Research On Switched Reluctance Motor Starting With Constant Acceleration

The SR motor has no winding around rotor and has no permanent magnets, so it has thecharacteristics of simple structure and high reliability. What’s more, it has advantages of large startingtorque, flexible control, good speed control performance, big power density and easy cooling. Thus SRmotors are widely used in various industrial drive occasion. The big starting torque of switch reluctancemotor is in favor of engine starting, while has larger load on engine rotor shaft system. In some extremecircumstances, if starting frequently, the aircraft engine shafting will accumulate large damage，even causethe shaft broken. Based on analysis of the power supply characteristics, it is the current of windingincreasing rapidly in starting moment. The big current impact goes against power system. This is to beavoided. In this paper, the purpose of the study of start with constant acceleration is to make the aircraftengine start smooth and to improve the reliability of starting.This paper first introduces the switched reluctance motor and the research status of starter/generatorsystem. For the effect and influence of switched reluctance motor to aviation engine starting process, itexpounds the significance of the research.Second, it analyzes the switched basic structure of reluctance starter/generator system and workingprinciple. It introduces the working principle and characteristics of asymmetric half bridge topology.Through the current method, control system model of switched reluctance motor is established onMatlab/simulink platform. Depend on which, three different control schemes are analyzed.Then several different load characteristic is analyzed, according to the characteristics of switchedreluctance starter/generator system two indicators of starting capacity and starting time are put forward. Onthe basis, three different starting solution of starting with constant torque, starting with power limited andstarting with constant acceleration are comparative analyzed. According to the requirements of aircraftengine starting, starting with constant acceleration is chosen.On this basis, starting with constant acceleration as the research direction, the characteristics ofblocked switched reluctance motor is studied. Based on different load torque characteristics, this paperputs forward two control methods of average torque control and PWM control, and carries on theoptimization of which.Then test platform with TMS320F2812DSP chip and CPLD as the core is build. Of which the ratedvoltage is270V and the rated power is9kW. The design of hardware and the digital controllerprogramming of software module are accomplished. Finally on this test platform starting with constant acceleration is tested, which proves that using PWM control method can effectively control the startingacceleration and verifies the theoretical analysis.