A Multiplex Data Acquisition System Applied in High Voltage Transmission Line Based on Electronic Transformers

摘要

A multiplex data acquisition system applied in high voltage transmission line based on electronic combined transformers is proposed in the paper. Employing an air-core coil for current measurement and current protection and a SF6 coaxial capacitance for voltage measurement, this paper proposes a method to acquisition signal based on the MSP430F1611 MCU and ADC AD7685. The data acquisition system can collect three channel analog signals (current measurement, current protection, voltage measurement) at the same time, and then pack the data, send them to the merging unit through the optical fiber. The multiplex data acquisition system is at the ground potential, so the optical power source could be abandoned and the reliability is effectively enhanced. The technology of multi-channel acquisition, high-speed communications, anti-electromagnetic interference are mainly introduced. Tests have been done and the experimental results show that this ECT meets the requirement of the 0.2 s class for measurement and 5PTE for protection in IEC60044-8, voltage channel meets the requirement of the 0.2 level in IEC60044-7.