Novel Design Method to Reduce Input Current for Multi-Operating Point IPMSM

Recently, interior permanent magnet synchronous motor (IPMSM) is paying attention because of its high power density and efficiency by adopting permanent magnet. The IPMSM has two control methods: maximum torque per ampere (MTPA) control and flux weakening control. Generally, an MTPA control is applied to a continuous operating point, and in case of a startup point, input current is applied which satisfies required output torque. To control the IPMSM, the various types of inverters with current and voltage limitations are used. The motor cannot be operated if these limitations are not satisfied. This paper proposes a method to satisfy the current and voltage limitations of the inverter with two different operating points. By changing the control method of the rated operating point by a stack compensation method, the current and voltage limitations of the inverter can be satisfied at a startup operating point, where the input current in MTPA control at the continuous operating point cannot be satisfied. The proposed method is verified by a 2-D finite element analysis.