Patent ID: 7420351

Claim:
A variable speed drive for a three-phase electric motor, comprising: a rectifier module that supplies a rectified voltage from a single-phase alternating current electrical network; a voltage step-up module that supplies a regulated bus voltage from the rectified voltage; an inverter module powered by the bus voltage and that supplies a control voltage to the three-phase electric motor from a control set-point; a digital processing unit that supplies the control set-point; and a hybrid power-factor correction device that drives the voltage step-up module and that comprises: a digital circuit including a voltage regulator module that receives a measurement signal of the bus voltage from the voltage step-up module and that supplies a correction signal based on the received measurement signal of the bus voltage, and an analog circuit that receives a measurement signal of the rectified voltage from the rectifier module, that receives the correction signal from the digital circuit, and that supplies a driver signal to the step-up module based on the received measurement signal of the rectified voltage and the received correction signal.