GB/T 45418-2025 General technical directives for distribution networks
1 Scope
This document specifies the technical requirements for the planning, grid structure and equipment, construction and transformation, operation and maintenance, customer and power supply connection, and secondary systems of 10kV and below AC distribution networks.
This document is applicable to the planning, construction, transformation, and operation and maintenance of 10kV and below AC distribution networks, and may serve as a reference for 20kV distribution networks.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 156 Standard voltages
GB 3096 Environmental quality standards for noise
GB/T 12325 Power quality - Deviation of supply voltage
GB/T 13955 Installation and operation of residual current operated protective devices
GB/T 14285 Technical code for relaying protection and security automatic equipment
GB 20052 Minimum allowable values of energy efficiency and the energy efficiency grades for power transformers
GB/T 29328 Specific configuration of power supply and self-emergency power supply for important power users
GB/T 33593 Technical requirements for grid connection of distributed resources
GB/T 33982 Technical specification for grid connection protection of distributed resources
GB/T 36278 Technical code for electric vehicle charging/battery swap infrastructure interconnecting to distribution network
GB/T 36547 Technical requirements for connecting electrochemical energy storage station to power grid
GB/T 36572 Guidelines of cyber security protection for electric power system supervision and control
GB/T 43025 Technical guidelines for power supply schemes of users connected to power grid
GB/T 43456 Specification of electricity inspection
GB/T 43526 Technical requirements for connecting user-side electrochemical energy storage system to distribution network
GB 50053 Code for design of 20 kV and below substation
GB/T 50064 Code for design of overvoltage protection and insulation coordination for AC electrical installations
GB/T 50065 Code for design of ac electrical installations earthing
GB 50168 Standard for construction and acceptance of cable line electric equipment installation engineering
GB 50217 Standard for design of cables of electric power engineering
GB 51302 Standard for design of overhead distribution line with insulated conductor
DL/T 599 Technical guide for enhancement of medium and low voltage distribution networks
DL/T 814 Technical specification of distribution automation system
DL/T 1344 Technical specification for connecting disturbing customer to power system
DL/T 1649 Technical specifications of operation and control system for distribution network
DL/T 5220 Code for design of 10kV or under overhead distribution line
DL/T 5729 The guide for planning and design of distribution network
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 29328, GB/T 33593, GB/T 43456, DL/T 599, DL/T 5220 and DL/T 5729, as well as the following, apply.
3.1
distribution network
power network that receives electric energy from the power source side (transmission network, power generation facilities, distributed energy sources, etc.) and distributes it locally or step-by-step to various customers through distribution equipment and facilities
[Source: DL/T 5729-2023, 2.0.1, modified]
3.2
maximum load
maximum value among the loads corresponding to each specified collection interval point within the statistical period
[Source: DL/T 5729-2023, 2.0.2]
3.3
saturated load
maximum electrical load in a planning area when the economic and social development has reached a mature stage
Note: When the annual maximum load growth rate is less than 2% or the annual electricity growth rate is less than 1% for five consecutive years in an area, and its electricity demand is basically consistent with the electricity demand forecast in the land space planning of this area, the maximum electrical load of this area at this development stage can be considered as the saturated load.
[Source: DL/T 5729-2023, 2.0.5, modified]
3.4
power supply area
area composed of districts with similar saturated load density, administrative level, economic development level, and planning goals, which should not be less than 5km2
Note: The division of power supply areas is an important basis for carrying out differentiated planning of distribution networks, and is mainly used to determine the planning and construction standards of distribution networks within the area.
[Source: DL/T 5729-2023, 2.0.6, modified]
3.5
power supply mesh
relatively independent area within the power supply area that is connected with the land space planning and has a certain number of 35kV~110kV power supply sources, with a clear power supply scope of 10kV distribution network
[Source: DL/T 5729-2023, 2.0.7, modified]
3.6
power supply unit
several relatively independent units divided on the basis of power supply mesh division, taking into account the functional positioning of the land, and comprehensively considering factors such as land attribute, load density, and power supply characteristics
[Source: DL/T 5729-2023, 2.0.8]
3.7
first circuit outage
fault or planned outage of a segment on the trunk line in a 10kV distribution network
Note: A segment here includes a segment of an overhead line, a segment of cable body or one side of a ring main unit on a cable line.
[Source: DL/T 5729-2023, 2.0.12, modified]
3.8
distributed energy sources
power sources located near customers, primarily for local consumption, and connected to the power grid with a voltage level of 35kV and below through synchronous generators, converters, or other means
[Source: GB/T 33593-2017, 3.1, modified]
3.9
trunk line
main part of an overhead or cable line that is fed out from a substation or distribution transformer and undertakes the main functions of electric energy transmission and distribution
Note: Line segments with interconnection functions are part of the trunk line.
[Source: DL/T 5729-2023, 2.0.10, modified]
4 Basic requirements
4.1 The distribution network shall have the functions of reliable power supply, clean energy integration and multi-load carrying capacity, supporting interaction between supply and demand parties and serving power production and consumption.
4.2 The planning of the distribution network shall be coordinated with the local social and economic development, compatible with the development of regional loads and distributed energy sources, and play a guiding role in the construction and transformation of the distribution network.
4.3 The distribution network shall be featured with applicable grid structure, reasonable equipment levels, necessary capacity margins, strong carrying capacity, and appropriate load transfer capabilities. It shall fully leverage digital and intelligent technologies to enhance overall efficiency and benefits.
4.4 The selection of voltage levels for 10kV and below AC distribution networks shall comply with the requirement of GB/T 156. The distribution network equipment shall be mature, applicable, low-maintenance (maintenance-free), green, low-carbon, and environmentally friendly products, with a gradual increase in intelligence levels.
4.5 The construction and transformation of the distribution network shall focus on improving the grid structure, enhancing equipment performance, ensuring power supply capacity and reliability, improving power quality, and reducing network losses.
4.6 During operation and maintenance of the distribution network, technologies such as status detection and uninterrupted operation shall be actively utilized to promptly eliminate equipment defects and reduce the number of faults; operational analysis shall also be conducted to optimize operation modes and improve economic operation levels.
4.7 The distribution network should adapt to the connection needs of different customers and leverage the role of adjustable loads on the load side, enhancing coordination and interaction with the distribution network and reducing the peak load on the grid.
4.8 The distributed energy sources shall be connected to the distribution network in an orderly manner and possess power regulation capabilities. The charging and swapping facilities should support orderly charging and two-way power exchange.
4.9 The distribution network should fully leverage its resource allocation capabilities, promote interaction and coordinated operation among generation, grid, load, and storage, and improve the level of economic and reliable operation.
4.10 The intelligent construction of the distribution network shall align with its development needs, coordinate the construction and transformation of distribution automation, measurement, communication, and other systems, enhance monitoring and control capabilities, and achieve the integration and sharing of data resources.
Contents Foreword III 1 Scope 2 Normative references 3 Terms and definitions 4 Basic requirements 5 Planning 5.1 General requirements 5.2 Division of power supply areas and planning period 5.3 Electricity supply-demand forecast 5.4 Power supply safety criteria for distribution networks 5.5 Short-circuit current levels and neutral grounding methods 6 Grid structure and equipment 6.1 General requirements 6.2 10kV distribution network grid 6.3 10kV overhead lines 6.4 10kV cable lines 6.5 Equipment for 10kV overhead lines 6.6 Equipment for 10kV stations and rooms 6.7 220V/380V distribution networks 7 Construction and transformation 7.1 General requirements 7.2 Overhead lines 7.3 Cables and channels 7.4 Switching stations, ring main unit rooms, and distribution rooms 7.5 Transformation of 10kV neutral grounding methods 8 Operation and maintenance 8.1 General requirements 8.2 Patrol inspection and maintenance 8.3 Maintenance and emergency repair 8.4 Operational analysis 9 Customer and power supply connection 9.1 General requirements 9.2 Customer connection 9.3 Connection of distributed energy sources and energy storage devices 9.4 Connection of charging and swapping facilities 10 Secondary systems 10.1 General requirements 10.2 Relay protection 10.3 Distribution automation 10.4 Electric energy acquisition 10.5 Distribution communication Annex A (Informative) Typical grid structure diagrams for 10kV overhead networks A.1 Radial type A.2 Multi-segment single-tie type A.3 Multi-segment moderate-tie type Annex B (Informative) Typical grid structure diagrams for 10kV cable networks B.1 Single-ring type B.2 Dual-radial type B.3 Opposing-radial typ B.4 Dual-ring type B.5 N-supply and one-standby (2ﾡￜNﾡￜ4) Annex C (Informative) Grid structure diagram for 220V/380V distribution networks Bibliography
