Research On Real-Time Simulation Modeling Method Based On Separation Method

As the topology of power electronic circuits becomes more and more complex,more and more switching devices bring challenges to the modeling work.The commonly used ideal switch modeling method is equivalent to the short circuit when the switch is turned on;the switch is equivalent to the open circuit when the switch is turned off;this modeling method changes with the change of the state of the circuit switch,the system matrix formed by it is a variable parameter.With variable structure,it is necessary to update the system matrix in the program to perform iterative calculations when the circuit work status changes.The amount of calculation is large.Therefore,it is the focus of this paper to study more suitable modeling methods for power electronic circuits.This paper first introduces the separation method,also known as VCCS(Voltage Controlled Current Source)modeling method,and deduces three aspects of device modeling,state space equation discretization,and simulation iterative solution flow.Finally,a Buck circuit is used as an example.C-mex S-Function program,the off-line simulation of the model,compared with the results of the SPS(Sim Power System),preliminary validation of the correctness of the separation method modeling.Secondly,taking the three-phase inverter as an example,the separation method mathematical model of the three-phase inverter is established,and the defects of the separation method in modeling the three-phase inverter are pointed out,the switching state is more,and it needs to iteratively calculate the pipe.Voltage and current,large amount of calculation,resource consumption,so on the basis of the separation method modeling proposed a solution to the three-phase inverter split modeling,with SPS and the overall modeling output as a reference to complete Off-line simulation shows that split modeling can effectively reduce the switching state,reduce the amount of calculation,and optimize the modeling process.Then the NPC three-level inverter is taken as an example to analyze the working principle of the NPC.The separation modeling method is used again to establish the equivalent mathematical model of the separation method of the NPC.The off-line simulation is completed and compared with the SPS simulation result.The relative error curve is given,which proves that when using the separation method to model power electronic circuits with symmetrical branch structures such as three-phase inverters and NPCs,the idea of split modeling can be used to optimize the separation method modeling Process.Finally,in the dSPACE real-time simulation platform,hardware-in-loop simulation experiments based on the FPGA-based three-phase inverter overall and split modeling two-mathematical models were implemented.Using the MCode module in System Generator to speed up the FPGA implementation process,compared two The FPGA resource consumption rate of this modeling method further proves that split modeling can reduce resource consumption,and at the same time,it proves that the separation method can be used for real-time simulation modeling of power electronic circuits.