| 摘要 |
PROBLEM TO BE SOLVED: To provide a device that performs burnout protection of motor winding at low cost with high accuracy, without using any temperature detector such as a thermistor and a thermostat, even when power is unintentionally shut down or fluctuated.SOLUTION: The motor winding burnout protective device includes: a detection means for detecting a main circuit voltage; a detection means for detecting an armature current which flows through a motor; a detection means for detecting a motor speed; a motor winding resistance calculation means for calculating a motor winding resistance based on a main circuit voltage, a motor current, and a motor speed which are obtained by the detection means; and a motor winding temperature calculation means for calculating a motor winding temperature based on a motor winding resistance. The device stops power supply to the motor to prevent motor winding burnout when a calculated motor winding temperature exceeds a predetermined threshold. |
