While the differences in the political, social and economic systems of Middle Eastern countries may cause unrest in the area, interconnecting the countries' electrical systems has so far gone smoothly. In November 1994 the Jordan Electricity Authority (JEA), Amman, Jordan, and the Egyptian Electricity Authority (EEA), Cairo, Egypt, approved construction of a 300-MW, 400-kV ac link to interconnect their networks.

The interconnection project, which will cost the two countries US$200 million, includes a 400-kV submarine cable that crosses the Gulf of Aqaba between Taba in Sinai and Aqaba in Jordan. This link, which is an important stage in the planned interconnection between Egypt, Jordan, Syria, Iraq and Turkey, will be the first electrical connection between Asia and Africa and will eventually lead to a grid loop extending all the way around the Mediterranean. Civil construction started in November 1995. Commissioning of this circuit is planned for mid-1997.

The completed project will economically benefit both countries and will limit the need to install new, expensive power stations to meet the increasing demand for electricity. Different climatic conditions, time zones and peak demand times will increase generating efficiencies and reduce the running and emergency reserves of the two systems, currently estimated at 1000 MW. The link will also improve system stability in the event of multiple outages.

Detailed economic studies have shown that the energy interchange will initially be no less than 120 MW, ultimately increasing to 2000 MW, the planned capacity of the inter-connector. The increase will ensure that the project is a successful investment. Electrification of the Sinai Desert will also help the economic and social development of the area. Potentially, the participation of local firms and subcontractors in this project will raise the level of skills and expertise of the local workforce, giving a much needed boost to the regional economies.

Existing Power Plants According to the 1994/95 Annual Report of the Egyptian Electricity Authority, the primary power stations in Egypt are mainly hydro and thermal. The total installed capacity in 1994/95 was 12,978 MW compared with 12,046 MW in 1993/94, an increase of 7.7%. The maximum load in 1994/95 was 8149 MW compared with 7657 MW the previous year, an increase of 6.4%. The country's 500-kV transmission network was constructed in the 1960s, and the nearest existing substation to the proposed cable link is at Suez, about 270 km (168 miles) from Taba and the Gulf of Aqaba (see Fig. 1).

The generation system in Jordan is considerably smaller than in Egypt. It comprises mainly oil- and gas-fired power stations and a number of small gas turbines, according to the Jordan Electricity Authority's 1995 Annual Report. The total installed capacity of the Jordanian system at the end of 1995 was 1167 MW with a peak demand of 894 MW, representing an annual growth of 5.4% and 8.4%, respectively, when compared with 1994 figures. The capacity will exceed 1500 MW when the three additional 130-MW units being installed in the Aqaba thermal power station are commissioned later this year. The increased generating capacity is required to reinforce the Jordanian network and increase interchangeable energy in the future.

Project Overview Figure 2 shows a simplified line diagram of the interconnection and associated transmission systems in Egypt and Jordan. The submarine cable will be connected to the existing networks via two new 400-kV overhead lines. In Jordan, the line will connect the cable to the Aqaba substation, which is located 10 km (6 miles) south of the port of Aqaba.

As there are existing plans to develop the beach area, the route of the proposed line to the substation, which is sited 2 km (1 mile) inland, will be extended to 10 km (6 miles). The second overhead line will be routed from the cable terminals to a new substation at Naqab 20 km (12 miles) west of Taba in the Sinai Desert (Fig. 3). The connection between Naqab and the existing substation at Suez will be via a 270-km (168-mile), 500-kV overhead line routed via a new 500-MVA substation at Ain Musa in Sinai, approximately 20 km (12 miles) southeast of Suez.

The Jordanian 400-kV network operates at 132 kV including a 230-kV tie line with Syria. The interconnection upgrades the 400-kV network to the design voltage. Hence, the two existing 400-kV overhead lines that connect Aqaba substation to the main population center at Amman will be operated at 400 kV for the first time.

The substation work associated with the project includes the installation of two 400-MVA, 400/132/33-kV transformers at Amman South substation; two 240-MVA, 400/132/33-kV transformers at Aqaba substation; and one 750-MVA, 500/400/15-kV transformer at Naqab substation.These transformers will be of the ONAN/ONAF/OFAF cooling type and will be provided with on-load tap changing facilities.

To control reactive power flow, especially during light load conditions, 100-MVAR shunt reactors are to be added at both ends of the Aqaba-Amman overhead lines. Another set will be installed at both ends of the line connecting the two substations at Naqab and New Suez.

At Aqaba and Amman South substations on the Jordanian side, 400-kV switchgear consisting of busbars, circuit breakers, isolators and earth switches of the SF6 indoor type will be installed. Similarly, 400/500-kV equipment will be installed at Naqab substation on the Egyptian side. Surge arresters will be gapless, zinc oxide types contained in porcelain housings. The short length of overhead line between Aqaba S/S and the cable terminals imposes circuit breaker transient recovery voltage requirements higher than standard values. The telecommunication link between the networks will consist of a power line carrier system and rented telephone lines.

Load flow and transient studies have shown that the steady state and transient stability at this initial stage can be achieved with ac transmission. Thus, high-voltage ac transmission was used to avoid the extra cost and complexity of HVDC transmission. When funding becomes available to expand the project and increase the link's interchangeable energy, it will then be necessary to employ HVDC. The main characteristics of the link for the initial and final stages of operation are shown in Table 1.

Submarine Cable The project tender documents specified a dc power cable as the mainstay of the permanent interconnection but included a condition that the cable should be suitable for ac operation at the initial stage of the project when the interchangeable energy is low so the cable will operate under light loading conditions. Oil-filled cable was preferred to a mass impregnated type because of its higher current carrying capability and its suitability for different cable routes and installation sites.

A sea-bed and land survey was carried out in 1994 to confirm the exact cable route and to calculate important parameters such as water depth, route length, sea-bed roughness, water currents, corrosion hazards and other factors.

Acatel Kabel Norge will supply the 1000-mm2, 400-kV submarine cable, which forms the most important part of this link. This cable will be the first oil-filled cable in the world to be laid at a depth of 845 m (2772 ft) in one continuous length of around 13.6 km (8.5 miles). To connect the cable to the 400-kV overhead lines at both ends of the link, SF6 terminations will be used as interfacing points.

The conductor consists of concentric layers of helically wound key-stone shaped copper wires. This structure improves the mechanical stability and the smoothness of the surface, which is important for the application of the insulation. The oil-filled single core cable is insulated with cellulose paper impregnated with a low viscosity mineral oil. Metal alloy sheaths prevent water from penetrating the paper insulation. Arsenic lead alloy F3 (0.15% arsenic, 0.1% tin, 0.1% bismuth and 99.65% lead) is employed because of its favorable mechanical properties such as resistance to vibration or low creep.

The cable is reinforced by a transversal stainless steel tape, applied over the metal sheath, to cater for differences in route elevation. The cable has two layers of galvanized steel wires to achieve the required level of armouring due to the great water depths and other mechanical forces. The cable is protected from mechanical and other external hazards, such as sharks, by a covering of polypropylene yarn and asphalt.

Each of the four single core cables will be separated from the next by a distance approximately equal to the cable depth. This separation insures that a healthy cable is not grappled when carrying out repair works.

Other Developments The development of the Middle East energy market is vitally important to the economic stability of the area and the continued progress of the Middle East peace process. This market is buoyant with investment in the energy sections in Egypt, Jordan, Israel and the Palestinian self-rule areas. In Jordan, for example, a new gas complex is planned in Aqaba to supply all countries in the region with natural gas piped from Qatar. This project will provide an opportunity to enlarge Aqaba power station and to help meet the rising demand for electrical energy. Recently, JEA and the Palestinian Electricity Authority agreed to increase cooperation between the two utilities with a view to a connection between the two networks in the near future. Similar discussions are occurring between Jordan, Israel and Egypt regarding possible overhead line interconnections.

Future Prospects The Red Sea Cable Interconnection Project linking the electrical networks of Egypt and Jordan will operate with an initial interchangeable energy of 300 MW rising to 2000 MW at a future stage. However, the funding necessary to achieve full utilization of this interconnector and the other developments, including plans to incorporate the Israeli and West Bank networks, are inextricably linked to the success of the ongoing Middle East peace process. The creation of a politically stable and investment friendly climate in the region will ensure continuity in the planned interconnection of transmission networks in Africa, Asia and Europe.TDW

Acknowledgements The authors wish to acknowledge K. Bjorlow-Larsen of Alcatel Kabel Norge, Norway; B. Drugge of ABB High Voltage Cables, Sweden; Dr. E. S. Ilbrahim of Halwan University, Cairo and I. Rida and W. Holeh of JEA for their contributions to this article. The authors also thank JEA for permission to publish this paper.

Editor's Note: This article is based on a paper presented by the authors to the IEE Sixth International AC and DC Transmission Conference held April 29-May 3, 1996, in London, and published in the IEE Conference Publication Number 423. Publisher Institution of Electrical Engineers Savoy Place London WC2R OBL, UK.

References Annual Report, 1994/95, Egyptian Electricity Authority, Cairo, Egypt Annual Report, 1995, Jordan Electricity Authority, Amman, Jordan.

Mr. M. Abderrazzaq received an electrical power engineering degree from Donitsk, Ukraine in 1983 and the M.Sc. degree in power systems from UMIST, UK in 1993. Since 1985 he's been with the HV substation design group of JEA. He is conducting research in the area of high voltage engineering at the University of Manchester, UK, leading to the degree of PhD. Abderrazzaq is a member of the IEEE.

Dr. Bashar A. T. Al Zahawi received the B.Sc. degree in 1983, and the PhD. degree in 1988 from the University of Newcastle upon Tyne, England. From 1988 to 1993 he was an electrical design engineer at Cortina Electric Co., England, a UK manufacturer of large ac variable speed drives and other power conversion equipment. In 1994, he joined the University of Manchester, England as a lecturer in electrical engineering. Al Zahawi is vice-chairman of the IEE North Western Centre Power Section and an IEEE member.