New active power filter and control method

A new active power filter with harmonic suppression and adjustable reactive power compensation is proposed. The power converter of the proposed filter can generate a compensating voltage, including a harmonic voltage for compensating the load harmonic current and a fundamental voltage for adjusting the reactive power of the utility side, connected to the power feeder via an impedance. The waveform of the utility current after compensating by the proposed active power filter can be approximated as a sinusoidal waveform, and the input power factor is also improved. A 20 KVA prototype has been developed and tested to verify its performance. The test results indicate that the proposed active power filter has the desired performance.