APF 工作原理 Working principle

有源电力滤波器通过外部电流互感器 CT，实时检测负载电流，并通过内部 DSP 计算，提取出负载电流的谐波成分，然后通过 PWM 信号发送给内部 IGBT，控制逆变器产生一个和负载谐波大小相等、方向相反的电流注入到电网中补偿谐波电流，实现滤波功能。 

The active power filter detects the load current in real time through the external current transformer CT, and extracts harmonic components of the load current through internal DSP calculation, and then sends the harmonic components to the internal IGBT through PWM signals to control the inverter to generate a current with the same magnitude and opposite direction as the load harmonic and inject the current into the power grid to compensate the harmonic current, thus realizing the filtering function.