Modelling of frequency control in an island system

Studying the Maximum Instantaneous Non-Synchronous Generation in an Island System—Frequency Stability Challenges in Ireland

“…A 'single-bus frequency model' (SFM) of the AIS has been developed, using MATLAB ® and Simulink ® , over a number of years, to study primary system-frequency dynamics during the initial 0-15 s post-contingency timeframe [21,32]. The model is based on the principle that the difference between the combined active power of the generation and the load, following the loss of a large generation in-feed, is fed to a connecting system block which calculates the system frequency based on the system power imbalance and the kinetic energy accessible to the system from the rotating masses, before being fed back to the individual generator and load models.…”

Provision of flexibility at high wind penetration levels using modern storage heater load

“…The Irish power system has been modeled with a single bus representation with storage heaters incorporated as flexible load. The power system model has been calibrated over a number of years with data obtained from the transmission system operator [15]. When the loss of export (250 MW) occurs and the system frequency exceeds 50.2 Hz, all appliances turn on, thus providing a sudden increase in demand and controlling the system frequency, Fig.…”

System-wide contribution to frequency response from variable speed wind turbines

“…Static sources of reserve include pumped storage, HVDC interconnection, interruptible load and load shedding. This model has been validated and extended over many years and full details are available in [20]- [21]. The system is assumed to be in steady state at nominal frequency prior to an event on the system and the change in power output from each unit due to a frequency disturbance is calculated in the model components.…”

“…The inertia of individual conventional generators, as well as load, are combined together to form a single inertia term, which then determines the rate of change of system frequency following a contingency event. This simplification is possible by assuming that the frequency at all points on the system is the same, and thus any change in inertial energy is seen uniformly throughout the network [20]- [21].…”