Impact of renewable power integration on VQ stability margin

With the increasing number of grid connected renewable energy sources in power systems, the requirements for in-depth studies to characterise the dynamics of power systems have also intensified. In this paper, the impact of renewable power generators on power system voltage stability is analysed. As the renewable power penetration increases, having adequate levels of reactive power generation in power systems for voltage support is a major challenge. Therefore, in this work, special attention was placed on VQ instability to investigate static voltage stability of a test network embedded with renewable power generation. The impact of different control strategies associated with doubly fed induction generator (DFIG) based wind power generation and solar PV generation on static voltage stability is analysed. The importance of the reactive power capability of the renewable generation systems is emphasised, employing the results related to the test network considered. By comparing the operational characteristics of the DFIG based wind power generation and solar PV generation technologies with conventional synchronous generation, the reduced support given by the renewable power generators for power system static voltage stability is demonstrated using DIgSILENT Power Factory simulated test network.