| With the proposal of the "dual carbon" goal,various industries have successively formulated action plans for energy conservation and emission reduction.The "Carbon Peak Action Plan by 2030 issued by the State Council requires promoting energy conservation and efficiency improvement of key electrical equipment such as motors,fans,and pumps in the industrial field.The Ministry of Industry and Information Technology has proposed a detailed plan that requires the annual output of high-efficiency energy-saving motors to reach 170 million kilowatts by 2023,Therefore,promoting the installation and application of high-efficiency motors is of great significance for energy conservation and efficiency improvement in the industrial field.Currently,the main motors widely installed and used are three-phase asynchronous motors and permanent magnet synchronous motors.Due to the advantages of simple structure and low production costs,three-phase asynchronous motors(ACIM)have been widely used in the early stage,with a large installed capacity,but they have problems such as low efficiency,large volume and weight,and low control accuracy;Permanent magnet synchronous motor(PMSM)has the advantages of high efficiency,high power density,and high control accuracy,so it is widely used in control situations with high accuracy requirements.However,due to the use of permanent magnets in the rotor,has brought about high manufacturing and maintenance costs,magnetic loss failures,and magnetic weakening difficulties in high-temperature situations.Moreover,with the development of rare earth elements in the country,The tightening of export policies and the rising price of rare earth raw materials in the world have constrained the further promotion and application of permanent magnet synchronous motors.Synchronous Reluctance Motor(Syn RM)has the advantages of high efficiency,simple structure,low loss,and high control accuracy.Its rotor is composed of silicon steel sheets stacked together,without permanent magnets,so there is no high-temperature loss of excitation.The magnetic weakening algorithm is simple and easy to implement and currently has a small installed capacity.It has a broad market prospect in replacing traditional inefficient motor applications.However,there are still some problems in its application:(1)The current mainstream control algorithms fail to fully exploit the advantages of the high saliency-to-pole ratio of synchronous reluctance motors;(2)Low power factor;(3)Poor startup performance;(4)The inductance is prone to change due to the on-site influence of magnetic circuit saturation.In view of the constraints on the promotion and application of synchronous reluctance motors caused by the above issues,this topic takes synchronous reluctance motors as the application object,with the goal of high-performance control,and studies the drive system of synchronous reluctance motors.To begin with,the operating principle of Syn RM is described and its mathematical model is constructed.The maximum torque per ampere(MTPA)control,maximum power factor vector control,and maximum rate of change of torque control methods for Syn RM are theoretically derived.Based on the theory of state observer,the mathematical model and state space equation of the Longberg state observer are derived,and the state space equations of the synchronous reluctance motor and its state observer are established.The causes of inductance changes during the operation of synchronous reluctance motors and their impact on motor control performance are analyzed.An inductance identification algorithm based on a combination of offline and online identification is proposed.An offline inductance identification algorithm based on the pulse voltage method and an online inductance identification algorithm based on the recursive minimum multiplication method are derived,respectively,Integrating the above control algorithms,a sensorless vector control method for no-ferrite synchronous reluctance motors based on parameter identification was obtained.In addition,in order to verify the effectiveness of the proposed algorithm,a simulation model is built based on the above theory,and simulation analysis is conducted based on Simulink.The simulation results of vector control algorithms show that the performance of the three vector control algorithms is equivalent in the low-speed range,and the MTPA algorithm has slightly better startup performance.In the medium and high-speed range,the MTPA algorithm has smaller steady-state fluctuations and torque fluctuations.Based on this conclusion,the subsequent sensorless algorithm,inductance identification algorithm,and vector control in the simulation and experiment of integrated control systems use the MTPA method;The simulation results of the sensorless algorithm show that the sensorless algorithm based on Longberg has good speed tracking performance,without significant hysteresis,and the steady-state error of rotor estimation is almost zero.During steady-state operation,the estimation errors of speed and rotor position under sudden load do not significantly increase,and the operation is stable;The simulation results of the inductance identification algorithm show that the proposed inductance online identification algorithm can quickly and accurately complete inductance identification under various operating conditions,and the vector control system incorporating the online identification algorithm has a faster dynamic response and steady-state performance with less steady-state error;The simulation results of the integrated control system show that compared to traditional basic vector control systems,the integrated control system incorporating the optimization algorithm has a faster dynamic response,better steady-state performance,and better resistance to load disturbances.Finally,to verify the feasibility of the proposed algorithm,an experimental platform for the synchronous reluctance motor drive system was built for verification.We designed the hardware and software of the driving system separately and built the platform based on this.The offline identification experiment results of inductance show that the identification errors of d-axis and q-axis inductance are 4.66% and 9.72%respectively;The experimental results of the integrated system control show that the offline online combined inductance identification algorithm proposed in this paper can quickly and accurately track and identify inductance values during low speed,high-speed operation,and sudden load changes.After introducing online identification algorithms,the integrated control system can respond and track changes in parameters more quickly,reducing the sensitivity of the control system to motor parameters,and improving the dynamic response performance,stability,and reliability of the system.The above experiments have verified the feasibility of the high-performance vector control system for synchronous reluctance motors studied in this project,meeting the application requirements of general industrial scenarios,and providing technical support and reserves for the promotion and application of no-ferrite synchronous reluctance motors to replace traditional inefficient motors. |
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