De Aar Wind Farm Facility Protection, Control, Automation and DC Solution

The challenge:

Adenco Construction was awarded the electrical construction for two wind farms in De Aar, Northern Cape South Africa by Longyuan South Africa Renewables.

De Aar 1 is a 100MW, 67 WTG wind farm. De Aar 2 is a 140MW, 96 tower wind farm. Longyuan will invest a total of R 5 billion into the two projects. The construction start date was 11 January 2016.

Adenco had the construction abilities but did not have the capabilities or the experience to tackle the electrical substation Protection, Control, Automation, DC system supply, testing and commissioning.

The solution:

iST with its vast experience with electrical substation secondary plant solutions including Protection, Control, Automation and DC systems was one of the companies approached by Adenco for the supply of these systems.

As part of the proposal process, iST engaged with Adenco to detail the technical scope and requirements in order to ensure the proposal was both technically sound and commercially competitive.

There are two electrical substations per wind farm. One for the independent power producer (IPP) and another for the connection to the Eskom grid.

iST being a value-added reseller of the GE range of Protection, Control and Automation products proposed a complete GE based solution for the independent power producer substations. The DC systems solutions included Cordex based charger systems and Nickel Cadium battery systems.

The Eskom substations had to be compliant with the Eskom specifications and therefore only the DC, RTU, HV high impedance bus-zone, Metering and Power Quality systems were supplied by IST.

The result:

The close interaction during the commercial process to understand the end-customer’s technical and cost requirements resulted in successful award for the supply of the secondary plant solution by IST. This extended to the supply, installation, testing and commissioning of the complete Substation Automation solution for both the independent power producer and Eskom substations.

Through technical workshops and close interaction with the customer’s consulting engineers, technical designs were finalised.

The Protection, Control and Automation solutions included equipment from GE Multilin based in Markham, Canada. These comprised the GE UR range for the Transformer, Bus zone, Point of Connection, F650 Bay Controller, D400 Substation Data Manager, D20 Substation gateway devices. GE Reason substation hardened Ethernet switches and GPS clocks completed the communications interface required for the automation functionality. A-Eberle automatic voltage regulators were responsible for the monitoring and control of the transformer tap changers.

All of these equipment used latest substation communication architectures allowing for communications to the substation SCADA control system, Eskom SCADA Master Stations as well as Independent Power Producer Control Centres. This architecture also allowed for engineering access to any of the equipment at the IPP substation, thereby facilitating remote connection and diagnosis of this equipment.

The substation wide monitoring and control is handled by the GE D400 Substation gateway. This device is wholly responsible for the communication with all the devices within the substation and concentrates this data to provide this to the respective control centres.

The assembly of the system began at the end of August 2016. Factory acceptance testing for the all systems were completed during September/October 2016. All systems were delivered in October 2016.

The construction for the individual sites began in December 2016 and was completed in March 2017. Testing and commissioning for the plant was completed by May 2017. The commercial operation date commenced at the end October 2017. Both wind farm facilities have been successfully generating onto the Eskom grid since October 2017.