Electrical machine rotor position identification
First Claim
1. A method of identifying the position of magnetic poles of a rotor of a multi-phase electrical machine relative to a stator of that machine, including the steps of applying a voltage pulse to stator windings of each phase, sensing current flow in the stator windings of each phase due to the application of the voltage pulse to the respective stator windings and determining the position of the magnetic poles of the rotor relative to the stator using the sensed current flow in the stator windings of each phase, wherein the phases of the stator winding are star-connected at a neutral junction and the voltage pulse is applied to the stator windings of each phase in parallel, wherein the differences between the current flow sensed in the stator windings of each phase and the current flow sensed in the stator windings of each of the other phases are determined and those differences are used to identify a phase angle sector, the identified phase angle sector being an indication of the position of the magnetic poles of the rotor relative to the stator.
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Accused Products
Abstract
A method of and system for identifying the position of magnetic poles of a rotor of a multi-phase electrical machine relative to a stator of that machine is disclosed. The method includes the steps of applying a voltage pulse to stator windings of each phase, sensing current flow in the stator windings of each phase due to the application of the voltage pulse to the respective stator windings and determining the position of the magnetic poles of the rotor relative to the stator using the sensed current flow in the stator windings of each phase. The method is characterized in that the phases of the stator windings are star-connected at a neutral junction and the voltage pulse is applied to the stator windings of each phase in parallel.
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Citations
13 Claims
- 1. A method of identifying the position of magnetic poles of a rotor of a multi-phase electrical machine relative to a stator of that machine, including the steps of applying a voltage pulse to stator windings of each phase, sensing current flow in the stator windings of each phase due to the application of the voltage pulse to the respective stator windings and determining the position of the magnetic poles of the rotor relative to the stator using the sensed current flow in the stator windings of each phase, wherein the phases of the stator winding are star-connected at a neutral junction and the voltage pulse is applied to the stator windings of each phase in parallel, wherein the differences between the current flow sensed in the stator windings of each phase and the current flow sensed in the stator windings of each of the other phases are determined and those differences are used to identify a phase angle sector, the identified phase angle sector being an indication of the position of the magnetic poles of the rotor relative to the stator.
- 9. A system for identifying the position of magnetic poles of a rotor of a multi-phase electrical machine relative to a stator of that machine, including means operable to apply a voltage pulse to stator winding of each phase, means operable to sense current flow in the stator winding of each phase due to the application of the voltage pulse to the respective stator windings and means adapted to determine the position of the magnetic poles of the rotor relative to the stator using the sensed current flow in the stator windings of each phase, wherein the phases of the stator windings are star-connected at a neutral junction and said means operable to apply the voltage pulse are adapted to apply it to the stator windings of each phase in parallel, wherein means are provided for determining the differences between the current flow sensed in the stator windings of each phase and the current flow sensed in the stator windings of each of the other phases, and means adapted to use those differences are provided to identify a phase angle sector, the identified phase angel sector being an indication of the position of the magnetic poles of the rotor relative to the stator.
Specification