IEC and CIGRE hold symposium on International Standards for ultra high voltage

The IEC and CIGRE (International Council on Large Electric Systems) joined forces from 18 to 21 July 2007 at the Holiday Inn Central Plaza in Beijing when they held a joint international symposium on International Standards for ultra high voltage.

From left to right at IEC and CIGRE joint symposium on UHV in Beijing, China: Zhou Xiaoxin, Member of the
Chinese Academy of Sciences, Jean Kowal, Secretary General CIGRE, Shu Yinbiao, Deputy
President General of SGCC, Shi Baoquan, Secretary General of Chinese NC of IEC, Jacques Régis, IEC
President Elect, Yves Filion, President of CIGRE, Lu Yanchang, President, Chinese National Committee of
CIGRE, Klaus Froehlich, CIGRE TC Chairman, Hisatoshi Ikeda, IEC SB 1 Chairman

One of the challenges of today is that of being able to supply growing demand for large amounts of electrical energy in a manner that is both efficient and has minimal impact on the environment. Often electricity is generated thousands of kilometres away from the urban populations to whom it needs to be delivered and, in the process of transmission, it loses energy.

During the symposium, Jacques Régis, IEC President Elect, commented how apt he felt Beijing to be for this conference. “China is a large country and the growing economy is facing some big challenges. Electricity demand in Southeast Asia and China is projected to grow rapidly at 5.4% and 6.3% per year, due mainly to rising income and increased access to electricity networks. APEC’s total generating capacity will increase almost two-fold by 2030 at an annual average rate of 2.4 percent. It would be easy if we were able to raise the voltage of the power lines, but technically this is impossible. Today’s equipment, transformers and cables simply will not withstand these higher voltages.” Continuing, he said, “It seems to me that the principal issues for this technology concern the reliability of the equipment and the stability of the network. We need to be able to develop new means for delivering electricity stably and safely.”

When electrical energy is transmitted over long distances, because of the various leakages due to windings, cores and surrounding structures such as insulators, it loses energy. Ultra high voltage (UHV) usually considered as alternating current (AC) voltages of 1 000 kV, or higher, or direct current (DC) voltages of 800 kV, or higher, is a highly efficient means of transmitting large quantities of power over a transmission line, since the higher the voltage on the line, the lower the current and therefore the lower the loss. At the same time, by transmitting more power over a single line, the number of power corridors needed is reduced. Potentially then, UHV offers a solution to the need for more electricity in a space-restricted world. International standards for UHV do not exist yet, so they need to be developed to ensure the safe and efficient use of this technology.

It is in this climate that some of the world’s most eminent specialists on the question of UHV met together, some of them for the first time. Indeed, such an event is unusual and it is uncommon for experts from far apart areas of the planet to have such an opportunity and to be able to share their opinions and experiences. Since the technology on a broad scale is only in its initial stages, questions on UHV are still very much open to debate. There is no consensus yet as to what voltage to adopt in the future and standards on which to set future strategy still remain to be developed.

Following the opening of the symposium by Shi Baoquan, Vice Administrator of the Standardization Administration of the People’s Republic of China and Secretary General of Chinese National Committee of the IEC, the Chairman of IEC Sector Board 1, Electricity transmission and distribution, Hisatoshi Ikeda, presented the background and objectives of the symposium. His introduction was followed with a speech by Shu Yinbiao, Deputy President General of SGCC (State Grid Corporation of China), a company employing 1 500 000 people which is at present carrying out UHV DC tests in a gigantic complex which covers 80 000m². Attendees at the conference were later given the opportunity to visit what, at present, constitutes the world’s biggest laboratory. This Chinese site in the Changping District of Beijing, with both outdoor and indoor facilities, is commencing tests on atmospheric simulations and the effect of high voltage on the earth, human beings and animals.

Chinese UHV DC test base is the world’s largest laboratory
It is equipped with the longest test line section in the world (1 100m strung over six towers, the portal being 88m high), the highest DC voltage grade of double circuit bi-pole testing line and the highest (7 200 kV) impulse voltage generator in China. In line with its mammoth dimensions, it also boasts the world’s largest test chambers for artificial climates and ice coating tests and, with its dimensions of 70m x 22m x 13m and double frame, the world’s largest corona cage. The DC voltage is sourced from a ±1 200kV/0.5A generator.

The Symposium was attended by some 350 delegates from 18 different countries with numerous IEC and CIGRE experts present including Klaus Fröhlich, TC Chairman of CIGRE and Professor at EPFZ, Switzerland, who also gave a keynote address, Mark Waldron, Chairman of the Symposium Programme Committee, Robert Jeanjean, IEC SB 1 member, Denis Dufournet, Chairman IEC TC 17 and SC 17A, Hiroshi Okamoto, IEC SB 1 member, Mario Szechtman, Chairman of CIGRE SC B4, HVDC, Bernard Dalle, Chairman of CIGRE SC B2, Overhead lines, Auke Wiersma, Chairman of CIGRE SC B3, Substations. It was divided into eleven main sessions: Needs and plans; AC UHV Systems, Substations and equipment; DC challenges; Testing and Standardization.

Session 5 papers concerned high voltage AC and DC and the present standardization situation of the IEC and CIGRE in each respective area. In this respect, the presentations considered common technology, design, facilities, construction and commissioning test standards, operation and maintenance standards and system control and protection. The session was chaired by Gabriel Barta, Secretary SB 1, with Li Guangfan of China Electric Power Research Institute (CEPRI) as rapporteur.

After the introduction given by Jean Kowal, Secretary General of CIGRE and co-chairman of the Steering Committee, on the role of CIGRE and IEC in the standardization process, Hermann Koch, Secretary of IEC SC 17C, High-voltage switchgear and controlgear assemblies, presented a paper on the need for IEC standardization to coordinate network requirements with design rules. He introduced the IEC TCs and SCs concerned with UHV, and the CIGRE SCs that pertain to AC and DC UHV systems. Having presented four steps in developing UHV standards he suggested setting up a coordination committee for standards which would consist of members from each related product and other committees.

Concerning HVAC transmission, the presentation given by Fan Jianbin, CEPRI host coordinator of the symposium, summarized the numerous uses of high voltage AC transmission throughout the world and the plans for increased use in the future. He pointed out that, despite this, there were few IEC standards on UHVAC transmission and a need therefore to set up a new TC or coordination group capable of taking on specific responsibility for alternating current in this field.

Continuing with a presentation on high voltage DC, Fan underlined the plans China had to use DC in the near future. He explained this interest as having become more popular because of the environmental and economical (cheapest solution) advantages, the possibility for asynchronous interconnections, power flow control, enhanced transmission stability and power quality.

Here, he pointed out that, although there were a number of standards that had already been published concerning HVDC, including those on terminology, insulation coordination for high-voltage DC converter stations, power transmission, power losses, converter transformers, conductive clothing and audible noise in substations, there was no dedicated technical committee (TC) or working group (WG) yet responsible for these standards. He underlined that, until recently, work had mostly concentrated on research, but in today’s situation, where building work is commencing in various parts of the world (India, USA, Canada, Russia, Japan) with two in China alone on UHVDC ±800kV systems, there was now a need to create International Standards that would cover construction and operation needs.

Karl-Heinz Weck, Chairman of IEC TC 28, Insulation co-ordination, in his presentation on standardization of insulation withstand levels, looked back at some of the history on UHV research, drawing parallels with the requirements and rules needed to establish insulation levels able to withstand performance criteria. He analysed various protective and limiting devices in relation to operating voltages and surges, whether these are due to switching or lightning and, in terms of standardization, in order to be in line with the various projects throughout the world, recommended selecting one, or possibly two, values of highest voltage for equipment for operating a wide range of ultra high voltage systems from 400kV to 800kV.

Finally, after a summary had been given by session rapporteurs from both the IEC and CIGRE, Hisatoshi Ikeda rounded up talks and presentations, leading discussion on the issues concerning the future of an IEC-CIGRE UHV standardization coordination group. The symposium, apart from bringing together experts and allowing them to share and discuss their knowledge and experience, generated several clear conclusions and decisions:

There is a definite need for standardization in the field of UHV for both AC and DC underlined by the Chinese market’s commercial plans to operate a 1 100 kV AC line in 2008 and, in 2009/2011, a 800 kV UHV DC line; longer-term, China expects to develop a hybrid AC-DC UHV network of 40 000 km.

A joint ad-hoc group of IEC and CIGRE experts is to be set up, the latter of which have already been nominated. On the IEC side, the organizational aspects and finalization of the terms of reference are to be brought up for final agreement at the next IEC SMB (Standardization Management Board) meeting.

The Chinese national committee proposed Fan Jianbin as a member of SB 1. This nomination brings expert knowledge and experience to the future work of the sector board.

Far from being daunted, although much remains to be done and achieved, the IEC welcomes this type of challenge. It opens the path to future developments, dialog and the expectation of new International Standards that are brought about by the consensus of opinion of a new committee composed of world experts who bring with them their widely differing experience and knowledge and with it the hope of new guidelines to lead new globally promising technology.