Switched-mode power supply system for speed variator, has balancing circuit whose one end is connected to mid-point of two buffer capacitors for balancing leakage currents of buffer capacitors

摘要

The system has a secondary winding (Ns) magnetically coupled to a primary inductive assemblies (Np1, Np2) to output direct current output voltage (Us). The assembly is connected in series between a positive input terminal (A2) and two MOSFETs or insulated gate bipolar transistor switches (SW1, SW2). A drain (D2) of the switch (SW2) has a current injection module for injecting current at a mid-point (PMC) of two buffer capacitors (CB1, CB2). One end of a balancing circuit (15) is connected to the mid-point, to balance leakage currents of the capacitors. An independent claim is also included for a speed variator.