基于数控电容的PWM整流器直流侧电压改善研究

Improvement of DC-side voltage of PWM rectifier based on programmable capacitor

在电压型PWM整流器的控制中,广泛采用在同步旋转坐标系下的直接电流控制方法和双闭环控制结构,基于PSCAD软件建立了其仿真模型。PWM整流器中直流侧电容的设计取值对电压环的控制性能有重要影响。综合考虑直流侧电压跟随性能和纹波要求,基于软件仿真验证确定了电容取值在较小范围。提出了在直流侧采用数控电容与传统电容器并联替代传统单一电容器的方法,使得电容值在线可调,该方法对于实现PWM整流器直流侧电压的灵活、精细控制有一定实用价值。

In the control of voltage source PWM rectifier,the direct current control and dual close loop control structure in d-q synchronous reference frame were widely adopted,and the simulation model was built up based on PSCAD software.DC-side capacitor had an important effect on voltage loop control performance.The capacitor value was within lesser range based on software simulation verification considering DC-side voltage following-performance and ripple.The conventional capacitor could be substituted for programmable capacitor parallel with it.The method possessed some practical values at the aspect of realizing flexible and elaborate control of PWM rectifier DC-side voltage.