The Impacts of Demand Side Management on Combined Frequency and Angular Stability of the Power System

Demand Side Management (DSM) has attracted significant attention over the past decade due to its potential contributions to power systems stability and flexibility improvement. The impact of DSM on system stability is traditionally assessed from one or two stability aspects, which may lead to less than comprehensive understanding and ambiguous deployment decisions that subsequently, deteriorate and even endanger system stability. This paper assesses the impact of transmission level advanced DSM on combined system angular and frequency stability using a newly proposed composite stability index. The versatility of the proposed composite stability index and the critical factors (i.e., penetration level of Renewable Energy Source (RES) and modelling of system demand) influencing the impact of advanced DSM on combined system stability are identified using a range of case studies. Such studies were conducted under different operating conditions based on a modified IEEE 68-bus test system and an equivalent network comprising four interconnected real power systems in a mixed environment of Matlab and DigSilent PowerFactory.