含多种分布式电源的直流配电网多模式调压策略

直流配电网凭借适于分布式电源接入等优势成为未来配电网的发展方向,其稳定运行控制策略是亟待解决的问题之一。该文以包含风电、光伏和储能系统的直流配电网为研究对象,提出了一种基于下垂控制的多模式调压策略。根据电压偏离额定值程度和各端调压能力,该策略将直流配电网的电压调节分为主调压模式、后备调压模式和紧急调压模式,实现了多种工况下直流电压的分散自律控制。主调压模式和后备调压模式分别为联网换流器和储能系统按下垂特性调节直流电压,紧急调压模式则包括新能源降功率运行和负荷减载。此外,对蓄电池荷电状态达限值及直流电压偏差问题进行了研究,并提出了相应的解决方法。最后,利用Matlab/Simulink搭建了包含风电、光伏和蓄电池的六端环状直流配电网仿真平台,验证了所提调压策略的有效性。

Multi-Mode Voltage Regulation Strategy of DC Distribution Network with Various DG Types

DC distribution network has become the direction of future power distribution for its suitability in access of distributed generation (DG) and other advantages,and its stable operation control strategy is one of the problems to be solved urgently.For DC distribution network with wind power,PV and energy storage,this paper proposes a multi-mode voltage regulation strategy based on droop control.According to DC voltage deviation and voltage regulation capacity of the terminals,the strategy divides the voltage regulation of DC distribution network into main voltage regulation mode,reserve voltage regulation mode and emergency voltage regulation mode,which realizes the decentralized and autonomous control of the DC voltage under various operating conditions.Grid-connected converter and energy storage regulate DC voltage with droop control respectively under main voltage regulation mode and reserve voltage regulation mode.The emergency voltage regulation mode includes new energy sources' power-down operation and load-off operation.Moreover,this paper studies the state of charge (SOC) of battery and DC voltage deviation problem,as well as presents the corresponding solution.At last,a six-terminal ring-structure DC distribution network simulation platform with wind power,PV and battery is established on Matlab/Simulink,which verifies the effectiveness of proposed voltage regulation strategy.