Research On Control Of Integrated System Of Dual Three Phase PMSM And Hybrid Energy Storage System

Dual three-phase motor has been widely researched due to the advantages as low torque ripple,low vibiration noise and fault tolerance ability.With dual stator winding sets in same magnetic circuit,it has the potential for power management through the"virtual bus" while providing mechanical power.The hybrid energy storage system(HESS)power can be controlled through the motor when battery and ultracapacitor(UCs)are connected with the dual winding sets respectively.Both the advantages of dual three-phase motor and the HESS are achieved in the integrated system.However,the dynamic response of HESS is restricted by the coupling effects between windings,which limits the application of the integrated system.Thus a torque distributed control strategy is proposed in this paper to achieve decoupling control for the dual three-phase permenant magnet synchronous motor(PMSM),which relieves the restriction for HESS.Firstly,the coupling characteristics are researched for the dual three-phase PMSM and the relation between distributed torque and fluxes are analyzed.The coupling between phases caused by mutual inductance is revealed at first.Then the effects of coordinate transformation is considered.It's found that the coupling effects and the degree of freedom for winding control are both eliminated with the six-dimention coordinate transformation,which can't be used for integrated HESS.With dual dq coordinated transformation,the freedom of control is maintained while the coupling effects exists.The coupling effects of voltage/current relation and torque/flux relation are both studied in the dual dq coordinate system,which indicates that there's no current differential term and speed term in the coupling term of torque/flux model.So the distributed torque in torque/flux model are chosen for the control system design.Secondly,a torque distributed control strategy is proposed for dual three-phase PMSM and HESS operation modes switch are realized.Based on the torque/flux model and the constraints of the circular flux in motor,the expression of the incremental flux angle is derived.The expression is used as the basis to design the forward channel of the motor controller.A decoupling strategy is proposed for the coupling part and the closeloop control unit is designed for the linear part.The torque distributed control system is then proposed combined with the feedback unit as flux observer.Multiple operation modes and dynamic power control of HESS is achieved with the proposed torque distributed control strategy.Finally,the proposed method is verified through simulations and experiments.It's shown that the coupling effects is suppressed with the proposed method,which has better dynamic performance compared with the other control strategy.It provides guidance for the integrated design of energy storage and motor drive system.