| 摘要 |
PURPOSE: To enhance the reliability by arranging the power supply of a dynamic brake as the output from the control power supply for an inverter unit and incorporating the brake circuit part into the inverter unit thereby stabilizing the gate power supply for a self-extinguishing element. CONSTITUTION: A control section 27' is provided with a control power supply A102 from a control supply 26' receiving an intermediate DC voltage A101 in addition to an inverter control circuit. A dynamic brake control section 29 generates a brake command A103 when a detected intermediate DC voltage A101 is higher than a predetermined level and delivers a gate command, i.e., a gate drive signal A104, to a dynamic brake 5' disposed on the outside of an inverter unit 2'. Furthermore, a brake resistor 6 and a dynamic brake 5' are disposed on the outside of an inverter unit 2'. A transistor in the dynamic brake 5' is driven by the gate drive signal A104 outputted from the dynamic brake control section 29. |
