Dynamotor rotor voltage and current measuring method and its device

Abstract

The invention relates to a method and apparatus for measuring voltage and current of generator rotor, which belongs to generator excitation parameter measuring technical field, including: collecting firstly voltage signal and current signal of generator rotor; converting the collected signal into optical signal; transmitting for long distance and receiving the optical signal, and outputting the electrical signal after conversion. The apparatus includes a voltage divider, a proportional amplifier, and an optical modulator of generator rotor side, an optical fiber transmission system, an optical receiving converter and an isolation power source of lower voltage side. The rotor voltage is scaled down by the voltage divider, and the voltage signal for reflecting rotor current variation information outputted by current divider is amplified by the proportional amplifier, then modulated to be optical pulse signal by the optical modulator and transmitted to the optical receiving converter by the optical fiber transmission system, demodulating the optical signal and finally outputting measurement signal of rotor voltage and current. The invention is superior in accurate measurement result, reliability, and excellent temperature stability and anti-vibration characteristics.

Description

technical field [0001] The invention relates to a generator rotor voltage and current measurement method and a device thereof, belonging to the technical field of generator excitation parameter measurement. Background technique [0002] Generator rotor voltage and current signals are the key parameters to monitor the generator excitation parameters. Since the monitoring equipment is far away from the generator, metal cables are generally used to transmit the voltage and current signals of the generator rotor. Due to the high voltage on the rotor, if a very long metal cable is used to transmit the signal to the measuring device, there will be a great hidden danger in terms of safety. Once the cable fails (grounding or short circuit), it will bring serious consequences. ; In the measurement of the rotor current of the generator, since the output signal of the shunt used for rotor current measurement is generally weak (millivolt level), it is easily affected by electromagnetic...

AI Technical Summary

Problems solved by technology

Due to the high voltage on the rotor, if a very long metal cable is used to transmit the signal to the measuring device, there will be a great hidden danger in terms of safety. Once the cable fails (grounding or short circuit), it will bring serious consequences. ; In the measurement of the rotor current of the generator, since the output signal of the shunt used for rotor current measurement is generally weak (millivolt level), it is easily affected by electromagnetic interference during long-distance cable transmission, resulting in measurement accuracy decline

Due to the effect of the measurement loop inductance, this measurement method cannot accurately measure some transient processes

At present, there is no transmitter with good transient performance and high accuracy specially used for generator rotor voltage and current measurement on the market.

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