Research On Hybrid System Simulation Based On Quantized State

With the development of computer technology and the various derived information technologies,the components of engineering systems are increasingly diverse and complex,which contain many different types of subsystems.This kind of engineering system is generally called hybrid system.Hybrid system is a kind of system in which is interacted by the discrete time dynamic system and the continuous time dynamic system,so it has the characteristics of discrete system and continuous system.Nowadays,the simulation solution and discontinuity processing of hybrid systems have become one of the research hotspots and difficulties in the engineering field.For hybrid systems,it is meaningful to study the simulation algorithms of it because the existing theoretical research is rare and not perfect enough.For a long time,almost all the methods used in hybrid system simulation are integration methods based on time discretization,such as Euler method or Runge-Kutta method,which discretize the model according to algorithm simulation time,advancing the integral point by point in time.However,these algorithms have some defects,such as difficult choice of step size,low efficiency,poor convergence and so on.To solve this problem,this paper proposes a new modeling and simulation solution method based on the Quantized State System(QSS)method and the Discrete Event System Specification(DEVS).The method discretizes the state variables of the system,advances the integrals by the state variables,and combines the DEVS theory to make the modeling of the hybrid system easier.The method firstly uses a DEVS model to represent the discrete behavior of the hybrid system,and then uses the QSS method to discretize the continuous part of the hybrid system,so it can be represented by the DEVS model.Finally,the two parts of the DEVS model can be coupled to obtain the simulation model of the entire hybrid system.In this paper,the feasibility and accuracy of this method are preliminarily proved through modeling and simulation solution of PWM controlled DC motor and marble problem for the first time.In order to further verify the effectiveness and applicability of the proposed method,the complex model of electric vehicle power system is selected for simulation analysis.Compared with the traditional method,it shows that the algorithm has certain advantages in simulation accuracy and simulation efficiency.Secondly,it is also proved that the method is more accurate in detecting discontinuous points.Therefore,the method proposed in this paper has certain reference significance for the processing of hybrid systems.