Dynamic interactions among multiple DER controllers in distribution systems

The increasing penetration of small sized distributed generators within close proximity to each other in distribution systems can bring about negative interactions among them. This paper presents the issues of system and control interactions among several distributed energy resource (DER) controllers that can affect the operation and design of a distribution system. The impact of tuning controllers on system damping is also investigated through a widely used approach. A number of studies are carried out to investigate possible interactions among several controllers under different operating conditions. An industrial mesh 43-bus distribution test system is used for both modal analyses and nonlinear simulations. It is found that negative interactions can arise among multiple DER controllers located close to each other but proper tuning can significantly enhance system damping and stability margin.