Simulation calculation method and simulation system based on state variable discretization

Abstract

The invention discloses a simulation calculation method and a simulation system based on state variable discretization. The simulation system comprises a system parameter acquisition processing module, a simulation value calculation module and a simulation control module, wherein the system parameter acquisition processing module is used for acquiring a state variable matrix during kth-step simulation calculation according to changed system input of the kth step relative to the (k-1)th step and a uniquely changed state variable during kth-step simulation calculation; the simulation value calculation module is used for executing a simulation calculation method based on state variable discretization; the simulation control module is used for judging the relation between the system simulation calculation current moment updated after kth-step simulation calculation and the system simulation ending moment, if the system simulation calculation current moment is larger than or equal to the system simulation ending moment, simulation is ended and a simulation result is output. Therefore, simulation calculation is performed on the basis of state variable discretization, the accuracy of the simulation result is improved, simulation velocity is increased, and numerical stability is improved.

Description

technical field [0001] The invention relates to the technical field of power electronics simulation, in particular to a simulation calculation method and a simulation system based on discretization of state variables. Background technique [0002] At present, the power electronics simulation model considering the non-ideal model of power semiconductor devices and line stray parameters has the characteristics of complex system, many discontinuities, nonlinearity and strong rigidity. Traditional numerical calculation methods (such as trapezoidal method, Runge-Kutta method, etc.), it not only needs to iterate or interpolate to determine the discontinuity point, which seriously slows down the simulation speed, but also faces serious numerical instability, and the algorithm has poor convergence. Therefore, commonly used power electronic simulation software (MATLAB, PSIM, PSpice, etc.) will have speed and convergence problems when performing power electronic system simulation cons...

AI Technical Summary

Problems solved by technology

[0004] However, when using the traditional QSS method (such as QSS1 method) to simulate a power electronic system with strong rigidity, due to the huge difference in the speed of change of each state variable, the Q function of the fast variable will continuously jump at the upper and lower boundaries, which causes the waveform to appear as shown in 1(a) shows a small high-frequency oscillation; in order to speed up the simulation, a larger quantization length vector ΔQ modulus value is often selected, which leads to an increase in the simulation error, and the simulation waveform will appear as shown in Figure 1(b). low frequency oscillation

The two oscillations adversely affect the simulation speed and simulation accuracy respectively

Therefore, the simulation performance of this method in the simulation of power electronic conversion systems considering non-ideal factors is not ideal.

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