Stability Analysis And Parameter Optimization Design Of Digital-analog Hybrid Simulation System

Under the background of China’s energy transformation and electric power system reform,the power system presents many new features.High proportion renewable energy get access to power grid and large-scale power electronic equipment are widely used.The application of new technology and new equipment brings technological advancement to the power grid,but also makes the management,control and research of the power grid more complex.As a new generation of power system simulation technology,digital-analog hybrid simulation combines the advantages of real-time digital simulation and physical dynamic simulation.It plays a very important role in the study of modern power system simulation and has received extensive attention.It has high research value in the characteristics of the digital-analog hybrid simulation system and the system interface.For the stability of digital-analog hybrid simulation system,this thesis introduces the concept of the delay stability margin of the digital-analog hybrid simulation system and gives the corresponding solving method.Through the stability analysis of the digital-analog hybrid simulation system from the delay aspect,we can get more accurate results.The change of delay stability margin has been explored according to the parameters change of the simulation system.For the situation of insufficient stability margin of the digital-analog hybrid simulation system,the Smith compensator is introduced into the system interface to improve the system stability performance.The simulation results show the effectiveness of the proposed stability analysis and improvement method.This thesis presents a method for the evaluation of the accuracy of digital-analog hybrid simulation.This method can take into account factors such as the characteristics of the system interface and frequency range of interest,and it is applicable for the actual situation of the parameters change of the simulation system.On this basis,using the evaluation index function as the objective function,the structural and control parameters of the interface device on the physical side of the digital-analog hybrid simulation system are optimized to obtain more accurate simulation results.This thesis also focuses on the research of DC interface in digital-analog hybrid simulation system and proposes a design scheme of universal DC interface.The effectiveness of the proposed scheme is verified by simulation.Then,the single-interface digital-analog hybrid simulation system is extended to the category of multiple interfaces.Corresponding mathematical models are established according to the different structures of multi-interface systems and summarized into a unified form.The implementation method of shared multiinterface is given in this thesis,and the feasibility of the multi-interface digital-analog hybrid simulation system and the shared multi-interface is verified through simulation.