Abstract
Recently, numbers of distributed generators (DGs) connected to distribution systems have been increasing. It is important to know how large capacity of generators output is permitted when the generators are connected to the distribution system under the regulated condition of line voltage, line current and power factor of the generator connection point. The authors show difference of maximum output of DGs caused by various voltage regulation systems in an average length system and a long length system by load flow calculation. The voltage regulation systems include six following types; (1) no control equipment, (2) SVC (Static Var Compensator), (3) existing SVR (Step Voltage Regulator), (4) reverse flow type SVR which operates even in reverse flow, (5) existing SVR and SVC, (6) reverse flow type SVR and SVC. A synchlonous generator is considered as DG in this paper.
The numerical simulations showed that the maximum output of the DG is about 3300[kW] in the average length system and about 540[kW] in the long length system. However, maximum output of the DG increased up to about 3750[kW] in the case of existence of a SVC, further capacity of SVC decreased in the case of exchange to the reverse power flow type SVR in the long length system.
