基于离散域控制的电压暂降治理研究

Research on Voltage Sag Compensation Based on the Discrete-time Domain Control

针对电压暂降电能质量问题,研究了动态电压恢复器(DVR)的离散域控制策略。通过分析电压环离散域被控对象,基于根轨迹分析提出了内环最佳增益设计方法,实现了有源阻尼的最优化。在此基础上,提出了电压环离散域控制器,实现了与被控对象弱阻尼极点的对消,并设计控制器极点在同步旋转坐标系(SRF)下为直流信号提供无穷大开环增益,从而实现了对静止坐标系下交流信号的无静差调节。针对所设计控制器,提出了电压环临界阻尼参数设计方法,避免了输出电压的超调并实现了调节时间的最优。实验结果验证了所提设计方法的正确性与有效性。

Aiming at the issue of voltage sags power quality,the discrete-time domain control strategy of dynamic voltage restorer(DVR)is studied.By analyzing the controlled object in the discrete-time domain of voltage loop,the optimal gain design method of inner loop is proposed based on root locus analysis,and the optimization of active damping is realized.Based on this,a discrete-time domain controller of voltage loop is proposed to achieve to cancel the weakly damping poles with controlled object,and the controller poles are designed to provide infinite open-loop gain for the DC signal in the synchronous reference frame(SRF),so as to achieve the non-static-state error adjustment of the AC signal in the static frame.Aiming at the designed controller,a design method of critical damping parameters of voltage loop is proposed,which avoids overshoot of the output voltage and achieves to optimize the adjustment time.The experimental results verify the correctness and effectiveness of the proposed design method.