12kv Current Sensor Based On Rogowski Coil Developed

Current transformers are important component for current measurement and relaying protection in power system. With the development of power system, on one hand, the capacity of the power system is increasing very rapidly and the system current becomes larger and larger. On the other hand, with the optimization of the administration and allocation of the power energy, the traditional CT can't meet the demand. Our company'new product(VSM) is very urgent to develop a new type of CT to meet such requirement.According to the actuality of the present research on CT, this paper introduces the measurement principle of Rogowski coil and analyzes the factor that influence the precision of measurement, we bring forward a new design scheme based on the Rogowski coil. In this design, the protection in short circuit failure and the measurement in normal condition are both fulfilled. It can also communicate with the computer through the communicating interface, sending the parameter of the system current and accepting the instruction.In order to validate the rationality of study, the rogowski coil was designed and manufactured. The controller based on STC89C51, including the hardware and the software, are designed according to the measurement and control demand of system. The CT worked well through the experimental test. According to the causation of the error, the adjustment part is adopted in the design. For instance, the screen cover for rogowski coil are designed. In the processing of signal, the adjustment part is adopted. In the programming of software we put forward the methods to solve these problems. This can make the system more secure and reliable.Based on the research in theory, the prototype of rogowski coil CT was manufactured and tested, the practicability was validated.