Photovoltaic systems with local maximum power point tracking prevention and methods for operating same
AssigneeSunPower Corporation
InventorsZachary S. JUDKINS, Keith JOHNSTON
Life of this patent
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Abstract
A photovoltaic system includes solar cells and an inverter configured to convert direct current generated by the solar cells to alternating current. The photovoltaic system includes a maximum power point (MPP) tracking module configured to perform MPP tracking for the photovoltaic system. The MPP tracking module is configured to detect shading of the solar cells and to modify its MPP tracking to prevent tracking of local MPPs. The MPP tracking module may be incorporated in the inverter.
Claims20
A photovoltaic system comprising:
- a plurality of solar cells;
- a photovoltaic inverter that is configured to convert direct current generated by the solar cells to alternating current and to induce the solar cells to generate an output voltage based on a setpoint signal;
- and
- a maximum power point tracking (MPPT) module that is configured to adjust the setpoint signal by a step size to follow a global maximum power point (MPP) on a current-voltage (I-V) curve of the photovoltaic system and, in response to detecting that the MPPT module is following a local MPP instead of the global MPP on the I-V curve, to increase the step size.
A method of operating a photovoltaic system, the method comprising:
- inducing, by a photovoltaic inverter based on a setpoint signal, a plurality of solar cells to generate an output voltage;
- adjusting the setpoint signal by a step size when an output current and the output voltage of the solar cells indicate that an output power of the photovoltaic system is approaching a global maximum power point (MPP) on a current-voltage (I-V) curve of the photovoltaic system;
- and
- increasing the step size when the output current and the output voltage of the solar cells indicate that the output power of the photovoltaic system is approaching a local MPP instead of the global MPP on the I-V curve of the photovoltaic system.
A photovoltaic inverter comprising:
- an inverter circuit that is configured to convert direct current generated by solar cells to alternating current and, based on a setpoint signal, to induce the solar cells to generate an output voltage;
- and
- a maximum power point tracking (MPPT) module that is configured to adjust the setpoint signal by a step size to follow a global maximum power point (MPP) on a current-voltage (I-V) curve of the photovoltaic system and, in response to detecting that the MPPT module is following a local MPP instead of the global MPP on the I-V curve, to increase the step size.
Dependencies are inferred from the claim text.