Research of Bidirectional Power Flow Algorithm of Micro-Grid Based on the Improved Zbus Method

Abstract

Themicro-grid technology is an effective way to promote renewable energydevelopment and utilization. Low voltage micro-grid can absorb photovoltaic,wind power and other large number of scattered random distributed power supply,and the system may be three-phase asymmetry while operation, randomness of thepower output and load is stronger. Therefore an improved bidirectional power flow algorithm is putforward suitable for low voltage micro-grid. According to the physicalstructure components of the micro-grid and different kinds of micro powersupply, the types of micro-grid in power flow calculation is studied to dealwith complex node in the micro-grid, improved Zbus algorithm is proposed tocalculate the power flow of micro -grid .IEEE-69 is taken as an example for simulation, the resultsshow that the proposed method is better for the biggest error ratio of voltagedrop and calculation time than traditional method. Atthe same time the algorithm is also suitable for island operation state of the microgrid.