Research On Modular Driver Technology For Switched Reluctance Motor

With the development of modern industry,modular design is more and more widely used in industry because of its advantages such as generalization,serialization and standardization.The increase of power density can be achieved by increasing the number of phases and the number of teeth,but the increase of the number of phase will lead to the rapid increase of the number of multi phase SRM power converters,which will lead to a significant increase in the cost of the drive system.The modular design for the whole system of product family,the general module of the system which focuses on product family system decomposition and re combination of income,so the research of motor industry integrated modular drive system has attracted much attention,has important significance in the new SRM power converter with high performance and low cost.This paper presents a scalable modular driver scheme for arbitrary phase SRM and discusses three ways to expand the modular driver for different applications.High performance modular driver is designed,and the hardware design is introduced.In order to reduce the size of the modular drive,based on the N/2 module,this paper studies the current sensor reduction scheme.First of all,the neutral point capacitance phase splitting topology main circuit is introduced.The advantages and disadvantages of double current sensor are analyzed.A single current sensor is proposed,but there is a problem of phase current ripple.The cause of phase current ripple and the coupling relationship between the amplitude of fluctuating current and the parameters are analyzed.By injecting a single high frequency pulse,according to the fluctuation of the bus voltage,the suppression of the pulsating current is realized.Finally,the experiment proves the feasibility of the scheme.In the existing design scheme,the electrolytic capacitor on the bus bar has many problems,such as short life,large volume and high temperature.In order to solve the influence of the electrolytic capacitor on the high integration of the module driver,the bus current control strategy is studied in this paper.Firstly,the bus side is equivalent to the first order RC circuit,and the basic principle of reducing bus capacitance is introduced in detail.The basic principle of bus current average method is introduced in detail.The method is applied to the multi phase motor,and the simulation results show that the average value method can realize the limitation of the bus capacitance,but there is a problem of the upper limit of the speed.Under multi-phase SR motor,the interleaving control strategy is used to improve the speed limit,but there are still problems with speed limits.Based on the above problems,this paper puts forward the control strategy of bus current peak value,and calculates the equivalent impedance.According to the equivalent circuit of the power supply side,the capacitance value equation of the bus is calculated under the condition of fixed frequency.Finally,experiments are carried out to compare the different control strategies to prove the feasibility of the strategy.