Power Conditioning Units
4 Assignments
0 Petitions
Accused Products
Abstract
We describe a power conditioning unit with maximum power point tracking (MPPT) for a dc power source, in particular a photovoltaic panel. A power injection control block has a sense input coupled to an energy storage capacitor on a dc link and controls a dc-to-ac converter to control the injected mains power. The power injection control block tracks the maximum power point by measuring a signal on the dc link which depends on the power drawn from the dc power source, and thus there is no need to measure the dc voltage and current from the dc source. In embodiments the signal is a ripple voltage level and the power injection control block controls an amplitude of an ac current output such that an amount of power transferred to the grid mains is dependent on an amplitude of a sinusoidal voltage component on the energy storage capacitor.
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Citations
35 Claims
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1-12. -12. (canceled)
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13. A power conditioning unit with maximum power point tracking (MPPT), for delivering power from a dc power source to an ac mains power supply output, the power conditioning unit comprising:
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an input for receiving power from said dc power source; an output for delivering ac power to said ac mains power supply; an energy storage capacitor for storing energy from said dc power source for delivering to said ac mains power supply output; a dc-to-ac converter coupled to said output for converting energy stored in said energy storage capacitor to ac power for said ac mains power supply output; a power injection control block having a sense input coupled to said energy storage capacitor and having an output coupled to said dc-to-ac converter, to control said dc-to-ac converter to control power injected into said ac mains power supply; and wherein, in operation, a voltage on said energy storage capacitor has a sinusoidal voltage component at twice a frequency of said ac mains; wherein said power injection control block is configured for controlling an amplitude of an ac current provided to said ac mains power supply output such that an amount of power transferred to said ac mains power supply output is dependent on an amplitude of said sinusoidal voltage component on said energy storage capacitor, and wherein said power injection control block is configured to track a maximum power point of said dc power source by controlling said dc-to-ac converter. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
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22-30. -30. (canceled)
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31. A method of maximum power point tracking (MPPT) in a power conditioning unit for delivering power from a dc power source to an ac mains power supply output, the power conditioning unit including an energy storage capacitor for storing energy from said dc power source for delivering to said ac mains power supply output, the method comprising:
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tracking a maximum power point of said dc power source by controlling a dc-to-ac converter converting energy stored in said energy storage capacitor to ac power for said ac mains power supply input, wherein said tracking comprises; sensing, at a circuit node coupled to said energy storage capacitor, a signal responsive to a level of power drawn from said dc power source; and controlling said dc-to-ac converter to adjust an amplitude of an ac output to substantially maximise said sensed signal. - View Dependent Claims (32, 33, 34, 35)
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Specification