Composition of inertial response emulation mechanisms for power system frequency stability analysis

Nowadays, the electric power system is rapidly changing around us. Policy makers found a way to incentivise the renewable energy sources to reach the ambitious climate protection goals. Power system operators must adapt to the whole new constraints. The once heavily centralized generation is now dispersed all around the grid and causes problems that were previously unknown. Some of the emerging technologies - such as the most common wind and solar generators - are connecting to the grid via power converters so they are practically decoupled from the grid. This means that the system inertia is decreasing which affects the stability. With less rotating mass behind it, the power grid will face higher rate of change of frequency. One of the possible solutions could be the emulation of inertial response through power converter control methods. This paper introduces some possible implementation of such controlling with different kind of parameters and selectivity. The described algorithms are using the frequency gradient and absolute value, activation and cutting signals for mechanical protection of wind turbines. The purpose is to provide an effective simulation method for the evaluation of the effectiveness of the emulation. The power grid of the future will definitely need some stability support. As one of the most intriguing solution, the effectiveness of the physical inertial response emulation is a crucial question. This paper examines the success of controlling and the impacts of several approaches with different constraints. With the detailed modelling of technical capabilities this approach could be used for evaluating the synthetic inertia as the substitute of the natural inertial response. The controlling methods being tested on different power system models with the DigSilent Power Factory dynamic simulation tools.