A model of the non-linear switched reluctance motor (SRM) has been developed that provides an analytical representation based on static measurements of the j l u x linkage by simple polynomial functions. Using an approximation of the y(i)-characteristic with the rotor position angle y as parameter it is possible to calculate the dynamic pedormance of the drive in the whole torque-speed range. Depending on the torque command T, the switching angles yo ("on") and yc ("off") are determined with minimum ohmic losses under the assumption of a constant supply voltage. For the ease of demonstration the results are restricted to the field weakening range. It turns out that the switching angles are parabolic functions of the torque with the well-known tendency for advance-shijting at increasing speed. The calculated current waveforms and average torque values coincide well with those measured at the test drive.

With a conventional hysteresis current controller the power output of an inverter fed synchronous machine decreases if the set point of the current becomes to high. This appears because the voltage of the DC link is too low to apply the desired Pow er dependent of the set point