Research On The Multi-time Scale Real-time Hybrid Simulation Technologies For AC/DC Large-scale Power Grid And Its Engineering Application

The situation of large-scale west-east transmission,north-south exchange,extra-high voltage(EHV),high-capacity,AC&DC hybrid structure in the power grid of our country comes into being.Profound changes have taken place with the configuration and operating characteristicsof the large-scale power grid,in which the interaction between AC and DC systems isincreasingly marked.With the expanding of HVDC transmission and the widely application of power electronics devices,the time scale range of power system dynamic analysis extents accordingly.The different physical characteristics processes,such as ?s-level fast transient of multi-module MMC valve,ms-level transient of HVDC control and protection,and s-level dynamic of power grid,are intertwined and strongly coupled.As a result,the operation and control characteristics of the AC/DC large-scale power grid become much more complicated.In order to accurately analyze the AC/DC hybrid complex large power grid with massive power electronic,it is necessary to develop a new generation of simulation technology which is with the features of panoramic simulation scale,important control device in closed-loop and power system actual operation data interface.However,the existing technology cannot meet the requirements of simulation and analysis of AC/DC complex large power grid in the simulation precision,scale and speed.This dissertation focuses on the advanced technology exploration and engineering application development of the simulation technologies for AC/DC complex large power grid analysis.The major work of this dissertation includes:(1)Based on the in-depth analysis on the technical development of AC/DC large power grid and its requirement to the simulation technology,this dissertation presents and designs a multi-time scale hybrid real-time simulation system for AC/DC large-scale power grid,which is based on the "FPGA+RTDS+PC" heterogeneous platforms and is able to simulate the fast electromagnetic transient,electromagnetic transient and electromechanical transient hybridly.(2)The small time-step multi-rate real-time simulation technology on VSC power electronics device is developed.And the tiny-grained parallel computing algorithm for VSC converter valve based on 2-3?s time-step simulation is implemented in FPGA.Furthermore,this dissertation develops and realizes the hybrid simulation interface between FPGA and RTDS,and then establishes the accurate and efficient VSC small real-time simulation and testing platform.(3)This dissertation improves an efficient real-time algorithm and a high accuracy interface algorithm for the electromagnetic-electromechanical transient hybrid real-time simulation platform,which is composed of RTDS and parallel computer.As a result,the accuracy and efficiency of the hybrid real-time simulation platform is significantly improved.In the simulation platform,the HVDC systems are fine-grained parallel computed on RTDS with time-step of 50-100?s and the AC system are coarse-grained parallel computed on parallel computer with time-step of 10ms.(4)This dissertation develops a high speed and large capacity digital communication interface,which is used to realize the high precision,low delay and high speed real-time communication between the multi-time scale heterogeneous simulation platforms.As a result,the VSC device,HVDC system,AC power system simulation sub-systems are connected together by the closed-loop interfaces between them.And then the multi-mode united calculation in multi-time scale and multi-grain parallelism is implemented,which provides an accurate and efficient simulation platform for the operation analysis,testing and research on the AC/DC complicated power system.(5)The hybrid real-time simulation technologies in this dissertation are applied to the actual operation of AC/DC power grid.Based on the multi-source data communication and heterogeneous system model mapping technologies developed in this dissertation,the hybrid real-time simulation system,whose initial operating status is come from the actual operation section of EMS,can set up a "mirror system" with highly similar operation state as the actual power system.Simultaneously,the system can realize the interactive of the simulation process and the visual display of the simulation results.As a result,the high integration of real-time simulation,power grid operation and dispatching automation are realized in this dissertation.The effectiveness of the simulation platform is verified by the practical examples based on the simulation and mirror system of the power system dispatching and operation in this dissertation.The co-simulation on fast electromagnetic transient,conventional electromagnetic transient and electromechanical transient of power system is realized in this dissertation.It provides a more accurate and efficient simulation and experiment research tool for complex dynamics analysis and risk assessment of AC/DC large-scale power grid,which would effectively promote the development of power system simulation technology and has important engineering application value.