Power conversion device with overvoltage suppression

• Main Author: Sugahara Tetsuo
• Format: Patent
• Language: English
• Published: 10.10.2017
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROL OR REGULATION THEREOF; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

Even when an overvoltage suppression circuit is not formed due to failure of an overvoltage suppression switch, overvoltage application to semiconductors and a filter capacitor is prevented. A control unit controls the overvoltage suppression circuit to short-circuit the filter capacitor when the voltage thereacross exceeds a predetermined value. Then when non-operation of the overvoltage suppression circuit is detected, the control unit opens an AC breaker and AC switch, and closes a charging switch. Thereafter, the control unit turns ON the converter element (or converter element) connecting to the filter capacitor terminal (or terminal) and a charging resistor, and turns ON converter element (or converter element) connecting to terminal (or terminal) of filter capacitor and connecting to the terminal of the transformer not connected to charging resistor.