| Abstract |
A drive system is presented which allows the practical exploitation of the outstanding performances theoretically predicted for the high anisotropy IPM synchronous machines. For torque ratings from 10 to 300 Nm, with a large constant-power speed ratio, special IPM motors with high torque density are adopted. Their quadrature inductance is minimized to allow the use of low cost permanent magnets for its compensation. The linear anisotropy ratio reaches the value of around one tenth. Driving with fast torque response these motors, their complex and non-linear magnetic model is the main problem, especially when the supply voltage is not greatly redundant with respect to the motor emf. A simplified trade-off among different approaches is outlined. By considering the control algorithm as well as the hardware design, a control structure has been implemented, based on a real time (HW) field observation and state regulation together with a full digital (SW) parameter adaptation. |
