Power Supplies for Cathodic Protection Applications
10 Aug 2015
Powering cathodic protection
Often dubbed the inconspicuous killer, rust costs the global economy $2.2 trillion dollars every year. It accounts for anywhere between 3.5 to 4.5 per cent of gross domestic product (GDP) and is responsible for the structural failure of steel frames around the world. From bridges and cars, transcontinental and marine pipelines, to industrial machinery, tools and parts, rust contributes significantly to plant downtime the world over.
By Steve Hughes
Whether it's steel pipelines or corrugated sheets in highly saline marine environments or reinforced concrete structures, impressed current cathodic protection (ICCP) is used widely to protect iron and steel structures against corrosion. Embedded anodes are connected to a control panel where the system produces an electrical current to suppress the naturally occurring electrochemical activity. In effect, the metal surface being protected becomes the cathode.
Often used over large geographic areas, cathodic protection systems have traditionally incurred high costs as engineers are required to perform extensive field surveys to ensure the system is working.
With the advent of concepts such as industry 4.0 and the Internet of Things (IoT) business leaders are increasingly pushing for increased transparency of business intelligence. Features such as remote monitoring, accurate control and measurement are now necessary to increase business process efficiencies in multinational organisations.
To overcome these challenges, REO has developed the REOTRON SMP-CP, a robust transformer rectifier power supply range specifically designed for cathodic protection applications. Built with the latest primary switch-mode technology, the REOTRON SMP-CP can be controlled from zero to maximum voltage or current.
This controllability is essential for cathodic protection applications. In newer installations that don't require a high degree of electrical power availability, if a power supply isn't driven to low voltages, over protection can lead to gas formation. This can contribute to surface bubbling and corrosion.
Voltage and current levels can be controlled through the range using an integrated keypad, external potentiometers, by using analogue control signals (0-10 VDC, 0-20 mA), RS232 serial communication and, most excitingly, by industrial fieldbus interfaces such as Profibus, CAN, DeviceNet or EtherCat. The enhanced fieldbus network control allows easy integration with existing supervisory control and data acquisition (SCADA) systems, opening up the use of remote monitoring, a vital feature especially for geographically dispersed operations.
Using the latest primary switch mode technology, the REOTRON SMP-CP units offer a high level of efficiency, easy maintenance and very low output voltage ripple packed into a lightweight and compact housing. Providing a 4-20 mA feedback, the unit achieves a proportional output for current and voltage. This makes metering easier and eliminates the need for current shunts.
They say rust is the longest battle but with accurate, highly controllable and remote monitoring of ICCP applications, engineers may one day win the war.← Back to News