated by different methods can be explained by instability of the SC state of MgB2, caused by variation of the applied magnetic field. Using the transformer method AC losses per a cycle before quenching for the best materials were estimated around 0.75-1 J/cm3, while the power of losses was about 200 W. The FCL model with rings cut out from SC MgB2 materials prepared using various technologies demonstrated that MgB2 is a promising material for application in inductive FCLs.

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Singh, G. K., S. N. Singh, and R. P. Saini. "Steady-State Modeling and Analysis of Grid-Connected Six-Phase Induction Generator for Renewable Energy Generation." Advanced Materials Research 516-517 (May 2012): 645–59. http://dx.doi.org/10.4028/www.scientific.net/amr.516-517.645.

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This article presents the steady-state modeling and analysis of a grid-connected six-phase induction generator for renewable energy generation powered by hydro turbine. The basis of the analysis is nodal admittance method as applied to the equivalent circuit, and used to analyze the behavior of the machine for the operating mode such as (i) when only one three-phase winding set is connected to grid, (ii) when one three-phase winding set is connected to grid and other three-phase winding set is subjected to load, and (iii) when both the three-phase winding sets are connected to grid through an interconnecting Y-/Y six-phase to three-phase transformer. Nodal admittance based matrix equations are easier to modify in order to account for mutual leakage coupling between two three-phase winding sets, core loss component, and make the analysis very easy, fast and accurate. Through analytical and practical studies, it is shown that machine can feed direct, reliable, and low cost power to grid without interface network. The analytical results are found to be in good agreement with experimental results.

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Korkh, Oleksandr, Andrei Blinov, Dmitri Vinnikov, and Andrii Chub. "Review of Isolated Matrix Inverters: Topologies, Modulation Methods and Applications." Energies 13, no. 9 (May 11, 2020): 2394. http://dx.doi.org/10.3390/en13092394.

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This paper presents a review of isolated matrix inverters. The study contributes to creating a point of reference for a comprehensive classification of existing solutions. Over 30 topologies were reviewed, and the main advantages and disadvantages discussed. Applications of isolated matrix inverters are summarized in a tabular form to demonstrate their flexibility for different power and voltage levels achieved due to the presence of a transformer. These inverters have been proposed for the uninterruptible power supplies, high and low-voltage/power photovoltaic systems, low-power fuel cell, different low- and high-voltage battery and/or electric vehicle chargers, audio amplifiers. The fully controlled switches on both terminals of these converters typically can provide the bidirectional power transfer capability, which is also addressed for most of the topologies, but requires some modification in their modulation strategy. Average efficiency of today’s isolated matrix inverters is comparable with the two-stage power converters; however, they can provide higher reliability and lower cost.

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Li, Jian Sheng, Jun Liang, Zhi Hao Yun, Li Zhang, and Feng Zhang. "Dynamic Condition Assessment of Electrical Equipments Based on Markov Prediction." Applied Mechanics and Materials 556-562 (May 2014): 1696–99. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.1696.

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A novel method for electrical equipments condition assessment is proposed based on Markov prediction. Firstly, the condition representation parameters are induced according to the general volt-ampere characteristics, which can be identified by least square method. Secondly, the number of samples falling into different intervals is counted and the state transition probability matrix is calculated. Last, the distribution of parameters in future detection periods is predicted and the equipments condition is assessed by the ratio of the length of current operation time and the estimated life. Take a single phase two-winding transformer as an example, Monte Carlo simulation is used to generate the leakage inductance data and the electrical data is derived by PSCAD. The equipment condition assessment results verify the effectiveness and feasibility of this proposed method.

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Schmidt, J. R. "A modified Bethe Ansatz for the two-dimensional dimer problem." Canadian Journal of Physics 85, no. 7 (July 1, 2007): 745–62. http://dx.doi.org/10.1139/p07-075.

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The two-dimensional dimer problem is studied using the tools of modern solvable models. The transfer matrix is constructed from local monodromy matrices, and is diagonalized by a modified Bethe Ansatz that does not begin with a Bethe ground state, but rather with a pair of states transformed one into the other by the transfer matrix. The resulting Bethe eigenvectors have a structure very different from those constructed in other models from a ground state, and have some properties in common with the free-fermion eigenvectors of the squared transfer matrix encountered in the literature. PACS Nos.: 05.50+q, 02.10.Ox, 02.30.Ik, 05.20.–y

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He, Zhongwei, and Wei Xie. "State estimation for a class of Linear Parameter-Varying systems with parametric uncertainties." Transactions of the Institute of Measurement and Control 42, no. 15 (July 20, 2020): 3035–42. http://dx.doi.org/10.1177/0142331220940201.

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This paper is concerned with interval state estimation for a class of Linear Parameter-Varying systems with parametric uncertainties. Firstly, sufficient conditions to guarantee both the cooperativity and stability of observation error dynamics are presented in terms of parameterized matrix inequality formulations. Secondly, a novel method for scheduled controller law design is proposed in the framework of interval observer design. Under the assumptions that scheduled parameters have a polytopic structure property, the problems of the existence conditions of observers and scheduled controller design are transformed into finite linear matrix inequalities ones, which can be solved by convex optimization algorithms. The validity of the proposed state estimation methods is illustrated through a simple example.

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Fan, Ning, Hang Liang, and Pei Quan Guo. "Tool Wear State Diagnosis Based on Wavelet Analysis-BP Neural Network." Key Engineering Materials 431-432 (March 2010): 253–56. http://dx.doi.org/10.4028/www.scientific.net/kem.431-432.253.

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Cutting force collected by experiment is transformed by continue wavelet in order to overcome the disadvantage that signal processing analyzes single variable. The eigenvector which can reflect tool wear state is extracted from scale-energy matrix based on analysis, and BP neural network is established to predict tool wear. Trained network is used for prediction by unknown sample. Results show that this method can identify and diagnose accurately tool wear state.

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Liu, Long, and Fu Zhen Xuan. "Damaged Structural Vibration Analysis Using the Hamiltonian Matrix Perturbation Theory." Advanced Materials Research 44-46 (June 2008): 91–96. http://dx.doi.org/10.4028/www.scientific.net/amr.44-46.91.

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This paper proposes a Hamiltonian perturbation approach for analyzing the dynamic characteristics of the damaged structure. Firstly, structural vibration governing equation is transformed to the general expression of state variables composed of displacement and momentum. On the basis of the conjugate symplectic orthogonal relation, the first-, and second- order perturbation expression of the damaged structural eigensolution are obtained. Finally, the numerical simulation and cantilever experiment prove the effectiveness of this approach.

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Shao, Lei, He Huang, Heming Zhao, and Tingwen Huang. "Delay-Dependent State Estimation of Static Neural Networks with Time-Varying and Distributed Delays." Mathematical Problems in Engineering 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/951973.

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This paper focuses on studying the state estimation problem of static neural networks with time-varying and distributed delays. By constructing a suitable Lyapunov functional and employing two integral inequalities, a sufficient condition is obtained under which the estimation error system is globally asymptotically stable. It can be seen that this condition is dependent on the two kinds of time delays. To reduce the conservatism of the derived result, Wirtinger inequality is employed to handle a cross term in the time-derivative of Lyapunov functional. It is further shown that the design of the gain matrix of state estimator is transformed to finding a feasible solution of a linear matrix inequality, which is efficiently facilitated by available algorithms. A numerical example is explored to demonstrate the effectiveness of the developed result.

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Podus, A., D. Patalakh, and S. Tykhovod. "Gyrator-capacitor method for modeling of electromagnetic processes based on magnetoelectric substitution circuits." Electrical Engineering and Power Engineering, no. 4 (December 30, 2020): 8–17. http://dx.doi.org/10.15588/1607-6761-2020-4-1.

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Purpose. Development of magnetoelectric substitution circuits using gyrator-capacitor models Methodology. Numerical methods for solving differential equations of state, mathematical apparatus of matrix algebra, computer programming and methods of electrical circuit theory. Findings. As a result of modification of the known method of calculation of transient electro-magnetic processes on the basis of magnetoelectric substitution circuits, the method using gyrator-capacitor models is developed. On the basis of the developed method the computer program for calculation of transient process in the single-phase transformer which showed adequacy of a method is made. The universal software complex for modeling magnetoelectric substitution circuits Colo was modified. An example of using a modified Colo software complex to calculate a transients in a three-phase transformer is shown. This example demonstrates additional clarity of compilated magneto-electric substitution circuits and reduction of the computer time modeling. Originality. Further development of methods for calculating electromagnetic processes based on nonlinear magnetoelectric substitution circuits was carried out. The mathematical model, which is taken as a principle of the universal Colo software complex, was modified by the way of a new element application - a gyrator. It is allaw to achieve the systemic application of the gyratory-capacitor method of magnetoelectric substitution circuits. Practical value. The proposed modification of the universal software complex Colo allows to reduce the time of model development, preparation of initial data and to reduce the processor time of modeling of complex nonlinear electromagnetic devices.

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Zhang, Yichi, Tao Shu, Xincheng Song, Yan Xu, and Pengxiang Zhang. "Research on Fault Diagnosis of Launch Vehicle’s Power Transformation and Transmission System Based on Big Data." Mathematical Problems in Engineering 2021 (July 21, 2021): 1–11. http://dx.doi.org/10.1155/2021/3108000.

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The on-board power supply system provides power for the launch vehicle. The power transmission and transformation system plays an irreplaceable role to ensure that the on-board power supply system receives the normal working voltage of the launch vehicle. There are many types of faults in power transmission and transformation systems. The traditional faulty diagnosis method of power transmission and transformation equipment has the disadvantages of being susceptible to experts’ subjectivity and model’s ossification. In this paper, a new method of equipment fault diagnosis based on big data is proposed. On the basis of big data, this paper introduces the failure mode clustering algorithm, the state parameter correlation analysis algorithm, the fault diagnosis method based on the correlation matrix, and other key fault diagnosis technologies. The fault record data of the 400 kV voltage grade oil-immersed transformer bushing in the past ten years by a Chinese combat unit is used as a case for demonstration. The results show that the accuracy rate of SC-LSTM-K-means clustering model exceeds 95%. And the fault classification mode can be accurately obtained. A priori correlation algorithm with TA coefficient can be used to evaluate the strong and weak relationship between the state parameters; the fault diagnosis matrix based on Pearson’s correlation coefficient can accurately determine the fault mode consistent with the actual operation and maintenance test results. Therefore, the fault diagnosis method of power transmission and transformation system based on big data can both effectively obtain the inherent laws of historical data and realize more accurate fault diagnosis with data adaptability.

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Lozynskyy, A. O., O. Yu Lozynskyy, and L. V. Kasha. "Control synthesis by full state vector in systems with fractional-order derivatives using Caputo-Fabrizio operator." Mathematical Modeling and Computing 8, no. 1 (2020): 106–15. http://dx.doi.org/10.23939/mmc2021.01.106.

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In the paper, the control system synthesis by means of the full state vector is considered when using fractional derivatives in the description of this system. To conduct research in the synthesized system with fractional derivatives in the Caputo--Fabrizio representation, a fundamental matrix of the system is formed, which also allows us to analyze the influence of initial conditions on the processes within the system. In particular, the finding of the fundamental matrix of the system in the case of multiple roots of a characteristic polynomial, which are obtained by transforming the synthesized system to the binomial form, is demonstrated. The influence of the fractional derivative index and the location of the roots of the characteristic polynomial transformed to the binomial form on the system operation is analyzed.

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Ren, Gexue, and Zhaochang Zheng. "A Quasi-Decoupling Approach for Nonclassical Linear Systems in State Space." Journal of Applied Mechanics 64, no. 4 (December 1, 1997): 946–50. http://dx.doi.org/10.1115/1.2789004.

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By adopting the orthogonal transformations provided by the generalized real Schur decomposition, it is shown that every nonclassical linear system in state space can be transformed into block upper triangular form, to which the quasi-decoupling solution can be progressively carried out by solving the either first or second-order component equations with the “back substitution.” The distinct characteristics of generalized eigenvalue problems from those of standard ones are discussed. Favorable properties of the proposed method include: no inverting of any system matrix, indiscriminate applicability to both defective and nondefective systems, the simultaneous decoupling of the adjoint problem, and numerical stability. Illustrative examples are also presented.

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Huang, Kewang, Tao Ma, and Feng Pan. "H∞ Control for LPV Discrete Systems with Random Time-Varying Network Delay." Mathematical Problems in Engineering 2018 (October 29, 2018): 1–9. http://dx.doi.org/10.1155/2018/9095014.

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In this paper, we study the H∞ control problem for Linear Parameter Varying (LPV) discrete systems with random time-varying network delay. The state matrices of LPV discrete systems are deterministic functions and changed with parameters; the range of parameters is measurable. Considering the characteristics of networks with random time-varying delay, we proposed a new parameter-dependent H∞ performance criterion based on the Lyapunov stability theory. The coupling between Lyapunov functions and system matrices could be eliminated by introducing an additional matrix in this criterion, which made it easier for numerical implementation. On this basis, we designed a state feedback controller by virtue of linear matrix inequalities, which transformed the sufficient conditions into existence condition of solution of parametric linear matrix inequalities. The designed controller could keep the closed-loop system asymptotically stable under given time delay and probability and meet predefined performance metric. The validity of the proposed method is verified by numerical simulation.

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Xiaohua, Li, Liu Xiaoping, Liu Yang, and Gao Jiawang. "Organically Structured Control of Large-Scale Systems with Expanding Construction Based on State Observation." Abstract and Applied Analysis 2015 (2015): 1–21. http://dx.doi.org/10.1155/2015/807202.

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This paper presents a new method on the problem of organically structured control based on state observation for a class of large-scale systems with expanding construction. This problem is to design a local state feedback controller and an observer for a new subsystem which is added to a large-scale system without changing the decentralized state feedback control laws of the original construction, so that both the new subsystem and the resulting expanded system are robustly connectively stable. Firstly, based on state observers, the mathematical model of a large-scale system with expanding construction is reestablished and analyzed. In addition, the sufficient condition for robust decentralized connective stabilization of the expanded construction of large-scale systems is deduced by taking an LMI approach, which is further relaxed by removing the square matrix condition on the output matrix. This problem is transformed into solving an LMI problem. The new design method of an organically structured controller and observer for the expanded construction is also given. Finally, the simulation examples show the effectiveness of the proposed method.

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Liu, Da, Yanan Wei, Shuxia Yang, and Zhitao Guan. "Electricity Price Forecast Using Combined Models with Adaptive Weights Selected and Errors Calibrated by Hidden Markov Model." Mathematical Problems in Engineering 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/648101.

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A combined forecast with weights adaptively selected and errors calibrated by Hidden Markov model (HMM) is proposed to model the day-ahead electricity price. Firstly several single models were built to forecast the electricity price separately. Then the validation errors from every individual model were transformed into two discrete sequences: an emission sequence and a state sequence to build the HMM, obtaining a transmission matrix and an emission matrix, representing the forecasting ability state of the individual models. The combining weights of the individual models were decided by the state transmission matrixes in HMM and the best predict sample ratio of each individual among all the models in the validation set. The individual forecasts were averaged to get the combining forecast with the weights obtained above. The residuals of combining forecast were calibrated by the possible error calculated by the emission matrix of HMM. A case study of day-ahead electricity market of Pennsylvania-New Jersey-Maryland (PJM), USA, suggests that the proposed method outperforms individual techniques of price forecasting, such as support vector machine (SVM), generalized regression neural networks (GRNN), day-ahead modeling, and self-organized map (SOM) similar days modeling.

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He, ZeFang, and Long Zhao. "Quadrotor Trajectory Tracking Based on Quasi-LPV System and Internal Model Control." Mathematical Problems in Engineering 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/857291.

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Internal model control (IMC) design method based on quasi-LPV (Linear Parameter Varying) system is proposed. In this method, the nonlinear model is firstly transformed to the linear model based on quasi-LPV method; then, the quadrotor nonlinear motion function is transformed to transfer function matrix based on the transformation model from the state space to the transfer function; further, IMC is designed to control the controlled object represented by transfer function matrix and realize quadrotor trajectory tracking. The performance of the controller proposed in this paper is tested by tracking for three reference trajectories with drastic changes. The simulation results indicate that the control method proposed in this paper has stronger robustness to parameters uncertainty and disturbance rejection performance.

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Lazaropoulos, Athanasios G. "Practical Coupled Resonators in Domino Arrangements for Power Transmission and Distribution: Replacing Step-Down Power Transformers and Their Branches across the Power Grid." Journal of Energy 2013 (2013): 1–25. http://dx.doi.org/10.1155/2013/795835.

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This paper considers the potential of replacing step-down power transformers of the entire power grid as well as part of their transmission line branches with wireless power transfer (WPT) technology components. Exploiting the state-of-the-art evolutions in the fields of WPT technology, coupled resonators in domino arrangements—domino coupled resonator (DCR) configurations—are proposed as suitable technological substitute for step-down power transformers and are investigated in terms of performance metrics such as power transfer efficiency (PTE) and transformation ratio (TR). The contribution of this paper is fivefold. First, an analytical theoretical analysis appropriate to the study of practical DCR configurations is demonstrated. In order to support the DCR configuration replacement venture, a detailed set of assumptions regarding efficient mid- and long-range high-power WPTs as well as related technical issues is first presented. The validity of the theoretical analysis is verified through experimental measurements. Second, applying the proposed theoretical analysis, a wealth of system parameters that mainly influences the PTE and TR of DCR configurations is identified. Their quantitative effect as well as corresponding DCR configuration adjustments are first presented. Third, an approximate method, denoted as approximate chain scattering matrix (CSM) method, is first introduced. Based on the scattering matrix theory formalism, the approximate CSM method is suitable for mid- and long-range DCR configurations when the theoretical analysis becomes computationally slow. The numerical results of approximate CSM method are compared with the respective ones of theoretical analysis validating the extent and the accuracy of approximate CSM method. Fourth, the potential of power transformer replacement with practical DCR configurations is thoroughly investigated in terms of their TRs. A plethora of high-voltage/medium-voltage (HV/MV), MV/low-voltage (MV/LV), and HV/LV power transformers used across the world is investigated verifying their replacement potential with practical DCR configurations in all the cases examined. Fifth, based on a detailed collection of dimensions concerning power transformers and transmission line branches, it is first verified that practical DCR configurations cannot only substitute all step-down power transformers of the today's power grid but also replace entire transmission line branches too. Finally, it is obvious that there is a long journey ahead for WPT technology and its ultramodern DCR configurations to be affordably, widely, reliably, sustainably, and safely adopted in the human society. During these first steps of WPT development for power transmission and distribution, theoretical analyses and visions are necessary. The last cable problem, that is, the seamless power delivery as easily as information is now transmitted through the air, is one of the major technological challenges of the 21st century, and, thus, WPT technology will certainly play key role.

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Tyagi, Suresh C., Suresh Kumar G., and Susan Borders. "Reduction-oxidation (redox) state regulation of extracellular matrix metalloproteinases and tissue inhibitors in cardiac normal and transformed fibroblast cells." Journal of Cellular Biochemistry 61, no. 1 (April 1, 1996): 139–51. http://dx.doi.org/10.1002/(sici)1097-4644(19960401)61:1<139::aid-jcb15>3.0.co;2-j.

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Li, Ping, and Kaiyu Qin. "Distributed Robust H∞ Consensus Control for Uncertain Multiagent Systems with State and Input Delays." Mathematical Problems in Engineering 2017 (2017): 1–15. http://dx.doi.org/10.1155/2017/5091756.

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Robust H∞ consensus control problem is investigated for multiagent systems. Each agent is tackled in a more generalized form, which includes parameter uncertainties, external disturbances, nonidentical time-varying state, and input delays. Firstly, a distributed control protocol based on state feedback of neighbors is designed. By a decoupling method, H∞ consensus control problem for multiagent systems is transformed into H∞ control problem for the decoupling subsystems. Then employing Lyapunov-Krasovskii functional and free-weighting matrices, a lower conservative bounded real lemma (BRL) is derived in terms of linear matrix inequalities (LMIs) such that a class of time-delay system is guaranteed to be globally asymptotically stable with the desired H∞ performance index. Extending BRL, a sufficient delay-dependent condition of lower complexity in terms of the matrix inequalities is obtained to make all agents asymptotically reach consensus with the desired H∞ performance index. Furthermore, an algorithm is elaborately designed to get feasible solution to this condition. Extending this algorithm, an optimization algorithm for control protocol parameter is proposed to improve the disturbance attenuation capacity or allowable delay bounds. Finally, simulation results are provided to illustrate the correctness of the theoretical results and the effectiveness of the algorithms.

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Lin, Gui Hua, Tao Wang, and Yu Ying Wang. "Linear State Estimation Based on Measured Quantity Transformation and Calculation of Transmission Losses." Applied Mechanics and Materials 672-674 (October 2014): 1027–31. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1027.

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A linear static state estimation on measured quantity transformation is proposed in this paper utilizing the high precision measurements of WAMS. Using transformation of measured quantity, the current measurements of WAMS are transformed into equivalent voltage measurement, and after simplification a constant real number information matrix is obtained, so the decoupling calculation of real part and imaginary part of nodal voltage is realized. The calculation has many advantages such as fast proposed algorithm, high estimation precision and better numerical stability. Finally, the algorithm is applied to the calculation of network loss in theory, the calculation accuracy of transmission loss is improved. The calculation results of IEEE 30-bus test system validate the effectiveness of the proposed method.

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Shugart, Kathleen N., Gerard M. Ludtka, Gail Mackiewicz-Ludtka, and William A. Soffa. "Exchange Coupling Nanophase Fe-Pd Ferromagnets Through Solid State Transformation." Solid State Phenomena 172-174 (June 2011): 273–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.172-174.273.

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This study continues previous work on off-stoichiometric Fe-Pd alloys using a combined reaction strategy during thermomechanical processing [1,2]. Severe plastic deformation of the initial disordered fcc gamma phase (γ) of compostion Fe-35at.%Pd, followed by heat treatment in the two phase field produces a nano-composite ferromagnet comprised of soft alpha phase/ferrite (α) in a high-anisotropy L10 FePd matrix. The length scale and morphology of the transformation products have been characterized using x-ray diffraction, and scanning electron microscopy. The transformed microstructures exhibit strong texture retention similar to the stoichiometric alloy suggesting a massive ordering mode. The alloy has shown a proclivity to exchange couple at a length scale not in agreement with proposed theories of exchange coupling [3,4]. The magnetic properties were measured using standard vibrating sample magnetometry (VSM). This research has been supported by the National Science Foundation (NSF-DMR).

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Tsitsulin, Anton, Marina Munkhoeva, Davide Mottin, Panagiotis Karras, Ivan Oseledets, and Emmanuel Müller. "FREDE." Proceedings of the VLDB Endowment 14, no. 6 (February 2021): 1102–10. http://dx.doi.org/10.14778/3447689.3447713.

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Low-dimensional representations, or embeddings , of a graph's nodes facilitate several practical data science and data engineering tasks. As such embeddings rely, explicitly or implicitly, on a similarity measure among nodes, they require the computation of a quadratic similarity matrix, inducing a tradeoff between space complexity and embedding quality. To date, no graph embedding work combines (i) linear space complexity, (ii) a nonlinear transform as its basis, and (iii) nontrivial quality guarantees. In this paper we introduce FREDE ( FREquent Directions Embedding ), a graph embedding based on matrix sketching that combines those three desiderata. Starting out from the observation that embedding methods aim to preserve the covariance among the rows of a similarity matrix, FREDE iteratively improves on quality while individually processing rows of a nonlinearly transformed PPR similarity matrix derived from a state-of-the-art graph embedding method and provides, at any iteration , column-covariance approximation guarantees in due course almost indistinguishable from those of the optimal approximation by SVD. Our experimental evaluation on variably sized networks shows that FREDE performs almost as well as SVD and competitively against state-of-the-art embedding methods in diverse data science tasks, even when it is based on as little as 10% of node similarities.

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Korotyeye, Igor, and Beata Zięba. "Analysis of three-phases matrix reactance frequency converter with two pulsations of control signal." Archives of Electrical Engineering 61, no. 3 (September 1, 2012): 359–71. http://dx.doi.org/10.2478/v10171-012-0029-8.

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Analysis of three-phases matrix reactance frequency converter with two pulsations of control signalThis paper presents a method of calculation of steady-state processes in three-phases matrix-reactance frequency converters (MRFC's), in which voltages and currents are transformed by control signals with two pulsations. A solution of nonstationary differential equations with periodic coefficients that describe this system is obtained by using Galerkin's method and an extension of equations of one variable of time to equations of two variables of time. The results of calculations are presented in an example of three-phases MRFC with buck-boost topology and compared with a numerical method embedded in the program Mathematica.

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Zhang, Ni, Mei Chun Fu, and Tao Zou. "Delay-Dependent Non-Fragile Robust H∞ Control for Switched Systems with Multiple Time Delays." Applied Mechanics and Materials 130-134 (October 2011): 222–26. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.222.

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The non-fragile robust H∞ control problem is investigated for the uncertain switched discrete time systems with multiple state and input time delays. As the system and controller parameters are polytopically uncertain, the delay-dependent sufficient conditions for the existence of the non-fragile robust H∞ controller via state feedback are presented for the systems based on the multiple Lyapunov functions and state dependent switching rules. By using the cone complementarity linearization algorithm, the nonlinear matrix inequalities relevant to the controller design can be transformed into the nonlinear programming problems constrained by the linear matrices. The simulation results show the effectiveness of the controller design method.

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Bian, Zuguang, Shuai Yang, Xiaoliang Zhou, and David Hui. "Band gap manipulation of viscoelastic functionally graded phononic crystal." Nanotechnology Reviews 9, no. 1 (June 5, 2020): 515–23. http://dx.doi.org/10.1515/ntrev-2020-0042.

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AbstractIn this study, band gaps of SH-waves (horizontally polarized shear waves) propagating in a thermal-sensitive viscoelastic matrix are investigated. Metallic films acting as heat sources are periodically embedded into the matrix, which establishes a periodically inhomogeneous thermal field. The homogenous matrix is therefore transformed into functionally gradient phononic crystals (PCs). A three-parameter solid model is employed to describe the viscoelasticity of the present matrix. By virtue of a transfer matrix method incorporated within a laminated model, the dispersion equation of SH-waves is finally obtained, from which the band gaps are determined. The transmission spectra of a finite-periodic PC are also solved to validate the band gaps. In numerical examples, the influences of incident angles of SH-waves and viscoelasticity of matrix on band gaps are discussed first. Then the research focuses on the means to tune the band gaps by manipulating the inputted powers of heat sources. Numerical examples demonstrate that such a strategy is effective and convenient in tuning the positions and widths of band gaps. A viscous parameter, i.e., the ratio of initial-state to final-state storage moduli, significantly affects the band locations and bandwidths, while the locations of low-order band gaps hardly move with the incident angle of SH-waves. Band gaps of several orders are expected to locate in lower-frequency domain, and the total bandwidth becomes larger as the inputted heat flux increases. This paper lays theoretical foundation to manufacture viscoelastic functionally graded PCs which can be used in frequency-selective devices.

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Alsmadi, Othman M. K., and Zaer S. Abo-Hammour. "A Robust Computational Technique for Model Order Reduction of Two-Time-Scale Discrete Systems via Genetic Algorithms." Computational Intelligence and Neuroscience 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/615079.

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A robust computational technique for model order reduction (MOR) of multi-time-scale discrete systems (single input single output (SISO) and multi-input multioutput (MIMO)) is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA) with the advantage of obtaining a reduced order model, maintaining the exact dominant dynamics in the reduced order, and minimizing the steady state error. The reduction process is performed by obtaining an upper triangular transformed matrix of the system state matrix defined in state space representation along with the elements ofB,C, andDmatrices. The GA computational procedure is based on maximizing the fitness function corresponding to the response deviation between the full and reduced order models. The proposed computational intelligence MOR method is compared to recently published work on MOR techniques where simulation results show the potential and advantages of the new approach.

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Journal articles on the topic 'State and transformer matrix'

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