Deepen the application of new grid technologies to promote greener substation operation and maintenance

"According to the design, if the Yonggang substation wants to achieve 'one-button smooth control' intelligent operation, 240 industrial video-grade cameras need to be installed to realize intelligent recognition, and the control system needs to speed up testing and upgrading." On March 11, the construction site of Zhejiang's 52nd ultra-high voltage substation, the 500 kV Yonggang substation, has resumed work. Power technology experts from State Grid Zhejiang Electric Power Co., Ltd. came to the site to participate in the preparation and construction seminars. The "one-button smooth control" technology they discussed is one of the "hot" key technologies for the iterative upgrade of smart substations.

As one of the means to achieve fully automatic and more intelligent, efficient and safer operation and maintenance management of smart substations, the application of "one-button sequential control" technology is a microcosm of Zhejiang's continuous promotion of intelligent substation construction. In recent years, State Grid Corporation of China has actively promoted the construction of smart grids. As early as 2011, the company proposed that all new substations of 110 kV and above should be built using the smart substation technology model. State Grid Zhejiang Electric Power takes the construction of smart substations as a starting point, continues to deepen the application of three-dimensional design, smart construction sites and other means, and comprehensively improves the level of intelligent substation construction; deepens the application of technologies such as "one-button sequential control", robot inspection, industrial video, promotes unmanned substations, and comprehensively improves the intelligent level of substation operation and maintenance. As of now, the number of 500 kV intelligent substations in Zhejiang Province has reached 20, accounting for 40% of the total number of 500 kV substations in the province.

Deepening the application of digital information technology to promote safer substation operation and maintenance

The "one-key sequential control" technology uses the preset sequential control tickets and operating rules of the monitoring system to automatically complete a series of operations according to the sequential control tickets during the one-key sequential control process, ultimately changing the system operating status and realizing automatic switching of different states of electrical equipment, thereby optimizing the substation operation and maintenance methods.

In fact, in the operation and maintenance of substations, "one-button sequential control" is not a new technology. In 2019, Zhejiang has used this technology for the operation and maintenance of 500 kV substations. In June of that year, the 500 kV Genshan substation was put into operation, becoming the first ultra-high voltage substation in Zhejiang Province to use "one-button sequential control" technology. On January 17 this year, the 500 kV Changtan substation was put into operation. This is the first fully automatic "one-button sequential control" ultra-high voltage intelligent station in Zhejiang. Compared with the Genshan substation, the technology is more advanced and the degree of automation is higher. Earlier, the technology has been applied to the operation and maintenance of 220 kV substations with lower voltage levels, achieving coverage of substations of different voltage levels.

"Safety is one of the biggest features of smart substations. Computers and automation replace manual work to automatically complete a series of actions that previously required manual operation. At the same time, it realizes 'double verification' to prevent errors and 'double confirmation' of status, effectively avoiding misoperation and making operation and maintenance safer." said Ji Rongrong, automation technology expert at Zhejiang Electric Power Maintenance Company.

In 2014, the first fully digital substation in Zhejiang and the first fully digital ultra-high voltage substation in East China, the 500 kV Wuning substation, was put into operation. This substation was built in accordance with digital and intelligent standards, with the basic requirements of full station information digitization, communication platform networking, and information sharing standardization. Its commissioning kicked off Zhejiang's promotion of digital substation construction and transformation. Today, these digital technologies have become basic configurations in the operation and maintenance of the 500 kV Yonggang substation.

The fully automatic "one-button sequential control" is just a microcosm of the application of information technology. In the 500 kV Changtan substation, a large number of intelligent monitoring videos are used on substation equipment. Monitoring personnel can mobilize any camera in the background to check the operation status of the equipment, find defects in the first place, and ensure the safe and reliable operation of the equipment.

Deepening the application of robot inspection to promote more efficient substation operation and maintenance

The efficiency of new technologies is being fully reflected in the operation and maintenance of smart substations. Taking the switching of the operating status of a 500 kV line as an example, if the traditional operation method is used, two monitoring backends and one on-site checker are required, and it takes 40 minutes to complete the entire operation task. The "one-button sequential control" technology shortens this process to 5 minutes. Statistics show that compared with conventional substations, smart stations using the "one-button sequential control" technology save 50% of manpower and improve work efficiency by 70%. The emergence of intelligent inspection robots has further improved the efficiency of substation operation and maintenance.

At noon on March 10, inside the 500 kV bottle kiln transformer, a robot drove out of the room on time and carried out routine inspections of the equipment in the substation according to the preset route. After completing the prescribed actions, the camera on the front end of the robot immediately generated an image and transmitted it to the monitoring background in real time. The operation and maintenance personnel can understand the operation status of the substation by analyzing the image. "Before this, these basic inspections had to be performed by the operation and maintenance personnel. They manually transmitted the pictures they took to the system for analysis, which was very cumbersome." said Wu Jinxiang of Zhejiang Electric Power Inspection Company.

In recent years, State Grid Zhejiang Electric Power has continued to deepen the application of robots. Outdoor intelligent inspection robots for substations, indoor rail inspection robots...manual inspections in traditional substations are gradually being replaced by robot inspections. Under automatic control or manual pan-tilt control inspections, robots use various sensors to complete image inspections of primary equipment in substations, record equipment information, and automatically alarm for abnormalities. They can replace manual infrared inspections, visible light inspections, and meter inspections of on-site equipment, effectively reducing human resources and greatly improving the operation and maintenance efficiency of substations. According to statistics, the robot coverage rate of 220 kV and above substations in Zhejiang Province currently exceeds 75%.

The application of robots in substations has played an important role during the prevention and control of the new crown pneumonia epidemic. "Due to the need for epidemic prevention and control, the number of substation operation and maintenance personnel has been greatly reduced. At this time, robots that will not be 'poisoned' have shown unique advantages." Wu Jinxiang said. The application of intelligent inspection robots not only effectively prevents cross-infection among personnel, but also ensures the safe operation of substations. State Grid Zhejiang Electric Power has also promoted the intelligent networking of inspection robots. Through the networked comparison of substation equipment data, it has realized the comparison of the same type of equipment at multiple sites with massive data resources, and achieved "horizontal + vertical" data analysis, so as to more efficiently discover and handle potential abnormalities of equipment.

"Further promoting the optimization and adjustment of human resources and realizing the replacement of humans for routine inspections by robots is one of the effective means for us to promote more efficient substation operation and maintenance. Ultimately, we want to use robots to replace humans for routine operation and maintenance in the substation." Qian Ping, head of the Zhejiang Electric Power Equipment Department of State Grid, said. It is understood that all 500 kV substations in Zhejiang Province are basically equipped with the conditions for robot monorail inspections, thus realizing unmanned operation.

Deepen the application of new grid technologies to promote greener substation operation and maintenance

Under an elevated bridge on the west side of Qiantang Smart City in Hangzhou, a gray building is built next to a residential building. If it weren't for the wires extending from it, it would be hard to tell that this is an ultra-high voltage substation. This is Zhejiang's first fully indoor ultra-high voltage substation - the 500 kV Genshan substation.

Qiantang Smart City is a digital fashion industry cluster in Hangzhou with a dense population. The construction of ultra-high voltage substations places high demands on land and environmental protection. In order to minimize the occupation of land resources and promote the development of substation construction in an intensive, green and environmentally friendly direction, State Grid Zhejiang Electric Power proposed to build a fully indoor smart station. In June 2019, the 500 kV Genshan substation was completed and put into operation, covering an area of ​​only about 14,000 square meters. In sharp contrast, the first 500 kV substation in Zhejiang, which was put into operation in 1987, is nearly 100 times the area of ​​the Genshan substation.