Modelling and Analysis of Load Frequency Control in Small Power Systems: a Case Study of New Zealand Network

Some challenges experienced by small power systems are escalating as penetration of renewable energy sources (RESs) increases. To overcome the challenges related to frequency stability, this paper discusses about a load frequency control model that can respond to an emulation of a real operation. The inclusion of energy storage systems to the model to support frequency control in a low inertia condition is also addressed. The increase of RES penetration is simulated by a decrease in the system inertia constant. To compensate for the low inertia and to improve the frequency response of the system, a virtual inertia is installed. The proposed load frequency control model is implemented in Matlab/Simulink. The multiple frequency keeping (MFK) ancillary service and the frequency keeping control (FKC) are included in the proposed model. The proposed model is simulated in a New Zealand power system as a case study for small networks. The simulation results verified that the developed model works as expected.