Current predictive control of three-phase voltage source PWM rectifiers under unbalanced grid voltage conditions

2016 ◽  
Vol 39 (7) ◽  
pp. 976-986
Author(s):  
Meng Wang ◽  
Yanyan Shi ◽  
Zhen Qi ◽  
Minghui Shen
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
Voltage Source ◽  
Phase Voltage ◽  
Two Phase ◽  
Grid Voltage ◽  
Three Phase ◽  
Pwm Rectifiers ◽  
Current Error ◽  
Unbalanced Grid

To improve the performance of three-phase voltage source pulse-width modulated (PWM) rectifiers (VSR) under unbalanced grid voltage conditions, a fixed-frequency current predictive control (CPC) strategy is presented. Instantaneous power of the three-phase VSR is analysed in a two-phase stationary frame. The calculation method for the reference current is improved to achieve the power stability at the AC side of the rectifier. Based on the current predictive model, the optimal duration of the voltage vectors is computed under the restricted condition of minimizing current error at α- and β-axes in fixed intervals. The control system is free of synchronous rotation coordinate transformation, and avoids positive and negative sequence decomposition, which simplifies the calculation. The simulation and experimental results show that the proposed control strategy is able to eliminate the AC current distortion effectively and depress DC link voltage fluctuation under unbalanced grid voltage. Furthermore, the control strategy has faster dynamic response ability, enhancing the control performance of the three-phase VSR system.

scholarly journals A New Control Strategy of Three Phase Voltage Source PWM Rectifiers

2012 ◽  
Vol 24 ◽  
pp. 997-1005 ◽  
Author(s):  
Jiuhe Wang ◽  
Hongren Yin ◽  
Shengsheng Xu
Keyword(s):  
Control Strategy ◽  
Voltage Source ◽  
Phase Voltage ◽  
Three Phase ◽  
Pwm Rectifiers

Design and Simulation of the New Three-Phase Voltage Source PWM Rectifier

2013 ◽  
Vol 273 ◽  
pp. 343-349
Author(s):  
Yi Ming Zhang ◽  
Zhi Hui Zeng ◽  
Fei Yu ◽  
Jin Lan Feng
Keyword(s):  
Coordinate System ◽  
Control Strategy ◽  
System Stability ◽  
Voltage Source ◽  
Current Loop ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Two Phase ◽  
Loop Control ◽  
Three Phase

Based on the principle of the three phase voltage source PWM rectifier, firstly, describes the topology of the three-phase VSR, and establishes the three-phase VSR’s mathematical model based on the three-phase stationary symmetric coordinate system (a,b,c) and two-phase synchronous rotating coordinate system (d,q); then analysis the three-phase VSR’s control strategy, and discusses the feedforward decoupling control strategy of the inner current loop, the outter voltage loop control strategy and the Space Vector PWM (SVPWM) control strategy. Secondly, builds a simulation model, simulates it in Matlab\Simulink environment.The simulation results show that the system has good current waveform of AC side current, high system stability, fast dynamic response speed, and can realize two-way flow of energy, energy feedback, and unit power factor control.

scholarly journals A Control Strategy for Suppressing Zero-Sequence Circulating Current in Paralleled Three-Phase Voltage-Source PWM Converters

2020 ◽  
Vol 10 (5) ◽  
pp. 1703 ◽  
Author(s):  
Zhao Han ◽  
Xiaoli Wang ◽  
Baochen Jiang ◽  
Jingru Chen
Keyword(s):  
Control Strategy ◽  
Voltage Source ◽  
Duty Ratio ◽  
Phase Voltage ◽  
Pwm Converters ◽  
Circulating Current ◽  
Three Phase ◽  
Zero Sequence ◽  
The Difference ◽  
Zero Vector

In microgrids, paralleled converters can increase the system capacity and conversion efficiency but also generate zero-sequence circulating current, which will distort the AC-side current and increase power losses. Studies have shown that, for two paralleled three-phase voltage-source pulse width modulation (PWM) converters with common DC bus controlled by space vector PWM, the zero-sequence circulating current is mainly related to the difference of the zero-sequence duty ratio between the converters. Therefore, based on the traditional control ideal of zero-vector action time adjustment, this paper proposes a zero-sequence circulating current suppression strategy using proportional–integral quasi-resonant control and feedforward compensation control. Firstly, the dual-loop decoupled control was utilized in a single converter. Then, in order to reduce the amplitude and main harmonic components of the circulating current, a zero-vector duty ratio adjusting factor was initially generated by a proportional–integral quasi-resonant controller. Finally, to eliminate the difference of zero-sequence duty ratio between the converters, the adjusting factor was corrected by a feedforward compensation link. The simulation mode of Matlab/Simulink was constructed for the paralleled converters based on the proposed control strategy. The results verify that this strategy can effectively suppress the zero-sequence circulating current and improve power quality.

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