China is becoming the world leader in smart substation technology

With the continuous development of wind energy, solar energy and other renewable energy sources , the national grid system is brewing to "intelligence."

However, the amount of electricity produced by renewable energy sources fluctuates greatly with changes in weather conditions. For example, when there is no wind, the blades of wind power generation basically do not rotate; the sun cannot reach and solar power generation does not play much. Once it is added to the grid, it will cause frequency changes to the grid system, causing voltage rises and how to absorb surplus power. This requires the grid system to become more "wisdom." The concept of "smart grid" that has been frequently mentioned in recent years was originally intended to solve similar problems.

But what are the opportunities for smart grids? In which areas can state-owned assets flex their muscles? Perhaps one or two words are not clear, the right to start from doubts.

Battery and Smart Grid

In the power grid, it is very important that the output of power generation be consistent with the demand. If the output exceeds the demand, the frequency will increase. On the contrary, the frequency will decrease. To ensure the quality of electricity, it is necessary to stabilize the frequency.

At the beginning of the beginning, the amount of electricity generated by wind power and solar power generation was very small, and the power grid (power system) could absorb changes in its output. However, with the increase in the amount of electricity generated by this part of the grid (a goal of the plan is 20%-30%), it will soon exceed the current grid's absorption capacity. The direct consequence is that the frequency of the power system will change accordingly, causing power outages or reducing the quality of power supply. For example, at present, the standard voltage of our national grid is 220v, and the voltage setting of household appliances is also 220v. If wind energy and solar power systems are directly integrated into the power grid, their voltage will rise according to Ohm's law, exceeding 220v. In this way, all the appliances in your home will be completely abandoned.

In order to ensure the stability of power grid operation, one solution is to use large batteries and controlled through a sensor. The specific approach is: for the energy output of wind power generation and solar power generation, the use of batteries as a buffer to ensure the stability of the power grid; and then install sensors in the network, used to monitor (ie load control) ordinary houses, office buildings, factories and other power users The electricity demand (load), so that both the power generation and the load side can achieve optimal control.

This is the embryonic form of the "smart grid."

Expo site

The 2010 Shanghai World Expo Park is an experimental venue for the exciting display of the Chinese version of the "Smart Grid."

State Grid named the "smart grid" as "Strong Smart Grid". It is said that "Strong" means building a high-reliability power grid with less power outages, and "Smart" means building a power grid that can use communication to grasp power supply. According to the relevant interview of "Technology Online", the focus of the strong smart grid will be "even if the import of renewable energy with unstable output power can also stabilize the operation of the power grid."

As we all know, the Expo site is a gathering place for solar power generation. Among them, China Pavilion, Expo Center, Theme Pavilion and future museum attached to each of 302kW, 1040kW, 520kW and 2825kW solar power generation facilities, the total installed capacity of solar cells on the main facilities more than 4.68 MW.

These power generations are all connected to the “strong and smart grid” in the Expo site. Because there are 32 10kV substations and 200 step-down transformers installed in the park . Part of these devices are configured with a server, thus build a network to collect power information.

This “strong and wise” power grid works like this: it keeps abreast of the solar cell power generation in the Expo site, the power consumption of major facilities, the power consumption of air-conditioning and lighting equipment, and the power supply and demand of electric vehicles that can be charged and discharged. Quantity, etc., also confirm the electricity bill. The collection of power information uses self-developed communication lines bundled on optical fibers and power lines. One of the more cattle is: When a fault such as a broken wire is detected, this system can automatically switch to the other path's power system and repair it.

In the surrounding residential communities outside the Expo site, smart metering pilots were conducted to collect and analyze data on household electricity using an energy management system.

New market opportunities

After the World Expo, more and more comprehensive demonstration parks have emerged in China's "smart grid."

Recently, as the first comprehensive smart grid demonstration project in China, the Sino-Singapore Tianjin Eco-City Smart Grid Project, Hekang Road 110 kV smart substation, was basically completed and entered its voltage equipment commissioning phase. This is also Tianjin's first smart substation. On March 30th, the “Smart Grid Comprehensive Demonstration Project” construction plan of Yangzhou Development Zone also passed the review of State Grid Corporation.

Earlier, the State Grid has already completed and put into operation 7 kilovolts of Sichuan Beichuan and 220 kV Qingdao and seven smart substations at the beginning of the year. Smart substation is one of the core platforms for achieving energy conversion and control in the construction of strong smart grids. It is an important component of the smart grid and an important support for the integration of new energy sources such as wind energy and solar energy into the grid. As the key to connecting the smart grid power generation, transmission, transformation, distribution, electricity and dispatch, the smart substation can better meet the requirements of smart grid information, automation, and interaction in technology and function.

Undoubtedly, China's strong smart grid construction has achieved major breakthroughs and is becoming the world leader in smart substation technology.

More importantly, during the “12th Five-Year Plan” period, the State Grid will invest 500 billion yuan to build a “three horizontal and three vertical” UHV backbone backbone and 13 long-distance tributary transmission projects connecting large energy bases and major load centers. Initially built a core world-class strong smart grid. The three synchronous power grids with "Sanhua" (North China, Central China and East China) as strong receivers and Northwest and Northeast China power grids as strong delivery terminals have been established. The trans-regional transmission capacity has reached 250 million kilowatts, and the national grid's resource allocation capability and economic operation have been established. The level of efficiency, safety, technology, and intelligence will be fully enhanced.

The smart grid combines the power transmission and information technology to achieve two-way transmission of electricity, intelligent regulation and reasonable balance of transmission and distribution and electricity consumption. This undoubtedly brings more market opportunities.

Installing the battery in the power grid and achieving the best balance between supply and demand through load control is the ideal state of the smart grid. To achieve this ideal state, in addition to the traditional power system technology and products, may also need some new systems. For example, batteries, smart meters, load control devices, etc.

According to reports, the key technologies of smart grids include high-speed, two-way, real-time, integrated communication technologies, parametric measurement technologies, equipment technologies, control technologies, and support technologies. In terms of smart meters alone, components such as sensors and communication modules are included, as well as components for measuring the power consumption of external devices. Compared with ordinary electricity meters, it has more functions such as communication, electricity management, electricity billing and so on.

At present, the world's leading manufacturers have entered the smart grid market. In addition to general power (GE) and other leading power companies, there are also giant electronics companies such as IBM and Intel.