On November 12, 2020, a technical report entitled "Optimal power system planning under growing uncertainty" completed by C1.39 Working Group of CIGRE (Conference International des Grands Reseaux Electriques) in 4 years was officially approved by CIGRE and published on its website https://e-cigre.org/. Professor Kang Chongqing and Associate Professor Zhang Ning of EEA, Tsinghua University served as the convener and secretary of the working group respectively.

Fig. 1: Cover and Contents of the Technical Report of CIGRE C1.39 Working Group

CIGRE, the most important international organization in the field of large power grids founded in 1921, consists of 16 study committees in four fields: electrical equipment, electrical technology, power systems and new electrical materials and information technology, and each technical committee sets up 1 to 2 technical working groups each year to study the new challenges and solutions in the own technical field. The C1.39 working group was proposed and planned by the Technical Committee C1 during the CIGRE conference held in Paris in August 2016, and was formally established in 2017. The working group consists of 28 power industry experts and university scholars from 17 countries on 6 continents. The C1.39 working group has implemented for more than four years and organized a number of international exchange seminars in Dublin, Paris, Chengdu and other places, as well as online sessions on CIGRE 2020 Session platform during the pandemic.

Fig. 2: Schematic diagram of countries where CIGRE C1.39 working group members are located

Fig. 3: Group photo of some members of the working group in the CIGRE Paris Seminar 2018

The technical report released this time summarizes the measures and methods of various countries or regions in the world to deal with the increasing uncertainty challenges such as the high proportion of renewable energy incorporated to the grid and the change of load structure in power planning. Focusing on the theme of power system planning under the environment of great uncertainty in the future, the working group has carried out sufficient investigation and research on the current situation in many countries and regions. The main contents of the technical report include: analysis of the organizational structure of power industry in each country, analysis and importance of uncertain factors in power system, modelling method in consideration of uncertainty in planning, practical experience on dealing with uncertainty and so on. The technical report also summarizes seven global power planning cases in uncertain environments and five planning assistant decision-making software. Finally, the technical report points out that the key to considering uncertainties in power system planning depends on many factors such as the data collection of relevant uncertain boundary conditions, the computing capacity of model algorithms and the public acceptance of uncertainty criteria. Practices in future industry needs to be carried out in three parts: establishing a reliable database, improving the efficiency of the algorithm and putting forward uncertain planning standards which are easy to be accepted by the public.

At the CIGRE annual meeting held in Chengdu, Sichuan Province, China from September 21 to 26, 2019, the C1.39 Working Group was invited to give a technical tutorial on behalf of the C1 Technical Committee, and the tutorial, particularly given by Associate Professor Zhang Ning, was widely praised. During the CIGRE Paris Symposium in August 2020, the working group was again invited to attend the online meeting and give a technical tutorial on the final research results of the working group with C1/C6.37 in the form of a joint working group according to the voting result of the Technical Committee C1, the tutorial was particularly given by Professor Kang Chongqing, Associate Professor Zhang Ning and Juan Carlos Araneda Tapia, Director of the Power Grid Planning and Designing Department of the Chile State Power Company. The tutorial summarized the challenges of clean and low-carbon transformation to power grid planning and the sources of uncertainty in the future power system, introduced the practical engineering solutions in the industry at present in combination with the research result of this working group on the power transmission and the research result of the Working Group C1/C6.37 on the power distribution.

Fig. 4: Kang Chongqing and others jointly gave a technical tutorial at CIGRE Paris Symposium 2020 (Online Session).

The research content of CIGRE Working Group C1.39 is also one of the core issues of the key special project 1.1 "Basic Theory of Power System Planning and Operation Incorporated with High Renewable Energy" in the national key research and development program "Smart Grid Technology and Equipment" in 2016. The project is directed by Professor Kang Chongqing of EEA, Tsinghua University, led by the China Academy of Electrical Sciences, and undertaken by 15 universities including Tsinghua University, Shanghai Jiaotong University, Huazhong University of Science and Technology, Tianjin University, and 3 scientific research institutes including China Electric Power Research Institute, State Grid Economic and Technological Research Institute and State Grid Energy Research Institute. The project studies the great uncertainty caused by the grid incorporation of high renewable energy and electronized power system in five parts including the future power system structure evolution model and power prediction method, the multi-objective collaborative planning method of AC/DC transmission network considering the temporal and spatial distribution characteristics of high renewable energy, the distribution network planning method considering flexible load incorporated with high permeability renewable energy, the power system stability analysis theory of highly electronized power system source-grid-load system, and the collaborative optimal operation theory of AC/DC hybrid system with high renewable energy. The research work of the Working Group C1.39 provides an international perspective for the project to solve the planning and operation of high renewable energy grid incorporation, and also provides a broad platform for the research result of this project to impact the international industry and academia. The research of this project also provides theoretical and technical support for the development of the CIGRE C1.39 working group, and the release of the technical report of the working group is an important output and milestone of the research work of this project.

The technical report of CIGRE C1.39 Working Group is of great significance for being used as a reference by power system planners, researchers and relevant standard makers at home and abroad, and its research result and empirical cases will provide theoretical and technical support for the transformation of power system in China.

In the four years since the establishment of the Working Group, outstanding achievements have been made in personal development. Associate Professor Zhang Ning, as the Secretary of the CIGRE C1.39 Working Group, was invited to give a report at the Young Member Presentation session of the C1 Technical Committee Open Meeting of the CIGRE Paris Symposium in 2018 because of his excellent work in the Working Group. After his work in the CIGRE C1.39 Working Group was completed, Associate Professor Zhang Ning was designated into the "Integrated Energy Network Coupling" Working Group as the convener, and the new working group will be launched from January 2021.

Fig. 5: Associate Professor Zhang Ning gave a technical tutorial on behalf of the working group at the CIGRE Chengdu Symposium in 2019.

CIGRE C1.39 Working Group Technical Report link

https://e-cigre.org/publication/820-optimal-power-system-planning-under-growing-uncertainty