METHOD AND APPARATUS FOR UNAMBIGUOUS DETERMINATION OF THE ROTOR POSITION OF AN ELECTRICAL MACHINE
First Claim
1. Method for operating an electrical machine having a rotor and three phases and a connection associated with each of the phases, for determining the rotor position including the rotor polarity at a standstill, the method comprising for at least two of the phases the following steps are carried out:
- a) applying a pulsed voltage between the two connections associated with the other two phases;
b) measuring the voltage thus induced at the connection associated with the phase;
c) analyzing the variation over time of said induced voltage;
and carrying out the following step;
d) determining the rotor polarity on the basis of said analyses.
2 Assignments
0 Petitions
Accused Products
Abstract
The method for operating an electrical machine (32) having three phases (A, B, C) and a connection associated with each of the phases (A, B, C) for determining the rotor position (φ), including the rotor polarity at a standstill, comprising, for at least two of the phases:
- a) applying a pulsed voltage (Up) between the two connections associated with the other two phases;
- b) measuring the voltage thus induced at the connection associated with the phase;
- c) analyzing the variation of the referenced induced voltage over time; and
- d) determining the rotor polarity on the basis of the referenced analyses.
A measure of the deviation of the variation of the induced voltage over time compared to the variation of the pulsed voltage (Up) over time is advantageously determined in step c).
Rotor position (φ) is determined in a quick, accurate, cost-saving, and space-saving manner.
12 Citations
24 Claims
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1. Method for operating an electrical machine having a rotor and three phases and a connection associated with each of the phases, for determining the rotor position including the rotor polarity at a standstill, the method comprising for at least two of the phases the following steps are carried out:
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a) applying a pulsed voltage between the two connections associated with the other two phases; b) measuring the voltage thus induced at the connection associated with the phase; c) analyzing the variation over time of said induced voltage; and carrying out the following step; d) determining the rotor polarity on the basis of said analyses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 17, 18, 19, 20, 21, 22)
and the following step is carried out; f) determining the rotor position based on said voltage differences.
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9. Method according to claim 2, wherein step d) comprises a comparison to predefined values.
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10. Method according to claim 2, wherein the steps are carried out for all three phases.
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17. Method according to claim 1, wherein the pulsed voltage has at least a portion showing a substantially constant voltage, and in step c) a measure of the slope of the induced voltage is determined during the at least one portion showing the substantially constant voltage.
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18. Method according to claim 1, wherein the voltage-time integral of the pulsed voltage substantially vanishes.
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19. Method according to claim 1, wherein the pulsed voltage is a rectangular or pulse width modulation signal.
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20. Method according to claim 1, for determining the rotor position including the rotor polarity at a standstill, for the at least two phases the following step is carried out:
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e) determining a voltage difference from said induced voltage; and the following step is carried out; f) determining the rotor position based on said voltage differences.
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21. Method according to claim 1, wherein step d) comprises a comparison to predefined values.
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22. Method according to claim 1, wherein the steps are carried out for all three phases.
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11. Applicance for determining a rotor position including the rotor polarity at a standstill, of a rotor of an electrical machine having three phases and a connection associated with each of the phases, wherein the appliance comprises:
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a voltage source for generating a pulsed voltage; a voltage measuring device for measuring electrical voltages; a wiring system for wiring the three connections selectably with the voltage source or the voltage measuring device; wherein the appliance is designed in such a way that to at least two different pairs of the connections the pulsed voltage is successively applicable and an induced voltage thus occurring at the respective third connection is measurable using the voltage measuring device wherein the appliance further includes; an analysis unit for analyzing the variation over time of the induced voltages measured using the voltage measuring device; and an evaluation unit for determining the rotor polarity based on at least two of said analyses. - View Dependent Claims (12, 13, 14, 15, 16, 23, 24)
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Specification