A Framework for Assessing Renewable Integration Limits With Respect to Frequency Performance

The increasing penetration of nonsynchronous renewable energy sources (NS-RES) and demand side-technologies alter the dynamic characteristics, and particularly, the frequency behavior of a power system. Given this, we propose a framework for assessing renewable integration limits concerning power system frequency performance using a time-series scenario based approach. By considering a large number of future scenarios and their sensitivities with respect to different parameters, we can identify maximum nonsynchronous instantaneous penetration limits for a wide range of possible scenarios. Further, we derive a dynamic inertia constraint and incorporate it into the market dispatch model to reduce the detrimental impacts of high NS-RES penetration on the frequency performance. The results using the Australian future grid as a test case show that such an explicit inertia constraint ensures power system frequency stability for all credible contingencies. To improve the frequency performance, we assess and quantify the contribution of a wide range of technologies, including synchronous condensers, synthetic inertia from wind farms and a governor-like response from de-loaded wind farms. The results show that the last option is the most effective one.