Sunpower Corporation

Lars Johnson

Robert Johnson

Andrew Joseph Ponec

William B Peter

Methods, systems, and computer readable media are disclosed for maintaining photovoltaic power plant reactive power capability, e.g., through the manipulation of direct current (DC) voltage. In some examples, A control system includes a monitor input for receiving a monitor signal indicative of an input voltage of an inverter system and a control output for outputting a control signal to a voltage-clipping device of a solar panel system supplying a solar output voltage to the inverter system. The control system includes a control circuit configured to perform operations comprising: determining, using the monitor signal, that the input voltage of the inverter system exceeds a threshold voltage; and in response to determining that the input voltage of the inverter system exceeds the threshold voltage, causing, using the control signal, the voltage-clipping device to reduce the solar output voltage by shorting out one or more photovoltaic solar cells of the solar panel system.

Methods and systems for maintaining photovoltaic power plant reactive power capability

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.

Automatic voltage regulation for photovoltaic systems

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.

Methods and apparatus for controlling operation of photovoltaic power plants

A photovoltaic power plant with master-slave control architecture. The photovoltaic power plant includes slave plant controllers, with each slave plant controller controlling operation of photovoltaic inverters that convert direct current generated by solar cells to alternating current suitable for delivery to a utility power grid at a point of interconnection (POI). A master plant controller controls and coordinates the operation of the slave plant controllers. The master plant controller generates a global inverter real or reactive power setpoint, which is provided to each slave plant controller. In each slave plant controller, the global set point is processed to generate individual inverter real or reactive power setpoints that are provided to corresponding photovoltaic inverters controlled by that slave plant controller. A photovoltaic inverter generates an output based on received individual inverter setpoint to achieve a desired real power, voltage or power factor.

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Concord, CA, United States of America

Lars Johnson