Research On Deadbeat Control Of Permanent Magnet Synchronous Motor Based On Three-Level Topology

Three-level inverters are receiving widespread attention in high-power,high-voltage,and large-capacity industrial sites.The main reason is that three-level inverters are based on output performance in comparison to two-level inverters.The on-off loss and electromagnetic disturbance are superior.PMSMs has the characteristics of high dynamic performance,high efficiency and light weight.Therefore,the PMSMs system with midpoint clamp type three-level topology is taken as the research object,and the SVPWM is applied.Modulation methods and current control strategies have been studied.Firstly,the research status of the three-level topology is briefly explained,and the working principle of the mid-point clamp type three-level is described in detail.The SVPWM modulation mode is introduced theoretically.The simulation of SVPWM modulation mode is verified by Matlab/Simulink.Finally,the feasibility of modulation mode is demonstrated.Secondly,the control strategy of the current inner loop of PMSMs is analyzed.This thesis studies the two strategies of traditional PI control and DBC,and carries out parameter design and principle analysis according to classical control theory.Focusing on the study of the deadbeat current control algorithm,the DBC algorithm is an algorithm that keeps the output waveform undistorted when the switching frequency is not large;however,the traditional DBC strategy needs to be relatively accurate.Modeling has a large dependence on system parameters and is not very robust.Therefore,this paper proposes an improved DBC strategy based on Lyapunov stability theorem,which improves the robustness,and the algorithm has the characteristics of suppressing motor torque ripple.Then,the traditional PI and improved DBC algorithm are simulated and verified on MATLAB/SIMULINK.It can be seen from the results that the improved DBC strategy has the characteristics of suppressing torque ripple compared with the traditional PI control strategy.Finally,the hardware and software design of the PMSMs vector control system based on the three-level topology is completed,and the control system based on DSP is designed.Experiments on the two algorithms of PI control and improved DBC on the trailer are mutually validated.