System Integration & Control Systems Design


Reliable water treatment requires high availability

April 2012 System Integration & Control Systems Design

It has been said that water is the oil of the 21st century, making the continuous operations of today’s water treatment facilities of great importance. Uninterruptible power supplies (UPSs) at these facilities are therefore essential, as these protect process controllers and monitor and control the facilities from power outages.

According to Ravi Saman, water and wastewater manager at Schneider Electric South Africa, the raw material needed to produce drinking water comes from different sources, such as springs, aquifers, rivers and oceans, and appropriate technologies to treat each have to be used. “The available space and the volume of water to be treated also determine the technical choices. In all cases, however, the required water quality has to be reached and proved in accordance with regulations and the authorities.”

Systems availability

Both the automation system and the electrical network at a water treatment plant must first be studied in order to provide high performance and a high level of availability. The solution includes software and hardware architecture with redundancy at all levels.

“A high level of availability affects power as well as automation and is requested for all parts of an application identified as being critical. It may include redundancy for power architecture, standby generators, UPS, motor control, programmable logic controller (PLC), communication and scada.

“Different circuit configurations can also be selected and are, in increasing order of power availability, radial single feeder, two-pole configuration (secondary selective) and double-ended power supply (primary selective),” says Saman.

The implementation of back-up generators is very common in water treatment plants where water distribution cannot be interrupted for periods longer than a few minutes. “No instantaneous takeover is necessary as buffer tanks are generally present. Automatic transfer switches are naturally associated with generators for rapid takeover and smooth switchback to normal supply,” adds Saman.

Coordination is required

“Protection coordination is a key aspect for improving supply continuity. Two examples are discrimination between functional units so that a problem on a grid does not stop biological treatment for instance, and coordination of motor protection and control minimises downtime.”

Schneider Electric South Africa’s solutions for high availability in water treatment facilities are mainly focused on the following three levels:

Scada: On the scada side, Schneider Electric South Africa offers seamless, integrated and scalable redundancy. This flexible redundancy can be enlarged to avoid not only network errors, but also PC hardware faults, with a resultant highly optimised and available solution.

Industrial Ethernet: has proved itself over the years as being the reliable industrial standard. It provides the solution for communication architectures requiring high levels of availability. Communication can easily be adjusted to the required level of availability such as redundant media or network interfaces, self-healing fibre-optic rings and communication backups.

Control doubling a PLC: this provides a highly optimised solution that avoids the negative effects and process downtime caused by problems at the control level. In the event of an error, there is an automatic ‘bump-less’ switchover between the primary and the standby PLC – both, are connected by a dedicated high-speed Ethernet link. Duplicating the I/O level, along with the corresponding sensors and actuators, can increase the availability level of the control system.

“In water applications, the environment is sometimes polluted and may have negative impacts on the ageing of the electronic components used,” concludes Saman. “This results in unexpected downtime and higher maintenance costs. However, based on extensive field experience, Schneider Electric has developed a special protection process (conformal coating) to improve service life in such aggressive chemical and corrosive environments.

“Water is a planetary resource that concerns all countries. Strong global players are present but it is still a local market and Schneider Electric South Africa has all the solutions this sector needs.”

For more information contact Jacqui Gradwell, Schneider Electric SA, +27 (0)11 254 6400, [email protected], www.schneider-electric.co.za



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Turbomachinery controls: the call of duty
Schneider Electric South Africa Motion Control & Drives
There’s a lot to be said about the unsung heroes of this world; those men, women and machines that deliver such important functions, often overlooked and recognised. One such machine is turbomachinery, and while the name does sound quite obvious to the layman, its rich history and daily functions are not.

Read more...
The state of the SI industry remains strong
System Integration & Control Systems Design
The system integration (SI) industry is expanding with the adoption of AI, automation and data sharing, allowing companies to improve operational efficiency and competitiveness across diverse sectors.

Read more...
Schneider Electric again named World’s Most Sustainable Corporation
Schneider Electric South Africa News
Schneider Electric has been named the World’s Most Sustainable Corporation 2025 by Corporate Knights, and is the only company to rank first in the Global 100 twice.

Read more...
Proactive maintenance for long-term sustainability
Schneider Electric South Africa IT in Manufacturing
: Businesses should prioritise long-term sustainability by implementing proactive maintenance strategies, acknowledging the strategic value of investing in maintenance and after-sales support

Read more...
Three financing trends driving clean energy in the Global South
Schneider Electric South Africa Electrical Power & Protection
The Global South is at a critical juncture in its energy transition, grappling with challenges that demand immediate action. To finance its energy targets, the World Economic Forum’s Network to Mobilise Clean Energy Investment in emerging markets and developing economies has developed a playbook of over 100 financing mechanisms and de-risking tools that have successfully helped narrow the clean energy financing gap in emerging and developing economies.

Read more...
Shifting from CapEx to OpEx in utility networks
Schneider Electric South Africa IT in Manufacturing
Modernising power networks through digitisation and innovative technologies such as artificial intelligence and machine learning is essential for utilities and municipalities to improve efficiency and manage the growing complexities of energy distribution

Read more...
Microgrids in buildings pioneer the future of energy management
Schneider Electric South Africa Electrical Power & Protection
Microgrids are emerging as a game-changing concept, particularly within commercial and industrial buildings, in a world that continues to shift towards more sustainable practices. By offering a decentralised approach to energy, microgrids allow buildings to generate, manage and utilise their electricity more efficiently.

Read more...
There’s green and then there’s blockchain green
Schneider Electric South Africa IT in Manufacturing
Greener blockchain, who would have thought? Blockchain’s very nature sees it consuming a lot of energy; with great power comes great power usage. But here we are, and green blockchain continues to garner significant attention, driven by the heightened awareness of the environmental consequences of blockchain-related systems.

Read more...
How AI and ML are enhancing utility management with advanced predictive maintenance
Schneider Electric South Africa IT in Manufacturing
The integration of artificial intelligence and machine learning is significantly transforming the management of utilities by providing advanced technology that delivers real-time insights into the operational conditions of facilities.

Read more...
Appointments
Schneider Electric South Africa News
     

Read more...