LV AHF for Reducing Harmonics in the Electrical Network

Faced with the severe problem of power harmonic pollution, AHF is the most effective tool to improve power quality. AHF is a new specialized equipment for power harmonic control developed using modern power electronics technology and digital signal processing technology based on high-speed DSP processing devices. AHF is equivalent to a harmonic current generator, which tracks the harmonic components in the harmonic current and generates harmonic currents with equal amplitude and opposite phase.AHF consists of two parts: the instruction current operation circuit and the compensation current generation circuit. The instruction current operation circuit detects the current in the circuit in real time, converts the analog current signal into a digital signal, and sends it to a high-speed digital processor (DSP) for signal processing. The harmonic and fundamental currents are separated to obtain the instruction current, which is then sent to the compensation current generation circuit in the form of a pulse width modulation (PWM) signal through the current tracking control circuit and drive circuit. The IGBT and IPM power modules are driven to generate a compensation current with the same amplitude and opposite polarity as the harmonic current, which is injected into the power grid to compensate or cancel the harmonic current, actively eliminate power harmonics, and achieve dynamic, fast, and thorough processing of power harmonics.