In the context of building a new power system - how to optimize power grid dispatching

China Energy Storage Network: At present, as the proportion of new energy increases year by year, the safety foundation of the power grid is changing, the mechanism of power grid operation is changing synchronously, and the dispatching method must also evolve accordingly.

Grid dispatching is the core link for the safe and stable operation of the power system. With the iterative upgrade of the power system, grid dispatching also needs to make corresponding changes.

At the seminar on "Thinking about the underlying logic of the new power system - how to achieve low-carbon supply under the dual carbon goals" held recently, Xu Xiaodong, senior consultant of the State Grid Planning and Design Institute, publicly stated that "my country's existing power system has high carbon emissions and is not suitable for the development goal of carbon neutrality. When new energy is developed as the main energy source, it is necessary to consider allowing new energy to play a greater role in ensuring system security and power supply. The current grid dispatching method is still mainly oriented towards the planned dispatching method based on conventional power sources, which is relatively rigid."

So, in the new power system with new energy as the main body, how should the grid dispatching model be optimized and upgraded?

Coping with peak load and new energy challenges

It is understood that the current power grid load has a significant "peaking" characteristic, showing a "two peaks and two valleys" characteristic of higher loads in summer and winter and lower loads in spring and autumn. At the same time, new energy sources have replaced conventional units in large quantities, and the system's frequency regulation and voltage regulation capabilities have declined significantly.

So, in this case, can the traditional power grid dispatching method still work?

"To develop a high proportion of renewable energy on a large scale, achieve low carbon and decarbonization of the power system, and ensure safe and stable operation of a high proportion of renewable energy systems, a new power system must be built." Xu Xiaodong believes that "in the future, market players will shift from single to diversified, and power transmission will shift from generation, transmission, distribution and use to flexible 'source, grid, load and storage'. The traditional control and operation system is not suitable for a flexible market environment."

However, a staff member of the Guangdong Dispatching Center told reporters that the current dispatching system is constantly upgrading with the access of new energy sources. "With the deepening understanding of the operation and control system of the new power system, the dispatching system realizes that it is necessary to strengthen the detection and analysis of new energy sources and the external environment, improve the ability to perceive events and control risks, and rely on the existing advanced information and communication technology to achieve the overall coordinated control of massive and broad new energy sources."

Traditional dispatching needs to adapt to the development of power system

It is understood that the traditional dispatching method is for the dispatching agency to make overall considerations in accordance with the national mandatory plan, the framework agreement between local governments, the annual and monthly power purchase plans and other medium- and long-term plans, combined with the system operation status on the second day, the load forecast level and other conditions, in accordance with the principles of unified dispatching and hierarchical management.

Zhou Ji, director of the Technical Management Department of the National Electric Power Dispatching and Control Center, said that at present, the security foundation of the power grid is changing. As the proportion of new energy increases year by year, the operating mechanism of the power grid is also changing accordingly.

"The stability characteristics of power electronic equipment are characterized by low rotational inertia, strong nonlinearity and weak anti-disturbance. In addition, the dispatching control mode needs to be adjusted according to changes in the system. This requires that traditional dispatching plans be closely integrated with the current market-oriented power reforms." Zhou Ji said.

Pan Ersheng, president of the State Grid Economic and Technological Research Institute, believes that with the large-scale grid connection of highly random and volatile new energy sources and the large-scale access of interactive devices such as electric vehicles and distributed power sources, dispatch automation requirements are higher. "In order to achieve the goal of clean and low-carbon development, it is necessary to coordinate the dispatch of all system resources in real time, establish a coordinated interactive mechanism between sources, grids, loads and storage, and develop technical support means for the power market to meet higher requirements for dispatch compliance, refinement and information transparency."

How to adapt dispatching to the new power system

Zhou Ji pointed out that this year, the power grid has specially deployed eight major scientific and technological projects, two of which are related to dispatching. "One is to improve the technical research on the security defense of high-proportion new energy access to the power system; the other is the analysis technology research on the carbon peak and carbon neutrality goals."

"We need to use scientific and technological innovation to cope with new changes and new situations," Zhou Ji said. "We need to accelerate the research on the basic theory of stability of dual-high power systems, enhance the full electromagnetic simulation and analysis capabilities of large power grids, and comprehensively improve the scale and efficiency of calculations to meet the needs of the operation of new power systems. At the same time, we need to enhance the resilience to power grid failures and the recovery capabilities of power systems."

An expert in the power market said that in addition to the upgrade of the dispatching system itself, in the future market-oriented environment, dispatching behavior will have a greater impact on the interests of market members. With the increase in the degree of information disclosure and the strengthening of social supervision, dispatching must improve the lean level of dispatching decisions while strictly implementing relevant technical standards in accordance with laws and regulations to achieve the coordination and unification of power grid security and market efficiency.