Automation and power products for Gold Coast desalination plant

The Gold Coast desalination project, owned by the government statutory authority Seqwater, was the first large-scale desalination facility on Australia’s eastern seaboard. The plant, constructed by the Gold Coast Desalination Alliance (Veolia Water, John Holland, SKM, Cardno and the facility owner), produced the first desalinated water in November 2008. It has the capacity to provide drinking water to 650,000 people in South East Queensland, one of Australia’s worst drought-affected regions.

The Gold Coast desalination plant uses a process called reverse osmosis, where pressurised intake water is forced through a semipermeable membrane. The membrane filters block the salt, leaving concentrated brine on one side of the membrane and drinking water on the other. ABB supplied a wide range of automation and power products and systems for the Gold Coast desalination plant which ensure that the plant is operated at a high level of efficiency and reliability.

ABB supplied the following variable speed drives with a total power of 40.3 MW for various processes in the desalination plant:

• ACS800 low-voltage drives in the power range between 1.1 and 710 kW to control intake, booster, filter backwash and potable water pumps;
• ACS 1000 medium-voltage drives in the power range of 1120 and 4800 kW to control high-pressure and energy recovery booster pumps.

ABB supplied the following induction motors with a total power of 28.8 MW:

• M3BP low-voltage motors rated at 550 kW;
• HXR high-voltage motors rated at 800 kW;
• AMA high-voltage motors rated at 1.1 MW;
• AMI630 high-voltage motors rated at 4.8 MW.

ABB supplied the following transformers:

• 11 kV vacuum-casted (VCC) dry type variable speed drive supply transformers rated at 1.5 and 6 MVA, phase-shifted for 24-pulse operation;
• 11 kV VCC dry type distribution transformers, rated at 1, 2.5, 3.5 and 4 MVA.

ABB supplied the following equipment to meet the power factor requirements and improve the power quality of the installation:

• Metal-enclosed capacitor banks (MECB), each rated to deliver 4 MVAR at 11 kV. Each of the four MVAR banks has two steps of 2 MVAR each. The capacitors are provided with detuning reactors to protect them from possible harmonic overloading.
• PQFS active harmonic filters, rated at 415 V, 120 A.

For motor protection and control, ABB supplied low-voltage soft starters PSTB 370 and 470 for booster pumps rated at 355 kW and 450 kW/690 V, including integrated bypass contactors, flexible bus communication and torque control for less mechanical wear.