| According to the latest requirements for energy storage equipment in the 14 th Five Year Plan and the Outline of Vision Goals for 2035,the new energy storage is the basic technology for building a modern smart grid and an important support for achieving the goal of carbon peaking and carbon neutrality.Flywheel energy storage is widely used in fields such as new energy generation,distributed power systems,and electric vehicles,with advantages such as high energy storage density,high instantaneous power,fast charging and discharging speed,and high energy conversion rate.The core of flywheel energy storage is the motor/generator.The permanent magnet synchronous motor/generator currently used has the advantages of small size,simple structure and high efficiency,but it has the problems of large friction,serious wear and short service life.High speed,low loss,and high efficiency have become the research direction for the development of high-speed motors.The outer rotor coreless bearingless permanent magnet synchronous generator(ORC-BPMSG)combines the advantages of magnetic bearing technology,bearingless motors,permanent magnet synchronous motors,and coreless motors,and has the characteristics of no friction,wear,loss,and small torque ripple.The ORC-BPMSG is taked as the research object,and the working principle,mathematical model,decoupling control,sensorless control,and digital control system of the ORC-BPMSG are mainly elaborated in this dissertation.The main work and achievements of the dissertation are as follows:1.The research background and significance of bearingless motors,and their domestic and international development status are summarized in this dissertation.Based on this,the research status and future development trends of the ORC-BPMSG is summarized.2.The basic components of the ORC-BPMSG are described,and the principles of power generation,suspension force generation and electromagnetic torque generation are analysed in detail.Based on the eccentric displacement of the motor rotor,a mathematical model of the motor’s suspension force,generation voltage,PWM converter and electromagnetic torque is established.3.According to the non-linear and strongly coupled characteristics of the ORC-BPMSG,the fuzzy neural network decoupling control of the ORC-BPMSG is proposed by combining the basic theory of fuzzy neural networks.In this dissertation,the right inverse model of the ORC-BPMSG is established by the method of fuzzy neural network,which is connected to the original model at series level to decompose the control problem of the ORC-BPMSG into the control problem of two low-order pseudo-linear subsystems,and the closed-loop controller is designed to obtain the decoupling of generation voltage and suspension force.Finally,a complete set of simulation models is built on MATLAB/Simulink to simulate the proposed algorithm and prove the effectiveness of the method.4.In order to improve the accuracy of the ORC-BPMSG displacement detection,reduce the cost of displacement detection instruments,and at the same time overcome the shortcomings of conventional detection instruments,a soft measurement method for the ORC-BPMSG displacement detection is carried out using a combination of the left inverse system method and a neural network.Using the left inverse method for accurate observation of the ORC-BPMSG displacement and using neural networks to solve the inverse system,thus reducing the complexity of observer design,the study of sensorless technology for the ORC-BPMSG based on the left inverse system of neural networks is proposed.The proposed detection scheme is modelled using MATLAB/Simulink and simulations are carried out.5.The ORC-BPMSG digital control platform is built,the hardware design is carried out,and the software program is written.The hardware circuit and software program are combined and a test platform is built on this basis to test and verify the proposed control method. |
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