Electric Oil Pump Control System Using Brushless Dc Motor Without Position Sensor

Electrical fuel pump has been extensively applied in the top and middle grade automobiles abroad. At home, the electrical fuel pump has also been applied in some homemade automobiles. At present, the electric motors for the fuel pump have widely employed brushless DC motor, which has brought some disadvantages such as short life-span, low reliability and bad EMC characteristic. In this paper, based on the practical demands and using Magneforce/BLDC software, a brushless DC motor for the fuel pump is designed in stead of the original brush DC motor, in order to ameliorate the electric fuel pump operation performance, improve the reliability, and prolong the life-span. The paper gives two schemes which satisfy the performance demands, and compares their performance characteristics and rated operation. In addition, based on the obtained scheme-6/4 structure motor, the influence of the permanent magnet pole arc and the advanced firing angle on the motor characteristic is investigated, and so is the influences of various design parameters on the cogging torque. After the prototype is designed, based on the ANSOFT/MAXWELL, the magnetic field of the prototype is analyzed, leading to obtaining the magnetic field distribution in the prototype in one electrical period. Furthermore, the temperature field is analyzed based on ANSYS.In order to analyze the reliability of the BLDC motor, the Simulink model of the BLDC motor is instablished, and possibly happened failures are studied based on the simulation model. Three kinds of failures of the BLDC, including the failures of the motor, the inverter and the position sensor, are simulated respectively, and the detailed theoretical analysis of these failure simulation results is given, In addition, the simulation results are validated by the experiment on the prototype machine, which is beneficial for the improvement of the diagnosis of the failures and the reliability of the BLDC.Finally, according to prototype operation parameters and actual application demands, a BLDC sensorless controller is developed. Then it is experimented, which proves that the sensorless controlled BLDC for fuel pump could replace the original brushed DC motor, and satisfy the actual application demands.