The Research Of Rogowski Coil And Its Applications

Current measurement is indispensable in the field of measurement. It is important to improve product quality?ensure power system safe and stable?protect electrical equipment. Rogowski coil can measure current or the relevant parameter of a variety. Rogowski coil is widely used in the device of metering?monitor and protection. However, there are different index to the performance of sensor in different application environment. For example, metering device require sensor with high accuracy?monitoring device require sensor stable and reliable?protection require sensor with quick response. The performance of sensor is influenced by material selection?structure design?signal processing and terminal resistance matching. Therefore, it is very important make sensor good performing by adopting reasonable design methods according to different requirements in different application environments.This paper researched and analysed the characteristic of the Rogowski coil sensor making its various application as the main line. In this paper, the author confirms different performance demanding of Rogowski coil according to different application requirements based on the engineering practice. Then the paper analysis three sensors with representative: current sensor with wide-range and bifurcated structures used for power quality analyzer?quick current rate sensor used for short-circuit protection of direct current transmission line?pulse current sensor used for monitoring lightning current. This paper established the lumped parameter equivalent model and the distributed parameter equivalent model of Rogowski coil and analysed the influence of various parameters on the sensor used the two kinds of models. Lumped parameter equivalent model can be used for the analysis of sensor performance when signal frequency is in the below of 100 k Hz. The distribution parameter equivalent model is mainly used for the analysis of the high frequency response characteristics of rapid current rate sensor.This paper concluded the changing rule of Rogowski coil accuracy?frequency?response time and signal-to-noise ratio along with Rogowski coil structure size?shielding method and terminal resistance. The conclusion of this paper can guide the design of Rogowski coil in different application environment. This paper developed three different kinds of sensor according to the research conclusion. The measurement range of the current sensor with bifurcated structure is 3A~3k A, and its accuracy in the circumstances of laboratory is ±1%. The sensitivity of the rapid current rate sensor is 0.3(V??s)/A, and its response time is about 1?s. Lightning current monitoring sensor can accurately obtain the parameters of 8/20?s standard lighting current.