一种新型PWM整流器间接电流控制策略及其有源阻尼方法

An indirect current control scheme for PWM rectifier and its active damping strategy

PWM整流器的控制策略可分为直接电流控制和间接电流控制,前者至少需要两个高精度的交流电流传感器,增加了系统的体积和成本。本文提出一种新型PWM整流器间接电流控制策略。该方法采用电流观测器获取电流反馈量,无需使用交流电流传感器。其电流环只包含有功电流反馈控制,对无功电流,则依据稳态电压平衡关系生成控制量,使其稳态时自然为零。对所提方法的电流响应进行深入分析,引入有源阻尼策略,使电流动态性能得到很大改善。仿真结果表明,本文提出的间接电流控制方法具有很好的稳态、动态性能。该方案成本低,性能高,且结构简单,是一种新颖的PWM整流器控制策略。

Three-phase PWM rectifier can be controlled by direct and indirect current control schemes. The former requires at least two current sensors with high accuracy which increases the volume and cost of the system. In this paper, a new indirect current control strategy for PWM rectifier is proposed. The current feedback is obtained by current observer, so the current sensor is not needed in this method. The current loop only contains the active current feed- back control; as for reactive current, the control signal is generated according to the steady-state voltage relationship, which makes the reactive current to zero at steady-state. A thorough analysis of the current response of the proposed method is given, and the active damping strategy is introduced, which can improve the current dynamic response. Simulation shows that the new scheme obtains a good steady performance and dynamic response. This scheme has a low cost, high performance and simple structure, which is a novel PWM rectifier control strategy.