The Research Of Electronic Current Transducer And Its Interface Technique

The traditional TA can't satisfy measurement, control, and protection in power system because of its limitation. Recently much attention has been focus on Electronic Current Transducer (ECT) which is based on fiber and digital technique. On the overview of the development of ECT currently, the thesis carries out a series of research on the transient performances and interface technique of ECT based on Rogowski coil, aiming at the development of power system protection and the requirement of ECT characterizing the transient process of primary current with nicety.Rogowski coil is a new pattern sensing component. Its characteristics have a direct influence on the performances of ECT. After introducing the basic theory of Rogowski coil, the thesis put forward the practical design principle with parameter calculation on the basis of measuring range of ECT.The current signal provided by TA for secondary facilities can characterize primary fault current truly at the beginning of the transient process when fault. It is most important to control and protection in power system. Integrator is the key element in ECT based on Rogowski coil. It is appropriate or not would affect the transient performances of ECT deeply. The thesis presents three types of integrators, including the integrator designed by analog circuit, digital integrator designed by numerical formula and digital integrator designed by chips. And the thesis compares the transient response performances of them.The thesis makes a further study on the application of VFC as the A/D conversion link in ECT, and suggests a new A/D conversion method having integral characteristic. Also compares with ADC.As the important component of signal process unit in the low voltage side of ECT, the thesis introduces the architecture and interface regulation of information merging unit.