Control circuit for reducing of total harmonic distortion (THD) in the power supply to an electric load

摘要

A control circuit for reducing Total Harmonic Distortion (THD) in the power supply to an electric load, includes an input stage (10) for receiving a network voltage (V1) and providing a corresponding rectified sinusoidal output supply voltage (Vbus); an output stage (20) associated with the input stage (10) for providing power supply to an electric load (L); a control module (30) designed to control the power factor and the harmonic distortion (THD) of the energy obtained from the network voltage (V1), by regulating a pulse current (S1) that acts upon the power supply absorbed by the output stage (20); a regulating module (40) which is designed to: sense a main signal (SW) representative of the supply voltage (Vbus); compare the main signal (SW) with a preset reference (Vref); generate a regulating signal (S3) designed for the control module (30). The control module (30) is designed to modify the pulse current (S1) according to the regulating signal (S3).