| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive unit for synchronous motor, freezer, air conditioner, refrigerator using the same, and drive method for synchronous motor, capable of appropriately detecting a shaft lock.SOLUTION: The drive unit for synchronous motor includes: control means 100 that drives a synchronous motor in a position sensorless manner by outputting a control signal to a switching element of an inverter circuit, and current detection means that detects an output current of the inverter circuit or a DC side bus-bar current and outputs the current to the control means 100. The control means 100 calculates input effective power on the basis of a correlation value of a current value input from the current detection means and a voltage command value corresponding to a voltage applied to the synchronous motor, and determines that a shaft lock occurs at the synchronous motor when the input effective power is smaller than a predetermined threshold value and stops driving of the synchronous motor. |
