Control Strategy Research Of Double Switched Reluctance Motor Sensorless Control System

Real-time and accurate rotor position information is a necessary prerequisite forreliable operation and high performance control of switched reluctance motor (SRM).However, shaft position sensor of SRM increases system cost and complexity, themore important is that it reduces robustness and adaptability of the system, affectingthe reliability of the operating system, especially in the humid, vibration, dust andother harsher environment situations. Therefore, sensorless SRM control technologybecomes a research hotspot at home and abroad.Sensorless control of SRM is studied, using double SRM traction shearer as theresearch background. For the purpose of improving the reliability of SRM controlsystem, it has very high social effects and economic value. Three phase12/8-pole18.5kW SRM is the research object, on-line flux linkage characteristics detectionmethod, position sensorless control over the entire speed range, dual cross-couplingsynchronization control of double motor and predictive current control strategy forPWM rectifier are studied.On the basis of a brief analysis of mathematical model, operating characteristicsand control mehtod, off-line static flux linkage characteristics experiment is carried on,static flux linkage-current-rotor position angle curves are obtained; three-dimensionalfinite element analysis of prototype SRM is analyzed by JMAG software, the resultsverified the credibility of the flux linkage characteristics data. In order to elimatelimitations of static locked-rotor test or finite element analysis method, on-line fluxlinkage characteristics detection method is proposed, obtaining flux linkagecharacteristics data by the serial communication interface (SCI) module when SRM isoperating. Flux linkage-current-rotor position sample data are sent to host computerand then trained by boundary value constraints radial basis function neural network(BVC-RBF). Ultimately, the flux linkage characteristic data results of three powerlevels of SRM verified feasibility and portability of the on-line detection method.In order to avoid the inconvenience and drawbacks of SRM position sensor, abrief introduction of position sensor feedback and speed feedback is taken. Fourierseries expansion and harmonic analysis of inductance curve is carried on, rotorposition estimation method based on dynamic inductance model of SRM is proposed.Three-phase inductance calculation method and Fourier series expansion coefficientschange law are given. Calculation method of rotor position angle based on dynamic inductance model is proposed. Excitation pulse method combining with dynamicinductance model method for four-quadrant sensorless control strategy over all speedrange including standstill is proposed, a position sensorless SRM controller isdesigned and achieved.Considering electrical power output balance of double SRM in traction shearer,on-line SRM average torque calculation model is proposed. Double motor powerdeviation caused by single feedback method has many disadvantages. Dualcross-coupling feedback of speed and torque is proposed. Double position sensorlessSRM control system hardware architecture and software design is produced. Fuzzycontrol regulator design method of double SRM torque is given.Exsisting topology using diode rectifier or simple feedback method in doubleSRM traction system caused harmonic pollution. Deadbeat predictive current controlstrategy is proposed for the shearer in large inclined work surface and reliablefour-quadrant operation. Rectifier topology and low-frequency mathematical model isanalyzed. PWM rectifer performance caused by one unit delay in current controlperiod and Bode graph analysis are given. On this basis, the deadbeat predictivecurrent control strategy is proposed and control algorithms are given.On the basis of shearer load characteristics analysis, SRM sensorless controller isapplied to a domestic double drum electrical traction shearer system relying on theresearch of this article, traction experimental results and its performance verified thefeasibility and effectiveness of the overall strategy.