Energy saving method for use with active pwm rectifiers in regenerative drives
AssigneeYaskawa America, Inc.
InventorMahesh M. SWAMY
Life of this patent
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Abstract
As described herein, a drive circuit for a three phase AC motor comprises an AC/AC converter. The converter has an input for receiving multiphase AC power from an AC source and converting the AC power to variable voltage and variable frequency from the AC source for driving the AC motor. A filter circuit is connected to the AC/AC converter and comprises at least one inductor per phase and at least one capacitor per phase. The capacitors are connected in a broken wye configuration with one side connected to one of the inductors and an opposite side connected via a three phase diode bridge rectifier to a switch. The switch is controlled by a converter control to selectively open or short a neutral point of the broken wye capacitor configuration.
Claims6
The method for saving energy with active PWM rectifiers in a regenerative drive, comprising:
- providing a voltage source inverter comprising an active PWM 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 and a PWM inverter for converting the DC power to AC power to drive a motor, the PWM rectifier and PWM inverter being controlled to control flow of power into and out of the AC source;
- and
- providing a filter circuit connected between the AC source and the voltage source inverter and comprising at least one inductor per phase and at least one capacitor per phase, the capacitors connected in a broken wye configuration with one side connected to one of the phases and an opposite side connected via a three phase diode bridge rectifier to a switch;
- and
- controlling the switch to selectively open or short a neutral point of the capacitor broken wye configuration.
Dependencies are inferred from the claim text.