Automatic voltage regulation for photovoltaic systems
AssigneeSunPower Corporation
InventorsLars Johnson, Robert Johnson
Life of this patent
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Abstract
A photovoltaic system includes solar cells and photovoltaic inverters configured to convert direct current generated by the solar cells to alternating current. Grid voltage at the point of interconnection (POI) of the photovoltaic system and the power grid is measured and compared to a setpoint. A control signal is generated based on the measured grid voltage. The control signal is provided to the photovoltaic inverters. The control signal is adjusted to cause the photovoltaic inverters to generate or absorb reactive power to respond to transient grid voltage changes.
Claims20
A method of operating a photovoltaic system, the method comprising:
- measuring a grid voltage delivered by a photovoltaic system at a point of interconnection (POI) with a power grid to generate a measured grid voltage;
- comparing the measured grid voltage to a reference voltage, the reference voltage indicating a setpoint voltage for the POI;
- generating a control signal based on a result of comparing the measured grid voltage to the reference voltage, the control signal indicating a reactive power setpoint for a photovoltaic inverter;
- presenting the control signal to the photovoltaic inverter at the location of the photovoltaic inverter, the photovoltaic inverter converting direct current generated by solar cells to alternating current for delivery to the power grid;
- and
- adjusting the control signal to respond to transient changes to the grid voltage.
A photovoltaic system comprising:
- a plurality of solar cells;
- a photovoltaic inverter that is configured to convert direct current generated by the plurality of solar cells to alternating current;
- and
- a plant controller configured to adjust an inverter reactive power setpoint based on a measured voltage measured at a point of interconnection (POI) of a photovoltaic system with a power grid, and to provide the inverter reactive power setpoint to the photovoltaic inverter to adjust a reactive power output of the photovoltaic inverter and respond to a changing grid voltage at the POI.
A method of operating a photovoltaic system, the method comprising:
- measuring a voltage provided by a photovoltaic system at a point of interconnection (POI) to a power grid to generate a measured voltage;
- generating a control signal to control operation of a photovoltaic inverter, the control signal being generated based on the measured voltage and indicating an inverter reactive power setpoint;
- and
- adjusting the inverter reactive power setpoint to adjust a reactive power output of the photovoltaic inverter in response to a change in the measured voltage.
Dependencies are inferred from the claim text.