基于物理背景的微网总体模型

General microgrid model based on physical background

微网是集分布式电源、负荷和储能设备的小型电网,通过公共耦合点与大电网相连,与大电网之间的功率可双向流动,需对微网进行建模以研究微网接入。从微网基本元件出发,分析了微网负荷、电源元件模型与传统电力系统元件模型之间的联系,借鉴负荷建模理论,提出了微网整体建模的思路,将微网中静态负荷与外部表现为静态特性的电源等效为等效静态模型,推荐采用幂函数模型;将风力发电机、电动机等动态元件等效为等效电机模型,并从理论上推导了等效电机的通用模型。

Microgrid is a small power system,composed of loads,DG（Distributed Generators） and storage devices, and connected to the power network via common coupling point. Power flows bidireetionally between microgrid and power system. It is necessary to build the microgrid model for studying its connection to power network. The relation between the load and DG models of microgrid and the element models of traditional power system is analyzed and the general microgrid model is developed based on the load modeling theory. The static elements of load and DG with static exterior characteristic are represented as the equivalent static model,for which the exponential function model is recommended,and the dynamic elements of synchronous generator,wind generator and motor load as the equivalent machine model,for which the universal equivalent machine model is theoretically derived.