Three Substations Exposed to Electronic Transformer Explosion involving the "Case"

In the first day of December 2011, the newly built Beixing 220KV substation was under intense debugging at a distance of 500 meters to the east of the 13th team of Beixing Farm, Qitaihe City, Heilongjiang Province, next to Qibao Road. Suddenly, the internal insulation of the electronic transformer was electrified. Breakdown, the transformer exploded in a flash.

The Beixing 220KV substation is one of the first 42 pilot projects for the construction of a smart substation by the State Grid Corporation of China, and is also the first pilot project for the construction of a smart substation in China's first high-altitude and cold regions. The total investment of the project is 73.19 million yuan. The electronic transformer explosion in the Beixing 220KV smart substation is not an isolated phenomenon. According to industry sources, since the autumn of last year, electronic transformers, one of the core components of the first batch of completed demonstration smart substation projects, have been broken down and an explosion has occurred.

State Grid issued a document to strengthen supervision According to industry sources, in Hunan, Yunnan, Fujian and other places of smart grid substations have occurred transformer explosions, involving electronic transformer manufacturers Nanrui, Xi'an Huawei, Xinning photoelectric.

A related company person, who did not wish to be named, told the newspaper that the State Grid Corporation of China had done statistics on the problems exposed by all the smart substation electronic transformers that were put into operation. The failure rate was as high as 5%. However, this person did not show the 5% data basis, but said that he was heard at an internal meeting of the State Grid System. The source also claimed that the State Grid Corporation also analyzed each faulty electronic transformer one by one, with different conclusions. For example, the explosion of the electronic transformer in the Beixing 220KV substation is not in the manufacturer's Nanrui, but is the supply of Nanrui. The capacitor voltage divider provided by the company has quality problems; Xi'an Huawei and Xinning are caused by their own reasons, but for what reason he does not know.

A newspaper issued by the State Grid Corporation of China on January 13, 2012 issued a "Notice on Effectively Strengthening the Management of Electronic Transformers" (hereinafter referred to as "Notice"). The documents show that the State Grid Corporation does The frequency of transformer faults is highly vigilant and measures to reduce risks are proposed. According to the document, "In recent years, with the development of the company's smart grid, nearly 2,000 units of various types of electronic transformers have been put into operation. Operational conditions indicate that due to the weak design capabilities of some manufacturers and the lack of strict process controls, test and test equipment Incomplete, the failure rate of electronic instrument transformers in transport is much higher than that of traditional transformers, which has a certain impact on the safe operation of the power grid." The "Notice" requires all operational subordinates to subordinate companies, "when the relay protection device is not integrated or In most transformations, transformers should not be replaced with electronic transformers; based on the current maturity and cost-effectiveness of electronic transformers, it is not appropriate to digitally transform 35KV and below transformers. The company's attitude is that the current electronic transformer technology is not yet mature, for safety reasons, some do not need to replace the new electronic transformer, try not to change, the traditional transformer performance is stable, reliable, in some projects Will be preferred.

Although smart substations are designed to be unattended, based on the current high failure rate of electronic transformers, State Grid Corporation has proposed a number of suggestions to enhance the operation of electronic transformers.

Smart grid or deceleration In the middle of last year, the State Grid requested the construction of smart substations in Changchun to speed up the construction of smart power transmission and transformation projects. Since then, Liu Youwei, deputy director of the Strategic Development Research Center of the China Electric Power Academy, a research institute directly under the State Grid, said in an interview that during the “Twelfth Five-Year Plan” period, the State Grid will build about 5,000 smart substations nationwide. He explained that the 5,000 seats are not all newly built, and some will use intelligent transformation, but "we must intelligently upgrade all the substations to be built."

According to a research report of Shanghai Securities, due to the construction of smart substations, by 2020, the total investment for smart transformers will increase by 350 billion yuan, the total investment for smart switches will increase by 280 billion yuan, and the total investment for new transformers will increase by 90 billion yuan.

An electronic component manufacturing company executive revealed to this newspaper that due to the current technical instability of the electronic transformers, the State Grid Corporation may slow down the advancement of the smart grid, and it will always be the safest place for the grid. . “In the widespread application of new technologies and new products, large-scale promotion, some problems are exposed. This time, we need to slow down and think about how to solve these problems.”

According to Pan Jimeng, chief engineer of the Liuzhou Bureau of the South Network EHV Transmission Company, all this need not be too worried. “Actually, these problems are not significant. The problem is only a part of the electronic transformer. Now we are careful about the application. With the gradual maturity of technology and products, there will certainly be no problem.”

The investment community is still optimistic about the smart grid. Zhou Sili, assistant director of the Northeast Securities Research Institute, believes that the problems will not affect the progress of the entire smart grid investment. The State Grid tender is still on schedule. "Not that transformers can't be done anymore after being bombed several times. This can be improved. For example, ultra high voltage equipment, 5 years ago, don't say UHV, or UHV, we can't do it. Nowadays, there are several major transformer companies in China. Isn't it also doing UHV equipment? It's all running on the grid. We don't have to worry about several accidents. It's not as bad as it is in the industry. After all, China's manufacturing capabilities are still there." Zhou Sili said .

However, it is worth noting that, not long ago, State Grid Transmission and Distribution announced the first batch of centralized tendering projects in 2012. Although the speed of smart substations is still rapid, the transformer tendering scale is down by 18.04%.