Estimation of permanent magnet motor parameters

To properly design and optimize a control system of a permanent-magnet (PM) machine, the machine model and its parameters must be known. This study presents a method for developing a model and estimating the parameters of a PM machine from standstill time-domain step response data. A dq-axis equivalent circuit model with a general number of damper windings is defined to describe the behavior of the PM machine. Standstill simulation studies were performed on a known PM machine to generate synthetic test data to be used for estimation procedure verification. The stand-still dq-axis model is subjected to a step-input signal and the resulting output is used for parameter estimation. The output-error estimation algorithm is used to estimate the unknown parameters of the dq-axis model. Stand-still tests were then performed on a 4 pole, 1 kW PM machine to obtain data. The PM machine parameters were estimated and the model verified against experimental input and output test data.