The Study For The Part Of Signal-processing On Active Optic-electrical Voltage Transformer

Active Optic-electrical Voltage Transformer (AOTV) is a new-style electric equipment. because of its good stabilization, reliability and well-performed sensor technology. According to analysis and comparison for different sensor technology, this paper chose the project with capacitor divider as its sensor, optical fiber as inter-media between its primary circuit and secondary circuit, and signal processing mainly in control room. This paper introduces signal processing in secondary circuit based such AOTV in details including principles and functions. To receive data correctly from primary circuit is the first task for secondary circuit. In consideration of reducing of power in primary circuit, this paper use transmission with single optical fiber to fulfill data sending and receiving, so its principle is outlines firstly. Then it comes the details of how to fulfill data-receiving and decoding accordingly in secondary circuit with CPLD (Complex programmable logic device). The simulation waveform and dada are also presented. Data processing in secondary circuit is based upon DSP system. This paper introduces the technology how to synchronize three-phase sampling, and puts emphasis on the function of synchronization with GPS. With correct input of sampling data, the function of scaling of measure system is put forward, including RMS calculation, storage of scaling coefficient and communication with PC. Then it presents the logic for multi-phase data processing and technology of data recombining for analog interface and digital interface. Finally, this paper lists some data result for linearity experiment and makes some analysis. This paper also gives some discussion on causation that leads to error for capacitor divider of AOTV. Error that caused by arithmetic of RMS and its emendation are also discussed.