Hubei Power ensures the smooth operation of provincial and inter-regional power grids

Protecting the power "artery" in the battle against epidemic prevention and control

——State Grid Hubei Electric Power ensures the smooth operation of provincial and cross-regional power grids

China Electric Power News Network Correspondent Zhu Ke Zhou Qiangming Shi Yuxin Reporter Long Qun

"The 500 kV Yuxian substation that supplies power to the Huoshenshan Hospital has a load of 320,000 kilowatts, and the main transformer is in good condition..." At 10 a.m. on February 12, Jin Qiyun, an employee of Hubei Electric Power Maintenance Company, inspected the operation of important substations through the remote monitoring system. On that day, the Hubei power grid and the cross-regional power grid were in good condition.

Since the outbreak of the COVID-19 epidemic, State Grid Hubei Electric Power Co., Ltd. has made ensuring the safety of the large power grid a top priority in accordance with the requirements of the Party Leadership Group of State Grid Corporation of China. From January 20 to February 12, the company focused on strengthening the operation and maintenance of 36 500 kV and above substations and more than 13,470 kilometers of 500 kV and above transmission lines in Hubei Power Grid, and made every effort to ensure the operation and maintenance of the 1,000 kV Nanjing I loop line, ±800 kV Jinsu line, Fufeng line and other ultra-high voltage AC and DC lines in Hubei, the Yihua DC and other Three Gorges transmission lines, and the Chongqing-Hubei DC back-to-back and other inter-provincial interconnection lines, to ensure the smooth operation of the transmission and transformation equipment of the Hubei Power Grid and cross-regional power grids, and to protect the power "artery" to win the battle against the epidemic.

Collaborative Operations to Protect Hubei from Central China

Hubei Power Grid is the starting point of the Three Gorges Power Transmission, the channel for west-to-east power transmission, the hub for north-south power supply, and the center of the national networking. It is interconnected with the Central China, East China, North China, Southwest China, and Southern China Power Grids through 20 AC and DC transmission lines. The length of cross-provincial and cross-regional transmission lines ranks first in the country.

The COVID-19 epidemic not only seriously threatens the lives and health of the people, but also poses severe challenges to the operation of large power grids. Under the triple test of rainy, snowy and freezing weather, large fluctuations in electricity load during the Spring Festival, and comprehensive control of epidemic prevention and control, once a large-scale power outage occurs in the main grid, it is like bleeding in the "aorta", and the consequences are disastrous. Hubei Electric Power adheres to the bottom line thinking, looks at the worst, makes the most adequate preparations, and strives for the best direction, protecting the lights of thousands of homes and enhancing people's confidence and determination to fight the epidemic.

In the early stage of the epidemic, the power load of Hubei power grid maintained a rapid growth. On January 24, the maximum power load of Hubei power grid reached 27.216 million kilowatts, an increase of 12.75% year-on-year. It is imperative to allocate more power resources to ensure reliable power supply. In accordance with the principle of "the whole network protects Central China, and Central China protects Hubei", State Grid Corporation of China added 500,000 kilowatts of Northwest Power to support Hubei through the ±800 kV Qi Shao DC channel. The Central China Branch of State Grid organized Henan, Hunan, Jiangxi and other provinces to carry out inter-grid peak power mutual assistance, optimize and adjust the startup combination mode of units in the province, and effectively reduce the coal consumption and water consumption of power generation in the province.

After the traffic control, environmental consumables such as limestone and liquid ammonia needed for desulfurization and denitrification of thermal power plants could not be supplied, and the power generation capacity of 7 million kilowatts of thermal power generating units in the province was restricted. On January 27, Shao Lizheng, director of the Planning Department of Hubei Electric Power Control Center, reported the relevant information to the Hubei Provincial Energy Bureau and the Central China Energy Supervision Bureau as soon as possible after learning about the situation. Under the coordination of relevant government departments, multiple parties worked together to ensure supply, eliminating the worries about the supply of fuel and auxiliary materials for these generating units.

With the active help of the National Electric Power Dispatching and Control Center and the Central China Branch of the State Grid Corporation of China and the active organization and coordination of relevant government departments, Hubei has sufficient power resources. As of January 31, the province's coal storage was 4.7724 million tons, an increase of 728,200 tons year-on-year; hydropower storage was 6.746 billion kWh, a year-on-year increase of 10.95%.

Stick to your post and maintain intelligent operation and maintenance

To effectively prevent and control the epidemic, Hubei Power has implemented "four isolations" in 36 important substations and converter stations above 500 kV, namely, isolation inside and outside the station, isolation for maintenance and operation, isolation for rest and meals, and isolation for material distribution. By extending duty hours and conducting contactless shift handovers, it ensures that each station is an impenetrable fortress for the virus.

On February 7, the fog in the mountains had not yet dissipated, and in the equipment area of ​​the 500 kV Enshi substation, stationmaster Mo Changyu began his day's work. This was his 17th day of perseverance.

Enshi Substation is the most remote ultra-high voltage substation in Hubei, which guarantees the electricity supply of more than 4 million people in Enshi Prefecture and is an important connection point of the cross-regional power grid between Chongqing and Hubei. Once the 220 kV line in the station fails, it will seriously affect the power supply of several major hospitals in Enshi Prefecture and the daily electricity consumption of urban residents.

In order to prevent cross infection, Mo Changyu and 256 other employees have been working continuously in various substations (converter stations).

Hubei Electric Power has also optimized its inspection methods, making full use of online monitoring equipment such as drones, inspection robots, and video surveillance to implement remote status monitoring of power transmission and transformation equipment. For equipment that really requires special inspections and care, it tries to use a one-car-few-people approach to reduce human contact.

"Master Zheng, the robot inspected the 220 kV equipment area this morning. I confirmed on the computer that the oil-filling and air-filling equipment meters were normal by taking photos and sending back data." On February 4, Zheng Ting, the duty officer at the 500 kV Cihu substation, reported to the stationmaster Zheng Hanming via the intercom.

"Okay, keep the records, and then set the patrol route and time for the evening." Zheng Hanming reminded, "During the epidemic prevention period, you must do your daily work well while ensuring your health."

The maintenance staff of Cihu Substation divides the equipment into three areas according to the voltage level. The robot inspects one area every day, mainly inspecting the equipment meters in the morning and measuring the temperature of the equipment in the evening, with a cycle of every three days. The maintenance staff only need to check the information sent back by the robot to fully understand the operation status of the equipment in the entire station.

To combat the epidemic, Hubei Electric Power arranges more than 1,800 main grid power transmission and transformation professionals every day to patrol 384 key transmission lines, conducts more than 2,970 aerial and remote inspections using drones and video image online monitoring systems, and uses in-station robot inspection equipment more than 2,400 times. The status of the main grid equipment is controllable and under control.

Quick response to eliminate hidden dangers in time

Hubei Electric Power has formulated 10 measures for equipment maintenance during the epidemic prevention and control period, increased special inspections on power transmission and transformation equipment above 500 kV, and promptly discovered and dealt with safety hazards; formed a fault repair commando team mainly composed of live-line team members in advance to perform live-line operations to eliminate faults and carry out emergency repairs on urgent defects that endanger the safe operation of the lines.

On February 4, Tang Kaibo, the stationmaster of the 500 kV Fenghuangshan substation, found that the outer wall of the No. 2 main transformer bushing of the station had oil leakage, and the oil level of the transformer dropped from one-seventh to one-eighth, and there were obvious oil droplets dripping. The 220 kV Fengyue II and III loops connected to it are the source power supply of Wuhan Leishenshan Hospital. At that time, the construction of Leishenshan Hospital was at a critical stage, and the oil leakage risk must be eliminated as soon as possible.

State Grid Hubei Maintenance Company took immediate action, and repair personnel, spare parts, tools, testing equipment, protective equipment, and maintenance vehicles were quickly assembled.

Checking the equipment status, untying the low-voltage bushing leads, applying grease to seal the oil leakage points, testing the main insulation of the bushing, and conducting electrical tests... all the work was carried out in an orderly manner. After 5 and a half hours, the defects were dealt with and the main transformer was successfully transmitting power.