Wide-area Synchronous Sampling Technique for Terminal Devices of Distribution IoT

Abstract

With the rapid development of the scale of the power grid, problems such as the changing operation mode of the distribution network and a large amount of monitoring data have become increasingly prominent. At present, the centralized sensing system based on synchronous phasor measurement has been researched, but there are still problems such as synchronization data delay mismatch in the implementation process, and the sampling data caused by clock differences are not timely and asynchronous, which is a problem in the construction of the power distribution IoT. The emergence of Beidou satellite timing, voltage-controlled crystal oscillator and other technologies provide new solutions to the above problems. This paper proposes a wide-area synchronous sampling technology for power distribution IoT terminal equipment that combines Beidou satellite timing with automatic frequency control. This technology can effectively solve the problems of too long time delay and too large synchronization error, and is an important technology to improve the real-time performance of synchronization data in the distribution network. The paper firstly compares various clock synchronization technologies, and then focuses on analyzing the causes of crystal oscillator errors, and then supplements the error control algorithm. Finally, the Beidou satellite timing and automatic frequency control combination of sampling synchronization software and hardware design methods are proposed, and the experimental data is analyzed. Experimental verification shows that the above method can control the clock synchronization error within one hundred nanoseconds, and realize the wide-area high-precision synchronous sampling of the power distribution IoT terminal equipment.