Research On Direct Torque Control System Of Permanent Magnet Synchronous Motor For Vehicle

Today,in the 21 st century,the development of new energy has attracted much attention.As a deep substitute for traditional energy,green electric energy has become an inevitable trend for energy to restore its basic commodity attributes.Pure electric vehicles are accepted and recognized by more people because of the use of clean electric energy.Permanent magnet synchronous motors(PMSM)are more widely used in electric vehicles with excellent dynamic and static performance.This paper first introduces the construction and control strategies of PMSM,coordinate transformation and mathematical models in different coordinate systems,and provides necessary theoretical support for subsequent chapters.Secondly,the operation principle of traditional DTC and its algorithm derivation are introduced in detail.The modules of DTC system simulation are built under MATLAB/Simulink software.The simulation results show that DTC system has excellent anti-interference ability,and the speed and torque response are extremely fast.Dynamic and static performance is good.Meet the basic requirements of the vehicle AC speed control system.However,torque ripple and flux linkage fluctuations occur at low speeds.A DTC system based on voltage space vector control technology(SVPWM)is introduced to solve the above problems.The inverter with continuous smooth adjustment of voltage output replaces the traditional discrete two-value hysteresis controller to solve the problem of low speed instability.The simulation results show that the system can significantly reduce the low-speed torque ripple and improve the system performance.Finally,the problem of inaccurate flux linkage observation in traditional DTC system is given,and the algorithm derivation of related solutions is given.The problem of the easy saturation of the traditional PI integrator is solved.The PI controller with freely switchable value is designed.Combined with the modern control theory and the role of zero voltage space vector in the DTC system,the fuzzy controller is designed to make the PMSM-DTC for the vehicle.The system's low speed performance is further improved.Figure [112] Table.[11] reference [53]...