Reconfigurable voltage and current line conditioner

The paper describes the specifications, circuit, control strategy and some practical results of a voltage and current line conditioner based on high frequency active filters implemented with IGBT for a range of 50 kVA to 1000 kVA in development under a PIE project led by the utility company Iberdrola. The power circuit is based on a parallel current active filter which cancels harmonics and reactive power. This filter feeds a series voltage active filter which reduces line voltage distortion, steps, flicker and slow changes. During line outages of less than 500 ms, the current filter works as an inverter feeding a critical part of the load. The control is based on two independent DSPs which implement deadbeat controllers