Rotor field current measuring device for brushless synchronous machine

摘要

PROBLEM TO BE SOLVED: To measure the rotor field current of a brushless synchronous machine easily with a high precision. SOLUTION: A rotor field current measuring device 21a is attached to a brushless synchronous machine and measures a rotor field current supplied to a rotor field winding 9 from a rotary rectifier 6. For that purpose, a q-axis winding 10 which detects the q-axis component of a gap flux in an AC exciter 1 and outputs a voltage waveform; a reference calibration value holding means 19 which obtains a proportion coefficient between a DC output current applied to the AC exciter 1 and the voltage level of the voltage waveform outputted by the q-axis winding 10 at the time of the unit test of the AC exciter 1, and holds the proportion coefficient as a reference calibration value; and a field current calculating means 16 which calculates the product of the voltage level of the voltage waveform outputted by the q-axis winding 10, and the reference calibration value held by the reference calibration value holding unit and obtains the rotor field current are provided.