Error Assessment Method For Electromagnetic-Electromechanical Hybrid Simulation Of Power Systems

In recent years,more and more new technologies and equipments such as new energy power generation,microgrid,electric vehicles,and UHV DC transmission have emerged in the power system.The input of these new technology equipment and the determination of the operation mode are based on the power system simulation results.Because direct power system experimental research is often very difficult,costly,and time consuming,it is necessary to use simulation methods to simulate various scenarios in the power system and conduct experiments in the simulation system.Electromagnetic-electromechanical hybrid simulation can simultaneously realize electromechanical transient simulation for large-scale power systems and electromagnetic transient simulation for local networks in one simulation process,which can guarantee the simulation accuracy of local systems under the premise of saving computing resources.However,the strong coupling and complication of modern power network AC and DC systems brings more challenges to hybrid simulation technology.The accuracy of the simulation results directly affects the safe and economic operation of the power grid.The research on accuracy and efficiency evaluation methods is important.Theoretical significance and engineering value.In this paper,the error and efficiency evaluation methods of electromagnetic-electromechanical hybrid simulation are established.Based on the simulation results,measures to improve the hybrid simulation error and efficiency are proposed.The research results are as follows:(1)The characteristics of electromagnetic transient simulation and electromechanical transient simulation are analyzed,and the basic principles of its operation are briefly analyzed.Aiming at the error mechanism of hybrid simulation,the paper extracts the instantaneous value or phasor of the physical quantity on the electromagnetic side and the electromechanical side,the interaction of data,the error of iteration,etc.,and provides theoretical guidance for engineering experiments.(2)Aiming at the existing electromagnetic-electromechanical hybrid simulation,the FSV method is the main body,and an error evaluation method combining multiple simulation results and a hybrid simulation efficiency evaluation method based on the acceleration ratio theory are proposed.Improvements to situations that may cause evaluation failures ensure an effective assessment of hybrid simulation errors and efficiencies.(3)Combined with the 36-node system of China Electric Power Research Institute and the AC/DC hybrid simulation system of Shandong Power Grid,considering the measures to improve the hybrid simulation error and efficiency,the control variables are used to experiment with multiple simulation methods and parameters of electromagnetic-electromechanical hybrid simulation.For example,the selected subnet location,different simulation steps,different damping algorithms,etc.,summarize the improvement measures of hybrid simulation error and efficiency.This conclusion can provide methodological support for future electromagnetic-electromechanical hybrid simulation engineering experiments.