Research On Single-stage Multi-port Motor Drive Based On Double Modulated Wave Modulation Strategy

Hybrid electric vehicles are an effective solution that can effectively solve the shortcomings of current pure electric vehicles and meet the energy-saving level advocated by the country.As a low-cost,high-efficiency,and small-sized electrical energy conversion device,the single-stage multi-port motor driver is a key component in hybrid electric vehicle applications and has important research value.However,the driver has problems such as port voltage imbalance,output power path coupling with switching states,and difficulty in power control modeling that limit its large-scale application.The research work carried out in this paper to achieve flexible power distribution between ports of a single-stage multi-port motor drive system is summarized as follows:Firstly,the power distribution between ports in single-stage multi-port motor drive is realized through a reasonable modulation strategy,which is the key to realize the advantageous complementation of energy sources in hybrid vehicles.To address the problems of port voltage imbalance and output power path coupling with the switching state,a double modulation wave modulation strategy based on carrier modulation is proposed in this paper,and the objective of reducing the number of switching actions and increasing the freedom of port power distribution is achieved by analyzing the adjustment range of control parameters and using zero-sequence component injection.The relationship between the control parameters and the output power of the power supply port and the regulation range of the power supply port are analyzed in depth.The simulation results verify the effectiveness of the proposed modulation strategy.Second,the single-stage multi-port motor drive system is a strongly coupled and nonlinear system,and the power control modeling is difficult.In order to achieve flexible port power allocation,this paper introduces a model-free adaptive control(MFAC)strategy in the double modulation wave modulation strategy to optimize the power control,which achieves power control by modeling equivalent dynamic linearized data at each dynamic operating point of the closed-loop system using historical input and output data,and the algorithm incorporates a reset algorithm mechanism to give it a stronger tracking capability and increase the anti-disturbance of power control.The simulation results verify the superiority of the model-free adaptive control introduced in the paper.Finally,to verify the correctness and effectiveness of the above algorithm,a singlestage multi-port motor drive experimental platform is built in the laboratory for further experimental verification.The experimental results show that the double modulated wave modulation strategy has the capability of power distribution between ports with certain degrees of freedom;the MFAC strategy enhances the resistance of the system to external load perturbations.