Research On Switched Reluctance Motor Control System For Crane

Switched Reluctance Motor(SRM)has a simple structure of stator and rotor.At the same time,the winding is relatively independent,with good starting performance,large starting torque,and strong fault tolerance.In addition,SRM is easy to realize four-quadrant operation and is suitable for frequent start and stop,positive and reverse occasions,high reliability.The traditional crane motor has the characteristics of low starting torque and low efficiency,which cannot' meet the needs of modern cranes for the motor.The application of switched reluctance motors in the field of cranes not only makes crane systems more efficient and reliable,but also broadens the scope of SRM applications.First,the background of SRM for cranes,SRM torque ripple suppression strategy,and research status of power converters for SRM are introduced.The torque and load problems during the lifting of the bridge crane are analyzed.Provide theoretical guidance for the follow-up SRM four-quadrant control.Secondly,it introduces the three basic control methods of SRM,the running characteristics of the motor,and gives the common theoretical analysis of direct torque control.A four-quadrant SRM control strategy of mixed DITC/DTC control is proposed.For the problems of excessive current peaks in the DITC during the motoring period,increasing torque ripple and reducing efficiency,a DITC optimized control strategy based on PWM technology is proposed.The overlap area was divided more carefully and the conduction rules were re-optimized.The composition of the main circuit of the system and the selection of power device parameters and the use of two IPMs to construct an asymmetrical half-bridge power topology are introduced.Aiming at the energy feedback during motor braking,a power converter topology with energy feedback for SRM four-quadrant operation is proposed.The new topology of the power converter can provide another path for the energy feedback under braking Battery,save energy and improve efficiency.Finally,under the environment of Matlab/Simulink,the simulation of SRM speed regulation system was built.From the simulation results,it can be seen that the four-quadrant switching is smooth,and the torque and speed are smooth in each quadrant operating interval,which verifies the effectiveness of the four-quadrant strategy.Comparing PWM-DITC and traditional DITC in the simulation,it can be found that PWM-DITC can effectively reduce the peak current in the initial stage of DITC current rise,reduce torque ripple and increase the torque-current ratio.The comparison and verification of the two algorithms are carried out on the experimental platform.