Assessment of Voltage Stability Risks under Intermittent Renewable Generation

A quantitative framework is presented for assessment of voltage stability risks in power networks with intermittent renewable generation. The framework first identifies the critical surfaces which comprise a continuum of critical points for voltage stability at each bus. Then, a risk probability is computed for the entire system based on a given joint probability distribution of demand which takes into account variability due to intermittent renewable generation. Finally, the voltage stability risk is calculated using the potential financial cost of a voltage collapse event based on the official figures published by the Australian Energy Market Operator. The framework is illustrated with the IEEE 30 bus test system using real demand and wind generation data. In contrast to existing local stability indices and qualitative risk approaches, the framework introduced provides an analytical, global, and quantitative assessment of voltage stability risks under intermittent generation.