Micro-balance trading mechanism will be the key and breakthrough point of energy Internet

Energy Internet is a future development trend and will be implemented. Its construction is of great significance to my country's energy. Energy Internet breaks through the constraints of fossil energy, optimizes the energy structure, and makes energy transactions more free, enabling surplus energy to be connected to the Internet, free transactions, and market pricing.

Taking into account the open market transactions and demands of the Energy Internet, it is necessary to establish a supply and demand interaction mechanism that is different from the traditional trading model. Therefore, the micro-balance trading mechanism for the Energy Internet will be the key point and breakthrough point.

By Liu Dunnan (Deputy Director of Energy Internet Research Center, North China Electric Power University)

New term explanation: Micro-balance trading

Improving efficiency and achieving goals are important principles of the market economy and important rules summarized from traditional organizational management experience. The market economy is a complex large system, and the overall optimal purpose of the system can be achieved by solving the optimal control of the relatively independent but interdependent and mutually constrained subsystems in the large system.

Micro-balance trading is based on the principle of large system decomposition and the basic idea of ​​coordinated control. It organically combines centralized decision-making with decentralized decision-making to establish an economic trading system with multi-level, decentralized, coordinated and optimal control performance.

The necessity of promoting micro-balance transactions in energy internet

①The need for the development of distributed power sources.

Distributed power sources are relatively dispersed in space and use new and renewable energy to supply or generate electricity. Compared with traditional energy production equipment, distributed energy equipment is clean, environmentally friendly, flexible and efficient. It can achieve cascade utilization of energy and improve energy efficiency. Distributed energy equipment is often close to the demand side and is used to match local energy supply with demand. With the support of the country, a large number of distributed power sources will be connected in the future. Due to the randomness and dispersion of distributed power sources, it may have a certain impact on the safety and stability of the entire distribution system. It is necessary to increase energy storage facilities and rely on the dispatch guidance and support of the main grid.

②The needs of microgrid development.

Microgrid is the basic unit of energy Internet, which can realize the complementarity of multiple energy sources and allow multiple energy access, including hydropower, photovoltaic, wind power, gas, fuel, energy storage, fuel cells, and can achieve continuity and stability of energy supply. It can independently supply energy and operate independently when disconnected from the main grid. Microgrid can achieve instantaneous balance of power in a small range, while distributed energy represented by photovoltaic power generation and wind power generation has strong randomness and volatility, which increases the difficulty of operation and control of microgrid. Although it has more complex composition and multiple operation control strategies, it still needs to be connected to the main grid through tie lines for two-way energy exchange to achieve power balance.

③ The decision-making needs for self-generated and self-used surplus power to access the Internet.

With the development of energy internet, it will eventually move towards the consumer end and attract energy users to participate in energy interaction. The emergence of smart communities, smart homes, electric vehicles, combined heat and power, and intelligent system development has transformed the flow of energy from the previous one-way flow to two-way interconnection and interaction, and energy users are both energy consumers and energy producers. Under a scientific and reasonable mechanism, energy users participating in power balance transactions can not only improve their own energy costs, but also improve the flexibility and efficiency of the energy network, and ultimately achieve a "win-win" situation for the energy network.

④The integration of information provides the possibility for more efficient decentralized decision-making.

In the energy internet, the sources of data are widely distributed and in large quantities. There is information from distributed power generation, energy storage, and power consumption devices, as well as information from the transmission and distribution network and its equipment. The types of information are also diverse. In addition to information related to electrical quantities, there is also non-electrical quantity information including temperature, humidity, pressure, wind speed, etc. These massive amounts of data and information can be transmitted through the developed Internet, which reduces the cost of information acquisition compared to traditional energy management. The lower the cost of information acquisition, the higher the degree of decentralization of spontaneous and autonomous energy transactions between individual energy suppliers and users, and the optimal allocation of resources also develops from the original centralized to decentralized.

The difference between energy internet micro-balance transactions and traditional power grid centralized balance

The traditional energy and power industry conducts dispatching business under the three-level management model of national, grid and provincial levels, and is coordinated and controlled by a unified grid dispatching and control system. The provincial power trading center is responsible for the overall balance of the province, and is in charge of the province's units, loads and inter-provincial exchange information. Information on all power plants and substations in the system is concentrated in this central dispatching and control center. The dispatching agency directly determines the operating mode and output plan of each unit, which is a centralized resource allocation method for optimized decision-making.

The power grid under the energy Internet is huge in scale and complex in operation. The regional resource allocation of each network is uneven, and there are obvious differences in time and space. Some areas have high-penetration distributed resources. The forms of energy supply and consumption are also flexible and changeable, and centralized scheduling cannot ensure the depth of optimization.

Microgrid is the terminal nerve tissue of energy Internet. In the autonomous mode, each microgrid unit in the region is responsible for the local consumption of energy under the control target of the main grid. There is no power exchange with the main grid. At the same time, the load situation and energy level are reported to the upper level. The control center of the main grid supervises and verifies the operation of the power grid. When the microgrid fails or the autonomous operation fails to ensure the energy and load balance in the microgrid, the main grid will use the microgrid as a flexible load and provide auxiliary services, such as energy and load transfer, demand-side response, and intelligent switching of distributed power grids for power exchange, so as to ensure the safe and economic operation of the microgrid. Ultimately, each region of the entire power grid system ensures micro-balance, achieves cross-regional and cross-energy form coordinated balance, and optimizes the energy balance between multiple energy sources, so as to maximize the comprehensive energy efficiency of the energy operation of the entire system.