Methods and apparatus for controlling operation of photovoltaic power plants
AssigneeSunPower Corporation
InventorLars Johnson
Life of this patent
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Abstract
A photovoltaic power plant includes a photovoltaic inverter that converts direct current generated by solar cells to alternating current. The output of the photovoltaic inverter is provided to a point of interconnection to a power grid. A meter at the point of interconnection may be read to detect the output of the photovoltaic inverter at the power grid. The photovoltaic power plant includes a plant controller with a state machine. The plant controller is configured to adjust setpoints of the photovoltaic inverter to control the output of the photovoltaic power plant. The plant controller is also configured to soft start and soft stop automatic voltage regulation (AVR) of the photovoltaic power plant to prevent perturbing the AVR.
Claims20
A method of controlling a photovoltaic power plant, the method comprising:
- providing a reactive power setpoint to a photovoltaic inverter that converts direct current generated by a plurality of solar cells to alternating current;
- detecting a real power output of the photovoltaic power plant at a point of interconnection (POI) of the photovoltaic power plant to a power grid;
- comparing the real power output of the photovoltaic power plant to a minimum real power generation level;
- and
- changing the reactive power setpoint to unity power factor in response to detecting that the real power output of the photovoltaic power plant is below the minimum real power generation level.
A method of controlling a photovoltaic power plant, the method comprising:
- providing a setpoint variable limit to a photovoltaic inverter that converts direct current generated by a plurality of solar cells to alternating current;
- detecting an output of the photovoltaic power plant at a point of interconnection (POI) to a power grid in a first state of operation;
- and
- dynamically adjusting the setpoint variable limit from a first inverter setpoint to a second inverter setpoint to lower a limit on a reactive power output of the photovoltaic inverter when the output of the photovoltaic power plant exceeds a maximum allowable reactive power or power factor of the photovoltaic power plant.
A method of controlling a photovoltaic power plant, the method comprising:
- detecting an output of the photovoltaic power plant that is provided to a power grid;
- comparing the output of the photovoltaic power plant to a maximum allowable output limit of the photovoltaic power plant, the maximum allowable output limit being a maximum allowable reactive power or power factor of the photovoltaic power plant;
- and
- in response to detecting that the output of the photovoltaic power plant exceeds the maximum allowable output limit, lowering a limit on a reactive power output of a photovoltaic inverter that converts direct current generated by a plurality of solar cells to alternating current.
Dependencies are inferred from the claim text.