Self tuning IPMSM direct torque controller

An online adaptive routine is presented for optimum direct torque control of Interior permanent magnet synchronous machines (IPMSM). Optimum control is provided by minimizing of a predefined particular cost function which causes proper selecting of the voltage vector to minimize electrical torque variations. In addition, the required parameters of cost function are estimated continuously. For this purpose, IPMSM dynamic parameters including inductances and resistances are estimated by recursive least squares routine on the base of the bus current and voltage waveforms. Estimation is carried out in the loaded conditions of IPMSM. Consequently, the estimated parameters are in the actual conditions of the motor from the view point of magnetic saturation level. The estimation needs no data and initial assumptions. Digital filtering techniques are used for noise elimination on the measured data.