A study on dynamic behavior of load supply system including synchronous generators with and without load drop

In recent years, installation of renewable energy into load supply systems has drastically increased. Load modeling considering dispersed generators is indispensable to improve the accuracy of power system analysis. Most of the installed capacity of dispersed generators currently consist of synchronous generators equipped with excitation controllers with Automatic Q Regulator (AQR) or Automatic Power Factor Regulator (APFR). These excitation controllers are thought to give large influence on dynamic behavior of load supply systems, because the behavior of load bus voltage is strongly related to load characteristics. The post-fault dynamic behavior of load supply systems including generators with AQR was investigated using CRIEPI´s AC and DC power system simulator. In this paper, load drop characteristics and features of transient and steady state responses of the load bus voltage are experimentally demonstrated. Some key issues for developing the load model including generators are also discussed.