Source: China Enterprise News Author: Yu Yixin
For us, the intelligence of power grid is actually the second intelligence. The first time of intelligence was from 1970 to the beginning of 1980, when power grid blackouts occurred frequently, represented by the blackouts in New York, so the United States government at that time required power companies to use computers, so in the power system, 2TU was installed on the ultra-high voltage transmission lines of large power plants, and some data were sent to the dispatching center, The dispatching center has developed an energy management system for the safety analysis and optimization of the power grid. At that time, there was no development to the distribution network, that is, the power grid below 110 kV. Now, a large number of power grids in the city are not intelligent, because the price of communication technology, information technology and some power electronic technologies at that time was too expensive to afford.
The current situation has changed. Because communication and information technologies are too cheap, it is very appropriate for us to do this cost-effectively. So this time, we will focus on the first shortage, that is, power distribution. Of course, in the field of power generation and transmission, it will also continue to improve.
The whole driving force of the intelligent power grid this time includes market factors, safety factors and environmental factors, among which the environmental factor is particularly prominent. Because it is time to limit the emission of carbon dioxide in the atmosphere, especially in China, the problem of air pollution makes us feel that this problem is very urgent, so the driving force of this time is far greater than that of the first time.
First, let's look at renewable wind and solar power generation. Our country is extremely rich in wind and solar energy resources, and the price advantage is increasingly obvious. We have no energy crisis. The solar energy resources on the earth are 100 times that of wind energy, and the wind energy resources are 100 times that of water energy.
There are resources, but the problem is how to cover them. You can use roofs, roads, fish ponds, farmland, etc., as well as deserts and mudflat. In fact, 76% of China's land area can be installed with wind turbines, and 100% of China's land can be installed with solar energy. China's conditions are very good. As you know, Germany's solar energy utilization is very good, and our resources are much better than Germany's.
Let's look at photovoltaic. The price of PV and wind power has gradually declined over the years, especially for PV, which has decreased to 1% from 1987 to 2013, and is still declining at the rate of 15% per year. Considering the cost of the whole society, including investment, operation cost, fuel cost, reliability cost, environmental cost, network loss, etc., if the power generation from 2000 kilometers away from the northwest region, such as wind energy, is sent to the east region, the total cost is probably more than 90 cents. If it is developed and utilized on the spot, it will cost more than 60 cents now. So now it is more cost-effective to develop and use on the spot.
But what is the problem when using it? That is, wind energy and solar energy are intermittent, fluctuating and uncertain, which makes it difficult to use them. Therefore, some measures are needed. The power system needs some smoothing measures. These smoothing measures include the adjustable energy of large thermal power generation units, including energy storage, user demand coordination, and other factors. But to make good use of these factors, we need the power grid, which is the smart grid.
The general idea of smart grid is to use new energy, internet and other new technologies to realize smart grid. What is the result to be achieved? It is to change people's way of life and work like the Internet. At present, we are actually a smart power grid. The smart power grid we are building now is the power grid that can be realized by using existing good technologies or technologies that may be available in the next few years.
There is no clear definition of smart grid now. The characteristic of smart grid is the two-way flow of power and information, so as to establish a highly automated and widely distributed energy exchange network. In order to exchange information in real time and achieve near-instantaneous balance of supply and demand at the equipment level, the advantages of distributed computing and communication are introduced into the grid. Two words: the smart grid is a power network and a communication network. The two networks have been combined since the basic electrical equipment. The purpose is to build a highly automated and widely distributed energy network. When we started to build smart grids, we all recognized automation, but we were too slow to recognize widespread distribution, which actually brought great economic losses to our country.
The second sentence is to achieve real-time information exchange and near-instantaneous balance of supply and demand at the equipment level, which are two more things. Information sharing is the core content of smart grid. Power balance. The power of the grid must be close to the balance between supply and demand on time, otherwise the grid cannot operate safely. Now that users can cooperate with the grid, then our load and power generation can be controlled. This is a very important feature of smart grid.
What are the engineering problems of smart grid? One is wide-area monitoring and control. In the past, the data measured at each point in a large range of power grids, hundreds of thousands of kilometers, were sent to the dispatching center differently because of the test. Now with satellite positioning, you can use GDS or Beidou satellite to locate, and the data sent can be marked, which is a big change. It should be said that our country's wide area measurement system is a well built system in the world, but there is still a lot of work to develop its potential.
The second is the integration of communication and information technology. The third is the integration of distributed renewable energy generation. The fourth is the expansion of transmission system. The fifth is the management of distribution network.
There are two common terms in intelligent distribution network: one is microgrid, and the other is active distribution network.
Because the traditional power grid has no power at the level of distribution, it is distributed from the large power grid like a tree. Now that there is power at the end of the tree, the traditional power grid cannot adapt to it. Therefore, it needs to be able to adapt to these distributed power sources in the distribution network. The power grid that can measure and control distributed power is called active distribution network.
In the intelligent distribution network, we often hear a term called microgrid.
The microgrid is a part of the distribution network. There are both power generation and load in the grid. There are important loads and controllable loads in the load. The whole area is relatively independent from the power grid company, so it is particularly suitable for an enterprise or a community.
In the future, micro-grid will be very common. At present, micro-grid can smooth the volatility of distributed wind and solar energy, and the investment is relatively high. Therefore, it is mainly used in areas with high reliability requirements, such as military departments or hospitals, or desert areas, remote areas, or islands. It will be expanded in the future.
In terms of user demand coordination, in order to achieve demand response, the communication system needs to be established. What we need to complete now is to drive the improvement of the one-kilometer communication line at the end of the entire power grid through the user's electricity meter. Because the above communication line has been built well, this improvement is not only good for the power grid, but also provides an opportunity for the development of smart cities.
The data provided by smart meters now accounts for about 40% of the total power big data. This part of data has many uses to be developed. China's smart meters have installed 400 million, which is probably much higher than the smart meters of all countries in the world combined. But the problem now is that our communication system cannot send all the data quickly, and the communication system needs to be further improved and improved. On the other hand, we need to pay attention to the realization of real-time sharing of data. At present, the islanding of data is more prominent. Some data even remain in the hands of some teams and cannot be shared by others. In this way, the whole big data cannot play its due role. Therefore, we need to carry out reform and open the market. These two things need to be noticed in the development of any new technology.
What is the benefit of smart grid? According to two estimates of the American Academy of Electric Power Sciences, the direct benefits of improving reliability, improving economy, reducing network loss and so on are about four times the investment.
It should also be noted that the smart grid is actually an enabler and a promoter. We say that the Internet is "Internet plus", and the smart grid is also "smart grid+". After the implementation of the smart grid, because of the wide range of technologies, it can provide new energy technologies, communication technologies, software technologies, automation technologies, and energy storage technologies, including electric vehicles, advanced sensor technologies, power electronics technologies Smart appliances and other aspects provide huge business opportunities, and this market is very large.
According to Cisco's estimation, the benefits of smart grid may be 50 times that of the Internet, but then the IOT came out, and smart grid has become a typical part of IOT. In this way, we know that the Internet of Things is a disruptive technology in the 21st century. What is one of the most important meanings of disruptive technology? Its market scope is too large, so the market provided by smart grid as a typical Internet of Things is very large in the future. Our country must seize this opportunity.
