| With the rapid development of China’s national economy and national defense construction,“Made in China 2025” provides guidance for the development of the field of "energy saving and new energy vehicles",pointing out that the development of energy saving and new energy vehicles is the only way for China to become a powerful automobile manufacturing country.The development of new energy vehicles is limited by battery capacity and charging and discharging efficiency,so it is of utmost importance to vigorously develop flywheel energy storage batteries for electric vehicles.Compared with traditional chemical fuel cells,flywheel energy storage batteries have the advantages of high storage density,high efficiency,and rapid charge and discharge.The core component of flywheel energy storage is the motor,and the permanent magnet synchronous motor is usually used for traditional flywheel energy storage.However,it has the problems of friction and wear,low efficiency,and short lifespan during high-speed operation.Therefore,the outer rotor coreless bearingless permanent magnet synchronous generator(ORCBPMSG)is proposed as the energy conversion device for flywheel energy storage.The ORCBPMSG combines the advantages of bearingless motors and outer rotor coreless motors,therefore it includes the characteristics of high speed and precision,non-contact stator and rotor,high efficiency,large moment of inertia,and small torque ripple,making it more suitable for the working scenarios of flywheel energy storage systems.The ORC-BPMSG is selected as the research object in order to study the key problems such as the working principle,the mathematical model,parameter optimization,decoupling control,and other aspects.The main contents and achievements of the dissertation can be summarized as:1.The background,significance,and development status of bearingless motors are summarized,and the key technologies of the BPMSM are analyzed.Based on the research background and current status of the ORC-BPMSG and in response to its existing problems,the future development direction is expected.2.The basic structure of the ORC-BPMSG is introduced,and the power generation principle and suspension force generation principle of the ORC-BPMSG are analyzed.The mathematical models of Maxwell force,Lorenz force,generation voltage,and PWM rectifier have been derived3.In order to improve the performance of the motor,a multi-objective optimization method based on improved genetic algorithm was proposed to optimize the motor.The size and fluctuation of suspension force selected as optimization objectives,and the finite element software is used for simulation.Based on the selection of parameters with significant impact,an improved genetic algorithm is used for optimization to obtain the optimal parameters.By comparing and analyzing the motor performance before and after optimization,it can be proven that this design method can effectively improve the suspension performance.4.The ORC-BPMSG is a multivariable and strongly coupled system,and a generalized inverse decoupling control method based on OLS-SVM is proposed to improve its performance.The rectangular window algorithm is combined with LS-SVM to form OLS-SVM,the inverse system can be identified in real-time and connected to the original system to achieve decoupling control.To further improve the robustness of the system,the internal model controllers are designed as additional closed-loop controllers of the system.The simulation results show that this strategy has better control effect compared to the traditional strategy.5.The software and hardware of the ORC-BPMSG digital control system are developed.The relevant main program and interrupt service subroutine are designed based on the proposed decoupling control algorithm,and the experimental platform for the ORC-BPMSG is constructed.Based on this experimental platform,the proposed control method is compared and analyzed,and the experimental results show the superiority of the proposed method. |
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