Design On Electronic Current Transformer Base On VFC

Electronic current transformer with its high insulation, saturated, measurement range and high performance becomes current transformer new development direction. Along with the gradual development of the electronic current transformer, sensing head, high power, the industrialization of data transmission, standardized interface, modulation and emc reliability problems such as error compensation practical research also appears even more necessary and pressing. This article mainly aims at the head, high pressure sensor, standardized interface of power, with practical IEC60044-8 electronic current transformer etc, according to relevant standards for electrical current transformer is studied and design.Rogowski coils used as a high-voltage power line sensor head.After the output of Rogowski coils was digitalized,then transmitted to low-voltage terminal through fiber-optic to carry out LED display or restore the original analog signal,so the high-voltage power-side bus current was measured. The system used fiber-optic digital transmission to achieve high-voltage side and low-voltage side of the complete electrical isolation and signal transmission , enhanced the signaling anti-jamming. Based on the GPS synchronous sampling design, using a merge unit based on field programmable gates array (FPGA) and digital signal processing (DSP) technology of multi-channel electronic merge unit digital output transformer, receive and processing function method, data output module will set of data transferred after frame, and then sent to Ethernet controller for tt&c equipment, secondary protection level measurement, after the protection and control equipment provides a good interface.VFC conversion circuit was the core of high-voltage side, this paper focused on the design of high-voltage side of the high-precision, high reliability, low power VFC conversion interface circuit. In addition, this paper also discussed power supply scheme of active devices in high-voltage side, a new power supply circuit was proposed; the electronic circuit anti-jamming of high-voltage side was discussed and designed, and the accuracy of the measurement system was improved.The experiment proved that the electronic current transformer designed was simple and practical,which had good linear degree and measure precision,and could measure current in the wide range.These current transformer have many virtues,Such as response speedily,wide bandwidth ete.Comparing with the traditional electromagnetic current transformer,questions such as being flammable and explosive caused by oil,the magnetism saturation and insulation between the high-voltage and low-voltage,that the electronic current transducer designed has been overcame because of the loweost,wide bandwidth.Simple and practicality the electronic current transformer have greater application prospects.