66 Urban Disaster-Proof Power Grids Established in CSG Power Supply Area

To take preventive measures that prevent extreme disasters and guarantee significant power loads and power supplies to millions of business and leisure customers of the major cities of South China to the maximum extent possible, the entire staff and senior management of China Southern Power Grid is dedicated to ensuring the sustainable power supply to its core areas and key consumers.

On December 31, 2020, the key project of Guangdong Power Grid Corporation - 220 kV Subscriber Station Grid Connection Project of Sinopec Maoming Petrochemical Company - was completed, which met the need of ever increasing power loads and reliability for the Maoming petrochemical industry.

In 2018, Zhuhai, Guangdong, CSG engineering staff were working at heights for tunnel cable laying. At present, through the construction of disaster-proof power grids, CSG is able to supply secure and more reliable full power flows to Hong Kong and Macao. Photo by Lin Feng

At 15:54 on December 31, 2020, in Bijie, Guizhou - by the side of the No.68 tower on the 110 kV Hejiu line, Qin Xingyuan, power supply maintainer of Zhanghe Power Supply Bureau of Guizhou Power Grid Corporation, called his colleagues at transformers stations to begin the remote deicing programs.

On December 17, in Guilin, Guangxi – Challenges by electrical lines covered by ice, workers of Guilin Power Supply Bureau of Guangxi Power Grid Corporation began the initial steps to measure the temperature of the electrical line, observe ice conditions, and clean line corridors to ensure safe and stable operation of all electrical power lines.

Since mid-February, an unprecedented winter storm has led to a power crisis in Texas. A topic on "What if we Encounter A Texas Cold Wave?" later went viral online.

Year 2020 marked the fourth consecutive year that the World Economic Forum marked the extreme climatic event as one of the Top 10 risks with the highest likelihood of happening.

Guangdong, Guangxi, Yunnan, Guizhou and Hainan, which are under China Southern Power Grid's operation, are in remote areas where natural hazards like typhoons, sub-zero temperatures, rain, snow, and ice conditions take place frequently.

To cope with these extremes in climate change … in recent years, CSG senior managers have pressed forward in major power grid construction projects, power supply security, and emergency response techniques. During the last four years, CSG has established urban disaster-proof power grids across China … which for the first time is expected to fully guarantee significant electrical power load management and power supplies to the millions of business and leisure customers in the major cities of south China and ensure sustainable power supply to the Company’s core areas and key consumers.

Construct Disaster-Proof Power Grids

Strengthen Four Lines of Defense to Guarantee Electrical Power Supplies

Since the launch of "13th Five-Year" Plan, CSG senior managers have learned from the experience of preventing ice, winds, and flooding as engineers constructed secure and reliable urban disaster-proofd power grids, improve the ability of supplying unremitting electrical power to Hong Kong and Macao and constructed power grids of coastal areas according to local conditions, which strengthen the grid security.

After the strong typhoon Rainbow in 2015 made landfall onto the Motherland, the concept of “disaster-proof power grids” was first proposed domestically by CSG senior managers and later was incorporated in the plan and research of power grids of the "13th Five-Year" Plan.

In April 2017, China Southern Power Grid launched a special plan of disaster-proof construction across 28 major cities in South China, which served as the backbone of the project and start of the construction.

Years later, CSG senior managers increased the number of cities where disaster-proof power grids will be constructed to 66, covering all the cities in the CSG power supply area.

According to working documents from CSG Planning Department, “When facing serious natural disasters and impacts of external forces, disaster-proof power grids with stronger resistence ability is the lifeblood of preventing disasters for urban power grids.”

Disaster-proof power grids serve to guarantee significant power loads and electrical power supplies to millions of people throughout South China. It also means careful and appropriate preparations have now been put into motion for China Southern Power Grid to be ready for extreme natural hazards and endeavor for the best result that ensures sustainable power supply to the Company’s core areas and key consumers.

To date, CSG has basically established disaster-proof power grids covering:

·Sixty six cities of five provinces in the south

·Laid out 147 emergence-response power sources

·Built an overall defensive system with four defense lines that support of the overall power grid

·Emergence-response power resources with self-balanced voltage-grading and district-dividing structures

·Self-prepared emergency power supplies, and

·Replenishment of mobile emergency power supply.

Taken in unison have significantly had improved the Company’s power grids' resilience to natural disasters.

By taking into account the requirements of urban planning and development and utility tunnel construction, CSG engineers have continued to:

·Reinforce "cable lines plus indoor stations" channel construction in coastal strong wind cities (Class I) such as Guangdong and Hainan

·Laid specific route maps of cabling disaster-proof power grids and constructing or reconstructing indoor stations, and

·Accelerated reconstruction of cabling disaster-proof power grids and of indoor guaranteed power transformer stations that serve to improve the ability of power grids to prevent wind and other disasters.

By the end of Year 2020, seven 220 kV "cable lines plus indoor stations" channels have been constructed with 99-kilometer cable lines newly established.

In emergency power supply construction, 17 new disaster-prevention power stations with "black start" or "islanding operation" have been developed in five South China provincial areas. In Year 2020, seven have been put into operation or completely reconstructed with installed capacity of 3.87 GW.

The so called "black start" is an electricity generator set that can restart without external power when electrical power is cut off and/or systems “black out”. It can transmit power to the power grid and facilitate other generator sets to generate and connect to the grid, which will achieve the restoration of power supply of the grid.

For example, when the typhoon Tiange slammed into Zhuhai and other coastal cities in Year 2017, factory A has supported the Zhuhai western power grid in "islanding operation" and Hongwan Power Plant in "black start", which helped Zhuhai power grids avoid an entire black-out.

Concurrently, China Southern Power Grid have improved its ability to supply power to Hong Kong and Macao.

In providing continual electrical power supplies to Hong Kong, "two lines and one station" in Shekou and other projects have been completed and put into operation. These new operations facilitates the shift of power supplies from the Shekou power grid to the Shenzhen power grid.

In addition, wind preventions of power lines connected to Hong Kong and related nuclear power plants have been reinforced and adjusted seven times. Steps have been taken to improve the working operation, maintenance, and management of transformer substations connected to Hong Kong and crucial related equipment.

All these efforts join to promote economic, social prosperity and stable development of Hong Kong.

In providing power supplies to Macao, guided by the principles of "systematic, integral, and science-based development", CSG has established "3+2" grids to supply power to Macao, which achieves the construction goal that channels of power supply to Macao will not be closed and supply capacity will not be weakened when a rare typhoon strikes.

During the "13th Five-Year" Plan period, CSG completed 247 power grid construction projects. In its related power supply areas, 147 anti-disaster power stations with total installed capacity of 77.19 GW have been established spanning hydropower, coal, natural gas, and pumped storage for which a diversified disaster-proof power supply layout was initially formed.

Ice can be Observed, Deiced and Prevented

By March 1, there was no ice coverage on 10 kV and above lines of the overall grid. At 17:35 on Mach 1, the last information about the ice coverage this year sent by CSG Production Command Center marked the completion of the deicing task of CSG in Year 2021.

With years of practice, China Southern Power Grid senior managers summarized solutions that "to observe ice conditions closely and deice in time".

A new Ice Coverage Observation Center established by CSG is now able to achieve accurate positioning and grading of lines covered by ice and provide a precise emergency plan that can guide grassroots units for remote deice action. Since 2011, the period from December 1 to March 1 each year has been the Company’s fixed time period of deicing. During these months, ice conditions and information about deicing is reported daily.

Since December 2020, CSG has encountered five massive cold waves, for which the number of routes covered by ice under CSG's operation reached an all-time high and the intensity of cold waves in local areas surpassed that of Year 2008 in which this Olympic Year extreme cold from Siberia turned nearly all of China into an “ice cube”.

However, in a sharp contrast, electricity loads and power consumption in areas under CSG's operation have increased with safe and stable operation of power grid equipment and reliable power supply.

After the severe ice damage caused in Year 2008, CSG's business area has encountered great intensity of low-temperature, rains, and snow in Years 2014, 2016, 2018, and 2020, during which CSG operated stable electrical power creations and presentation.

According to the Head of the CSG Emergency Response Office, CSG has established an emergency response mechanism featuring "daily preacutions, disaster prevention, mitigation, and relief, as well as post-disater evalution".

Today, China Southern Power Grid mainly focuses on prevention by combining prevention with disaster relief, and a unified regular disaster reduction and disaster relief during each temporary emergence periods.

In recent years, through coordination of grid operation measures, promotion of reconstruction and improvement of grids, operation and maintenance of equipment that takers greater risks, and to help consumers improve power configuration, CSG senior managers have decreased the likelihood of power losses caused by natural disasters.

At the CSG Equipment Condition Observation and Evaluation Center, there is a map on the wall that depicts, "CSG Once-in-A-Half-Year Icing Areas Distribution Diagram".

Also on the map, most of the cities in Guizhou and power transmission lines with ice coverage are marked as yellow, red and blue.

According to Fan Lingmeng, Senior Manager of Power Transmission Division of CSG Production and Technology Department, after the ice damage in Year 2008, on the basis of landforms, meteorologic features of the business area, CSG engineers revised distribution diagrams of once-in-a-30-year, once-in-a-half-year, and once-in-a-century ice storms. Using these diagrams as their guide point, CSG has taken targeted measures to reinforce windproof capacity, plan and develop new lines and the installation of online observation devices.

On the basis of icing areas distribution diagrams, CSG staff carried out numerous related tasks on reinforcing windproof capability for weak sections of transmission and distribution lines with total investment of more than 14 billion yuan, conducted reconstruction of 2,098 transmission and distribution lines, and fundamentally completed a massive reconstruction that began back in Year 2012.

Later in Year 2020, CSG senior managers continued to promote ice-preventing projects by revising icing areas distribution diagrams and has improved operation condition of electrical towers in the main icing areas as well as the ice-resistant capacity of lines by taking measures to increase planned thickness of ice, change paths, narrow distance and confirm the possible length of strain sections.

Concurrently, significant breakthroughs have been achieved in setting standards on deicing and measures of ice melting and deicing. In recent years, CSG has led the establishment of four national standards and six industry standards on deicing, applied new DC ice-melting devices, solved world-class problems of ground ice-melting technology, and significantly improved ice-resistant capacity of power grids, and the ability to melt ice on wires and deice on earth lines of 220 kV and above lines and 110 kV important lines in heavy icing areas.

Reliable Supplies of Energy and Power in the New Era

With the goal of reaching carbon peak and carbon neutrality close arriving, new energy resources will play an increasingly important role in recurring electrical power supplies.

Massive connections of the new energy grid and improved randomness, intermittent and volatility of power supplies challenge the safety and stability of power grid operation and also require higher efficiency of new energy grid connections.

During the "14th Five-Year" Plan period, to conform with the development of high-proportion renewable energy, CSG will construct:

·A safe, reliable, environmentally friendly, efficient and smart modern power grid

·Lay a foundation for large-scale connection of new energy and its efficient and stable operation

·Promote efficient utilization of integrated energies

·Increase the share of power in end-user energy consumption

·Better satisfy consumers' diverse needs of power, and

·Improve people's sense of gain, happiness, and security

According to international and domestic experts, extreme climates will have the greatest impacts on demand side and supply side of the power system, which poses significant challenges to the security and reliability of power supply.

Once the operation conditions exceed the design standards of the power system and operation capacity, the security of the electrical power supply will be significantly enhanced, for which much attention should be paid to low-probability and abnormal events … and the security of the grid operation and the ability to guarantee power supplies needs to be improved in terms of planning and design, operation and maintenance, and emergency response.

During the frozen winter months, China Southern Power Grid is pledged to provide:

·Continual updates to its important consumers

·Guarantee the scope of service while carrying out planning and development of disaster-proof power grids

·Promote planning and construction of anti-disaster emergence-response power sources

·Improve consumers' emergency power configuration

·Strengthen construction of portable emergency sources, and

·Accelerate application of emergency power guarantee technology

In this way, CSG senior managers improve the ability to guarantee a secure power supply when facing natural disasters and continue to carry out tasks of disaster prevention for energy and power in the new age.