Research On Real-time Simulation Modeling Method Of Multi-switch Power Electronic System Based On FPGA

Real-time simulation is not limited by the scale of the system and the complexity of the structure,and it can accelerate the process of power electronics system device optimization and system control strategy development.It is safe and convenient to simulate faults that are difficult to reproduce in actual systems,and has good economy,safety and convenience.With the application of new power electronic power devices(Si C,Ga N),the switching frequency range of power electronic converters has also increased to 10 k ? 200 k Hz.Under this condition,the real-time simulation step size requirement is less than 5us,and the traditional CPU-based real-time simulator has been difficult to meet the above simulation step size requirements.FPGA has parallel data processing capability and high-speed clock frequency,can achieve nanosecond simulation step size,and quickly becomes the first choice for real-time simulators of power electronic systems.This thesis focuses on the problems of traditional power electronic system modeling methods and studies the real-time simulation modeling method of power electronic systems suitable for high-frequency FPGA and multi-switch.It mainly completes the following tasks:(1)The detailed process of modeling method in power electronic system based on VCCS model is analyzed in detail,and it is pointed out that iterative solution can solve the implicit equation problem brought by VCCS model.The amount of calculation is too large.(2)In view of the above problems,this paper proposes a solution.By using a delay-free split method,the power electronic system is split at the passive components of the system,and the system model is split into multiple independent subsystems,which greatly reduces the system matrix dimension and the amount of calculation;the subsystem model can be run in parallel when implemented in FPGA to reduce the delay time;by establishing a system discrete model equation,the effect of simulation step size on system stability is analyzed.(3)Taking three-phase voltage source inverter and NPC three-level inverter as examples,the above modeling methods are simulated and verified.Using the SPS simulation results as a reference,an error curve is given,which proves the accuracy of the optimized VCCS model modeling method.(4)This paper introduces the structure of FPGA-based real-time simulation platform,and uses the VHLS tools for programming and development in high-level languages.The three-phase voltage source inverter and NPC circuit are implemented in FPGA.The comparison between the real-time simulation output waveform and the offline simulation is basically the same.From the analysis of resources,it can be known that the method proposed in this paper can reduce FPGA resource consumption,and has high efficiency and economy.