Patent ID: 8981703
Filing Date: 2015-03-17
Classification: H02P

Abstract:
1. A system for operating an electric machine, comprising: a rotor position sensor situated on the electric machine and configured to provide a rotor position indication as a function of a rotor position angular range which indicates the position of a rotor of the electric machine, wherein a change in the rotor position indication results from a change which occurs between rotor position angular ranges when the rotor moves; and a control unit configured to control the electric machine by associating a commutation angular range, which indicates a control state for stator coils, with at least one rotor position indication, so that a change in the commutation angular range is triggered by a change in the rotor position indication, and to change an association scheme of associations between the rotor position indications and the commutation angular ranges as a function of a predefined rotational direction indication which indicates a desired rotational direction, wherein: in each of the commutation angular ranges, a maximum torque rotor position is defined which indicates a rotor position for which the control state associated with the respective commutation angular range results in a stator magnetization having a direction that is perpendicular to a direction of a rotor magnetization; and the commutation angular ranges are situated between the maximum torque rotor positions, the control beginning at a rotor position which is situated around a commutation angular range which, with respect to the rotational direction, precedes the maximum torque rotor position of the respective control state, and the control ending at a rotor position which corresponds to the maximum torque rotor position.