State Grid ensures power demand of market players

At Jiangsu Longheng New Energy Co Ltd in Suqian, ensuring sufficient and stable electricity supply for the enormous plant, built at an investment of over 10 billion yuan ($1.37 billion), is what electricity manager Qiu Lei cares the most about.

Longheng, introduced to Suqian — a prefecture-level city in East China's Jiangsu province — by the local government in 2019, has been fast expanding and is in need of professional and personalized power services, Qiu said.

In December 2022, to meet the current and future power demand of its Phase III plant, Longheng applied to the local power supplier to build a 220-kilovolt transformer substation with a new 220 kV power supply line and a 150-megavolt ampere main transformer.

Suqian Power Supply Co of the State Grid immediately sent employees to the factory and discussed with Qiu on the design of the substation. The station, with a main transformer working as a core component, can receive high-voltage energy from the local power network, and distribute it to the factory after reducing the voltage.

State Grid, a State-owned enterprise and the world's largest utility crucial to China's energy security and economic lifeline, is charting innovative ways to ensure sufficient electricity amid a growing number of market players.

With six rounds of on-site services and professional guidance, the Suqian unit ensured the smooth operation of the substation on Oct 16 in Longheng, leading to "many thanks" from Qiu.

Qiu told Yan Kang, a staffer from the power supplier's market and key customer service workshop, "Your work has met our production and energy needs on time."

At Suqian, there are currently over 862,200 market players, a rise of 14.11 percent year-on-year. Among these, 2,300 are large enterprises with annual business income of at least 20 million yuan each.

As the municipal government makes every effort to turn Suqian into a city "with the best business environment in Jiangsu", Suqian Power Supply Co has put optimized power supply as one of its top six jobs this year.

As large local enterprises have a greater need for more substations, technical innovations are being made to meet the growing demand and avoid problems.

Zhongqi (Jiangsu) Solar Energy Technology Co Ltd, a local enterprise engaged in the production and supply of electricity and heat, applied for the construction of a new 110 kV substation in February.

According to rules, a 110 kV substation is required if the power need of an enterprise is above 20,000 kVA. This made the power workers think of better innovations.

Li Li, director of the power dispatch control center of Suqian Power Supply Co, noted: "In recent years, as a large number of substations for our clients were put into operation, and the level of operation and maintenance has been uneven, we faced hidden dangers to the safe operation of the grid.

"For example, staff in some companies did not disconnect their grounding switches due to improper operation, resulting in power transmission with the grounding switch, posing dangers to the grid."

In July, Li's agency started joint scientific and technological research and development with some mainstream equipment manufacturers, and two months later, an "error prevention device" for substations and main power networks was developed.

On Oct 31, the equipment was installed in the new 110 kV substation for Zhongqi. Since the start of this year, 10 other enterprises also applied for such 110 kV substations.

The device, consisting of a fiber optic signal-receiving module and an error prevention node output module, considers two such devices as one set.

For Zhongqi, one device was installed in its substation, while another was in the Liyuan 220 kV substation of Suqian Power Supply Co, ensuring the real-time transmission of the grounding switch's position signals at both ends.

If the grounding switch at the user's end is not disconnected, the Liyuan substation would automatically lock up to avoid improper power transmission.

So far, Suqian Power Supply Co has installed such devices on power lines and four substations in the local region, largely improving the safe operation level of clients' substations.

Contact the writers at zhuangqiange@chinadaily.com.cn