Novel Magnetization State Control Method Based on Modified Voltage Limitation for Hybrid Magnet Memory Machine

This paper proposes a novel magnetization state (MS) control method for a hybrid magnet memory machine (HMMM) based on modified voltage limitation. The effect of the voltage limitation on the MS manipulation is analyzed. The circumcircle of voltage vector hexagon is utilized as the modified voltage limitation instead of the inscribed circle to simplify the algorithm which can increase the voltage margin for MS manipulation under the same operating conditions. The maximum amplitude of the magnetizing current pulse under real-time voltage limitation can be calculated and utilized as the boundary for MS manipulation. Within the boundary, the target MS can be achieved. When the MS is limited, the proposed MS control method also provides a solution to achieve the target MS by calculating the optimal operating speed. The experimental validations are carried out on the HMMM control system to verify the feasibility of the proposed MS control method.