Resonant link topologies for fast power system transient compensation

New types of high power inverter based static VAr compensators (ISVCs) are generally restricted to fundamental voltage compensation applications. This is due to the limit in maximum switching frequency of the hard switched inverter. High frequency resonant topologies, which utilise zero voltage and zero current commutation of the inverter switches, result in high frequency lossless switching. Fast transient compensation of harmonics and random noise developed by rectifier and arc furnace type loads is now possible. Two types of resonant current source active power filters are discussed and modelled in this paper. Both compensators can perform active filtering and VAr compensation alongside power factor correction at the same time