PAC World:   When and where were you born?
GS:  I was born in an ordinary family in the Shangdong province in 1938.

PAC World:  What are your memories from your childhood?
GS:  My hometown had a large population and not enough land. We experienced poverty, the Anti-Japanese War, and the War of Liberation. I spent my childhood in a harsh environment. Due to the long war by at the age of ten  I hadn’t been in school for a complete semester. I followed my father to the city in 1949, when the new China was established. From that moment I had a peaceful study environment for the first time. Although I had missed school, because of the help of my brother I was able to continue from grade 4 of the elementary school. I was in school during the day and helping at home with housework after that. It was rather difficult.

A year later however, I became a part of the “excellent students” group. The experience from my childhood, which made me resolute and inured to hardships, is a valuable treasure of mine. I never give up, and I never bend over to difficulties. I was one of the best students in high school and college. I spent 6 years in middle and high school, 5 years in college, and I still remember my points being nearly excellent. I improved my study efficiency and was able to help students with poor performance, thus consolidating the newly-acquired knowledge while helping others.

PAC World:  What made you decide to become an engineer?
GS:  Enlightened by my physics teacher, I deeply loved science and engineering. Upon graduation from high school, I enrolled in the department of electrical engineering of the Harbin Institute of Technology, which was very famous and influenced from the Soviet Union. In 1961, our electric power system major was merged into the Beijing Institute of Electric Power, and I graduated from this institute. Influenced by my specialty teacher, I began liking the power system stability technology while still in school.

PAC World:    How did you start your career?
GS:  When I graduated in 1963, I was selected by the top research institution of the Ministry of Water Resources - “Technology Development Bureau”, to work in the stability technology team of the power system department. This started my nearly 50 year career on power system stability analysis and control. I’ve been to the “Five Seven School” during the Culture Revolution, and then was transferred to Nanjing with China Electric Power Research Institute, becoming one of the founding members of the Nanjing Automation Research Institute (NARI). I’ve long been engaged in the research of China’s stability control technology, the development of devices and field application. After I retired in 2001, I joined the R&D team of Nari-Relays Electric Co., Ltd., and continued to do my own R&D work.

PAC World:   What are the main projects that you worked on?
GS:  My generation witnessed too many situation changes in China and experienced too many physical and mental sufferings, but also enjoyed a lot of opportunities that cannot be experienced by the young people today. I witnessed the construction of the first 220kV transmission line from China's Xin'anjiang power plant to Shanghai in the1960s. I was engaged in the power stability analysis and control and developed the first emergency generator control device for the Xin'anjiang power plant in 1964. Later I developed an emergency control system that included a large-capacity water resistance for a generator shutting-down in the Hunan Zuoxi power station which was put it into operation in 1966, and was known as the technical founder in research and application of stability control technology in China. I was engaged in the first 500 kV transmission project from Pingdingshan to Wuhan in the early 1980s and the first 500 kV HVDC transmission project from Gezhou Dam to Shanghai in 1990s. Later, I was engaged in the 800kV HVDC and 1000kV UHV projects, contributing to the safe and stable operation of these transmission projects.

PAC World:   What is your role in the development of the Chinese electric power industry?
GS:   After the Culture Revolution, I was appointed as leader and the person in charge of the national power system stability control and automation technology in 1981. I had to organize and develop a team for R&D, manufacturing and application of new technologies in this area. This provided the most important opportunities and challenges in my life. I’ve always been on the forefront of this field, which gave me the opportunity to acquire a full picture of the latest power system stability control technologies. My team put lots of effort in research and developed different kinds of criteria, devices and solutions for stability control, as well as out-of-step relays and underfrequency/voltage load shedding devices with different algorithms. These devices and control systems have been successfully applied at various voltage levels in the Chinese grids, playing an important role in ensuring the system's safe and stable operation.

PAC World: What happened after your retirement?
GS: After my retirement, NR Electric Co., Ltd (formerly known as NARI-RELAYS) provided me with a platform on which I could continue my professional work. This allowed me to further enjoy my favorite work and to pass on my experience to the young people.

PAC World: Your main focus has been system stability. What methods did you develop to achieve it?

GS: I was lucky to establish a completed theory system in the stability control field during my career. From a single station stability control device to a bigger and more complex stability control system in a large region; from analyzing and calculating off-line stability control strategy table to automatically forming and refreshing on-line stability control strategy table based on real time data acquisition from the whole grid; from single-function digital frequency relay to world's fastest and reliable multi-function load shedding device; from single out-of-step relay to complex grid out-of-step isolation system based on the changes of the phase angle among the coherent generator groups; from single point oscillation supervision and isolation device to wide-area oscillation source tracking system based on various line power and phase angle changes. These achievements were helpful in establishing the ‘Three Defense Lines’ for power systems with theoretical guidance, engineering practical criterion and corresponding matched IEDs.

PAC World: Can you describe briefly the ‘Three Defense Lines’ approach?
GS: In the 1980s, after the Power System Stability Guide was issued in China, the commonly used “three defense lines” began to turn up and I defined it and promoted it to most of the power utilities in China after 2001. This definition was adopted in the latest China National Standard Specification of Power System Stability Control (GB/T 26399-2011). The reasonable power grid structure was the foundation of the safe operation and the “three defensive lines” were the guarantee and the experience accumulated for many years in China.

• The first defensive line refers to the quick and correct operation of preventive control and relay protection
• The second defensive line refers to the Power Stability Control System operation based on different fault contingencies and pre-defined strategies
• The third defensive line is when confronted with serious accidents, to adopt a planned islanding and emergent frequency and voltage control to prevent the accident from expanding into a large area power blackout

The definition of the “three defensive lines” is a clear with specific division of responsibilities and mutual coordination. Each performs its own functions and it is easy to understand and operate. With the establishment of the “three defensive lines”, for more than two decades in China, no power failure on a large scale has taken place except for some power failures in border districts such as Hainan and Tibet. In my opinion, this idea should be strengthened in China, and also promoted worldwide.

PAC World: What helped you achieve your accomplishments?
GS: I am grateful for the trust and support of all my leaders, which gave me the opportunity to do what I wanted to do without worries, and to accomplish a complete set of stability control technology system. I thank the leaders and the technical staffs of all power operation scheduling departments in China's power utilities. Numerous stability control systems and safe automation devices are installed in their power grids and it can be improved and enhanced with their cooperation and elaborate operation and maintenance.

PAC World: What is your relationship with your colleagues?
GS: We have contacts at work. They call themselves my students and I am addressed by them as teacher. What is more important, we are students, teachers and also friends. The relationship with the end users is critical to my career. I want to thank my colleagues in NR. Only with their joint efforts and arduous work, I could achieve these results.

PAC World: What is the role of your family?
GS: Of course, I am thankful to my family as well. Only with their support, I could devote myself to the work I love.

 

PAC World:  What are the main differences between your generation and the young engineers today?
GS: I must point out that few of our generation were engaged in this profession at the time. With the backward technology, I had to do everything by myself, from theory researching, designing, drawing, and programming, to source components and manufacturing. I had to be involved in the hardware and software and to participate in the equipment commissioning, acceptance test, on-site operation and maintenance, and even in equipment delivery.
In the 1970s, it took me more than 6 years to establish a dynamic simulation laboratory in the Nanjing Automation Research Institute since we needed it as an IED simulation test platform. The lab adopted the most advanced technologies, especially in automation. In the early 1970s, I was involved in solid-state relay R&D directly, which was a good experience for me for the later PSCS devices R&D.
The young generation is different. They have a good working environment, numerous advanced technologies, a foundation established by the predecessors, more staff, detailed division of labor. The staffs specialized in some field and thus numerous skills are not imperative. The result is that there are fewer opportunities for a comprehensive exercise. It is impossible to transfer some experiences from our generation to the youngsters. Of course, it is not necessary to experience hardship. However, I do not expect that they are satisfied to confine themselves to the little space of their own and to be content with small local work. They should have a global conception and comprehensive power system knowledge.

PAC World:  What would you recommend to the young engineers in our field?
GS: When I was at school, I paid a lot of attention to mastering basic concepts. I am always explaining it clearly and avoid blindly deeming the calculation results to be coming from the book or somewhere else. Only by understanding the basic concepts, we can grasp the nature of things and find out the solutions to the problems. Otherwise, if you do not understand the basic concept, you will not grasp the direction and it will be difficult to accomplish anything.
This is critical for the youngsters. One of my predecessors once said “at present the computer and the new technologies are developing fast. However, the basic conceptions of electricians are unchangeable, neither are the basic constituents and principles of generation-transport-supply-utilization of the power system. No major change may turn up in the future.” It is true that we learn and master the new technology to serve the basic objective of the power system. Only if we fully understand and master the theory and the principles, can we solve the problems and make the operation safer, more reliable, economical and environmentally protective. We hope that the young generation will gradually realize it.

PAC World:  What awards have you received for your work?
GS: I have won the 2nd prize of National Scientific and Technological Progress Award, 2nd prize of National Standard Innovation Award, and various first, second and third prizes: -- This is the confirmation by the State for my research results.

PAC World:  How do you share your knowledge and experience?
GS: I have written many thesis and training materials. I have given lessons to leaders and on-site technical staffs of the power scheduling departments throughout the country, seminars in universities and research units and have delivered keynote speeches at the annual meeting of Protection and Control Committee of CSEE for many years. The main goal was to share my research results and experience and to enable the stability control technology of China to further develop.

PAC World:  What do you consider as a personal achievement?
GS: I have experienced difficulties and failures in many aspects. With strong spirit and sense of responsibility, I never stopped halfway and would always overcome the difficulties in the end. Perseverance means victory.

PAC World:  What are the things you like to do when you are not working?
GS: In recent years, I had some leisure time beyond work and became interested in traveling and photography. Hiking and walking can exercise the body and delight the emotions; the photography can produce a lot of joy and enriches life. I have also visited many former colleagues and friends to share experiences.
Of course, I am willing to stay with the youngsters. Sometimes, I would talk to them about past experiences. They are enthusiastic, vigorous, and keep learning new things. This way, I also feel much younger.

PAC World: Do you have a motto?
GS: My creed of life is: be practical, innovative and be persevering when confronted with setbacks; be simple and plain in life.
When I was in high school, I read the novel- 'How the Steel was Tempered'. A paragraph of the protagonist still remains in my mind: “People should live life in such a manner so: when one recalls one's past, to not regret being on the loaf and feeling ashamed for accomplishing nothing.” I’m a lucky person for I did not fail to live up to this well-known saying.  

PAC World:  Is there any form of entertainment that you like?
GS: When I was young I liked music and even played some instruments.
I learned to drive when I was 60 years old. Now driving is one of the things I really like to do.

PAC World:  What is your favorite food?
GS: I find every food delicious. Maybe it is because when I was a child I didn't have much food to eat.

PAC World:  Is there anything else that would you like to share?
GS: I am not smart, but I am like a machine. When I face problems that are difficult to handle, I can't fall asleep.
Some solutions and inspirations are caught during these sleepless nights. 

 

Biography:
Guanghui Sun graduated from the department of electrical engineering of Harbin Institute of Technology, later merged into the Beijing Institute of Electric Power. When he graduated in 1963 he was selected by the top research institution of the Ministry of Water Resources- “Technological improvements Bureau”, and began his nearly 50 years career on power system stability analysis and control. He was later transferred to Nanjing with the China Electric Power Research Institute, becoming one of the founding members of Nanjing Automation Research Institute (NARI), being engaged in the research of China’s stability control technology, the development of devices and the field application. After he retired in 2001, he joined the R&D team of Nari-Relays Electric Co., Ltd. and continues to work.