Micro Power Grid And Power Distribution Network Interactive Features

New distribution network structure, Micro power Grid (Micro-Grid) is an organic part of the smart Grid, on the voltage stability of distribution network, three-phase unbalance and harmonic there are varying degrees of impact. Will many kinds of Distributed power supply (Distributed Resource, referred to as "DR), energy storage device in the form of micro grid access distribution of parallel operation, forming with the distribution network, energy and information between load the bidirectional interaction of multiple complementary intelligent dispatching power network, the implementation of active control and management of Distributed energy distribution network, is active in the smart grid development trend and the best operating mode of the distribution network.First of all, according to the structural characteristics of micro power grid, this paper combined with the actual demand, the micro grid components (including solar, wind power, energy storage, load, diesel generators, etc.) for digital modeling, packaging for each kind of element model as a whole, makes the model have the portability and the energy storage system with the various work modes:static and steady state. In view of the dynamic characteristics of distributed power supply and load, a mathematic model of the micro power grid is an important element, including wind power module (direct driving fan, doubly-fed fan), photovoltaic module and storage module (battery and super capacitors), diesel generator and load model (dynamic load model, static load model) modeling. Grid adopts synchronous generator modeling, its active power control module USES the given value generation module.Secondly, based on the running characteristics of micro power grid, will contain multiple source electrical equivalent charge of micro grid, form a micro power grid simplified model. In order to analysis and study of micro grid interactive features, on the basis of micro grid element model library, select case structures, grid simulation model, the support further research and analysis. Built a off-grid type micro grid model simulation system:the isolated net running in the micro grid simulation, respectively in the 5s for General Load Load is increased by 20%, photovoltaic components and energy storage components on the control and without prolapse control two situations, simulation in 5s to the General cut out 20% of the Load, the Load of pv components and energy storage components to join droop control and no sagging control two kinds of conditions are simulated. In DIgSILENT PowerFactory.Finally, with A distribution network simulation system as an example, studying the characteristics of power distribution network to interact with the micro grid. Assume that during the study, connected to the distribution network simulation system of three equivalent micro power grid are in a "virtual generator" state, each sending electricity to power distribution network with the greatest power,. According to analyzing the source of stream, micro power grid simulation system interactive features, research micro power grid and the interactive model of the distribution network. Research analyzes the characteristics of complementary flow and smooth effect, the source charge interaction mechanism, net interaction, interaction and interaction of micro grid and distribution network and micro grid access distribution network reliability and stability analysis, etc.