The challenge:

eThekwini Municipality had the need to upgrade and refurbish their existing 132/11kV substations to IEC 61850 compliance. This included the upgrade of various IEDs to IEC 61850 to perform both protection and control.

The solution:

iST was tasked with the supply, delivery, installation and testing of protection and control equipment as well as the testing and commissioning of associated electrical plants for various 132/11kV substations and switchyards in eThekwini Electricity.

This included:

• Integration of IEC 61850 RTUs
• Substation local area network (LAN) using optical fibre for inter-panel communication and applying the parallel redundancy protocol to achieve complete communication redundancy
• New human-machine interface (HMIs) combining supervisory control and data acquisition (SCADA) and data gateway functionality to the network control centre

The result:

A fully integrated protection and control system was delivered to eThekwini allowing for the operators to control, monitor and perform substation interlocking using the IEC61850 communication protocol over fibre optic networks. Other benefits include remote engineering access to every protection or SCADA equipment in the substations from the eThekwini Engineering offices.

The challenge:

ESKOM had a requirement to have a National Transmission Contract for capacitor bank protection schemes that will be able to protect, monitor and control their capacitor banks for voltages ranging from 88 kV to 400 kV and for capacitor banks ranging from reactive power of 36MVAr to 150MVAr.

The solution:

iST was tasked for the design, development, manufacture and testing, development of user documentation, training of Eskom personnel, supply, delivery, off-loading and if required, installation and commissioning of Transmission Shunt Capacitor and/or Filter Bank Protection and Control Schemes for a production period of 36 months with the option to extend for up to an additional 24-month period.

This included the following:

• Double Star Capacitor and/or Filter Bank (unearthed or capacitive earthed star points)
• Single Star Capacitor and/or Filter Bank (earthed)
• H-Configuration Capacitor and/or Filter Bank (single star earthed)
• C-Type Capacitor and Filter Bank with single or double filter resistors
• Model Power System Simulator Testing (RTDS) in Spain to verify the offered products’ performance under extreme power system conditions
• Complete Scheme Type Testing by a third party – Namely Gerotek

The result:

The GE C70 Capacitor Bank Relay and the GE MIB Restricted Earth fault relay successfully passed rigorous Model Power System Simulator Testing over a two week period in Spain.

This was accepted by ESKOM as suitable to be used on transmission systems.

The solution:

iST (Integrators of Systems Technology) offered Duvha Power Station an EMDAS covering both historical data reporting and real-time visualisation of power generated or consumed in the plant. This solution had been designed around the metering best practices accumulated in iST’s experience in metering of over 30 years in this specialised field.

Our device agnostic approach and integration skillsets enable us to directly interface to a variety of metering devices or other 3^rd party systems, depending on the best-fit solution for the client. Our current supported device list is provided below and new device drivers are added as their market uptake viably increases:

• Actaris
• Blue Star A2000
• EDMI Meter
• Elster Kent (A1700 & A1140 & AS1440 & A1160 & Waveflow)
• Energy Intellect VM Series
• Enermax & Enermax+
• GE SM Series
• Landis & Gyr
• Power Logic ION
• Premier
• Iskra (MT372 & MT831)
• SEL734
• Schneider PM3000 Series
• Synapses LM1AMR
• Unitrack DM50

Due to the age of the hardware at Duvha it was required to redesign the metering and measurement systems in conjunction with the new EMDAS for Units 1 to 6, station boards, HV Yard and other supplies at Duvha Power Station.

iST’s EMDAS solution at Duvha consists of two identical servers, both loaded with the same software packages namely ecWIN™ and Schneider Electric’s Struxureware Power Monitoring Expert. A third server acts as a Data Server pushing data to Eskom’s Phoenix system for visibility at National Control from where the electrical network is managed. This server is located in a protected network as depicted in figure below. The challenges and limitations mentioned previously motivated the decision to deploy the new EMDAS with a file exchange interface to the old EMDAS.

Each of the EMDAS servers acts independently to provide fully redundant system operation. In the event of one server failing, the EMDAS system as a whole will remain operational. The software from both servers will simultaneously connect to the meters to collect the real-time and logged data via Ethernet and RS485. This implementation of communication redundancy has been possible through the use of advanced power metering product, namely the ION8800 meter. Where existing hardware is utilized, the communication architecture restrictions should be considered.

The result:

The solution deployed addressed the requirements for an EMDAS system applying the latest available technology and future proofing the EMDAS system at Duvha.

The picture below shows the real-time monitoring for each unit and Station Boards, including single line diagrams with power, voltage, currents and power factors from each metering point.

The picture below shows the real-time reading accuracy comparisons. The analogue transducers are utilised for control and should be verified to timeously identify any possible corrective actions required.

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.