摘要
针对网侧变流器双闭环控制中电压外环对DC-link电压振荡抑制响应慢及电流内环对前馈补偿延时的问题,提出了一种直接控制DC-link电容器充电功率的网侧变流器单闭环控制策略。本策略中引入的前馈补偿直接施加在控制电压的节点上,以及一个跟踪-微分器用于外界扰动动态前馈补偿的获取。在Matlab/Simulink平台中通过两种典型情况研究了所提出的网侧变流器控制策略对DC-link电压振荡抑制的有效性。结果表明,所提出的网侧变流器控制策略能有效抑制DC-link电压的冲击幅值及振荡,提出的前馈补偿方案及跟踪-微分器解决了电流内环对前馈补偿的延时以及经典微分器的噪声放大效应。
Aiming at the problems existing in the double closed-loop control of grid-side converter(GSC),such as slow response of voltage outer loop to the DC-link voltage oscillation suppression and the time delay in feedforward compensation by current inner loop,a GSC single closed-loop control strategy,which directly controls the charging power of DC-link capacitor,is proposed in this paper. Under this strategy,the introduced feedforward compensation is directly applied to the control voltage node;in addition,a tracking-differentiator is used to obtain the dynamic feedforward compensation for external disturbance. On a Matlab/Simulink platform,the effectiveness of the proposed GSC control strategy for the DC-link voltage oscillation suppression is studied in two typical cases. Simulation results show that the novel strategy can effectively suppress the impact amplitude and oscillation of DC-link voltage;moreover,the proposed feedforward compensation scheme and the tracking-differentiator can solve problems including the time delay in feedforward compensation by current inner loop and the noise amplification effect resulting from the classical differentiator.
引文
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