Research On Deadbeat-Direct Torque And Flux Control Of Switched Reluctance Motor

The energy shortage and environmental pollution are two major problems the human beings now face with,switched reluctance motor(SRM)with low energy consumption and low pollution will be the future development trend.Due to its simple structure,low cost,high efficiency and no need for rare earth materials,SRM has been widely concerned by the industry.However,SRM’s unique double salient pole structure and pulse power supply method make it torque ripple,which is the main reason that restricts its development.Direct torque control(DTC)can reduce the torque ripple for SRM,but as Bang-Bang control,it is a tolerance control method which adjusts the flux linkage and torque non-quantitatively.Torque ripple can not be minimized.In view of this,firstly,this paper starts with the quantitative adjustment of flux linkage,then puts forward the new scheme of deadbeat flux control(DB-FC).According to the flux linkage error,the space voltage vector which can quantitatively compensate the flux linkage and achieve the non-quantitative adjustment of torque is obtained,and the adjacent basic voltage vector is synthesized to control the motor to realize DB-FC.Secondly,the control requirement of torque is much more important than the flux linkage in the real SRM control occasion.Therefore,to further reduce the torque ripple of SRM,this paper also proposes the SRM’s deadbeat direct torque and flux linkage control(DB-DTFC)method.By analyzing the principle of SRM electromagnetic torque generation,the mathematical model of SRM in rotating coordinate system is obtained.The discrete time model of SRM is established by deadbeat control principle,and then the voltage control rate is deduced.Three voltage vector solutions of DB-DTFC algorithm are analyzed according to voltage limitation.Finally,a simulation system of DB-DTFC is built to verify its feasibility.DB-DTFC can quantitatively adjust the stator flux linkage and electromagnetic torque in each pulse width modulation period to minimize the torque ripple during motor operation.After theoretical analysis and simulation verification,a SRM hardware platform is built and two control algorithms are programmed with C language.Finally,both DB-FC and DB-DTFC are applied on the platform to carry out experimental research,which verifies the feasibility and practicability of them.