Deploying constant current power supplies for Active Corrosion Control
– Active prevention reduces environmental impact
High efficiency and the ability to control current and voltage across the broadest possible range are the main characteristics required for power supplies deployed in Active Corrosion Control. As a world-leader leader in technological research in the field of power supplies TDK-Lambda, a group company of TDK Corporation, has developed several ‘Constant Current’ power supply solutions – the ZUP, Z+ and Genesys™ allow full control of the current and the output voltage, as well as feedback on the same parameters.
Bridges, ships and offshore wind turbines are three examples where the prevention of corrosion of the structure is very important and greatly reduces operating costs. For environmental reasons, the traditional passive ‘Sacrificial Anode’ method of corrosion control is increasingly being replaced in favour of ‘Active’ prevention, which is implemented by applying an ‘impressed current’.
In the passive method, the anode of a different metal to the structure is ‘sacrificed’ in order to ensure that the structure is protected from corrosion. In the ‘active’ method, a sophisticated electronic current control system is used to inject a reverse current to that generated from corrosion to protect the structure. Since current flow is closely related to the flow of charge over time ( I = [dQ/dt] ), having constant current control allows the user to accurately control the process.
“In the first case, there is a need to periodically replace the sacrificial anode with consequent costs and dispersion of metals in the water,” explains David Buck, Market Development Manager, TDK-Lambda EMEA. “In the second case, the only costs will be that of the system and the energy used.”
The availability of isolated interfaces, analogue, digital RS232/485, IEEE488 and LAN allows a high flexibility of integration and system control. Power ratings range from 200W to 15KW, with the possibility of placing up to 4 units in parallel to increase the power up to 60KW and output currents up to 4000A. In addition, TDK-Lambda has the capability to optimise a standard product or even develop a custom solution to meet the specific needs of a particular user application.
For more information about TDK-Lambda’s ‘Constant Current’ power supply solutions, please call TDK-Lambda UK directly on +44 (0)1271 856600 or visit the website at: www.emea.lambda.tdk.com/uk/programmable