A Novel Phasor Diagram of Interior Permanent Magnet Synchronous Motors based on Spiral Vector Theory

The paper presents a novel phasor diagram of interior permanent magnet synchronous (IPMS) motor for steady state analysis. Starting from first principle, the phase decoupled spiral vector model of the IPMS motor has been obtained. A phase decoupled voltage equation in phasor can be obtained from the spiral vector IPMS motor at steady state. In the phasor diagram, the effect of reluctance variation is represented as reluctance voltage. The shaft power output of the motor is the sum of power due to field voltage and reluctance voltage. The steady state performance of the IPMS motor can be predicted with the use of this phasor diagram. The novel phasor diagram can also be used for steady state performance analysis of salient pole synchronous and reluctance machine.