Research On Voltage Vector Control Strategy Of AC-AC Frequency Converter Based On Instantaneous Slip

For the mine hoist,the existing AC-AC inverter control strategy is only considered to optimize its dynamic performance,such as vector control,the control algorithm is too complex.Or only consider optimizing its power index,such as the best voltage-frequency ratio control,because it is scalar control,dynamic performance is insufficient,most can not consider both dynamic performance and force index.If you can consider both the dynamic performance and energy index of the hoist,the operation performance of the hoist can be optimized by using the AC-AC frequency converter to output the voltage vector according to the load quickly.Therefore,the voltage vector control strategy of AC-AC frequency converter based on instantaneous slip is proposed.Compared with the vector control,this method does not need coordinate transformation,flux orientation and observation,based on the simplified control algorithm,the strategy is optimized to improve the dynamic performance of the system compared with the scalar control.According to the working principle of the AC-AC frequency converter,if the voltage fragments are taken as the research object,these voltage segments can be considered as the voltage vector composed of the amplitude and the instantaneous frequency,and the essence of the inverter to change the motor speed is to change the output voltage vector.The voltage vector control strategy of AC-AC frequency converter based on instantaneous slip is based on the rapid measurement of the speed,the advantages of slip frequency control and voltage vector control are combined together.Based on the air gap flux constant according to the slip rate change,The expert knowledge base is used to select the voltage vector to realize the fast control of the torque,And then use the proportional relationship between the torque and the instantaneous slip to adjust the speed change.In order to establish the expert knowledge base,on the basis of simulation and experiment,a large number of relationship between the voltage amplitude and instantaneous frequency is obtained under different load and speed,obtain the voltage vector range that can optimize the hoist force index,on the basis of the above,the voltage is selected to keep the air gap flux constant,building expert knowledge base,and develop a control strategy.In order to verify the control effect of voltage vector control strategy based on instantaneous slip,the AC-AC frequency converter speed control system simulation model is established in MATLAB/Simulink,and the corresponding S function is written,to verify control effect in the ideal operating conditions through simulation.Then,on the basis of the existing equipment in the laboratory,the experiment platform of AC-AC frequency converter speed regulation system is set up with Arm chip STM32F103 ZET as the main control chip,and the system software is written in C language.According to the analysis of simulation and experimental results,the control strategy can use the expert knowledge base to select the corresponding voltage vector according to the instantaneous slip,and can improve the speed and stability of the hoisting machine while optimizing the lifting force index.