Text/Photo by Yangcheng Evening News reporter Ma Can
"The substation that is several floors high is only separated from the community by a wall. Why not build it in a place with few people?" "Is there any radiation in the substation?" "The substation is downstairs. In the past few days, the reporter has received a lot of doubts about the "substation around" from the neighbors.
To this end, a reporter from the Yangcheng Evening News walked into the Guangzhou Substation Science Center and interviewed electric power experts to answer these questions one by one through this report.
Why build substations in urban areas?
What does a substation do?
According to reports, the substation is a place where the voltage is changed. Its main function is to boost or step down the electricity generated by the power plant. It is an important infrastructure to ensure everyone's electricity consumption.
why do you say so?
The reason for this is the inevitable loss of current in the transmission line.
In order to transmit the current farther, the electric power needs to go through the step-up substation to raise the voltage to a high voltage level, and then cross the mountains and rivers from the power line to the cities and villages; The required voltage level is transmitted to thousands of households.
"Why is the substation not far from us and must be built in the city center or in the residential area?" asked the neighbor Chen Bo.
It is reported that electricity is closely related to people's lives. With the improvement of living standards, people's demand for electricity is also increasing, but the power supply capacity of substations is limited.
For example, in an urban power-consumption-intensive area, a 110 kV substation usually only covers a power supply area of about two square kilometers. Exceeding this range is likely to lead to reduced power supply quality and unstable voltage.
Users can enjoy reliable and high-quality electric energy only if the substation is located in a location where the load is concentrated and the power supply radius covers as many users as possible. Therefore, the substation needs to be built near the city center and residential areas.
This is like a bus station. When the number of residents in the nearby community increases and the travel pressure increases, it is necessary to add a bus station nearby to facilitate the travel of citizens.
At the same time, when the city develops to a certain scale, the power grid needs to add more substations, so as to ensure that the entire load will not be lost in the event of extreme natural disasters.
Do substations generate electromagnetic radiation?
People talk about "substations" and change their color, mainly worrying that the "electromagnetic radiation" generated by the substations will be harmful to the human body.
To this end, the reporter came to the "Moonlight Treasure Box" in Guangzhou Zhujiang New Town - 110 kV Liebiao Substation (also known as Guangzhou Substation Science Center) to find out.
"In fact, the substation does not generate electromagnetic radiation, but there is an induced electric field and an induced magnetic field." He Zhihui, a famous environmental protection expert in Guangzhou and a senior engineer at the former Guangzhou Environmental Monitoring Center Station, said that electromagnetic radiation is energy in the form of electromagnetic waves. phenomenon, or energy propagates in space in the form of electromagnetic waves (according to "Electromagnetic Compatibility Terminology" GB/T4365-1995).
The energy derived from electromagnetic radiation depends on the frequency: the higher the frequency, the greater the energy.
In the Guangzhou Substation Popularization Center, it is equipped with professional facilities and instruments, which can conduct on-site inspection of substations.
The reporter saw that after testing, since the frequency of the power equipment in the 220 kV and 110 kV substations is 50 Hz, it produces a very low-frequency electromagnetic field (similar to the electrostatic effect generated when taking off a sweater in winter), which is impossible. Energy is transferred in space in the form of electromagnetic waves, so the actual impact of substations on the surrounding is mainly based on electromagnetic induction effects, rather than electromagnetic radiation.
The test data also shows that the magnetic field strength of the substation is only a few percent or a few thousandths of the national safety limit standard value, which is far lower than the national standard.
In the actual measurement interaction of electromagnetic induction, by comparing the values of home appliances, it is found that the electromagnetic induction value of the substation is far lower than the value of the home environment.
Liede villager Mr. Li said that when he heard that a substation would be built nearby, many villagers were worried about radiation. "I only learned from the on-site inspection that the electromagnetic induction value is not as good as that of the hair dryer at home."
In addition, in 1996, the World Health Organization (WHO) cooperated with more than 40 countries and carried out the "International Electromagnetic Field Research Program" which lasted for 10 years, and the National Institute of Environmental Health NlEHS of the United States cost 45 million US dollars and completed the "Electromagnetic Field Research and the Public" which lasted 6 years. The data dissemination plan” has concluded that the electromagnetic fields of power transmission and transformation facilities will not cause harmful effects to human health.
In fact, the most intuitive status quo is that employees of the power sector work in substations every day, including 500kV and 220kV substations, overhead lines, but do not need to do any radiation protection, and their health is not affected in any way.
He Zhihui said that in fact, electromagnetic induction is common in nature. The earth itself is a large magnetic field, and we live in a magnetic field all the time.
Modern substations are getting smarter and greener
It is the requirement of the times and the expectation of the people to integrate the development of modern cities with energy and power.
For a first-tier metropolis like Guangzhou, the requirements for the "quality" and "quantity" of power grid facilities will only be higher, including more reasonable site selection and planning and construction, smarter and greener functional upgrades, and better integration into the power grid. Residential living and urban landscape exterior design.
Taking technological innovation as an example, in the 13 years from 2008 to 2021, the number of substations of 110 kV and above in Guangzhou has doubled, but the number of substation workers has not increased.
The extensive application of informatization and Internet technology in administrative office and information communication has completely changed the working mode and method of traditional substation employees, and the intelligent operation and maintenance center has been gradually established.
With the blessing of comprehensive automation technology, unattended substations have also emerged.
In terms of green environmental protection, the biggest feature of Guangzhou's substation construction today is the integration with the urban landscape.
The 110 kV Yiyuan substation has become a beautiful scenery line in the golden position of the first-line river view in the CBD and next to the Canton Tower.
The design of the station follows the principle of harmonious development between man and nature. By optimizing the architectural aesthetics, reducing the height of the building, and adopting "vertical greening", the relevant person in charge of the Guangzhou Power Supply Bureau said that this kind of full use of wind, light, water, soil and other resources, Further reduce energy consumption and achieve sustainable development.
The 220 kV Knowledge City Substation in Huangpu District, Guangzhou is the first 220 kV indoor substation in Guangzhou with a building photovoltaic power generation system.
It is designed and constructed in accordance with the green substation standard. Through renewable energy utilization and building integration technology, large-scale integrated solar photovoltaic utilization, it saves 18% of the power consumption in the station.
According to reports, another major feature of the station is that it generates electricity while shading and heat insulation, thereby effectively reducing building energy consumption.
At the same time, the station also takes the building layout as a breakthrough, and adopts a built-in ventilation corridor layout inside, which effectively improves the ventilation effect, effectively reduces the spread of indoor noise from the main transformer to the outside, and allows the substation to “breathe” independently.
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Substations witness the development of the city
In Guangzhou, the appearance of substations and the trajectory of economic and social development of the entire city are interdependent and resonate at the same frequency.
In 1958, Guangzhou's first 110kV substation, Yuancun Substation, was in operation; in 1994, Guangzhou's 100th substation, 220kV Chisha Substation, was born; in 2014, Guangzhou's 300th substation - 220kV " Liuyuan Substation" was officially put into operation, and Guangzhou became the first provincial capital city in China with 300 substations of 110 kV and above.
From 1 to 100, Guangzhou took 60 years, from 100 to 200, it was reduced to 14 years, and from 200 to 300, it took 6 years.
The surge in the number of substations is evidence of the rapid economic development of Guangzhou and the continuous improvement of people's living standards.
As of 2021, Guangzhou has 387 substations of 110 kV and above.
From 100 to 300, from 13.2 kV to 500 kV, from the suburbs to the city center, the development of Guangzhou substations has been moving forward.
The rapid development of substations has brought more abundant and stable power support to Guangzhou.
Data show that in December 2021, the electricity consumption and power supply of the whole society in Guangzhou both exceeded 100 billion kWh.
In 2021, the average power outage time for full-caliber users in Guangzhou will be less than 0.41 hours, entering half an hour for the first time, and entering the ranks of the world's most popular.