Effect of rotor dimensions and cross magnetisation on Ld and Lq inductances of reluctance synchronous machine with cageless flux barrier rotor

The performance of a reluctance synchronous machine in terms of torque and power factor depends on the two-axis inductances L_d and L_q of the machine. A finite element analysis method is used to determine these inductances for a reluctance machine with a normal cross-laminated rotor with two flux barriers per pole. By varying the rotor dimensions, the change in the difference and ratio of the inductances is examined. The effect of cross magnetisation on the two axis inductances is investigated by means of finite element analysis and measurements on an actual reluctance synchronous machine with a two flux barrier per pole rotor. The measured torque of the current-controlled reluctance machine drive is also given and compared with calculated results showing the effect of cross magnetisation. Hence, important conclusions are arrived at regarding the rotor design and cross magnetisation effect