Adaptive demagnetization compensation for a motor in an electric or partially electric motor vehicle
First Claim
1. A hybrid electric vehicle comprising:
- a first motor coupled to wheels of the hybrid electric vehicle;
a second motor coupled to wheels of the hybrid electric vehicle;
a first voltage monitor coupled to the first motor to determine a first permanent magnet induced voltage of the first motor;
a controller that;
compares the first permanent magnet induced voltage with a first reference voltage that reflects an expected permanent magnet induced voltage for the first motor when a permanent magnet of the first motor is fully magnetized;
determines a state of magnetism of the permanent magnet of the first motor based on the first permanent magnet induced voltage, the first reference voltage and a predetermined speed at which the first permanent magnet induced voltage is determined;
makes the first motor inoperable if the state of magnetism of the permanent magnet of the first motor reaches a predetermined threshold; and
causes wheels of the vehicle to be driven with the second motor after the first motor is made inoperable.
4 Assignments
0 Petitions
Accused Products
Abstract
In an electric or hybrid electric vehicle, a voltage monitor (102) is directly coupled to a traction motor (38) and/or generator motor (30) to detect a permanent magnet induced voltage within the motor at a predetermined speed and no load condition (300). A controller (100) compares the detected permanent magnet induced voltage with an expected reference voltage that represents an expected permanent magnet induced voltage at full magnetization and the predetermined speed (302). The controller produces an indication of magnetization based on the reference voltage, the detected permanent magnet induced voltage, and the predetermined speed. If the indication of magnetism reaches a predetermined threshold, the motor is made inoperable and/or a current to the motor is limited to prevent damage to components (306, 308, 310, 312, 314). Preferably, a user of the vehicle is made aware of these actions by an audible and/or visual indicator (308, 314). If available, another source of motive power is substituted for the motor that is made inoperable (316).
12 Citations
18 Claims
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1. A hybrid electric vehicle comprising:
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a first motor coupled to wheels of the hybrid electric vehicle;
a second motor coupled to wheels of the hybrid electric vehicle;
a first voltage monitor coupled to the first motor to determine a first permanent magnet induced voltage of the first motor;
a controller that;
compares the first permanent magnet induced voltage with a first reference voltage that reflects an expected permanent magnet induced voltage for the first motor when a permanent magnet of the first motor is fully magnetized;
determines a state of magnetism of the permanent magnet of the first motor based on the first permanent magnet induced voltage, the first reference voltage and a predetermined speed at which the first permanent magnet induced voltage is determined;
makes the first motor inoperable if the state of magnetism of the permanent magnet of the first motor reaches a predetermined threshold; and
causes wheels of the vehicle to be driven with the second motor after the first motor is made inoperable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for compensating for permanent magnet degradation in a hybrid electric vehicle that includes a first motor coupled to rotate wheels of the hybrid electric vehicle and a second motor coupled to rotate wheels of the hybrid electric vehicle, the method comprising the steps of:
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determining a state of magnetism of a first permanent magnet in the first motor;
determining whether the state of magnetism has reached a predetermined threshold;
making the first motor inoperable if the state of magnetism has reached the predetermined threshold; and
causing the second motor to rotate wheels of the hybrid electric vehicle if the first motor is made inoperable. - View Dependent Claims (16, 17, 18)
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Specification