Abstract: Starting from the definition and project implementation objectives of Distribution Management System (DMS), this paper discusses the design principles, application scope, and functional design of the DMS system. It represents a phased technical summary of the international bidding and negotiation work for this system in the Ningbo urban power grid renovation project. Keywords: Distribution Management System; Dispatch Automation System; Distribution Automation; Geographic Information System 1. Characteristics of DMS System The Distribution Management System (DMS) is an integrated automation system encompassing the transmission and distribution network, substations, power plants, and users, possessing basic functions such as monitoring, control, protection, and management. The system's composition in terms of function and hardware characteristics is roughly as follows: ① The functions of the DMS are distributed across many data/application servers and workstations, which are interconnected through a computer network; ② The DMS system is a system combining real-time monitoring and offline management, and the DMS system has high security requirements; ③ The system combines power grid equipment data and user data, real-time data and historical data, power grid graphics and geographic graphics, and graphics and data, requiring a high degree of integration; ④ It adapts to the requirements of modern power distribution system management and has a complete set of functions to support power distribution system management; ⑤ It is a distributed open computer network system, and the various modules and their functions can cooperate with real-time data acquisition and information updates; ⑥ It features an expandable modular design. 2. Configuration of the DMS System 2.1 Basic System Requirements The DMS should consist of a secure and reliable basic platform that can provide various advanced services and provide powerful, open functions for the implementation and execution of various applications, and multiple relatively independent application subsystems running on this platform. It is a distributed, open, modular, and expandable automated system that meets the requirements of modern power distribution system management. In addition to providing basic hardware technology and operating system kernels, the basic platform also offers fundamental services such as database systems, information transmission, human-machine interfaces, real-time environment applications, and geographic environment applications, as well as interfaces with other systems. The application subsystems built upon this basic platform include: Distribution Automation (DA), Reporting Troubleshooting Management (TCM), Distribution Geographic Information System (GIS), Distribution Network Analysis Software, Distribution Work Management System, Distribution Network SCADA System, and Electricity Billing, and should also interface with existing systems, such as Management Information System (MIS). These subsystems are organically integrated horizontally and vertically on the basis of an Open Systems Architecture (OSA) to form a complete Distribution Management System (DMS). The DMS system should also be adaptable to the gradual development of the power grid and combine control and management. The system should ensure that the maintenance and expansion of each functional module has minimal impact on other modules. This requires that hardware equipment, operating systems, network interconnection, human-machine communication, and database management must adopt international standards or de facto industry standards. The entire DMS system has a completely open system architecture. It should also consider the coexistence of different operating systems in a single DMS; network interconnection using TCP/IP; system expansion using application programming interfaces (APIs); data exchange using mature database interface technology (ODBC); and the human-machine interface using the X-WINDOW or NT platform. 2.2 Brief Description of System Components The DMS system mainly consists of a file server, database management server, application server, GIS server, power distribution management server, TCM server, network management workstation, dispatcher workstation, communication server, GIS workstation, power distribution management workstation, TCM workstation, DTS workstation (OPTION), conference room demonstration workstation, operation base workstation, power supply bureau (including power management office) workstation, report workstation, director workstation, chief engineer workstation, engineer workstation, power grid operation workstation, network storage devices, printers, plotters, network equipment, and satellite positioning clocks, etc. 2.2.1 Servers ① The file server mainly undertakes the domain name management and file service coordination management of the system. ② The database management server, located in the distributed network, manages, coordinates, and maintains real-time and historical databases, providing data support for workstations and distribution network analysis software. ③ The application server provides SCADA and distribution network analysis functions for the regional power grid and distribution network. ④ The GIS server manages GIS data and stores GIS information. ⑤ The distribution work management server manages distribution equipment data and supports the operation of distribution work management software. ⑥ The TCM server manages user dispatch information and accident handling information, stores user information, and supports the operation of TCM software. 2.2.2 Workstations ① The network management workstation monitors, manages, and coordinates the network. ② The dispatcher workstation is the main human-machine interface of the DMS system, providing power dispatchers with a means to monitor and manage the power grid, and is applied to the dispatch management of urban distribution networks and related regional power grids. ③ The communication workstation is used to collect real-time information from 110 kV and above substations, SCS operation bases, local power plants, and direct-supply high-voltage users. It also has the function of receiving GPS satellite clocks to ensure the uniqueness of the system clock; collecting real-time information from substation automation or RTUs in 110 kV and below substations; collecting real-time information from distribution network FTUs; sending control commands from the DMS system to the controlled objects; exchanging information with remote provincial and county dispatch centers; and collecting information from dial-up RTUs. The communication workstation has a hot standby function (including modems). ④ The GIS workstation is used for the establishment and management of geographic basic information. ⑤ The distribution management workstation is used for distribution work management and equipment management and maintenance. ⑥ The TCM workstation is used for the management of fault reporting and handling responses. ⑦ The DTS workstation (OPTION) is used for dispatcher simulation training. ⑧ The conference room demonstration workstation is used for accident analysis, system demonstrations, etc. ⑨ The engineer workstation is used for system maintenance and the development of new applications. ⑩ The report management workstation is used for the editing, modification, and management of various operation, test, and management reports. The B11 operation base workstation and power supply bureau (including power management office) workstation are used for real-time monitoring of the SCS operation base and power supply bureau. The director's workstation, chief engineer's workstation, and power grid operation workstation provide necessary information to the director, chief engineer, and power grid operation engineer, respectively. 2.2.3 Network Structure: The DMS system computer network is a physically star-shaped, high-speed switched Ethernet network. Servers and some workstations are connected to 100M ports, while other workstations are connected to 10M ports. The network should employ dual-network redundancy technology, and the 100M port network medium should be fiber optic. The DMS system and the buyer's system (such as MIS) are connected via routers. Workstations can be added to the network as needed; therefore, special attention should be paid to network interconnection and the number of ports. With the expansion of distribution network automation implementation, FTU information will inevitably increase exponentially. To rationally organize the real-time information system, information layering and distribution is the future vision for Ningbo distribution network automation. Upgrading remote workstations to sub-distribution centralized control centers is a reasonable solution. 2.2.4 Network Extension Since DMS is a computer network system that integrates various subsystems of power distribution management and coordinates real-time and historical information, considering the security and reliability of real-time data, appropriate network technologies should be used to extend the network to the buyer's related systems, software, and hardware, thereby achieving system integration and resource sharing. Network coordination software and corresponding interface technology support should be carefully considered. The related systems, software, and hardware refer to: Load Management System (LMS), Electricity Business Management System (CMS), Management Information System (MIS), Provincial Power Dispatch Center (referred to as Provincial Dispatch), County Power Dispatch Center (referred to as County Dispatch), Dispatch Simulation Panel, Regional Power Grid Analysis Software, and Distribution Network Planning Software (PSS/U). 3 DMS System Functional Composition 3.1 Distribution Automation System (DA) The implementation of the Distribution Automation System (DA) aims to improve the reliability and management level of urban power grid distribution. As a component of the Distribution Automation System (DA) integrated system, the data flow between the DA and other related systems is roughly as follows: DA obtains distribution network information from FTUs, electricity business management, load management systems, etc., forming real-time and historical databases. TCM supplements the lack of real-time information, while GIS provides DA with geographic background information, offline graphic data, and equipment parameters. Conversely, DA provides TCM, GIS, and other systems with real-time distribution network operating parameters, faults, outages, and other information. The Distribution Automation System (DA) should include Distribution Remote Terminal Units (FTUs), supporting 10 kV pole-mounted load switches, ring network switchgear, communication channels, and corresponding functional software. 3.2 Geographic Information System (GIS) GIS is used to form a hierarchical management base database with spatial concepts (geographic environment information) and basic information (power grid data). It facilitates querying and management, and provides an effective and operable network model with geographic information for power grid operation management. Effective management of distribution network equipment assets, design, construction, and maintenance is provided, along with a basic database platform for the distribution management system. This supports the development of system application software and the implementation of other subsystem functions, such as the Distribution Automation (DA) system and the Telephone Complaint Management (TCM) system. 3.3 Distribution Work Management (DWM) Distribution work management utilizes GIS technology on a GIS database platform to conduct daily distribution management, including distribution network operation management, distribution network archive and statistical management, distribution engineering design, distribution network construction planning and work management, etc. It also extends to auxiliary applications, connecting with the business expansion process in the Consumer Business Management System (CMS) to achieve truly integrated business expansion-oriented management. 3.4 Fault Complaint Management (TCM) This handles various fault complaints from users and provides corresponding answers to electricity-related questions. It also compensates for the insufficient real-time information collection coverage of the DA system, serving as an auxiliary means for fault diagnosis. 3.5 Distribution Network Analysis Software: Based on the needs of the power grid, several distribution network analysis software programs are integrated into the DMS, including distribution network modeling and topology, load modeling and calibration, distribution power flow, network structure optimization and reconfiguration, and dispatcher simulation training (OPTION), to improve dispatchers' analysis and supervision capabilities. 3.6 Distribution SCADA: The distribution dispatch center primarily functions to monitor substations, large users, distribution networks, and related regional power grids in real time, collecting data and integrating corresponding distribution network analysis software. It has functions for monitoring substation automation and distribution network automation, meeting the needs of power grid dispatching and management. 3.7 Electricity Billing Function (EET): The development of the electricity billing system prepares the technical means for local power plants to bid for grid connection. It manages local power plants through economic means, better optimizing the allocation of power resources and reducing grid connection prices and operating costs. The system has functions for time-of-use electricity collection, statistics, and calculation from remote power plant metering terminals. Different prices are charged for electricity at different times; the changes in power generation and consumption at different times and with different electricity price structures are statistically analyzed; and real-time analysis data is provided for economic dispatch. References [1] Wang Mingjun. Automation of distribution systems in development [J]. Electric Power Automation Equipment, 1999, 19(3): 1-4 [2] Zhou Zhaomao, Shao Yuan. Discussion on integrated automation system of distribution [J]. Electric Power Automation Equipment, 1997, 17(4): 7-9