不对称电网故障下PWM整流器的控制  

Control of PWM Rectifier Under Unbalanced Input Voltages

作　　者：何鸣明[1] 贺益康[1] 潘再平[1] 

机构地区：[1]浙江大学电气工程学院,杭州310027

出　　处：《电力系统及其自动化学报》2007年第4期13-17,共5页Proceedings of the CSU-EPSA

基　　金：国家自然科学基金资助项目(50577056)

摘　　要：脉宽调制(pulse width modulation,PWM)整流是目前性能最优的交-直变流技术。但在不对称电网下,存在显著的谐波功率,严重影响其输出品质,须采用正、负序分解并分别控制的策略来解决。其关键是对正、负序电流分别进行跟踪。通过电压、电流和功率的关系,得到了正、负序d-q坐标系下的电流控制指令,以此修改了控制策略并建立仿真模型。结果表明,新方法能控制整流器在故障电网下的输入电流,抑制谐波功率的产生,保证直流电压的稳定,实现整流器的不间断运行。Pulse width modulation （PWM） rectifier is the best method for the AC-DC converting. But there exists harmonic power in the power grid under unbalanced voltages which can affect the output quality seriously. Positive and negative sequence separating method was presented to solve the problem, the key of which is to trace the positive and negative current. The current references under positive and negative sequence d-q axis were obtained using the relation of voltage, current and power, through which the control method was improved and simulation model was set up. The result shows that the new method can control the input current, decrease the harmonic power, keep the DC voltage steady and PWM rectifier working without interruption under unbalanced input voltages.

关 键 词：不对称电网 脉宽调制整流器 正 负序分量 

分 类 号：TM46[电气工程—电器]