MOTOR DRIVE UNIT

• Main Authors: YAEJIMA MAMORU, HORIKOSHI SHINICHI, SATO HIROSUKE
• Format: Patent
• Language: English
• Published: 21.06.2007
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To detect the deterioration of the insulation resistance of a motor simply and accurately. SOLUTION: The drive of the motor 10 is stopped and a contact point 5 of a magnetic contactor is turned off. Contact points a1, a2 are turned on and a charging voltage of a smoothing capacitor C of a power supply portion 6 of a motor drive main unit 1 is boosted by a power supply circuit 2a to supply the voltage between a motor coil and ground. A leakage current flows from a rectifier circuit 23 to an closed circuit of the contact a2, a resistor R2, a detection resistor R1, the motor coil, grounds G2, G1, the contact point a1, and the rectifier circuit 23. If a potential difference at both ends of the detection resistor R1 exceeds a prescribed value, a photocoupler 29 indicates the deterioration of the motor insulation resistance. The detected potential difference (a leakage current value) and temperature/humidity detected by a temperature/humidity detector 2d are displayed in a display circuit 31. Also, its history is displayed graphically. Simple and accurate detection can be achieved because the accumulated energy of the smoothing capacitor, an element provided on the motor drive unit, is used as a power source and the deterioration of the motor insulation is detected after boosting the voltage. COPYRIGHT: (C)2007,JPO&INPIT