| Nowadays the driving motor of electric drive engineering machinery are mostly about ac asynchronous motor and DC brush motor system. The SRM has not been widely used in the heavy vehicles. Because of its large torque ripple, and the resulting in noise and speed fluctuation, which limits the switched reluctance motor in the application of small electric passenger cars. In this article, we analysed the difference about SRM and asynchronous motor in the applications of heavy vehicles, and put forward the applications of SRM system in heavy vehicles. Because of the heavy vehicles is large inertia load, it can ignore the torque ripple and vibration noise problem of the SRM during the driving. Making full use of the switched reluctance motor current regulated torque, low starting current and start frequently overloaded traction characteristics and its own structural reliability, to meet the needs of engineering machinery under a variety of running conditions. In order to verify the feasibility, we begin with the prototype of small power.Firstly, after we took the theoretical analysis of switched reluctance motor running theory of operation and combined the design method of the traditional motor, this paper designed a power of4kW three-phase6/4switched reluctance motor. Making the machining drawings and asking the factory to manufacture. Using Ansoft finite element analysis software for the simulation about static characteristics of the motor and the dynamic performance under different control mode.Secondly, we took the TMS320F28335as the main control chip and designed a set of4kW switched reluctance motor driving system. On the test circuit Part, in order to take a real-time monitoring of temperature, a bridge temperature measurement circuit was designed; In order to get the RMS of motor phase current accurately, we used the discrete digital synchronous sampling measurement method and the effective value of current signal of one cycle could be real-time measurement. We choosed rotary transformer as the position detection sensors, and made the12bit decoding circuit to get accuracy of the position, which can get absolute position of the rotor accurately. Thirdly, after we made the motor and the driving system, the control system was designed. Aiming at the installation problem about rotary transformer as a position sensor, we put forward the self-learning method of motor rotor space position, what can make the corresponding between the space of the rotor position with the output of the decoding circuit. We Used single neuron adaptive PID control algorithm to control the speed and direct instantaneous torque control algorithm to control the output torque.The control effect was verified by experiments.Finally, we builded the experiment platform about the switched reluctance motor and the ac asynchronous motor with the same power level, comparing the performance of two systems, experimental results shown that the design of switched reluctance motor driving system has the advantages of big start torque with low current, strong torque overload capacity, low cost, high efficiency and reliability. It is compared favourably with the characteristics of ac asynchronous motor driving system, and suitable for the drive system of the electric driving engineering machinery. |
