Impact Of Time Synchronization Methods In Smart Substations On The Time Delay In WADC System

China's present power grid has stepped into an era called " power transimission west to east,power aid north and south mutually,and national networking" already.The wide-area control system,based on the synchro-phasor measurement unit(PMU),has become the key technology for dynamic mornitoring and controlling in power system.Time synchronization is not only the essential need for PMU,but also the key factor for the stability of wide-area closed-loop control.A hardware-based test platform for the performance testing of 1588 clock is accomplished,which is used to test the features of time synchronization system in smart substations.According to these features,taking wide-area damping control(WADC)as an example,the impact of timing methods on the time delay in WADC system is researched theoretically and simulationally.A general wide-area control and protection hardware platform is built for further closed-loop research.Aiming at the problems of poor tolerance against background traffic and poor consistency in 1588 applications,the timing mechanism,characteristics and influence factors of synchronous accuracy of two versions of 1588 standard are analyzed.A test platform for the 1588 clock performance is accomplished.A method for testing under background traffic is put forward,which is closer to the practical engineering.And the necessity to accomplish the domestic 1588 industry standard is pointed out.As for the impact of 1588 timing metods on WADC system,based on the implemented wide-area damping controller,it is figured out by theorectical and simulated research that the normal timing error does not affect the WADC system,but the controller will lose effectiveness because of the enlarged timing error during network attack.A general wide-area control and protection hardware platform is built.A strategy of "first-control,then-storage" for data flow at mainstation is proposed to improve the real-time performance of closed-loop control.The closed-loop WADC is realized on this platform.The closed-loop test is carried out to verify the impact of 1588 timing on the time delay in WADC system.As same as the results in simulation,it is pointed out that normal timing error does not affect the WADC system.And the mainstation will block out as the result of the poor consistency of 1588 products.The enlarged timing error will defect the controller.