Direct adaptive current control in space vector overmodulation mode

In this paper an algorithm is presented how the current slopes of the freewheeling switching states of an VSI- driven 3-phase isotropic synchronous machine can be obtained by only evaluating the measured current slopes during the two applied active switching states. This enables the identification of the freewheeling current slopes in operating conditions where the freewheeling switching states are too short for a direct measurement. Notably, the use of the “Direct Adaptive Current Control” in the overmodulation range is made possible with the proposed technique.