Study On Variable Speed High Efficiency Permanent Magnet Synchronous Motor And Its Drive System

This dissertation is devoted to the study on variable speed high efficiency permanent magnet synchronous motor (PMSM) drive system funded by the State "Tenth Five year Program" and the Science and Technology Project of Liaoning Province. Six parts are included as following:First of all, when the general inverter drives the PMSM in open loop there are many problems, the causes of those problems are analyzed in this part. When using the general purpose inverter, some measurements such as adding AC and DC inductors in the both sides of inverter and getting the reasonal U/f curve of pump application through simulation are taken to improve the system performance.Secondly, in view of the operation characteristics of pump application, a novel efficiency-optimization control strategy is presented to meet the demand of high efficiency of variable speed high efficiency PMSM. The core of this strategy is the excellent integration of loss model arithmetic in dynamic state and the gradient search technique based on fuzzy logic control method in steady state. A TMS320LF2407A DSP-based full-digital control inverter for variable speed high efficiency PMSM is developed, and the design method of hardware and software is presented. The performance experiments for control system of variable speed high efficiency PMSM have been completed. The system is verified to be of reliable and perfect performances by the experiment, also has obvious effect of saving on energy.Thirdly, when designs the space vector pulse width modulate (SVPWM) drive system, the controller of speed and the current hysteresis controller is optimized. A DSP and CPLD based full-digital control inverter for variable speed high efficiency PMSM is developed, and the design method of hardware and software are presented. Experiments of the whole system including PMSM and inverter are fulfilled.Fourthly, the operation demands of PMSM used in pump application are studied. Then parameters design rules of variable speed high efficiency PMSM are presented. The influence of variable speed high efficiency PMSM parameters of different rotor structure is analyzed and selection rules of PMSM rotor structure are determined. When design the prototype motors, there are some pieces of method to getting higher power factor and efficiency. The field-circuit coupling design method of variable speed high efficiency PMSM is studied considering the pump drive demands.Fifthly, due to the modification of ventilation system for variable speed high efficiency PMSM, the ventilation structure is analyzed in this part. First, the advantages and disadvantages of several structures are compared by fluid field. Though the studying of cooling structure for improved PMSM, the position of the cooling hole in the rotor is optimize by the finite element method. At last, the thermal field distribution of the motor is calculated by the 3D temperature field.Finally, three variable speed high efficiency PMSM's prototypes are designed and manufactured. Experiments of the whole system including PMSM and general inverter are concluded; the effect of saving on energy is very obvious.