Abstract: 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.