Energy-saving Operation Control Of Cooling Fan Drive System For Locomotive Traction Motor

As an important part of locomotive auxiliary drive system(ADS), the traction motor cooling fan guarantees the normal operation of the locomotive and its performance has a directly impact on the economy and reliability of locomotive. The cooling fan is driven by induction motor, and furthermore the induction motor frequency converter control(IMFCC) system has a character of energy-saving operation. At present, it captures a lot of attention on energy-saving operation control of induction motor for locomotive ADS to reduce the energy consumption and improve the economy of locomotive. Thus, the energy-saving operation control based on traction motor temperature model of cooling fan in drive system has been researched in the paper. The method enhances the energy efficiency of ADS by frequency converter fan drive motor speed real-time controlling.In this paper, the structure of locomotive ADS as well as the energy-saving operation control methods of induction motor driving system is described and summarized. Then the introduction and comparison of loss-minimization-based on model of motor, on-line search control and optimization control based on coordinated operation of the entire control system is presented. Since the traditional motor temperature detection methods requires corresponding hardware and software rendering a high cost, and meanwhile the finite element method has the disadvantage of poor real-time, the equivalent thermal circuit method is used. This method has a simpler calculation and a good real-time performance. However, it does not take the skin effect and the effect of rotor vents blockage on the temperature rising into consideration. Therefore, the equivalent thermal circuit is modified. A traction motor temperature rising model is given considering the effects above. The fuzzy control strategy is used in the cooling fan drive system. According to the IMFCC system characteristics, variable frequency energy-saving operation control strategy based on traction motor temperature for cooling fan is proposed. A Simulation model of control system is constructed by MATLAB/Simulink. The frequency of cooling fan under the varied temperature of traction motor is calculated. The effect of energy-saving operation control is analyzed. Simulation results illustrates this method has a good energy saving effect. And it has a strong anti-interference as well as a good control precision in the process of temperature control of traction motor. Moreover, it can ensure the temperature rising of tractor motor meet index of safety design during the operation.