Research On Vector Control Algorithm With Iron Loss Considered For Induction Motor

With the rapid development of social economy,energy shortage and environment pollution problem are becoming increasingly outstanding.The new energy industry has gradually become the focus of social development.The electric vehicles,as a clean and efficient way of travel,have been developed rapidly with the support of a series of policies,and are gradually popularized.Due to its significant merits such as low cost,simple structure,relatively mature design technology,weakening,maintenance-free,induction motor drive system has been widely applied safe magnetic field in the field of electric vehicle.However,most of the existing asynchronous motor control algorithms are based on the ideal motor mathematical model,and the impact of iron loss has not been paid much attention.In electric vehicle applications,the speed range of the motor is wider,and the high-frequency operation makes the impact of iron loss more prominent.At the same time,the magnetization inductance of the electric vehicle drive motor is usually designed to be small,making the current harmonics larger,which further exacerbates the impact of the iron loss.Studies have shown that iron loss not only affects the accuracy of vector control orientation and the dynamic performance of the system,but also affects the accuracy of torque and flux control,and reduces the system's steady state performance.Therefore,the establishment of a mathematical model including the iron loss and based on it,the corresponding control algorithm designed to reduce the impact of iron loss on the control system is of great significance for further improving the performance of the induction motor drive system.Based on the indirect vector control,this paper establishes the mathematical model of induction motor including the iron loss and analyzes the influence of the iron loss on the performance of the vector control.Then,the induction motor vector control system based on the iron loss model is designed to improve steady state and dynamic performance of induction motor drive systems.The main contents of this paper are the following aspects:1.A 6th-order mathematical model based on the equivalent circuit of the parallel-connected iron loss resistance of the magnetization branch is established.Based on this,the influence of the iron loss on the indirect rotor field-oriented vector control system is analyzed.2.On the basis of analyzing the shortage of the existing compensation and correction schemes,an induction motor vector control strategy based on magnetization inductance currents is proposed.3.In order to obtain the magnetization inductance current,a sliding mode observer is designed to observe the magnetization inductance current without the information of the iron loss resistance.4.In order to improve the stability of the control system,a series-type double-loop control structure,in which the magnetization inductance current loop works as outer loop and the stator current loop works as inner loop,is designed.5.In order to overcome the integral problem of obtaining the magnetization inductance current of the sliding mode observer,an adaptive full-order observer is designed,so that the observation and identification of the magnetizing inductance current,the rotor flux and the iron loss are realized at the same time.5.A MATLAB simulation model and experimental platform for a 4kW induction motor vector control system are set up.The proposed vector control strategies are simulated and experimentally studied to verify the analysis and design of this paper.