APFbrief introduction
APF（Active Power Filter）It refers to active power filter. It is a new type of power electronic device used to dynamically suppress harmonic and compensate reactive power. It can compensate the harmonic and variable reactive power, which is changed in size and frequency. It is called active. As the name suggests, the device needs to lift the power supply source, and its application can overcome the L C filter and other traditional harmonic suppression and reactive compensation methods (traditional only fixed compensation), the realization of dynamic tracking compensation, and can complement both harmonics and reactive power.
APF function
Active power filter (APF) uses modern power electronics technology, the main topology is three level inverter circuit, and a new type of power harmonic control equipment based on digital signal processing technology of high speed all digital control mode. It consists of two main parts: the instruction current operational circuit and the compensation current generating circuit.
Through the external current transformer, the load current is detected in real time, and the harmonic components of the load current are extracted by the internal DSP. Then the PWM signal is sent to the internal IGBT, and the inverter produces a harmonic current and the load harmonic current. The harmonic currents in the opposite direction are injected into the power grid to achieve the purpose of filtering.
