Study of algorithm synthetic inertia functioning in electric networks of different density

Abstract

The ability to use the algorithm synthetic inertia (SI) is one of the most important properties of renewable energy sources (RES) generating units connected to the network via a power converter (GUPC). Through the use of SI algorithm there is an opportunity to increase the inertia and damping properties of such plants. The effectiveness of the SI algorithm depends on the mains frequency input value, which is formed by the phase locked loop (PLL), which is an integral part of the power converter control system. However, the operation of the PLL can lead to oscillations with different frequencies when the GUPC is installed in weak electrical networks and, accordingly, adversely affect the performance of the SI algorithm. The studies have shown that the PLL in the photovoltaic plant (PV) control system allows to influence the performance of the SI algorithm, but the nature of this influence depends on the electric network density and can be positive or negative. The influence obtained on the test EPS is also confirmed for the power system of large-scale.