摘要
PWM整流器带谐波补偿器的比例谐振控制能够选择性地抑制电网电流中的谐波含量,然而其补偿的谐波次数受到电流环带宽的限制。当抑制谐波次数较高时,必须对谐振频率处电流环延时进行超前补偿,才能保证电流环的稳定性。随着抑制谐波次数的增多,数字信号处理器的运算量变大。针对上述问题,分析了电网电压谐波对电网电流的影响机理。提出了在电流环比例谐振控制的基础上,采用对电网电压超前预测的方法,在保证电流环良好动态性能的前提下减少PWM整流器电网电流中的谐波含量。最后进行了实验验证,实验结果表明本文提出的电网电压预测方法能够有效抑制电网电压谐波对电网电流的影响。
Proportional-resonant control with harmonic compensator of PWM rectifiers can selectively eliminate grid current harmonic.However,the eliminated current harmonic order is limited by the current loop bandwidth.To make current loop stable,delay compensation must be considered when higher order harmonics need to be eliminated.With the increasing of eliminated harmonic numbers,the controller computation expense will become heavy.The influence of grid voltage harmonic on grid current is analyzed in this paper.The grid voltage predictive method is proposed to minimize the grid current harmonic as well as to obtain high dynamic performance with proportional-resonant current controller.Experimental results show that the grid current harmonic caused by grid voltage harmonic can be eliminated effectively by the proposed method.
出处
《电工技术学报》
EI
CSCD
北大核心
2011年第5期45-51,共7页
Transactions of China Electrotechnical Society
关键词
PWM整流器
重复控制
比例谐振控制
网压预测
谐波
PWM rectifiers
repetitive control
proportional-resonant control
grid voltage prediction
harmonic
