微电网系统建模的挑战—“智能微电网与可再生能源系统的关键技术”专题(前言)

<正>随着可再生和绿色分布式发电系统渗透率的不断提高,含高渗透率分布式可再生能源的微电网成为智能电网发展的重要分支之一.微电网系统是由负荷、分布式电源、电力电子变换器通过电气网络紧密集成的可控供电系统,逐渐成为我国城镇化进程中重要的一种供电模式.典型微电网系统通过电力电子变换器接入多种分布式电源,其中风、光等分布式可再生能源接入比例较大,这些发电单元大幅度随机变化、各单元动态特性各异、不同单元的变化呈现多个时间尺

Modeling challenges for microgrids system

Microgrid, composed of load, distributed power supply and power electronic converter, is closely integrated into a controllable power supply system through the electrical network. The microgrid system gives solutions to interface distributed generation including wind, solar and other renewable energy, through power electronic converters. In a microgrid, different generation units have different dynamic characteristics, and appear to have multi-timescales feature, which bring huge challenges on the overall modeling and stability analysis of microgrid. In the practical microgrid engineering, it is usually equipped with a large-capacity energy storage system to ensure the stability under various operating conditions, because it is impossible to establish the mathematical dynamic model for microgrid under the environment with large random disturbances at present. In this situation, each practical microgrid system is obliged to establish a simulation model specially to determine the stability control strategy, with the result that the microgrid engineering relies on personalized customization and historical experience. Therefore, accurate dynamic modeling is extremely necessary. This paper studies the accurate transient modeling of the microgrid with a typical architecture, in which independent dynamic models for different distributed generations are established and the dynamic response characteristics of distributed generations are described in detail. In view of the challenge of overall modeling for microgrid, this paper put forward some reflections on external disturbance, multi-timescales, and stability control region solver, and we hope the experts and scholars could provide the recommendations and solutions on accurate dynamic overall modeling for microgrid.