Study of Distributed Generation System Characteristics and Protective Load Control Strategy

Due to the smaller inertia feature of a Wind Turbine (WT) involved Distributed Generation System (DGS), the WT's induction generator are more vulnerable to frequency and voltage disturbances. Therefore the study investigates the DGS characteristics respectively from power plants, i. e. WTs and load. Two kinds of wind turbines: Doubly-fed Induction Generator (DFIG) and Fixed-speed Wind Turbine (FSWT) are compared in this study. A conventional power system protective scheme may not response promptly, which could lead an undesired disconnection of WTs for the turbine protection purpose. Consequently a fast protective load control strategy to such a DGS is studied. In order to implement such a strategy a communication system associated with a DGS is configured. With this strategy a precise and prompt load shedding operation can be performed to ensure the stability of a DGS and WTs. The impacts of load characteristics are analyzed and utilized in the fast control strategy. Subsequently a case study is presented to demonstrate the theoretical investigations and analyses.