Power flow and economic dispatch of a microgrid in presence of feeder flow control distributed generators

In this paper, a power flow method and an economic dispatch model of a microgrid with feeder flow control (FFC) distributed generators (DGs) are formulated. When FFC DGs are present, the microgrid exchanges a prescheduled amount of active and reactive power with the main grid, and therefore, the substation power is known a priori. Under such a circumstance, the conventional classification of the system buses into slack, load and generator buses is not sufficient, and the bus classification has to be extended. So, a new power flow technique capable of dealing with such a situation is formulated in this paper. Further, for economic load dispatch with system loss, penalty factors are required to be calculated. Calculation of penalty factors with FFC mode DGs is different from that in a conventional system. An analytical method of finding the penalty factors is also presented in this paper. The developed power flow and economic dispatch methods are validated on a test microgrid system.