Basic principle of active power filter
The active power filter is a new type of power harmonic control special equipment made by modern power electronics technology and digital signal processing technology based on high-speed DSP devices. It consists of two main parts: the command current operation circuit and the compensation current generation circuit. The command current operation circuit monitors the current in the line in real time, converts the analog current signal into a digital signal, and sends it to a high-speed digital signal processor (DSP) to process the signal, separate the harmonic from the fundamental wave, and pulse width modulation ( The PWM signal form sends a drive pulse to the compensation current generating circuit to drive the IGBT or IPM power module to generate a compensation current equal to the harmonic current amplitude of the grid and opposite in polarity, which is injected into the grid to compensate or cancel the harmonic current and actively eliminate Power harmonics.