Horizontal generator for photovoltaic power station

6.6.1 The prediction of the power generation of a photovoltaic power station should be based on the solar energy resources of the site, and various factors such as the design of the photovoltaic power station system, the layout of the photovoltaic array, and environmental conditions should be considered before calculation and determination.

The calculation of the power generation of photovoltaic power plants can be carried out through software simulation, which is a commonly used method in modern photovoltaic system design and analysis.

There are two typical configurations of PV generator in power system applications, namely, single-stage and two-stage as shown in Fig. 1a, Fig. 1b. A single-stage PV generator uses only one converter to complete both the maximum power point tracking (MPPT) and the power grid connection.

With the increased integration of PV generators into the grid, the system operators start to require PV generators have capabilities to stay online during the fault, and provide the active power and the reactive power supports when being required to do so.

By controlling the instantaneous three-phase inverter output voltages, and, the PV generator controls the active power output and the reactive power interchanges with the external grid.

A PV generator is modeled as a constant active power and reactive power source in power system steady state studies. When PV generation changes due to the ambient environment, the power system steady state studies do not investigate the transients of the power system caused by the change in PV generation.