Converter lifetime improvement method for doubly fed induction generator
First Claim
1. A method comprising:
- operating a rotor-side converter and a line-side inverter of a power system, wherein the rotor-side converter is coupled to a generator;
calculating an aging parameter of the line-side inverter converter;
changing a first operational mode of the rotor-side converter to a second operational mode when the aging parameter is above a threshold parameter for achieving a desired lifespan of the line-side inverter, wherein changing the first operational mode to the second operational mode comprisesincreasing a first fundamental frequency of the rotor-side converter to a second fundamental frequency larger than the first fundamental frequency regardless of a speed of a rotor that corresponds to the generator.
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Accused Products
Abstract
The present techniques include methods and systems for operating converter to maintain a lifespan of the converter. In some embodiments, the operating frequency of the converter may be increased such that stress may be reduced on the bond wires of the converter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the converter operating in a maximum power point tracking (MPPT) mode and determining whether the MPPT operation results in aging the converter to a point which reduces the converter lifespan below a desired lifespan. If the MPPT operation reduces the converter lifespan below the desired lifespan, the frequency of the converter may be increased such that the converter may be controlled to operate at a percentage of MPPT. Thus, in some embodiments, power output may be optimized with respect to maintaining a desired lifespan of the converter.
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Citations
15 Claims
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1. A method comprising:
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operating a rotor-side converter and a line-side inverter of a power system, wherein the rotor-side converter is coupled to a generator; calculating an aging parameter of the line-side inverter converter; changing a first operational mode of the rotor-side converter to a second operational mode when the aging parameter is above a threshold parameter for achieving a desired lifespan of the line-side inverter, wherein changing the first operational mode to the second operational mode comprises increasing a first fundamental frequency of the rotor-side converter to a second fundamental frequency larger than the first fundamental frequency regardless of a speed of a rotor that corresponds to the generator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of delivering power to a load, the method comprising:
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determining an aging parameter of a converter in a power system based on a first operational mode of the converter, wherein the converter is coupled to a generator; comparing the aging parameter with a threshold, wherein the threshold is based on a desired lifespan of the converter; and changing the converter to a second operational mode by increasing a fundamental frequency of the converter when the aging parameter is beyond the threshold and regardless of a speed of a rotor that corresponds to the generator. - View Dependent Claims (14)
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15. A non-transitory computer readable medium, which when executed by a computer, causes the computer to perform the steps of:
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calculating an aging parameter of a line-side inverter in a power generator, wherein the aging parameter is calculated based on a junction temperature variation of at least one switch within the line-side inverter after one output cycle of the line-side inverter, a mean junction temperature of the at least one switch, and a fundamental frequency of the line-side inverter; changing a first operational mode of a rotor-side converter to a second operational mode when the aging parameter is above a threshold parameter for achieving a desired lifespan of the line-side inverter, wherein the rotor-side converter is coupled to a generator, and wherein changing the first operational mode to the second operational mode comprises increasing a fundamental frequency of the rotor-side converter regardless of a speed of a rotor that corresponds to the generator.
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Specification