FREQUENCY CHANGER Russian patent published in 2000 - IPC

FIELD: converter engineering; power supply for high-power ozonizer. SUBSTANCE: frequency changer has three- phase rectifier bridge built around six thyristors 2-7 and connected to output leads through transformer 1; diode 8; single-phase inverter bridge built around four thyristors 9-12 with switching capacitor 14 connected across two diagonally opposite ac terminals with its cathode group connected to negative output lead of three-phase rectifier bridge and anode group has center tap interconnecting secondary windings of transformer 1 through filter choke 13; second single-phase inverter bridge built around four thyristors 15-18 with second switching capacitor 20 connected across two diagonally opposite ac terminals its anode group being connected to positive output lead of three-phase rectifier bridge and cathode group, to center tap interconnecting secondary windings of transformer 1 through second filter choke 19; second transformer 2 whose first primary winding is connected in parallel with switching capacitor 14, second primary winding, in parallel with switching capacitor 20, and leads of secondary winding, to output leads of frequency changer; second diode 22 connected in series with diode 8; circuit of diodes 8 and 22 differentially shunts output leads of three-phase rectifier bridge; common point of diodes 8 and 22 is connected to center tap interconnecting secondary windings of transformer 1. EFFECT: improved operating reliability of frequency changer. 1 dwg