Analysis of ECT effect on accuracy of measurement and protection

Abstract Electronic current transformer (ECT) is responsible for collecting and transmitting measurement, protection, and control signals of substations, which is regarded as a critical device for the connection of primary and secondary equipment in an intelligent substation. Naturally, a well-designed ECT is essential to ensure a safe and stable operation of power systems. This paper attempts to provide a detailed discussion and analysis of the principle, structure and characteristic of ECT, which mainly focuses on the following three aspects, i.e., steady-state accuracy, frequency response test and transient spread characteristics test. For a comprehensive performance test, a laboratory test platform is established in intelligent substations to simulate actual operation condition of ECT and further implement error accuracy analysis, frequency response test, transient response test and long-term test. Simulation results show the influence of ECT on measurement and protection accuracy, which can provide theoretical basis and evaluation criteria for further improvement of digital measurement performance and large-scale application in intelligent substations.