利用卡尔曼滤波锁相环的有源电力滤波器研究

Research on Active Power Filter Using Kalman Filter Phase-locked Loop

有源电力滤波器(APF)需要锁相环(PLL)获得电网电压相位。当电网电压出现谐波干扰时,传统PLL易受到电压扰动的影响,其产生的相位延迟导致无法准确检测谐波电流。此处设计一种采用卡尔曼滤波PLL的谐波电流检测方法,通过最小均方差递推观测数据,实时预测多个状态变量。以单相APF为例,搭建Matlab仿真模型及实验平台。仿真结果表明,卡尔曼滤波PLL较传统PLL具有跟踪速度快、抗干扰能力强的优点;实验结果也充分验证了采用卡尔曼滤波PLL的APF补偿效果好、相位延迟小。

Phase-locked loop(PLL)is used to obtain the phase of grid voltage in active power filter(APF).When the harmonic interference occurs in the grid voltage,the traditional PLL is easily affected by the voltage disturbance.Because of the phase delay,harmonic current can’t be detected accurately.A harmonic current detection method based on Kalman filter PLL is designed.Multiple state variables can be predicted in real time through the minimum mean square error recursive observation data.Taking single-phase APF as an example,the Matlab simulation model and experimental platform are built.The simulation results show that the Kalman filter PLL compared with the traditional PLL has the advantages of fast tracking speed and strong anti-jamming ability.The experimental results also fully verify that the APF using Kalman filter PLL has good compensation effect and small phase delay.