Precise method for measuring Xd and Xq based on slip test of synchronous machines

An experimental method for measuring the direct and quadrature axis synchronous reactances of polyphase synchronous machines with salient pole is developed. It is based on a measuring method of the slip test. It can be applied to all synchronous machines, but primarily it has been developed and demonstrated for reluctance motors. A precise measuring method was derived by the use of the tensor analysis method, and was introduced to minimize measurement errors due to the stator resistance (Rs) as well as machine losses. Detailed results are presented for a reluctance motor with a highly variable Rs. Correlation with other methods is quite good. The effects of Rs are observed in the tested motor.<>