| 摘要 |
PURPOSE:To operate a compressor motor with maximum efficiency by changing an operating current which is given to the compressor motor by a method wherein an inverter power supply is controlled on the basis of an operating current value from a current detector. CONSTITUTION:In the case of an air conditioner, an inverter 2 supplies drive electric power to a compressor motor 3 at a frequency corresponding to a load according to a PWM control signal from a microcomputer 8a for a controller 8, and a current detector CT5 is installed at a power-supply interconnection at any one arbitrary phase out of windings U, V, W on the AC side of the inverter 2. As a result, a secondary current can be changed largely irrespective of the operating frequency of the compressor motor 3. However, since a detection signal is an alternating current, it is converted into a DC voltage via a rectifier circuit 6 so as to be given to an input port for the controller 8 as the detection signal. Consequently, the compressor motor can be operated with maximum efficiency by changing an operating current which is given to the compressor motor from an inverter power supply. |
