INVERTER OPERATION SYSTEM AT POWER INTERRUPTION TIME

• Main Author: KIDOGUCHI HIDETAKA
• Format: Patent
• Language: English
• Published: 05.02.1986
• 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; GENERATION

PURPOSE:To restart the operation of an induction motor immediately when a power interruption is recovered at AC side interruption time by receiving power for controlling an inverter from a DC middle circuit. CONSTITUTION:When an AC power source is interrupted, a DC middle circuit supplies power to a motor 6 while reducing the voltage. When the voltage of the middle circuit decreases to E1 of the first set value, the motor 6 becomes a generator to discharge the held kinetic energy while decelerating the speed as a generator to enter so-called brake operation. Thus, the voltage of the middle circuit again starts increasing, but if the power interruption is finished in a short time, and power transmission is restarted at a time t2, it returns to the original operation state. Then, when power interruption occurs for a long time at a time t3, the operation is continued while producing and receiving the kinetic energy, the speed continuously decreases by consuming the kinetic energy, and eventually stops.