Current harmonics compensation for electrolytic processes using a series active scheme

A series active filter to compensate current harmonics injected by high-power rectifiers [such as in copper electro-winning (EW) and electro-refining (ER) processes] is presented and analysed. The proposed current harmonic compensation method is accomplished by injecting a corresponding series voltage distortion at the rectifier ac terminals. The distorted ac voltage generated at the high-power rectifier ac terminal forces the line current to be sinusoidal and increases dc voltage distortion, but it does not affect the EW or ER processes. A complete design procedure for the series active system is presented. In conjunction with simulated results obtained from a 10 MVA copper EW facility, a 2 kVA laboratory prototype is used to validate the current harmonic compensator scheme. The results obtained through simulation and from the experimental prototype confirm the viability of the proposed compensator and associated control strategy.