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US 7,421,301 B2Granted
Speed-variable maximum delay clamping when using variable-delay random PWM switching
AssigneeGeneral Motors Corporation
InventorsSteven E. Schulz, Daniel L. Kowalewski
Life of this patent
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Abstract
A control system and a method of using the same for an electric machine having a random number generating module generating a random number ranging from a first value to a second value, a multiplying module multiplying the random number and a sample rate to generate an random delay value; and a delay limiter module limiting the random delay value as a function of speed of the electric machine and generating a limited delay value.
Claims22
A control system for an electric machine, comprising:
- a random number generating module that generates a random number ranging from a first value to a second value;
- a multiplying module that multiplies said random number and a sample rate to generate a random delay value;
- and
- a delay limiter module that limits said random delay value as a function of speed of said electric machine and generates a limited delay value, wherein a pulse width modulated drive signal is generated for said electric machine based on said limited delay value.
1 more element
A control system for an electric machine, said control system comprising:
- a random number generating module that generates a random number ranging from a first value to a second value;
- a multiplying module that multiplies said random number and a sample rate to generate a random delay value;
- and
- a delay limiter module that limits said random delay value as a function of speed of said electric machine and generates a limited delay value, that limits said random delay value as a function of speed for speeds great than a predetermined value, which is greater than a minimum speed of said electric machine and less than a maximum speed of said electric machine, wherein a pulse width modulated drive signal is generated for said electric machine based on said limited delay value.
1 more element
A control method comprising:
- generating a random number ranging from a first value to a second value;
- multiplying said random number and a sample rate to generate a random delay value;
- limiting said random delay value as a function of speed of electric machine;
- generating a limited delay value;
- and
- generating a pulse width modulated drive signal for said electric machine based on said limited delay value.
3 more elements
Dependencies are inferred from the claim text.