Reporter: In recent years, State Grid Co., Ltd. has made great efforts to promote the construCTion of “world-class distribution network” with remarkable results. Please tell us about the company's current work in the construction of distribution network? How is the specific effect?

Zhou Anchun: At present, the company covers 26 provinces (autonomous regions and municipalities directly under the Central Government), covering more than 88% of China's land area, with a power supply service population of more than 1.1 billion people, and operating and management distribution network 35~110 kV substation 29,500, line 79.4 Ten thousand kilometers, 3.15 million kilometers of 6~20 kV lines and 4.64 million distribution transformers.

For a long time, the company has continued to increase investment in urban and rural distribution network construction and transformation, and the power supply capacity, power quality and service level of the distribution network have been continuously improved. Since 1998, the company has implemented the first and second phase of rural power network reconstruction project, urban network reconstruction project, central and western agricultural network improvement project, power-free area power construction project, rural power network transformation and upgrading project, urban power distribution network project, and world-class development. The construction of urban distribution network has started the reliability improvement project of urban distribution network, and the appearance of distribution network has undergone tremendous changes.

In the past 10 years, the power supply capacity and power supply quality of the distribution network have improved remarkably. The reliability of power supply in urban and rural areas has increased from 99.745% and 99.380% in 2005 to 99.951% and 99.799% respectively. The average annual power outage time of customers is 22.35 hours. It fell to 4.3 hours and 17.6 hours in 54.3 hours. In particular, the rural power grid has achieved leapfrog development, and has injected the source of power for rural economic and social development and farmers' poverty alleviation. During the “Twelfth Five-Year Plan” period, the company solved the problem of electrification for the 1.17 million non-electric households and 7.496 million people without electricity in the operation area, and fully realized the “electricity of households”; solved the long-term “low voltage” problem of 30.71 million rural customers, and the western region. The problem of “isolated network operation” in 49 county-level power grids and the weak connection between 124 county-level power grids and the main network, 58 county-level power grids in the Tibet Autonomous Region have been connected with the main network; since the “13th Five-Year Plan”, the company has won a new round of rural networks. Renovation and upgrading "two years of hard work", completed 1.35 million eye farm wells new power and transformation, 66,000 small towns (central villages) power grid transformation and upgrading, 78,000 natural village Xintong power and transformation, built 74 well-off electricity demonstration In the county, the completion of the 4.27 million “coal-to-electricity” supporting power grid project in the northern region, and the history of the operation of the isolated grid operation in five new county-level power grids in Tibet. This year, the company launched the implementation of the “three districts and two states” deep poverty-stricken areas.

Reporter: What advanced and mature experience and effective practices does the company have in advancing the development of distribution networks?

Zhou Anchun: First, vigorously implement standardization construction. Full implementation of the "four one" work requirements (project requirements "one map and one table", equipment selection "one step in place", construction process "the same", management and control information "one clear two Chu"), the development of 10 kV and below The network standardization construction and transformation creation activities, determine the planning and construction standards according to local conditions, improve the interconnection rate and transfer and supply capacity, ensure that the corridor, site selection and construction are in place once, avoid large-scale demolition and construction, and build a strong and reasonable grid structure.

The second is to promote the upgrading of distribution network equipment technology. According to the equipment life cycle management requirements, repair the typical design, streamline the equipment type, oPTimize the equipment sequence, standardize the technical standards, research and apply the "integrated, fully insulated, maintenance-free, environmentally friendly" standardized custom equipment, improve the quality control system, and promote Distribution network equipment is moving towards the middle and high end.

The third is to improve the level of intelligent management and control of the distribution network. Actively apply advanced technologies such as automation, intelligence, and modern information communication to deepen the application of “two systems and one platform” with lean production management system, new generation distribution automation system and power supply service command platform as the main structure, and build intelligent distribution platforms. The district-centric distribution of the Internet of Things enhances the flexibility, self-healing and interactivity of the distribution network.

The fourth is to improve the lean management level of the distribution network. We will promote the coordination and integration of the battalion and distribution business, and build a new system of “strong front-end and large-back” services to improve the operational efficiency of distribution network operation services. Promote the integration of maintenance and repair and repair services for distribution network, do a good job in the construction of grassroots teams, strengthen the awareness of equipment owners, improve the capacity of the distribution network without power outages, and enhance the customer's power acquisition and use experience.

Reporter: The power grid has entered a new era. What is the company's future development goal in promoting the construction of distribution network?

Zhou Anchun: Facing the new era, under the strong leadership of the company's party group, the State Grid Equipment Department will adhere to the high-quality development of the distribution network, firmly establish a customer-centric concept, improve power supply reliability as the main line, strengthen standardization and lean. Operation and maintenance, intelligent management and control, highlighting safety, quality, efficiency and efficiency, and strive to promote the distribution network to a higher quality, more efficient and more sustainable direction. Coordinate the promotion of urban distribution network reliability improvement project, world-class city distribution network construction, new round of rural power grid reconstruction and upgrading project, rural electrification project, and “three districts and two states” deep poverty-stricken areas to solve key tasks, such as 2020 The reliability rate of urban and rural power supply reached 99.99% and 99.88%, and the coverage rate of distribution automation system reached over 90%, achieving a considerable and measurable distribution network. By 2035, a first-class modern distribution network with high reliability, friendly interaction, and high efficiency will be built.

Building a first-class distribution network, greatly improving the reliability of power supply

Narrator: Li Weisheng, general manager of Shandong Jining Power Supply Company

Since the reform and opening up, Shandong Jining Power Grid has written a glorious chapter of great development and great leap. Up to now, Jining Power Supply Company has 225 substations of 35 kV and above, with a substation capacity of 20,359,400 kVA, a transmission line of 5,844 km, a maximum power load of 6.06 million kilowatts, and an annual sales of more than 20 billion kwh.

Jining is an important channel for the “West-to-East Power Transmission” of Shandong Power Grid. After the reform and opening up, Jining Power Grid ushered in a spring of rapid development. At the same time that the main network of Jining Power Grid has developed by leaps and bounds, the development of distribution networks is also changing with each passing day.

In the 1990s, Jining Electric Power Bureau took measures to accelerate the construction of rural power grids. In 1993, the city realized “village and village electrification”. In 1995, households were electrified. In 1998, the implementation of the urban farm network construction and reconstruction project was initiated, 42 urban distribution lines were reconstructed, 24,874 rural distribution transformers and 366 distribution lines were reconstructed, which greatly improved the quality of Jining urban and rural power supply.

In the new century, Jining Power Supply Company continued to develop distribution automation systems in urban core areas and county towns. This system construction is equivalent to installing “eyes” for the distribution network, realizing online monitoring of equipment, online collection of operational status data and accurate location of fault areas, fundamentally changing the past “blind adjustment” status, bringing production methods and A major shift in management style.

Now it is possible to complete the fault range location within 1 minute, and provide multiple power-on-recovery solutions for fault isolation and non-faulty areas within 2 minutes, and automatically complete fault identification, isolation and non-faulty section recovery power supply, and the repair personnel accept within 5 minutes. The instruction rushed to the faulty section. At present, Jining Power Supply Company has completed the commissioning of 1498 intelligent distribution lines, with an automatic coverage rate of 100%, achieving a terminal online rate of 99%, a remote correct correct action rate of 100%, and a FA correct action rate of 90%. The average customer power outage time was shortened from the original 120 minutes to less than 5 minutes.

At the same time, Jining Power Supply Company continued to upgrade the urban and rural power grids and continuously optimize the distribution network structure and layout. Since 2015, Jining has implemented a new round of rural power grid reconstruction and upgrading projects, newly built 1626 kilometers of 10 kV lines, and replaced 5116 sets of new equipment; completed 393 small towns (central villages) and 31 villages with insufficient power and power projects. The construction has realized the power supply to the village, and the average household capacity has reached 1.92 kVA, which greatly improved the reliability of power supply.

High-quality development of distribution network

Narrator: He Wei, deputy general manager of Fujian Xiamen Power Supply Company

Xiamen, Fujian Province started the exploration and practice of intelligent distribution network in China. In 2009, Xiamen Power Supply Company started the construction of smart grid distribution automation, took the lead in building the largest distribution automation system in China, and realized the full coverage of Xiamen Island trunk node distribution automation. In the following years, a series of distribution network pilot projects were launched one after another, including high-reliability demonstration zones, demonstration zones of key cities, distribution network transformation and management of key cities, and Xiamen Haidao Xiamen Smart Grid Comprehensive Construction Project. And other demonstration projects. Xiamen Power Supply Company also undertook two national 863 projects, such as “Research and Demonstration of Key Technologies for Active Distribution Network” and “Research and Demonstration of Distribution Network Information Physics System”, and successfully passed the acceptance, integrated distribution terminal unit (IDU) and distribution network. A number of advanced equipment technologies such as fast switching devices and distributed distribution terminals, such as “plug and play” and “interconnected”, were implemented in Xiamen.

These pilot projects and innovative projects not only promote the geometrical leap of the Xiamen distribution network, but also enable Xiamen Power Supply Company to accumulate many typical experiences in the distribution network construction and operation and maintenance. We will do a detailed planning of the power grid, analyze various influencing factors of power supply reliability, focus on the precise input of weak links, and continuously improve the level of the basic grid of the distribution network; we strengthen the lean operation and maintenance of the distribution network, and deepen the state maintenance. Application of auxiliary decision-making system to improve the intelligent level of power distribution equipment inspection, deepen the application of integrated information distribution platform of distribution network in the planning, construction, operation and maintenance, regulation and control of distribution network, and realize the visualization of distribution network Control.

From the comparison of two typhoons that attacked Xiamen in front, it is possible to visually see the effectiveness of the upgrade of Xiamen Power Grid. In 1999, the 15th typhoon "Dan En" caused the power outage of the island of Xiamen Island, and the power supply was resumed 15 days later. In 2016, the world's strongest typhoon “Morante” swept through the Xiamen power grid, but there was no power outage in the core area of Xiamen Island. Seventy-five percent of the island's customers did not have power outages; in just 72 hours, Xiamen Island resumed power supply, and the efficiency of the power generation increased by 5 Times.

Since last year, as one of the first pilot cities in the world's first-class city distribution network construction, Xiamen Power Supply Company has accelerated the realization of “safe and reliable, high-quality and efficient, green and low-carbon, intelligent interaction” of urban distribution network. Lake high-end administrative business district, Jimei cultural and educational tourist area, Majiwan smart business and residential area, Tongji high-load density industrial area, Maxiang old town living area, five comprehensive demonstration areas, for different areas of load characteristics, implementation of differentiation, Multi-element demonstration. By creating these five replicable models, the future urban distribution network in Xiamen will be continuously upgraded from point to point, and finally reach the international first-class level in terms of power supply reliability and power quality. According to the plan, by 2020, the reliability of power supply in Xiamen will reach 99.995%, the reliability of power supply in the core area will be 99.999%, and the distribution network in the central city will reach the international advanced level.

By: JUCRO Electric (Focus on Vacuum Interrupter, Vacuum circuit breaker, Vacuum contactor and Switchgear)

           December 2018