Pole Assignment of Full-Order Flux Observer to Realize Both MTPA Control and Position Sensorless Control of IPMSM

A flux model that can easily achieve both maximum torque per ampere (MTPA) control and position sensorless control of interior permanent magnet synchronous motors (IPMSMs), is proposed herein. Flux is proposed to be estimated using a full-order observer whose pole assignment is difficult because the order of the error equations of the observer becomes four, and the pole assignment of the full-order observer is proposed. This pole assignment of the full-order observer, in which robust flux estimation against velocity estimation error become possible, is obtained by solving a γ-positive real problem and a H∞ control problem. Herein, the experimental result of the position sensorless control of IPMSMs indicates that the proposed pole assignment of the full-order observer is highly useful and can be used to realize MTPA control.