| 摘要 |
PROBLEM TO BE SOLVED: To operate a compressor stably by performing the detection of whether or not its load exceeds a load range without a time delay accurately, without raising an output limit and the strength limits of constituent components. SOLUTION: To drive a compressor by a brushless DC motor to be controlled by an inverter 12, the rotational position of the rotor 13a of the brushless DC motor 13 is detected, and a phase correction angle for an electric signal that the inverter 12 outputs, to the position of the rotor 13a of the brushless DC motor 13 is set, and a control signal is supplied to the inverter 12 to cause the brushless DC motor 13 to have an output and a number of revolution needed, in response to a command number of revolution and the detected rotational position of the rotor 13a. At this time, a compressive load is detected on the basis of the phase correction angle for an electric signal which the inverter outputs, to the position of the rotor 13a, and a control signal is supplied to the inverter 12, so as not to exceed the limit load of line compressor system on the basis of the compressive load detected. |
