Exploring the intelligent route of cables

Exploring the intelligent route of cables On October 26, the China Electric Power Enterprise Association Science and Technology Development Service Center held an experience exchange meeting on power cables in Qingdao, Shandong Province. For industry agencies, research institutes, or cable companies, this conference undoubtedly opened up quite timely: In the context of the overall construction of smart grids, the power cable industry really needs to brainstorm and think about how to adapt to the needs of the smart grid.

The Confusion of "Smart" Cables Since the State Grid Corporation of China proposed a smart grid development plan in 2009, domestic and foreign power equipment manufacturers have adjusted their R&D directions and tackled smart devices. In the primary equipment industry such as transformers, high-voltage switches, and reactors, the possibility of combining intelligence with sensors has been studied; secondary protection equipment such as relay protection devices and automation control equipment have cooperated with primary equipment manufacturers to explore first and second times. Device integration integration approach. So, where is the intelligent direction of the cable?

For the cable industry, this problem is not easy to answer, because the cable needs to be "smart", but the ways and methods to achieve it are different from those of transformers and other products.

One way to realize the intelligence of the transformer is to combine it with secondary equipment, such as installing sensors in certain parts of the transformer, so as to ensure that the temperature rise, noise, etc. of the transformer can be monitored at any time. Cables cannot be.

One reason is that the probability of failure of the cable within the unit life is small. The purpose of building a strong smart grid in China is to ensure the safety and reliability of the power grid, so that people can use it more conveniently and at ease. This requires more reliable grid-related equipment. Chen Peiyun, chief engineer of Qingdao Han Cable Co., Ltd., therefore stated that “the measures to reduce the occurrence of cable faults are the use of qualified cables, the installation of safe cable channels and the laying of regulations, periodic inspections, and status assessment.”

The more important reason is that the characteristics of cable products and transformer products are different. Wu Changshun, director of the National Wire and Cable Quality Supervision and Inspection Center, said: “Wire and cable products are different from high voltage electrical products such as transformers, capacitors, and bushings. The latter is a unit product that facilitates measurement and monitoring, facilitates intelligent control design and implementation, and has low costs. The former is a distributed product, with long lines, complex environmental conditions along the route, and many influencing factors, which are not conducive to the combination with sensors."

In fact, it also involves cost issues. If we want to add sensor products to such a large cable line, the cost will be enormous, and the reliability of the technology must be carefully explored.

The intelligence of the cable cannot go the same path as a primary device. It needs to open up new avenues.

One of the new ways of intelligent detection technology in incubation is to develop more intelligent cable detection technology.

Guo Gongkun, Senior Engineer of the State Grid Electric Power Research Center, said that in recent years, China's cable industry has developed rapidly. With the construction of smart grids, real estate development and the construction of new energy sources, all 220 kV and below cables and accessories have been domestically produced, and the quality of high-voltage cables has also been considerably improved. However, with more and more applications of cables, coupled with the improvement of reliability requirements for power supply in smart grids, cable faults occur from time to time, and it is urgent to research new and more intelligent cable detection technologies.

According to reports, currently used cable detection methods include DC test and AC test. The drawback of the DC test is that it accumulates charge inside the cable, causing damage to the cable. The AC test can only detect some of the larger defects and cannot evaluate the true state.

"Therefore, the status diagnosis and evaluation of the cable is an important technical means to arrange the replacement of the cable reasonably and ensure the power supply is safe and reliable. It is also an extremely important part of the effective management of the cable in the smart grid." said Wu Changshun.

According to Wu Changshun, state assessment is usually divided into online (charged) and offline (uncharged), but at present, both methods are just starting.

The online method can theoretically understand the status of the cable in real time. However, sufficient online monitoring experience has not yet been accumulated and the monitoring technology is not yet mature. For the cable that has been laid, installing an online monitoring device will inevitably add additional components to the cable system, which may affect the cable. Reliable operation.

The off-line method only obtains the status of the cable through evaluation when necessary (periodically), and therefore has more flexibility and operability. However, due to the short research time, there are many problems to be solved.

At present, the industry has recognized the importance of intelligent cable detection technology. Chen Peiyun said that Qingdao Han cable has cooperated with North China Electric Power University to develop on-line testing equipment.

Another way to explore new material cables is to use new materials to develop cable products suitable for smart grids. Compared with the beginning of cable intelligent detection technology, the research of new material cables has achieved good results.

For example, with the large-scale transformation of urban and rural power grids, water-resistant tree cables came into being. The dual-ring network power supply in big cities, the increasingly narrow space corridors, and the increased underground cable rate in the city center have brought great demands for cables. The maintenance-free requirements of cable and the life expectancy of insulation and pressure, and put forward higher requirements for insulation medium, performance indicators and brand reputation of distribution cables.

According to experts, the insulating medium of conventional cables gradually produces dendritic degradation under the synergistic effect of insulation defects such as electric fields, moisture, and impurities. When the dendritic degradation progresses further, it will cause a test breakdown or a rundown breakdown of the body or the accessory of the cable line. Therefore, water-resistant tree cables with special processes are naturally favored. Although the application of water-resistant tree cables is still limited, the superior anti-penetration performance and maintenance-free performance determine that the market share of water-resistant tree cables is expected to increase.

In addition, new energy construction also brings demand for dedicated cables. For example, Class 1E Class K3 environmental conditions outside the containment of nuclear power plants promote the application of nuclear cables with extremely strict limits on temperature, voltage life, and heat aging.

Driven by the smart grid construction, the face of the cable industry is changing. The cable industry, “changing its face”, is bound to take a more relaxed attitude to meet the arrival of the era of electric power intelligence.

Square Lighting Pole

Huayuan Lighting Co., Ltd. , http://www.jslightpoles.com

Posted on