Contribution of distributed generation to ancillary services

In power systems with conventional power plants, provision of ancillaries ensures safe system operation without significant compromise in return of investment cost as intended reduction in generator output power implies to less use of gas, fossil or nuclear fuels. While with renewable power generations, always there is a conflict of interest between transmission system operators (TSOs) and wind or solar farm owners, as the owners prefer the use of maximum power tracking to maximize returns on their investment and TSOs may ask for some kind of curtailment as a reserve for frequency support. In an attempt to answer these questions, this paper investigates the feasibility of wind and solar based distributed generations to provide ancillary services to medium-scale micro-grid, namely voltage support and stability services. A generic model of IEEE distributed generation system with 13 buses will be used as a test network in this investigation, with total generations from conventional power plants represent 30% of generated power (70% renewable power penetration). To assess technical feasibility of the contribution of DGs to ancillaries, the test network will be simulated by using the commercial DIgSILENT Power Factory, and results obtained will be discussed.