Research On Digital Substation Test Systembased RTDS

Nowadays, the digital technology is the forefront technology of the scientific development. The digital substation will play a significant role in enhancing the level of the substation automation, and it will be the direction of the future substation. With the rapid development of the parallel processing technology and power system simulation technology, the speed and accuracy of real-time digital simulation system used in the complicated power system have made considerable progress. RTDS(Real-Time Digital Simulator) will be the major direction for the future power system simulation and testing. Meanwhile, the maturation of the intelligent switch, electronic transformer, primary operating equipment online state detection, substation operating training simulation technology and the development and application of the computer high-speed network in real-time network have profoundly influenced the existing substation automation technology. However, it also raises a number of new requirements for the digital substation test systems.After comparing with the traditional testing system, this paper proposes a new digital substation testing system based on RTDS and establishes a typical primary system real-time models, such as transmission line models, transformer models, bus models as well as fault control subsystem and breaker controller subsystem models. At the same time, the digitalization of the process layer is mainly embodied in using a large number of electronic transformers and merging units, so it raises new demands on the digital substation testing system. However, RTDS still lacks the electronic transformer models so far. Therefore, this paper studies and establishes numerical simulation model and communication model of the Rogowski coil electronic current transformer based on RTDS.First, the mathematical models of the equivalent circuit of the Rogowski coil are established. The digital integrator, the re-sampling filter, and the phase compensation module are developed accordingly. Then, the sampled values are encoded and published according to IEC 61850-9-2 by the GTNET. After that, the communication model is built by using the concept of virtual terminal according to IEC61850. Finally, a system configuration tool is developed to configure and visualize the dataflow between RTDS and the protection and control IEDs. The closed-loop test results show that the real-time simulation model of the electronic current transformer proposed in the paper is conducive to improving the test efficiency of the digital substation systems.Afterwards, the paper introduces the protection real-time simulation model and analyzes the research significance of the real-time closed-loop simulation system of microcomputer protection. Then the paper describes two typical application approaches in the microcomputer protection simulation system, and introduces the system architecture of the real-time closed-loop simulation system based on RTDS. Then it also presents the development of the protection component in guidance of the integration and modularization thought, and divides the component in protection function unit in accordance with IEC61850 standard. The results show that the system based on RTDS can greatly enhance the efficiency of the computer protection testing, analysis and R&D.Finally, this paper proposes a network-based automatic application testing method for the all-digital protection system which fully takes advantage of IEC61850 standard, and introduces its hardware architecture and software implementation in detail. As the test system possesses a series of advantages, such as its networking and opening, it is easy for the users to customize and extend it.