| 摘要 |
<p>The three-phase asynchronous motor for the drive of the compressor of a refrigeration unit, which is intended for use in vehicles with their own on-board power supply has a control unit 20 with a frequency converter for the control of the frequency of the three-phase alternating current such that the latter frequency is approximately inversely proportional to the motor load and preferably approximately inversely proportional to the current intensity of the motor load. The control unit 20 may also be fitted with a device for controlling the value of the voltage of the three-phase alternating current and of a three-phase rectifier, connectable to a direct current source, for producing the three-phase alternating current. For this purpose, control of the value of the voltage of the three-phase alternating current is effected in such a way that, at the nominal frequency, the voltage remains constant; whereas, on lowering the frequency, the voltage is reduced proportionally to the reduction in frequency, taking into account the voltage value of the d.c. voltage source.</p> |
