Research On Electronic Current Transformer Based On Rogowski Coil

In recent years, the secondary substation system has been basically achieved with computer LAN-based substation automation. Although the data transmission substations have been digitally, but many current and voltage transformers are still the conventional electromagnetic transformer. With the requirements of building nation smart grid, strong grid, substation must be fully digitalized. The accuracy of measurement signals, stations digital signal transmission, network requirements will be higher. Conventional electromagnetic current transformer secondary side will be difficult with the number of measurement and relay protection device perfectly compatible with. Therefore, research into new electronic current transformers, to ensure the security and stability of power system to achieve intelligent grid, strong grid target has important practical significance.At first, this paper describes the structure of electronic current transformer and a few common principles of technical indicators, and then analyzes the electronic current transducer relative to the traditional advantages of electromagnetic transformer, and research status at home and abroad are introduced. The performance of the integrator determines the precision of measurement signal transformer, this paper based on Rogowski coil current transformer conducted a detailed analysis of the integral circuit. Analog integrator circuits used widely in this years, it has two kinds of state integral,differential and self-working state integral, but not a good choose of low-frequency small-signal. In this paper, the author designed a new type of integral circuit, it can effectively solve the integrator of the low-frequency signal measurement deficiencies. The integral circuit measurement range, and has a good linearity. Then analyzes the digital integral circuit and integrated circuit chip, the working principle of integration, and three kinds of integral circuit for comparison. Digital integral circuit analog integrator circuit is a relatively stable performance, simple structure, less susceptible to outside interference, has certain advantages. Temperature and electromagnetic interference is integral circuit design, one of the main issues to be considered in this paper a detailed analysis of the temperature of all kinds of interference and electromagnetic interference on substation integration and made the circuit of the main measures to reduce electromagnetic interference.Through theoretical analysis and experimental verification show that electronic-based Rogowski coil current transformer with a high accuracy, wide measurement range and the advantages of stable performance, the indicators are able to meet international standards. It could well replace the traditional magnetic current transducer for high-pressure system accurate measurement of large currents. Therefore, based on Rogowski coil Electronic Current Transformer for the early realization of smart grid, strong grid of the objectives of important theoretical significance and practical value.