Research Ontime Delay Of Multi-time Scale Hybrid Simulation Platform

In 2020s,China clearly put forward the goals of "emission peak" and "carbon neutrality"for the first time,and advocated a green and low-carbon lifestyle.Under this goal.China’s new energy industries such as wind energy and photovoltaic have developed rapidly.By 2021,power generation capacity of new energy has exceeded 1 trillion kwh.At the same time,lots of countries around the world have taken a variety of measures to transform the energy structure,and new energy and energy storage technologies have attracted the attention of the industry.With the penetration of new energy in the power system increasing year by year,the power system presents the trend of power electronics.This leads to the existence of short-time scale power electronic system and long response electromechanical process in the real-time simulation of regional power system,so the traditional power system simulation technology can not meet the needs of real-time simulation of power system.This research designs a hybrid real-time simulation platform based on multi-time scale,which combines central processing unit（CPU）,field programmable gate array（FPGA）and digital signal processing（DSP）.Among them,SpaceR realizes real-time simulation of power grid;Based on the interface and computing characteristics of FPGA,typhoon HIL has as low as 0.5 μs,which can realize the fast response dynamic process simulation of power electronics;dSPACE has strong scalability,and the digital signal sampling rate can reach 0.5 MSPS,which is used to realize the control of rapid prototyping.The communication delay between subsystems of hybrid real-time simulation platform is evaluated.Two power system models with different grid connection control modes are built on the traditional single real-time simulation platform and the multi-time scale hybrid realtime simulation platform designed in this paper to analyze the impact of time delay on the model.The theoretical analysis and simulation results all show that after introducing the communication delay,the positive resistance range of the virtual equivalent impedance Zeqtd of the grid-forming inverter is expanded,and the resonance damping characteristics in the weak grid are improved;For the grid-following inverter,the pole damping ratio of the system with communication delay is less than that without communication delay,which makes the power loop underdamped oscillation in the strong grid.The research shows that the time delay between subsystems of multi-time scale hybrid real-time simulation platform will create an illusion for the simulation and verification of grid connection of new energy power generation system,that is,the grid-forming inverter is more suitable for weak grid,while the gridfollowing inverter is narrowed.This research process of this topic provides theoretical support for carrying out multi-time large-scale simulation and implementing PCs simulation verification under power grid load scenario.