A fast and reliable fault diagnosis method for fault tolerant shunt three-phase active filter

This paper proposes a fault tolerant shunt three phase active filter topology. It mainly details converter reconfiguration and examined a fast and reliable optimised fault diagnosis method. This method avoids spurious semiconductor fault detection due to semiconductor switching. The converter topology is based on classical three-leg active power filter topology but includes bi-directional switches for converter reconfiguration after fault detection. The resulting post fault power structure is a two-leg topology with fault leg connected to the middle point of the filtering capacitor. A new fault diagnosis method is proposed, based on classical voltage measurements. It includes combinatory logic to analyse and validate error signals. An unique control is applied before and after fault detection, which avoids any controller reconfiguration. Simulation results obtained with Saber CAD tools validate the theoretical study and the modelisations