带补偿分量的时变卡尔曼滤波的电压凹陷检测方法

A Method for Voltage Sag Detection Based on Time-varying Kalman Filter With Compensation Component

针对电压凹陷的实时检测问题,提出了带补偿分量的时变卡尔曼滤波。将电压凹陷信号分解为稳态分量与补偿分量,建立带补偿分量的卡尔曼滤波模型;电压稳态期退出补偿分量,电压凹陷期投入补偿分量,检测的补偿分量直接作为动态电压恢复器(dynamic voltage restorer,DVR)的指令值。结合αβ/dq变换给出电压凹陷有效值和相位跳变。应用滤波残差法检测电压突变,并提出锁定延迟法克服补偿分量频繁投入与退出。仿真结果表明,该方法比普通卡尔曼滤波、虚拟三相dq变换方法具有更快的响应速度,满足DVR的实时性要求。

Aiming at the problem of voltage sag real-time detection, the time-varying Kalman filter with compensation component is presented. The model of Kalman filter with compensation component is constructed by decomposing sag voltage into steady component and compensation component. The compensation component which is to be controlled into effect by the compensation instruction of dynamic voltage restorer （DVR） is removed during steady period of voltage, and functioned when voltage sags occurring. The root mean square （RMS） and phase shift of voltage sags are confirmed by αβ/dq transformation. The residual error is adopted to detect the voltage step change and lock-delay method is proposed to overcome bouncing problem of compensation component functioning. Simulation results show that the proposed method is fast than Kalman filter and virtual three-phase dq transformation, meets the real-time request of DVR.