Software And Hardware Design Of Data Process System On All-fiber-optical Current Transducer

Transducer is one of the main protecting and monitoring equipment in power system.With the used voltage is getting higher and larger-capacity, all-fiber-optical current transducer(FOCT) replaces the traditional electromagnetic current transducer in power system for itsown advantages. At the same time, it is so important to improve the algorithm and hardwarecircuit of measurement system on all-fiber-optical current transducer. In this topic, thespecific scheme, used for the algorithm of data process on all-fiber-optical current transducer,is given and detailed studied. In addition, the right hardware circuit is designed.Through the zero-crossing detection and related demodulation method simulationverification, the related demodulation method is determined to be chosen in final. Because thealgorithm eliminates the effect of modulation depth and intensity to the signal demodulation,shows good linearity inπ/ 2, and presents strong anti-jamming capability. In hardware circuit,the scheme, combined DSP and FPGA, is chosen, in which FPGA controls the timing ofhardware circuit and data preprocessing, and DSP achieves data processing. With ahigh-level-integration, high-reliability, high-speed and low-power FPGA, and a high-speedand powerful data-processing-capability DSP, the conditions and assurances are provided toachieve the real-time measurement of weak signals.Through the design and debugging, the algorithm topic selected can normally operate inthe hardware circuit, and high-linearly detects the measured signal to meet the target. Butthere are still shortcomings and room for improvement, such as the approximate algorithmCalculation and the phase relationships of modulation signal and reference signal. All theycould be improved by other means.