不对称电压下PWM整流器的控制策略  

Control Strategy of Pulse Width Modulation Rectifier Under Asymmetrical Input Voltages

作　　者：叶盛[1] 黄守道[1] 黄科元[1] 肖磊[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南省长沙市410082

出　　处：《电网技术》2010年第10期94-98,共5页Power System Technology

基　　金：国家自然科学基金青年科学基金项目(50907020);高等学校博士学科点专项科研基金资助项目(200805321038)~~

摘　　要：在电网对称情况下,传统的脉宽调制(pulse width modulation,PWM)整流器控制方式拥有良好的动态和稳态性能,但在不对称电网下存在显著的谐波功率,严重影响PWM整流器输出电压及输入电流品质。通过将不对称电压与电流进行对称分量法分解,提出了在正负序同步坐标变换下,电网正负序电压分别定向的矢量控制策略,来消除功率传输中的波动分量,以实现在电网发生不对称故障时稳定直流母线电压。以此控制策略为基础令负序输入电流为零得到另一控制策略,以实现在电网发生不对称故障时使输入电流正弦。仿真及实验结果验证了2种控制策略的有效性。Traditional control strategy of pulse width modulation （PWM） rectifier possesses good dynamic and steady state performances while voltages of power network are symmetrical, however due to evident harmonic power in asymmetrical power network the quality of output voltage and input current of PWM rectifier are seriously affected. After analyzing the features of asymmetrical power network by symmetrical component method, two vector-oriented control strategies, which respectively orientate positive- and negative-sequence voltages under positive- and negative-sequence synchronous coordinate transforms, for PWM rectifier are proposed to eliminate the fluctuating component in power transmission, thus the DC bus voltage can be stabilized while unsymmetrical fault occurs in power network. Based on this control strategy and let negative-sequence input current equals to zero, another control strategy cart be obtained to make the input current sinusoidal while asymmetrical fault happens in power network. Results from simulation and experiments prove that the proposed two control strategies are effeetive.

关 键 词：不对称电压 PWM整流器 电压定向 正、负序分量 

分 类 号：TM46[电气工程—电器]