Where is apollo substation

Asset Maintenance. Eskom unbundling proceeding and loadshedding chances slim for weekend Nov 12, Africa moving up the EV battery value chain Nov 12, Private sector has big role to play in achieving sustainable cities Nov 12, ESG-related litigation looms for mining, oil and gas companies Nov 9, New coal project in Zimbabwe counterintuitive or necessary?

Nov 9, Kudos to COP26 commitments, but maybe not just yet Nov 9, Mapping every large solar plant on the planet Nov 5, These elements are expertly integrated in line with global operational standards, allowing for the production of clean energy with high fidelity and quality. The dam is located in a narrow river gorge with vertical slopes at the top and a v-shape at the bottom.

Area: km2. Max length: km. Maximum width: 30 km. Capacity: 52 km2. Foundation thickness: Maximum discharge capacity: The hydroelectric power station is situated on the south bank of the river: m long, 29 m wide and 57 m high.

The eight six-pulse thyristor bridges can function in both the rectifier and inverter modes. The system control are designed in principle to allow also for power flow back to Cahora Bassa to cater for possible future requirement s. The bridges are arranged in two poles of four around the earth electrode connection. Each bridge, rated at kV DC and 1 A MW is provided with the necessary switching equipment for polarity reversal and for its insertion into the series DC circuit — the main principle being that the DC current cannot be interrupted with impunity.

T wo parallel thyistors are required for the 1 A rating. The first stage equipment employs thyristor pairs in series per valve. The later stages, which have the advantage of an improved thryistor, require only pairs. The eight bridges at Apollo contain a total of 22 thyristors. DC line reactor.

A unique feature of this pioneering scheme is the use of oil-cooled and oil-insulated thyistors housed in outdoor valve tanks on insulated platforms. The use of these platforms makes the valve tanks, unlike the transformers, completely interchangeable. A special lifting vehicle, the Lifting Platform Hauler LPH , installs and transports the elevated valve tanks, the damping circuit tanks, the transformers and the DC reactors within the station.

The restricted short-circuit-current withstand capability of the thyristors available at the time of design necessitated the installation of unconventional fast-acting short-circuiting switches Overcurrent Diverters for valve protection.

As a direct consequence, the transformer had to be made short-circuit proof. An inductive loop firing system operating with energy supplied from ground level provides the necessary triggering pulses for the thyristor pairs.

Fibre optic light beam transmitters provide the isolation for the control impulses at ground level. Apollo converter bridge insulated for kV DC with overcurrent diverters, auxiliary power transforners and light beam transmitters in foreground. Two motor-generator sets with fly-wheel energy storage provide the essential power at 75 Hz for thyristor firing, control and protection.

Non-evaporative forced-air-cooled heat exchangers provide the cooling for the thyristor valve oil. At high ambient temperatures, spray water can be introduced for additional cooling effect. The thyristor technology development itself provides valuable spin-off advantages for other power electronic systems, such as static compensators, variable speed and battery storage plants.

Once the circumstances are more favourable it can also make significant contributions to the socio-political, agricultural, industrial and mining development in the southern African Continent. Clearing Faults. Transient faults on the DC lines are cleared by up to four full-voltage re-energising attempts, each subsequent attempt preceded by increasing times allocated for de-ionisation.

The second attempt to clear the fault is usually made with the lone voltage having been reduced by that of one converter bridge. Line faults are detected by a travelling wave system with backup provided by a slower differential current measure me nt. Operating the Apollo Converter Station. This team deals with all financial, technical engeineering an human resource issues and it is responsible for all major deisionsd affecting plant.

When required, specialists, stakeholders and customers join the team as ad hoc members. This team approach embraves the process organisation of Transmission and continues to add value. Three Ac harmonic filters and two shunt capacitor banks at kV provide 1 Mvar for power factor correction. The scheme contains many unique features which however, have not been carried forward into more recent schemes because of the rapid technological advances made in the HVDC field.

These include:. The scheme also marks the first successful use of parallel operation of two poles in a commercial installation. This is an important step in the development of multi-terminal operation for future HVDC grids.

AC filter branch. The pioneering development of the Apollo deep electrodes for 3 A continuous operation without any significant environmental influence is a noteworthy achievement. The km-long power line carrier telecommunication system between the two relay stations represents a notable technological feat.

The equipment and system designs the commissioning and operating experience and the production of a vast number of thyristors have provided valuable lessons, ideas and technology used internationally to improve and build successive HVDC systems.

Sluice Gates at Cahora Bassa Dam. In contract were singed in Lisbon between the State of Portugal and the Government of the Republic of South Africa to finalise plans f. At the same time, construction contracts were signed with Zamco, an international consotrium, constituted by 15 member companies from West Germany, France, Italy, Portugal and South Africa.

The contracts provided for the construction of a dam at Cahora Bassa in Mocambique, and underground power station on the south bank of the Zambezi River, terminal converter stations at Cahora Bassa and at the Apollo substation near Pretoria in South and double direct current transmission lines over 1 km between Cahora Bassa and Apollo. The project was one of the most exciting of the century. Esk o m is a recognized world leader in the field of high-voltage transmission at high altitudes over long distances.

At this stage, however, it was not the technological expertise which was a major consideration in the scheme. As the most advanced country in southern Africa, South Africa was the only viable market which could justify the development of such a massive project as that envisioned at Cahora Bassa, Mocambique and its neighboring countries were not sufficiently industrialized to utilize the amount of energy generated by the proposed hydro-electric scheme.

Eskom did not at the tie have a real need for energy generated at Cahora Bassa, yet by importing power it did stand to gain some advantages. For instance, importing power could obviate the necessity of building an additional coal-fired power station.

This would not only save coal resources, but also release internal water supplies for other industrial, commercial or domestic use. Energy fed from Cahora Bassa into the power grid could then be distributed to any point of demand along that network. Aerial view of the Dam. As the result of discussions held in , contracts concerning Cahora Bassa were renegotiated to include the now independent Peoples Republic of Mocambique.

The geographical framework. All these countries are rich in natural resources, from water supplies and fertile land to minerals.

Resources however, are of no use until they are developed and unless there is a market for them. Two of the main problems confronting most southern African countries are the lack of established infrastructures and the lack of markets to justify development of their resources. Only South Africa, with its rapidly developing industrial and commercial sectors, could provide the immediate market which these countries needed, In addition, South Africa possesses and established and rapidly developing infrastructure.

It has a sophisticated First world economy set in a Third World region and is consequently admirably situated, economically and industrially, to boost the economies of the neighbouring countries.

Aerial view of the dam. It would seem a natural step to sell something more lucrative than unskilled labour — namely water and power. Hydro-electric power and Mocambique. Where there are abundant water supplies, hydro-electric power is the obvious choice for the development of power generation projects since it is the most economical form of electricity. Cooperation between a country rich in water resources like Mocambique, with its dryer but industrially developed neighbor in establishing a grid of water and electricity networks would provide economic and social benefits for both, stimulating local industrial development and increasing export possibilities.

Mocambique is a Third World country rich in natural resources, but lacking an efficient infrastructure. The potential for agricultural development is vast — the land is fertile and capable of high production of tea, sugar cane, rice nuts, vegetables, citrus and subtropical fruit. It has vast and practically undeveloped fishing and mineral resources.

The potential for the tourist industry includes coastal waters, gam reserves and the scenic interior. Three harbours, Beira, Maputo and Ncala, could handle considerable quantities of trade. The Zambezi River has almost untapped potential for the development of hydro-electric power, which started with the Cahora Bassa Dam project.

The purpose of the project was to export power initially to South Africa which would give a surplus royalty to Mocambique to be channeled into a development fund. The fund would be utilsed mainly to promote agricultural development. Advantages of the Cahora Bassa project.

Irrigation schemes would encourage agricultural projects, forestry and fishing industries which in turn would raise the standard of living. Improved water supplies for riparian villages and settlements would also raise the general standard of health as well as encourage stock breeding. The dam regulates the flow of the river, lessening the consequences of drought and dramatically reducing the dangers and damage caused by flooding —common events in this part of the world.

The improved irrigation would enable farmers to introduce more efficient and scientific farming methods. Small-related industries are encouraged, such as food processing and canning. Hydro-electric power is generated more economically than that supplied by coal fired power stations. The availability of power at low cost triggers an upsurge in the growth of light and medium industries. Towns began to develop, employment opportunities profilerate and with them, improved training and education facilities.

Entrepreneurship is stimulated. As new areas open up for development of local resources, communication is improved and the general infrastructure developed. Economic and industrial development encouraged political and social stability. Economic and technological interdependence and joint participation in industrial and commercial projects foster cooperation between countries. The status of the project.

On 25 March , the first generating set was commissioned. The first transmission of energy from the power station on the south bank to the Apollo substation in South Africa took place on 19 May The second generating unit came into operation 3 July and he the third and fourth on 17 September and 25 January respectively. The final unit was commissioned on 22 June Total capacity of the five units is MW at 16 kV.

A second power station was scheduled for construction on the north bank at Cahora Bassa with four MW generating sets. Civil war in Mocambique disrupted the original construction and commission schedules and has since extensively damaged power lines and towers. This has effectively hindered commercial, agricultural and industrial development of the area and to all intents and purposes significantly delayed the eventual growth of a South African grid.

Surveys of damage. Recent surveys and inspections conducted along the length of the line from Cahora Bassa to Apollo in South Africa revealed that on the South African side of the border the lies were intact and operational. Extent of this damage varied from one region to another. In some cases it is slight and can be easily repaired, often using material on site. This is generally the situation between the Limpopo and Save Rivers.

In other cases, particularly north of the Save River, total reconstruction is necessary, requiring the replacement of both the towers and the foundations and insulation strings.