An Analytical Method to Determine the Maximum Wind Power Penetration Level

Frequency stability in power system is ensured by means of inertia of synchronous generator. As there is renewable power generation in the grid, system inertia gets reduced. This reduction in inertia causes reduction in stability of frequency, especially in the case of a large contingency. So, we need to calculate effectively and accurately the maximum renewable power penetration level before a contingency occurs. This calculation of maximum renewable penetration level is a function of the level of contingency, the allowed maximum rate of change of frequency (ROCOF) and allowed minimum frequency nadir. In this paper, we use the Inverse Laplace Transformation of the full multi-machine system frequency response (MM-SFR) model of the IEEE 39-bus 10-machine New England system to find maximum renewable (wind) power penetration level ( $WPPL_{max}$ ) for an allowed minimum level of frequency nadir and at a fixed contingency level of 8.27%. Finally, we use DIgSILENT PowerFactory Software to simulate this power system for the same contingency level, and thus $WPPL_{max}$ is calculated to evaluate the accuracy of the proposed method.