中低压直流配电系统的分散式统一控制策略

中低压直流配电系统由中压直流母线、低压直流母线、直流变压器等组成,具有多电压等级、多直流母线、多变换器的特点,系统的运行方式与协调控制策略更加复杂。文中以中低压直流配电系统为研究对象,提出了一种基于直流母线电压信号的分散式统一控制策略。直流母线上的光伏发电单元、储能单元、燃料电池单元均采用分散式控制策略,根据直流母线电压调整各自的工作模式。直流变压器采用统一控制策略,集功率控制、中压与低压直流母线电压调节功能于一身,直流变压器根据中压与低压直流母线电压偏差的标幺值,自动调节传输功率的大小与方向,从而实现系统的全局功率均衡。最后,在MATLAB/Simulink中搭建了中低压直流配电系统的仿真模型,并对多种运行状态和场景进行了仿真分析,验证了所提控制策略的有效性。

Decentralized Unified Control Strategy for Medium- and Low-voltage DC Power Distribution System

The medium- and low-voltage DC power distribution system consists of medium-voltage DC bus, low-voltage DC bus, DC transformer and so on, with the characteristics of multiple voltage levels, DC buses and converters. The operation modes and coordination control strategies of the system are more complicated. A medium- and low-voltage DC power distribution system is taken as the research object, and a decentralized unified control strategy based on the DC bus voltage signal is proposed. The photovoltaic power generation unit, energy storage unit and fuel cell unit on the DC bus adopt decentralized control strategies to adjust their working modes according to the DC bus voltage. The DC transformer utilizes a unified control strategy which integrates the functions of power control and the medium- and low-voltage DC bus voltage regulation. The DC transformer can automatically adjust the magnitude and direction of the transmission power based on normalized values of medium-voltage and low-voltage DC bus voltage deviations, and realize the global power sharing of the system. Finally, the simulation model of medium- and low-voltage DC power distribution system is built in MATLAB/Simulink, and simulation analysis of various operating states and scenarios is carried out to verify the effectiveness of the proposed control strategy.