针对双母线接线的母差保护,在母联死区发生故障时,因无法自动识别母线运行状态,导致故障跳闸缺乏选择性且实际故障母线切除时间长的问题,提出一种快速隔离母联死区故障的母线保护原理.新原理将母联断路器两侧CT同时接入母线保护,通过增加母联间隔比率差动,调整小差差流计算方法,使得故障时母线保护装置可自动识别母联断路器分合状态,并准确辨识故障位置,从而提高母联死区保护故障时故障切除的快速性和选择性.仿真结果表明:该方法实现了故障切除的快速性或最小范围隔离故障,提高了母线设备运行状态的自动化以及母线保护装置的智能化水平.

直流微电网是由分布式电源、 储能装置、 控制系统等组成的新型电网结构,其控制策略至关重要.首先介绍了直流微电网的组成结构,研究了各个单元的基本功能和作用.其次,从直流母线等效电路入手,进行了直流微电网系统控制目标分析,确定了协调控制策略的基础.然后,以网侧变换器和储能变换器的最低、 最高临界电压作为模式切换条件,构建了直流微电网4种工作模式,使直流微电网在各个状态下都能保持稳定运行,同时研究了各个变换器的拓扑结构及控制方法.最后,在MATLAB/Simulink中搭建相应的仿真模型,对所提出的控制策略进行了验证.

In view of the current situation of the relay pro-tection in smart substations,this paper proposes an architecture of smart substation relay protection. The architecture divides the replay protection into two levels. The devices of the first level consist of the protection of the single-unit, MU and smart terminal device locally mounted. The devices of the second level consist of the multi-unit, domain-level protection and local protection and control units. The locally mounted relay Protection links the TV/TA and trips with cable to improve the safety and reliability of the relay protection while the locally mounted MU and smart terminal device provide SV and GOOSE data to the multi-unit protection and domain-level protection. The control unit of the protection provides human-machine interface,status monitoring and other advanced management functions. In the architecture,the single-unit protection does not rely on the network,and the multi-unit protection uses the point-to-point data transmission, and the domain protection relies on the network. The architecture helps to solve the problem of the reliability reduction attributed to too much fiber and too many switches needed and increased protection links.

Because of the uncertainty and indeterminacy of time delay when exchanging data by industrial switchboards,the process layer network cannot provide data to the relay system.Based on media access control(MAC) simulation technology of field-programmable gate array(FPGA),data exchange units with characteristics of explicit transfer delay and equi-spaced exchange are designed,constructing sampled value(SV) network by data exchange units instead of industrial switchboards.Not only can the solution realize the sharing of sampling data at the process layer,but also the structure of sampling network for the relay system is simplified.The theory and schematic design of data exchange units are described in detail.

At present,network configuration of transformer substation automation abroad widely adopts Ethernet,security matter of Ethernet’s opening arose people′s keen attention.Security of remote control across network become even more important.To enhance the security of remote control,there is a good method on remoting control message encryption except for regulating operation flow and enhancing protective wall.This paper brings forward a sort of remote control realization based on token.It adopts ameliorative RSA-1 publicity secret key arithmetic and combines method of encrypting on every operations.The measurement-control device brings up token,the operator calculates encrypted database and feedback measurement-control device to detecting the legitimacy of operator.In this way,legal operator can process normal remote control,and can effectively avoid any illegal remote control of any illegal operator.