China's first primary frequency photovoltaic control system connects to grid



China recently put its first primary frequency photovoltaic (PV) control system for new energy into operation in Daqing, northeast China's Heilongjiang Province.

The system has been connected to a grid and operating for a month, according to Huanghe Hydropower Development Co., Ltd, the company responsible for the project's construction.

The successful installation and subsequent operation is a significant next step in the development of China's grid-connected PV system, as it makes it easier to control and maintain frequency.

Controlling frequency within predefined limits in an electric power system is crucial for ensuring safe operating conditions and supplying energy to all the users or loads connected. Unexpected disturbances can create problems for the connected loads or even cause system failure.

The primary frequency control technique used in PV penetration on power grids is troublesome and causes many technical problems because PV has no kinetic energy or inertia that is essential for maintaining the stability of the frequency and angle of the rotor during disturbances.

Daqing's National Photovoltaic and Energy Storage Demonstration Experiment Platform is now the only new energy power plant connected to a grid with a rotor, lithium titanate and supercapacitors as energy storage devices capable of handling frequency control.

The project was commissioned in November 2021, and its construction was completed in April this year.