Reconfigurable active front-end of adjustable speed drives for power quality improvement

A new control scheme is proposed to utilize the active front-end of a high performance adjustable speed drives (ASD) to solve power quality problems caused by conventional diode/thyristor drives. Under the proposed control scheme, a fully controlled active front-end ASD acts as a local power quality conditioner in order to compensate harmonic currents as well as reactive power generated by other neighboring drives. In this way, power quality problems caused by multiple motor drives can be solved locally. The proposed solution can fully utilize the capability of the active front-end of ASDs and does not require vast replacement of conventional diode/thyristor ASD sets. Therefore, it can provide flexible and economical solutions for power quality improvement compared to other custom power devices. Simulation results verify the performance of the proposed active front-end configuration and control schemes.