Intelligent grids make substation operation more reliable

On November 20, the author walked into Qinghai's first smart substation, Xining 110 kV Chengdong Smart Substation, which was put into operation for one full month. If it weren’t for seeing neat rows of gas-insulated combined electrical equipment (GIS) standing here, I suddenly forgot that I was in a substation. In fact, our every move has been clearly seen by the monitoring terminal 20 kilometers away. This "elderly" substation, which has undergone comprehensive automation after being put into operation in 1985, has now led the Qinghai Power Grid into the era of intelligence.

The patrol of the smart patrol gave a little mouse click. The density of SF6 gas in the 110-kilovolt GIS equipment, micro-water, temperature, and pressure... The values ​​that reflect the operation status of the equipment vividly displayed in the monitoring window of the GIS on-line monitoring system. Even the curve of each parameter is as clear and complete as the electrocardiogram. This makes Zhang Shaolin, deputy director of the transformer and electrical area of ​​Xining Power Supply Company, who has been working in the substation for more than a decade, feel more emotion.

"As the development scale of power grids expands and the GIS equipments are widely used in substations, the operating pressure of the operating personnel is gradually increasing. The work of simply copying the pressure of sulfur hexafluoride is enough to allow personnel of the operation and maintenance stations to run for more than half a day. There are more than a dozen risk prevention measures!” Xining Power Supply Company has a total of 35 substations with 35 kV and above substations, and 43 substations with 10 kV open and close. Due to the special climate of the Tibetan Plateau, sulfur hexafluoride gas pressure in GIS equipment is a key point in the daily inspection and maintenance work of the operating personnel. The site has made a daily copy of the sulfur hexafluoride gas pressure monitoring.

“Copying sulfur hexafluoride pressure is a tedious and very troublesome thing. Once monitoring is ineffective, the occurrence of low pressure locking and other problems is very harmful.” Since April 2010, Xining Power Supply Company has implemented “big operation” transformation and operation and maintenance management. Since the model, 22 individuals at the east of Chengdong Substation have owned a total of 10 110-kilovolt substations and 18 10-kilovolt open-closed stations. It is necessary to copy all GIS equipment pressures of substations once a day. It takes a whole day.

"Especially in the winter snow days, climbing up and down to copy pressure will often take a cold sweat." In the whole process of tracking and accepting the Chengdong substation for a month, Zhang Shaolin profoundly realized the benefits of intelligence. The operating personnel can sit in the control room and be fully aware of the status of the entire station equipment. The switch operation no longer requires the operator, the guardian, and the cooperating person to run around to see the position and nuclear information. A 17-inch LCD screen can be used in detail. See all the information from once to the second time, from the amount of device movement to the completion of the action. “Smart substations can free operating personnel from simple and repetitive labor, and we have more time to focus on management and training!”

Six major professional Qi "inquiry"

All beginnings are hard. Since the project of the intelligent transformation of the 110-kilovolt Chengdong substation was approved, Liu Hui, the director of the production technology department of Xining Power Supply Company, was concerned about the safety and progress of the project. He feared that it would be difficult for the existing technical forces to follow up on project quality supervision.

"The quality of the project cannot be guaranteed, and the project will run on thin ice." As the first pilot project for intelligent substations in Qinghai Province, it is necessary to get a good start and play a leading role. From the beginning, the real goal of the project was not as simple as putting it into operation. It is the ultimate goal for the smart grid to rise in the Qinghai Power Grid. The higher the goal, the greater the difficulty of the action.

"As soon as we can do it, we must do a good job!" As the lead project of the Qinghai Electric Power Company into the era of intelligence, Xining Power Supply Company has made every step of the transformation of the Chengdong Transformer Station very stable. From the review of the project drawings to the entire process of installation, commissioning, acceptance, and commissioning, the six substations involved in substation operation, maintenance, protection, switching, high-voltage testing, and communication are all on the spot, aiming at their respective professional issues: “look, smell, ask, and cut” "Vague information, check the information, ask the experts, until" break the sand pot in the end asked, "falling out.

“Following this project for nearly six months, the gains were too great.” Liu Zhigang, shift supervisor of the Xining Power Supply Company's substation maintenance and protection work area, was the project leader of the engineering protection profession, from the first contact with the digital protection tangles to the equipment manufacturers and other specialties. The personnel constantly exchanged ideas and ideas, and from a little exploration to bold ideas, after exploring the principle of each device and the direction of each secondary line, many protection problems were overcome and all the protection devices of Chengdong Substation were Performance, principles and exception handling are just a few.

In September this year, the project entered the stage of comprehensive commissioning and acceptance. When the 110 kV collector and the merging unit were commissioned and a 110 kV secondary voltage parallel test was performed, it was found that there was no voltage at one time, but the secondary always generated a large current, causing the main transformer protection to malfunction. After looking at the drawings, inspection devices, and test data, in order to ensure the safety of the pilots, measurement and other professional departments have been invited to do a number of routine test monitoring, and ultimately determine the problem is that the collector in the special environment of the plateau, its anti-jamming performance deterioration There is a mismatch between the optical PT/CT coefficients and the replacement of the equipment solves the problem. "When carrying out a 110 kV self-propelled transmission test, the equipment could not be carried out without a load test. Originally, after thinking about putting it into operation, we did not expect that a small idea would solve the problem." Considering that it will be applied after it is put into operation. In order to make the trials cumbersome and difficult, Liu Zhigang suggested using two protective calibrators to prepare the self-investment test at the same time. He did not think of this proposal and solved the problem of self-investment test. This method was also written into the typical experience of the Chengdong substation. Record of results.

10kV switchgear does not meet the technical conditions, digital protection can not be nuclear phase ... ... For the construction of construction personnel, the problems are encountered for the first time, but the method is always more than the problem, in a difficult problem of cracking, Out of a smart substation experts. "No longer have to worry about the technical quality of the smart substations in the process of advancement." Liu Hui, director of the Biotechnology Department of Xining Power Supply Co., Ltd., worried from worrying because of the strong backing of experts.

The 110 kV Chengdong Substation is the second batch of smart substation pilot projects of the State Grid Corporation of China and the first smart substation of Qinghai Power Grid. During the “Twelfth Five-Year Plan” period, investment in power grid construction in Xining will reach 3.3 billion yuan. Substations of 110 kilovolts and above will be implemented according to the standards of smart substations, and the intelligent rate will reach 100%. Xining power grid will also realize the transition from traditional grids to smart grids. With the upgrade and leapfrogging, by the end of the “Twelfth Five-Year Plan” period, the 330 kV power grid will cover important load centers in the Xining region, and the 110 kV power grid will form a power grid structure with dual power supplies and dual masters.