Injection-type hybrid active power filter in high-power grid with background harmonic voltage

In this study, an injection type hybrid active power filter (IHAPF) and its correlative key techniques are researched. Furthermore, the influences on IHAPF made by background harmonic voltage in power grid are analysed in detail. The IHAPF using the proposed recursive integral controller and harmonic detection method can not only mitigate harmonic ip-iq currents but also compensate high-capacity reactive power. Nevertheless, background harmonic voltage in power grid may damage IHAPF because it may lead to resonance and sharp rise of DC-link voltage. Two methods, which are parameter designs for avoiding resonance and hysteresis control for eliminating sharp rise of DC-link voltage, have been proposed to restrain the influences. The system realisation of IHAPF is introduced. Industry application results have confirmed the validity of the IHAPF and the methods to restrain the influences caused by background harmonic voltage.