| 摘要 |
PURPOSE:To shorten drying time by self-drying a rotary electric machine by flowing AC to the winding of the machine, switching to a DC in a short time to detect the variation of a resistor and the temperature rise from a temperature sensor, and controlling the AC along a temperature program. CONSTITUTION:A thyristor switch 8 is controlled at the winding 7 of a motor 1, AC is flowed through a contact 9 to self-dry the motor. The temperature at the starting time is detected by a sensor 12, amplified by a preamplifier 13, and inputted to an arithmetic circuit 15. A temperature program setter 17 controls contacts 9, 20, 21 by AC/DC switch 18 in accordance with the program to select suitable DC10 by a selector 11, supplied to the winding 7, amplified by a preamplifier 16, and inputted to the circuit 15. The circuit 15 calculates the temperature rise from the variation of the resistance value, and again switches a power source by a switch 18 to flow AC. A temperature regulator 19 controls the conducting angle of a thyristor switch 8 in response to the difference between the target temperature and the present temperature. This operation is repeated until reaching the target temperature. Thus, the drying time can be shortened to save the heating energy. |
