Novel all-fiber current transformer and its modulation and demodulation method

Abstract

The present invention relates to a novel all-optical fiber current transformer and its modulation and demodulation method. The data processing unit of the new all-optical fiber current transformer includes a cycle dividing and processing module, an open loop demodulating module, an open loop computing and processing module, a closed loop demodulating module, a closed loop computing and processing module and an amplitude error correcting and processing module. The cycle dividing and processing module divides a modulation and demodulation cycle into several modulation and demodulation sub-cycles and comprises at least one open-loop sub-cycle and at least one closed-loop sub-cycle. Both the open-loop computing and processing module and the closed-loop computing and processing module are connected with the amplitude error correcting and processing module. The amplitude error correcting and processing module outputs a current value for high frequency measurement, and the closed loop computing and processing module outputs a current value for energy metering or relay protection. The new all-optical fiber current transformer can meet the functions of energy metering, protection, harmonic measurement and traveling wave measurement.

Description

technical field [0001] The invention relates to the technical field of electric power equipment, in particular to a novel all-fiber current transformer and a modulation and demodulation method of the all-fiber current transformer using specific modulation. Background technique [0002] The current transformer is an important device for relay protection and electric energy metering in the power system. It is used to measure the current in transmission and send the measured current to the measuring instrument and relay protection device. Based on Faraday's magneto-optic effect and Ampere's loop law, the all-fiber current transformer adopts digital control technology and has the characteristics of safety, accuracy, and AC-DC compatible measurement, and adapts to the new needs of smart grids. The working principle of the all-fiber-optic current transformer is: after the light source of the all-fiber-optic current transformer passes through the incident light path, the sensitive ...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims at the problems existing in the existing all-fiber-optic current transformer using a single modulation method, and provides a novel all-fiber-optic current transformer, which is provided with a data processing unit with a specific structure, and adopts open-loop and closed-loop modulation and corresponding demodulation The signal processing method makes the current value have the advantages of good precision, good stability, fast response speed, small delay, high bandwidth, etc., and can simultaneously meet the functions of electric energy measurement, protection, harmonic measurement and traveling wave measurement.

Images