A Time Sequence Load-Flow Method for Steady-State Analysis in Heavily Meshed Distribution Network with DG

A time sequence load-flow method for steady-state analysis in large scale heavy meshed distribution system with Distributed Generations (DG) is proposed in this paper. Since DG is the intermittent type source, and distribution system has time delay based protection device, traditional single snapshot load-flow methods has limitations in the case with DG. Proposed time sequence load-flow method is based on iterative load-flow calculation and can estimate the timestamp of each time load-flow calculation result. The proposed load-flow calculation iteration starts when studied distribution system status changes, such as protection device operations, and stops when studied distribution system is in a steady-state. It also can used to determine a distribution system's final stage and when a system will be in its final steady-state. In simulations, a heavily meshed distribution network with DG and two different protection devices is modeled in the proposed method. Simulation results are compared with simulation in EMTP-RV. The results show that the proposed method can generate results very close to EMTP-RV while taking considerably less time.