Power-factor correction device for variable speed drive

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.