Derisking water through a digital twin

A Perth consultancy implemented a digital twin to help eliminate risk and help its client move closer to a more autonomous water system.

The American Water Works Association says that a digital twin for the water industry is a digital, dynamic system of real-world entities and their behaviours. They use models with static and dynamic data that enable insights and interactions to drive actionable and optimised outcomes; and the value of digital twins can be realised across the complete water cycle and asset lifecycle. From planning and modelling to design, construction and operations applications, digital twins are being used. Examples include real-time operational optimisation twins, construction progress twins, and asset health twins.

Today, digital twins can leverage static and live data streams such as SCADA, IoT, and AMR/AMI data to more precisely describe system performance, enable insights, and drive actionable user outcomes. They can also effectively use the power of artificial intelligence for improved decision-making.

What happened in Perth?

In Perth, a unique approach was taken to integrate new and existing water sources into the distribution system over time. Water from the different sources is supplied directly into a common existing trunk main system by several large pump stations and regulating valves. This approach maximises the use of existing infrastructure and minimises the annual volume of water pumped higher up into dams.

Eelko Van Der Vaart is the founder, managing director, and principal consultant of OneStone Consulting, a leading water systems consultancy. He has helped OneStone stand out from other consultancies by taking a whole-system approach.

“I’ve got a bit of a knack for looking at systems as a whole and how elements work together instead of getting into the details of individual aspects of a system,” Van Der Vaart said. “That’s important as well, but I have found that my strength is in taking that big-picture view of what is going on.”

This strength came to the fore when examining the complexity of Perth’s water system. Compared to other parts of Australia, much of the Perth water network is integrated. In the long term, this has saved the water utility money by connecting new pump stations and other infrastructure directly into the system.

“All the elements work well together, and I’ve implemented advanced techniques and control systems to ensure everything works well together,” Van Der Vaart said. “I suppose that is where my strength comes into play, as I can ensure that everything works well together for the client’s overall goal.”

How does it work?

In 2019, Water Corporation decided to replace and upgrade the control system for one of its pump stations to improve reliability. OneStone Consulting developed the functional description for the control upgrade in 2019, which became the basis for the programmable logic controller (PLC) and Supervisory Control and Data Acquisition (SCADA) programming undertaken by SPIN in 2021. Together, they developed a digital twin solution for the virtual commissioning of the new control system using a combination of Siemens’ SIMIT and a simulation system developed by OneStone called FluidSpace.

“By using a holistic approach, we can positively impact our clients, communities, and the environment by developing innovative and sustainable water solutions,” Van Der Vaart said. “Our FluidSpace simulation system lets controllers run a digital ‘twin’ of a water distribution system, providing accurate feedback to enable thorough testing of pump control logic programmed on physical PLCs for every scenario.”

The pump station model is integrated into the hydraulic model of the wider distribution system. This model consists of all the major trunk mains, regulating valves, and pump stations and includes all major demand offtakes and their associated pressure-reducing valves. The dynamic model of the pump station and the wider system was then connected to physical control devices such as PLCs (Programmable Logic Controllers) that were able to control the virtual pump station in the model. By testing the control logic on a dynamic model of the pump station and wider distribution system model, there was no need to take a pump station or any part of the system offline.

“After testing the control system on the digital twin, the actual testing on the system was only for a couple of days,” said Van Der Vaart. “With the digital twin, we can control the virtual pump station just like it would be controlled from the SCADA operating room. Naturally, small tweaks had to occur, but we ran through everything and ensured it all worked the way the client wanted it to.”

What are the benefits?

Implementing a digital twin is not an easy thing to do, but OneStone Consulting’s plug-and-play system comes after considerable effort. As a result of the work, the client had enough confidence after a day of site acceptance testing that the pump station could be handed over to the remote operators. The digital twin behaved almost identically to the system, even when tuning had to be extremely sensitive.

“One of the things that is important to remember is that it is all about derisking,” Van Der Vaart said. “If the client took one pump station down to test the system, it would have to be down for months. With a digital twin, we can leave the pump station running and test a vast array of scenarios. That eliminates several impacts on the business, as they can still run certain water sources into the system.”

While quantifying how much money or water the client has saved is extremely difficult, the focus on risk is appreciated.

“We reduced the duration of site acceptance testing from months to just a few days and minimised the risk of damaging critical infrastructure,” he said. “There’s also the reduced disruption to the operation of the live system. When we connect the hardware to the real-time simulation over the Internet, there’s no change in performance. During Covid, this allowed testing to continue remotely, with the PLCs located in one office and the real-time simulation running in the OneStone office. Those are the sorts of benefits.”

The future

OneStone Consulting has only just started flexing its muscles regarding digital twinning for water utilities. Van Der Vaart believes that there is interest in having more advanced controls that could optimise an entire system.

“At some point, we will have a client who wants to incorporate some artificial intelligence algorithm to optimise the whole system. That comes with risk, and we hope that with our software, we can safely implement such an algorithm in our digital twin. That way, we can build it into something more water utilities could use. We want this to become a good tool for developing and understanding how a system reacts to different things.”

For more information, visit onestone.com.au