Considerations for the feasible operating range of distributed generation interconnected to power distribution system

Nowadays, many small scale distributed generation (DG) project are being introduced into power distribution systems. In this case, it is difficult to properly maintain the terminal voltage of low voltage customers within a permissible range. This paper discusses some correlations between the traditional voltage regulation method by load-tap changing transformer (LCT) and line drop compensator (LDC) and the output of DG, and also proposes a method for determining the feasible operating range of DG under the proper voltage regulation of the power distribution system. This proposed method is applied to a 22.9 kV practical power distribution system, and its validity is clarified through simulation results.