Design Of 4kW Switched Reluctance Motor Drive Control System

Switched Reluctance Motor (SRM), have many advantages such as simple structure, low manufacturing cost and reliable work, these strong competitiveness is shown in many areas. But considerable difficulty is brought to design work because of so many control variables and strong nonlinear characteristics. In this thesis a 4-phases 8/6-pole Switched Reluctance Motor is studied; a control system include hardware and software is designed based on NEC's V850 microcontroller; an hydraulic loading system is founded to test the motor system and optimize the control variables.Firstly, the characteristic of SRM is introduced, including the development, the merit and demerit and study situation. The design goals are also decided.Secondly, the Switched Reluctance Drive system is analysised, including system composition and operation principle. The H bridge converter with two-phase conduction mode was chosen to drive the motor. Based on the bisec theory and equation of SRM, the ideal linear model of two-phase operation is established and is compared to which of single-phase operational mode. The control strategy of driving system is work out. The two-phase model was proved to be correct and practical through the experiment.Thirdly, the design of drive system including software and hardware is introduced. In the hardware design part, took the advantage of the powerful performance of V850 microcontroller, the hardware of the power converter is designed basing on the microcontroller's interface function, and also the position detecting circuit, the current detecting circuit and other interface circuits. The speed loop control theory is selected firstly designing the software, according to which the main program flow is established. Then, the mode conversion, velocity calculation and the control of the reversing and speed are introduced. Furthermore the angular fine division and the regulating theory of the PI loop with integral separation are introduced emphatically, The theory is proved to be advangtageous through the experiment.Finally, the motor system performance is test by the test-bed, whose load is hydraulic system. The experiment of the motor speed control is performed on the test-bed, improving the performance based on independent control of each phase for the inhomogeneity of each phase. Meanwhile, in order to make the motor perform well in the low speed condition, the turn-on angle, the turn-off angle and the PI coefficient are optimised.