Patent ID: 9099934
Filing Date: 2015-08-04
Classification: H02M,Y02B

Abstract:
1. A voltage source inverter comprising: a rectifier having an input for receiving multi phase AC power from an AC source and converting the AC power to DC power at an output; an inverter for receiving DC power and converting the DC power to AC power; a link circuit connected between the rectifier and the inverter and comprising a DC bus having first and second rails to provide a relatively fixed DC voltage for the inverter, and a DC bus capacitor across the first and second rails to smooth voltage ripple; and an active filter circuit comprising a pair of filter capacitors in series across the first and second rails to create a midpoint, bidirectional switches connected between the rectifier input and the midpoint, a current sensor connected between the bidirectional switches and the midpoint and an active switch controller operatively connected to the AC source, the first and second rails and the current sensor for controlling a conduction angle of the bidirectional switches to maintain DC bus voltage at a desired reference level under a wide load range.