外文文献：Double switched reluctance motors parallel drive based on dual89C52 single chip microprocessorsAbstractThe developed double Switched Reluctance motors parallel drive is presented, which is made up of two four-phase 8/6 structure Switched Reluctance motors, two four-phase asymmetric bridge power converters and the controller. The four-phase 8/6 structure Switched Reluctance motor, the four-phase asymmetric bridge power converter and the control scheme are described. The closed-loop rotor speed control of the main motor and the closed-loop rotor speed control of the subroutine motor could be based on the pulse width modulation fuzzy logic algorithm, which is implemented by dual 89C52 single chip microprocessor controller. The experimental results of rotor speeds and phase currents in two Switched Reluctance motors are given.Keywords: switched reluctance; fuzzy logic; microprocessor1.IntroductionThe electric locomotives in coal mines are driven by series direct current motor drive system. The accessional resistor regulated control or the chopping control is used to adjust the rotor speed of the series direct current motor and to control the speed of electric locomotive. The Switched Reluctance motor drive can be operated at four quadrant1s . It could be used as electrical traction for electric locomotives in coal mines23 . The soft mechanical characteristics of Switched Reluctance motor drive 4 contribute to parallel double Switched Reluctance motor drives system with synchronization of the rotor speed and the loads being in equilibrium. The double Switched Reluctance motors parallel drive system can be used to replace the series direct current motor drive system as the adjustable speed motor drive for the electric locomotives. The Switched Reluctance motor drive is made up of the Switched Reluctance motor, the power converter and the digital controller. There are four-phase 8/6 structure Switched Reluctance motor and three-phase 6/4 structure Switched Reluctance motor. The fault tolerance ability of four-phase 8/6 structure Switched Reluctance motor is higher than that of three-phase6/4 structure Switched Reluctance motor so that four-phase 8/6 structure Switched Reluctance motor is adopted in the system. There are asymmetric bridge circuit, bifilar winding circuit, common switch circuit, resistance commutation circuit, split supply circuit, inductance commutation circuit for four-phase power converter with four-phase 8/6 structure Switched Reluctance motor. The four-phase asymmetric bridge power converter circuit is adopted in the system due to its independence in each phase. The digital microprocessor has the advantages in high reliability and stability for control of Switched Reluctance motor drive. Some control algorithms can be implemented by the digital microprocessor. The Switched Reluctance motor drive is based on Intel 80315, Intel 80C196KB6, Intel 87C196KC 7. The 89C52 digital microprocessor had been developed for sliding mode and PI control of a single Switched Reluctance motor drive8 . The paper presents dual 89C52 single chip microprocessors controller for double Switched Reluctance motors parallel drive. It is not easy to gain the exact mathematical model of Switched Reluctance motor drive since it has nonlinear magnetic paths in the motor and nonlinear circuit topology in the power converter. It is not necessary for the fuzzy logic control to gain the exact mathematical model of Switched Reluctance motor drive. The rotor speed closed-loop control could be implemented based on the fuzzy logic algorithm.2.Scheme of systemThe developed double Switched Reluctance motors parallel drive consists of two four-phase 8/6 structure Switched Reluctance motors, two four-phase asymmetric bridge power converters and the digital controller.1.1. MotorTwo four-phase 8/6 structure Switched Reluctance motors are adopted in the developed double Switched Reluctance motors parallel drive. The cross section of the four-phase 8/6 structure Switched Reluctance is shown in Fig.1. There are eight poles in the stator, while six poles in the rotor. The two coils on the diametrically opposite stator poles can be connected to make up a phase winding. There is only phase winding in the stator. There is no winding, no magnet and no brush in the rotor. There is a rotor position detector on the motor for detecting rotor position and speed. The photograph of the developed dual four-phase 8/6 structure Switched Reluctance motors is shown in Fig. 2.Fig I.Cross section of the four-phase 8/6 structure SR motorFig 2.Photograph of the developed dual four-phase 8/6 structure SR motors2.2. Power con vertersis show nThe mai n circuit of the two four-phase asymmetric bridge power conv erters with phase windings, “ A1” ,“ B1” , “ C1” and “ D1” ,“A2” ,“ B2” ,“ C2 and“ D223 Con trol schemeThe turned-on angle and the turned-off angle of the main switches are fixed. The trig