Novel Magnetization State Closed-Loop Control for Variable Flux Memory Machine

In this paper, a novel magnetization state (MS) control method is proposed by utilizing torque deviation to achieve the MS closed-loop control for variable flux memory machine. Firstly, the relationship between the MSs and the demand magnetizing current pulses is built into a look-up table, which also contains information on the flux linkages and the dq-axis inductances under different MSs. Afterwards, a model-based torque calculation is adopted for torque estimation, and then, the torque deviation between the present MS and the target MS can be obtained and utilized to generate the MS switch signal, which will determine the type of MS manipulation. Subsequently, the calculated torque will also be used for real-time monitoring of MS. The feasibility of the proposed MS control method is verified by simulation. Finally, experiments are carried out on a hybrid magnet memory machine control system for validation.