Fast FCS-MPC-Based SVPWM Method to Reduce Switching States of Multilevel Cascaded H-Bridge STATCOMs

Wang, Xiuqin,Zhao, Jiwen,Wang, Qunjing,Li, Guoli,Zhang, Maosong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Finite control set model-predictive control (FCS-MPC) has received increasing attentions due to its outstanding dynamic performance. It is being widely used in power converters and multilevel inverters. However, FCS-MPC requires a lot of calculations, especially for multilevel-cascaded H-bridge (CHB) static synchronous compensators (STATCOMs), since it has to take account of all the feasible voltage vectors of inverters. Hence, an improved five-segment space vector pulse width modulation (SVPWM) method based on the non-orthogonal static reference frames is proposed. The proposed SVPWM method has a lower number of switching states and requires fewer computations than the conventional method. As a result, it makes FCS-MPC more efficient for multilevel cascaded H-bridge STATCOMs. The partial cost function is adopted to sequentially solve for the reference current and capacitor voltage. The proposed FCS-MPC method can reduce the calculation burden of the FCS-MPC strategy, and reduce both the switching frequency and power losses. Simulation and experimental results validate the excellent performance of the proposed method when compared with the conventional approach.

A Novel Double-Loop Vector Control Strategy for PMSMs Based on Kinetic Energy Feedback

Wang, Anbang,Wang, Qunjing,Jiang, Weidong The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

A novel vector control strategy for a permanent magnet synchronous motor (PMSM) based on the kinetic energy stored in the rotor is proposed in this paper. The novel strategy is composed of two closed loops, in which the current loop is the inner loop, and the kinetic energy serves as the outer loop. The theoretical basis and the design procedure of the two loops are given. The feasibility of the proposed control strategy is verified by experimental results. When compared with traditional vector control strategies, the proposed vector control strategy based on energy feedback has better dynamic performance. In addition, an effective estimation solution for the load variation is put forward.

A Novel Double-Loop Vector Control Strategy for PMSMs Based on Kinetic Energy Feedback

Anbang Wang,Qunjing Wang,Weidong Jiang 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

A novel vector control strategy for a permanent magnet synchronous motor (PMSM) based on the kinetic energy stored in the rotor is proposed in this paper. The novel strategy is composed of two closed loops, in which the current loop is the inner loop, and the kinetic energy serves as the outer loop. The theoretical basis and the design procedure of the two loops are given. The feasibility of the proposed control strategy is verified by experimental results. When compared with traditional vector control strategies, the proposed vector control strategy based on energy feedback has better dynamic performance. In addition, an effective estimation solution for the load variation is put forward.

Fast FCS-MPC-Based SVPWM Method to Reduce Switching States of Multilevel Cascaded H-Bridge STATCOMs

Xiuqin Wang,Jiwen Zhao,Qunjing Wang,Guoli Li,Maosong Zhang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Finite control set model-predictive control (FCS-MPC) has received increasing attentions due to its outstanding dynamicperformance. It is being widely used in power converters and multilevel inverters. However, FCS-MPC requires a lot ofcalculations, especially for multilevel-cascaded H-bridge (CHB) static synchronous compensators (STATCOMs), since it has totake account of all the feasible voltage vectors of inverters. Hence, an improved five-segment space vector pulse widthmodulation (SVPWM) method based on the non-orthogonal static reference frames is proposed. The proposed SVPWM methodhas a lower number of switching states and requires fewer computations than the conventional method. As a result, it makesFCS-MPC more efficient for multilevel cascaded H-bridge STATCOMs. The partial cost function is adopted to sequentiallysolve for the reference current and capacitor voltage. The proposed FCS-MPC method can reduce the calculation burden of theFCS-MPC strategy, and reduce both the switching frequency and power losses. Simulation and experimental results validate theexcellent performance of the proposed method when compared with the conventional approach.

Switched System Identification Based on the Constrained Multi-objective Optimization Problem with Application to the Servo Turntable

Qian Zhang,Qunjing Wang,Guoli Li 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.5

Multi-model switching controllers can handle the complexity of process plants and other engineeredsystems, based on the switched system model. In this paper, a switched Nonlinear Auto Regressive Moving AverageeXogenous (NARMAX) model for a continuously mechatronic servo turntable system is proposed to make a betterdescription than the single structure model. Then the identification issue is converted into a constrained multiobjectiveoptimization problem (CMOP). Further, a kind of multi-objective particle swarm optimization algorithmis developed on the basis of Pareto optimality. The selection of global best location for each particle and themaintenance of the external archive are ensured in the same procedure in this algorithm. Finally, our theoreticalfindings are supported by simulation and experimental results.

A Deflectable Switched Reluctance Motor/Generator for Wave Energy Conversion and Underwater Propulsion Systems

Gao Shihao,Wang Qunjing,Li Guoli,Qian Zhe,Zhou Sili,Li Zheng 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

This paper proposes a defl ectable switched reluctance motor/generator, which can be used in wave energy conversion and underwater propulsion systems. When an underwater vehicle stops working, the ocean current drives the turbine blades connected to the motor to rotate, and the rotating turbine blades drive the defl ectable generator shaft to generate electricity. The defl ectable motor can complete multi-degree-of-freedom motion, so it can receive ocean current energy in multiple directions, thereby improving energy extraction effi ciency. When the underwater vehicle starts to work, the defl ectable motor can freely adjust the course of the vehicle, so that the vehicle can yaw freely under water. The fi nite element method is used to analyze the air gap fl ux density during rotation and defl ection. The relationship between the fl ux, torque and current of a single coil under diff erent rotor positions is obtained, and then the output current and voltage of the defl ectable generator are obtained. Finally, a prototype was made for experimental verifi cation.

Geometry Optimization of PM Spherical Motor Using Response Surface Methodology

Zheng Li,Qunjing Wang 한국자기학회 2008 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Robust Adaptive Sliding‑Mode Control for Permanent Magnet Spherical Actuator with Uncertainty Using Dynamic Surface Approach

Yan Wen,Guoli Li,Qunjing Wang,Xiwen Guo 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.6

This paper presents a position tracking control method for a three degree-of-freedom permanent magnet spherical actuator (PMSA). The control method is designed based on a dynamic model of the PMSA with uncertainties including modelling errors and external disturbance. Sliding-mode surface are adopted to restrain and eliminate the efect of external disturbances. To compensate modelling errors, an adaptive law is employed to estimate unknown model parameters so that model information can be updated in real time. By the use of dynamic surface approach, three frst-order flters are introduced to avoid the explosion of derivative terms caused by traditional adaptive backstepping approach. The stability of the closed-loop system using the proposed controller is confrmed through Lyapunov theorem. The test bench consisted of the prototype of PMSA, the host computer, the current controller and the orientation detection device is established for experiments. Simulation and experimental results are provided to validate efectiveness of the proposed method.

Magnetic Field Analysis and Iron Loss Calculation of a Special Switched Reluctance Generator

Zheng Li,Xin Wang,Liping Zhang,Lei Du,Qunjing Wang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.5

In order to improve the efficiency and flexibility of the switched reluctance generator, a novel deflection double stator switched reluctance generator was proposed based on the structural characteristics of the switched reluctance motor. The magnetic flux of the generator was analyzed by magnetic circuit analysis method, obtaining the matrix expression of the average magnetic flux of the stator and rotor. Then it is transiently simulated by electromagnetic analysis software to calculate the radial and tangential components of the core magnetic density of the generator. At the same time, the calculation results of the finite element method are compared with the results of the analysis method to verify the correctness of the analytical method model. Finally, the calculated magnetic density component is transformed by Fourier transformation to obtain the corresponding harmonic analysis. And the ellipse method was used to calculate the iron loss of the generator, compared with the experimental results to illuminate the accuracy of the iron loss calculation scheme.

Torque Modelling and Validation for a Spherical Motor with Stepped Permanent Magnets

Jingxiong He,Guoli Li,Rui Zhou,Qunjing Wang,Yuanzhong Qiao 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6

A spherical motor is an electromagnetic device with multi-degree-of-freedom motion. Three-dimensional (3-D) magnetic fi eld analysis and torque analysis are needed for the design, optimization and control of the motor. Presently, these analyses are carried out by the fi nite-element method (FEM) with a large amount of calculation and time consumption. An analytical method (AM) can reduced the computational burden of the FEM without sacrifi ce of the accuracy. A stepped permanent magnet (PM) can obtain a large range of the magnetic fi eld while eff ectively saving PM materials. However, its special structure causes diffi culties in analytical modelling. This paper presents an AM for the 3-D magnetic fi eld and torque of a permanent magnet spherical motor with stepped PMs. The analytical model of the 3-D magnetic fi eld of the stepped PM is derived based on the loop current method, and the electromagnetic force of the stator coil is calculated based on the Lorentz force method. Thus the 3-D magnetic fi eld and torque can be calculated effi ciently with reasonable accuracy. The analytical model is verifi ed by the FEM and experimental tests. The test results confi rm the high accuracy of the developed model.