Maximum efficiency control for permanent magnet synchronous motors

The authors propose a maximum efficiency control algorithm for permanent magnet synchronous motors. This control method shows that motor losses are reduced considerably by controlling the d-axis component of the armature current at any speed and power levels. The optimum d-axis current is supplied by a controller which solves the maximum efficiency control algorithm. The steady-state and transient characteristics are examined in detail by computer simulations. The influence of the sensitivity to motor parameters on the efficiency characteristic is also investigated. A convenient control technique is described. Experimental results confirm the improvement of the efficiency with the proposed control system.<<ETX>>