Distributed generation: Voltage stability analysis

With the increasing use of distributed generation, which is usually connected to distribution or sub-transmission networks, the voltage stability phenomenon can be expected to occur when a system is operating with a high load. It is rarely mentioned in the literature that the problem can be associated with voltage-controlled buses or that voltage control can have the opposite effect to what is expected in generators. This study investigates voltage stability when a generator is connected to a distribution network. Using an analytical tool that can monitor voltage stability, this paper describes a case study of a 3-bus test system where the phenomenon is shown to occur. Then, using the IEEE 34-bus test system, tests are carried out to evaluate the impact of the connection of distributed generation on the voltage stability problem, active power loss and voltage profile.