论文部分内容阅读
针对传统比例–积分(proportional-integral,PI)反馈控制器应用于动态电压恢复器时存在稳态误差较大、负载适应性差、难以对非线性负载进行电压补偿等问题,提出一种任意负载条件下的动态电压恢复器(dynamic voltage restorer,DVR)控制策略。该控制策略利用谐振控制实现对负载的无静差电压补偿,结合前馈控制来提高系统的动态响应速度。针对非线性负载在DVR串接电容上产生的谐波电压问题,引入一种电容谐波电压的抑制方法,该方法实时检测电容谐波电压所对应的谐波电流成分并控制DVR产生反向的谐波电流,间接消除了DVR输出电压中的谐波成分,显著提高了动态电压恢复器对任意负载特别是对非线性负载的电压补偿能力。实验验证了所提控制策略的有效性。
Aiming at the problems of the traditional proportional-integral (PI) feedback controller when applied to dynamic voltage restorer, such as large steady-state error, poor load adaptability and difficult voltage compensation for nonlinear load, an arbitrary load condition Dynamic voltage restorer (dynamic voltage restorer, DVR) control strategy. The control strategy utilizes the resonant control to realize no-dead-voltage compensation for the load, and combines the feed-forward control to improve the system’s dynamic response speed. Aiming at the problem of harmonic voltage generated by nonlinear load on DVR series capacitor, a method of suppressing the harmonic voltage of capacitor is introduced. The method detects the harmonic current component corresponding to the capacitor harmonic voltage in real time and controls the DVR to generate reverse Harmonic current indirectly eliminates the harmonic components of the DVR output voltage and significantly increases the voltage compensation capability of the dynamic voltage restorer for any load, especially for non-linear loads. Experiments verify the effectiveness of the proposed control strategy.