The Design For Implementing Synchronization Of Merging Unit In Electronic Transducers

As the capability and voltage level of transmission lines increasing, Convertional inductive currunt transformers and potential transformers have several draws at extra-high voltage and particularly ultra-high voltage grades.High voltage electronic transducers replacing convertional transforms will be the certain developing tendency.MU(Merging Unit) is the important component of the interface between electronic transducer and protective device. The definition of MU and its international standards are introduced, and the main functions of MU and its implementation are researched, especially the demand of the synchronization according the international standards is expatiated On。This thesis points out the problem to resolve the synchronization of merging unit according to the IEC 61850-9-1 and IEC60044-8 standard, and proposes a method using FPGA and Verilog HDL.To improve the accuracy and stability of the synchronous timer. Then, this thesis presents a new method to implement a highly accurate and stable clock by synchronizing the crystal oscillator clock with the GPS clock, which is based on the complement of the errors between GPS and crystal oscillator. This method can identify the synchronous clock accurately, and it can synchronously sample the multi-channel current and voltage information accurately and reliably.When the synchronous clock is disturbed or lost temporaily, it can still make the sampling pulse and 1 pps by crystal oscillator accurately, quickly achieving the synchronization of the merging unit when the synchronous clock input is resumed.The simulation and experiment results demonstrate the validity of this method. This subject can be very important for raising the level of power system automatization, especially for the development of fault analyzing, fault locating, stabilization judging and controlling technology.