ZESCO, Zambia

Ensuring the best operation of large power stations

ZESCO, formerly known as Zambia Electricity Supply Corporation Limited, is a state-owned power company in Zambia. It is Zambia’s largest power company producing about 80% of the electricity consumed in the country, with some large hydro power plants as important producing units.

The government of the Republic of Zambia issued in 2013 the current Electricity Grid Code, which regulates the generation, transmission and operation of the electrical power system.

Solvina was awarded a contract to provide services in testing and developing models of power plants and at the same time build capacity among power station and system operations engineers in ZESCO to carry out similar work to ensure a long-lasting improvement of the power system.

The challenge

The power plants have a variety of control system equipment brands and models, with different possibilities and constraints – all must be mastered to tune each plant to its full capacity.

Tuning and testing of the plants is not possible to do without special equipment, which requires deep theoretical knowledge as well as practical experience to operate.

The aim

The mission of the project was to establish the capacity of ZESCO engineers to perform these services, with the very valuable benefit of power plants complying to the Zambian Grid Code.

The solution

The project was carried out by the following activities:

  • An extensive six weeks full-time off-site training at Solvinas facilities in Sweden.
  • A two weeks on-site training at one of the larger power plants.
  • Island Operations tests and tuning – services focusing on the turbine governors performing well, both grid connected and in Island Operation, demonstrating the capability for each unit.
  • Development of detailed tailor-made simulation models for the tested units, in order to achieve the best possible environment to further study the national grid.
  • AVR and PSS tests and tuning – services focusing on generators’ control equipment and the capabilities of handling grid disturbances.
  • Delivering the equipment required to perform these test and tuning activities.

The ZESCO engineers have been involved in all the steps required to improve a plant; from the first site visit and data acquisition, through the modelling and study phase and to the final test and implementation and demonstration of each plant’s full capability.

The result

Validated simulation models, both steady state and transient behavior, for system studies.

Well-tuned plants and in-house ability of ZESCO to continue this tuning work at other plants and to maintain this well-tuned status of the already existing plants.

Compliance to Zambian Grid Code.

Service areas



Sven Granfors
+46 31 709 63 18