The Egyptian Electricity Holding Co. Authority (EEHC) is the largest electric utility in the Middle East and Northern Africa, supplying a population of some 63 million in an area of more than 1 million km2 (400,000 miles2).
The EEHC forms part of the Egyptian Ministry of Electricity and Energy and is responsible for controlling the generation and transmission of electrical power for the entire country of Egypt. The first National Energy Control Center (NECC), commissioned in 1983, was designed to control the main 500-kV and 220-kV transmission systems and the existing generating plants, incorporating the latest energy-management techniques. This facility proved adequate until 1995, when increased demand and the growing electrical system prompted EEHC to upgrade the NECC. The turnkey contract was awarded to Harris Corp., Melbourne, Florida, U.S., to upgrade the NECC by installing one of the world's most advanced control centers.
In 1998, statutory changes were made to the electricity industry, affiliating the seven distribution companies to EEHC. Each distribution company was given responsibility for the power plants within its geographical zones. EEHC retained responsibility for the operation and management of the EHV transmission lines and all 500-, 220- and 132-kV substations. The Egyptian Unified Power System (UPS), which has a total installed generating capacity of 14,948 MW, is divided into two areas — northern and southern (Fig. 1). The northern area comprises five electric zones: Cairo, Delta, Behaira, Alexandria and Canal. The southern area is divided into two zones: mid-Egypt and upper Egypt. The southern area, which is connected to the northern area via a double-circuit 500-kV transmission line, has all the country's hydropower stations. During periods of low discharge, 1310-MW reduces the hydropower-plant capacity and aging equipment in thermal-power plants limit capacity by a further 500 MW, hence the available generating capacity is 13,138 MW. The maximum demand on the system in 1999 and 2000 was 11,736 MW, an increase of 7.5% from the previous year, while the total electrical output increased by 8.9% to 74,000 GWh.
|Zone||Installed Capacity in 1999/2000 (MW)||Total MW (%)||Zone Maximum |
|Steam Com.Cycle||Gas Hydro|
|Middle Egypt||1944||0||0||0||1944 (13.0)||876|
|Upper Egypt||0||0||0||2810||2810 (18.8)||1657|
Table 1 shows the distribution and type of generating capacity in each zone.
The NECC is assigned responsibility for the operation of all the generating units and the tie lines between the seven distribution zones to maintain security of supplies with optimum economic efficiency and safety. Regional control centers located in the zones control the 132-, 66- and 33-kV networks. Tables 2 and 3 include the main electrical characteristics of Egypt's transmission system.
NECC System Specification
EEHC's experience in control centers dates back to the 1960s, following the completion of the Aswan High Dam and 500-kV transmission network from Aswan to Cairo, when six dispatching centers controlled the operation of the UPS on a technical and geographical basis. This technology was not able to accommodate Egypt's rapidly expanding power network. Following feasibility studies in the mid-1970s, NECC, featuring the latest energy management techniques, began online operations in 1982.
EEHC's decision to replace the existing NECC was driven by several factors, not only to provide for the increasing demand and growing electrical system, but also to overcome the increasing difficulty in obtaining equipment to maintain and upgrade its time-expired control-system technology. EEHC signed a contract with Electricité de France (EDF) to undertake a conceptual study with EEHC personnel to design a hierarchical control strategy for the Egyptian UPS. The recommended strategy distributed the responsibilities between the NECC and Regional Control Centers (RCC) as follows:
|Zone||Length of Electric Circuits in 1999/2000 — km (miles)|
|500 kV||400 kV||220 kV||132 kV|
|Canal||385 (239)||20 (12.4)||3309 (2055)||-|
|Northern Sector||-||-||4285 (2661)||-|
|Southern Sector||1653 (1027)||-||3263 (2026)||2536 (1576)|
|TOTAL||2249(1398)||20 (12.4)||11,734 (7288)||2536 (1576)|
|Zone||Substation Capacities in 1999/2000 — MVA|
|500 kV||220 kV||132 kV|
NECC to be upgraded and assigned the responsibility for optimizing overall operation of all power plants, the 500-kV transmission system, and for the coordination between the regions at the 220-kV level.
The NECC to be equipped with state-of-the-art Automatic Generation Control (AGC) and Energy Management Systems (EMS) consisting of software to assist the operators in determining the most economic overall operation of the system.
The seven RCCs to be assigned the duties of coordinating the dispatch of energy within the zone at the 200-, 132- and 66-kV voltage levels, and responsibility for the preparation and transmission of data requested by the NECC.
Therefore, EEHC's primary functions for the new Control Center and the Backup Control Center (BCC) required for emergency operations were as follows:
Monitoring the operation of all generating units and the 500-kV system to secure economic operation and safety.
Monitoring the performance of the 220-kV system.
Ability to determine generation requirements and system voltage levels to provide the power flows to meet the demand on the UPS.
Economic operation of thermal and hydro generating units.
Coordinate the maintenance of generating units with the RCC.
Optimize the operation of the UPS under system fault conditions.
Optimize the operation of the UPS to minimize system electrical losses.
To monitor the electric energy exchange between each distribution zone in addition to neighboring countries. The Egyptian transmission system has interconnections with Jordan and Libya.
In part, Harris Corp. was awarded the NECC turnkey contract because its competitively priced bid also met EEHC's strict technical requirements to upgrade the NECC and install the BCC for emergency operations. This contract is one of the most complex energy management projects of its type in the world and is based on the comprehensive functionality of the XA/21 system developed by Harris. Basically, the computer-based EMS comprises five key elements:
SCADA software for control and monitoring of the high-voltage substations.
AGC software for maintaining power-system frequency by generator control.
Comprehensive Operational Planning & Scheduling (COPS) for optimizing hydro and thermal generation.
Power Network Application (PNA) software, which recommends operator actions to optimize the efficiency and security of the Power System.
Information and Retrieval System for data analysis, display, tendering and reports.
The technical specification also includes the facility to communicate with the RCCs; these smaller supervisory systems are responsible for medium-voltage distribution in seven regional areas of Egypt. Additionally, the NECC contract made provisions for the training of new energy dispatchers and a visitors center that showcases the NECC and the UPS with a multimedia presentation. The contract specified that the computer and communications systems be designed for redundancy of all critical components.
Remote Terminal Units (RTU) are installed in every power plant and high-voltage substation in Egypt, and the NECC upgrading project provides for replacement and additional RTUs as required. These RTUs transmit measurements of the electrical voltage, energy, active and reactive power and frequency to the NECC. In addition, they receive control signals from the NECC for the generators and circuit breakers at the power plants and for the transformers at the substations. The communication system will be expanded to include new microwave and fiber-optic links, a packet switch data communication network and new PABXs. The NECC communications network, shown in Fig. 3, includes six packet switch nodes located at the NECC, DAM, TAL, CNN, ISM and NTEB. The data network shall support communication protocols between NECC, Alexandria Regional Control Center (ARCC) and future RCCs. The communications system that extends to 6000 km (3730 miles) uses packet switches X.25 protocol, which automatically provide for alternate routings in case of communications equipment failure. The communication network also carries voice traffic between the sites through Harris DTSD PABXs and Telesets.
The New NECC
The new NECC Dispatch Center, located along the Nile River just north of Cairo, accommodates the GE Harris computer consoles that rely on XA/21 software to provide the EMS functionality. This NECC includes the operations center where energy dispatchers use 40 computer workstations and servers and consult a wall-size projection display showing the status of the entire UPS. The GE Harris computer consoles, which the visitor's center overlook, provide EEHC operators with the ability to monitor and control all the generation in Egypt as well as the 500-kV and 220-kV transmission network. They also manage the high-voltage interconnections to Libya to the west and Jordan to the east. In front of the consoles is a matrix of 12 projection display units that provide the wall-size overview of the entire system to both operators and visitors. Figure 2 shows a schematic diagram of the XA/21 system configuration.
An energy dispatcher at NECC, appraised of the status of breakers and switches anywhere in the system, can control their operation, see the resulting voltage, current, frequency, real and reactive power, and energy; and record those values for later analysis. The NECC jointly monitors critical substations controlled by the RCCs, and periodic performance reports are exchanged between the RCCs and NECC. The system also provides for energy accounting via hourly, daily, weekly and monthly reports. Generation can be controlled automatically to minimize frequency deviations and other constraints, and the system will recommend which generators should be committed in the event of a change in load during the day. A suite of PNAs model the entire power system and make recommendations on the configuration of the transmission network to minimize operating costs and the effect of potential disturbances. The system also includes hydro applications that manage the water resources in the Nile River basin, including the High Dam.
Also located in the NECC facility is the Dispatcher Training Simulator. Using a designated console, an instructor can mirror the configuration of the power system on a trainee's console and then simulate disturbances for student response. The vendor provided extensive training for EEHC's Control Center personnel in the United States and Egypt.
Backup Control Center
In addition, a BCC has been provided in the Egyptian Ministry of Electricity and Energy Building, about 25 km (16 miles) from the NECC. The BCC provides the capability of operating the entire power system in the event that an earthquake, fire or other catastrophe disables the entire NECC. The BCC is designed to be automatically updated daily with changes to the database defined by the EEHC's engineers at the NECC.
Project Contractors and Funding
The NECC project consortium was by GE Harris Energy Control Systems, and EEHC worked with the Harris/GE Harris teams on the design of the system database and they will be responsible for ongoing maintenance.
An Egyptian construction company, Kolaly Engineering, undertook all civil works and installation services, and KEMA Consulting was appointed as project engineering consultant. The contract was valued at US$30 million, US$27 million of which was funded by a grant from the U.S. Agency for International Development and the remaining US$3 million by the EEHC for the civil works subcontractor.
State-of-the-Art Technology EMS
Installation and testing of the NECC for EEHC was completed in October 1999, although the first elements of the project had been in commission for 12 months. This project provides a state-of-the-art system, a realization of EEHC's new hierarchical strategy for the entire electrical network, and ends four years of successful collaboration between EEHC and its contractors.
The NECC upgrade project satisfies the EEHC guidelines that were based on operational experience and the evolution of control strategies and used in the procurement process. Key features include:
Configuration based on open system standards providing transparency to the functionality of the system.
Distributed processing compliant with the Open Software Foundations, Distributed Computing Environment and Distributed Management Environment.
Processors, peripherals, workstations and interfacing equipment interconnected on networks using IEEE 802 series standards.
Operating system compliant with IEEE PPOSIX standards.
Databases and data management applications that use relational structures to conform to Structural Query Language standards.
Network Analysis Applications comply with IEEE standard formats.
Geographical Positioning System to synchronize the master station, the Data Communication Network and individual RTUs.
The NECC to be a full EMS and include advanced applications supported by the SCADA systems at RCCs.
The SCADA communications system for the ARCC, a contract undertaken by Seacor Services Inc. USA with Siemens Empros acting as subcontractor, was commissioned in advance of the NECC. The SCADA upgrading of the remaining six RCCs (Canal Zone, Mid-Delta Zone, West Delta Zone, North Upper Egypt Zone, South Upper Zone and the Cairo RCC) were subject to individual contracts and financing arrangements.
Advanced Control Center Benefits
By improving the availability and minimizing the cost of electrical energy, this internationally funded project will improve the quality of life for EEHC's Egyptian customers. Additionally, because Egypt has inexpensive resources of fuel and is strategically located, it is starting to benefit from interconnections with neighboring countries. The interconnection with Jordan, now in operation, is being extended to Syria and Turkey. Similarly, interconnection with Libya is in operation and will be extended to Algeria and Morocco. Hence, the importance and international operational responsibilities of the NECC seem poised to increase in the foreseeable future.
Dr. Magda Mostafa is the SCADA manager for the Egyptian Electricity Holding Co., Cairo, Egypt.