| 摘要 |
PROBLEM TO BE SOLVED: To recognize the operating state of a harmonic current suppressor, without requiring any special means by detecting the voltage of a resistor provided to divide a DC voltage rectified through a diode in a transistor module. SOLUTION: An AC three-phase power supply 1 is connected through a switch 2 with a transistor module 4, incorporating an AC reactor 3 and a plurality of transistors and diodes. Voltage and current, rectified through the transistor module 4, are passed through a resistor 15 and a smoothing capacitor 16 to a transistor module 19, in order to control the rotation of a compressor. An inverter control section 18 can grasp the DC voltage VDC constantly, based on the voltage of the resistor 15 by taking advantage of the feature that the DC voltage is higher, when a harmonic current suppressor 17 is operating than when it is stopped. Consequently, the operating state and the stopping state of the harmonic current suppressor 17 can be recognized. |
