Powering Impressed Current Cathodic Protection

Introduction

The field of cathodic protection and, in particular, Impressed Current Cathodic Protection (ICCP) has progressed dramatically in the past fifty years, with numerous improvements in the areas of coatings, anode materials, monitoring devices, monitoring methods, etc. Yet, the power converter which interfaces between the source of input power (utility power lines, motor-generators, solar cells, etc.) and the precise DC voltages typically required to achieve effective protection has not benefitted from implementation of modern electronic technologies.

Present state-of-the-art power conversion technology offers potential benefits with regard to system size, weight, cost, performance, and operational efficiency. However, adaptation of this technology has been slow for a number of reasons, including a lack of focus on addressing the various physical and electrical environment challenges associated with typical ICCP systems, lack of knowledge within the ICCP community on power conversion technology, industry norms constructed around traditional technology based systems, and the risk-adverse approach to implementation of new solutions.

A number of factors are now motivating the industry toward adoption of improved methods of power conversion, including the desire for improved monitoring and control methods not well-served by existing technology, an improved maintainability model in deployed equipment, reduced physical footprint, reduced salvage value for theft reduction, and cost optimization of the overall system.

This is the first article of a two-part series to be published in Inspectioneering Journal and will provide a basis for understanding the differences between traditional tapped-transformer, fixed voltage type rectifiers, and High Frequency Switched Mode (HFSM) units. It will also highlight the opportunities for optimization provided by HFSM. Moreover, the aforementioned barriers to acceptance of HFSM are explored, along with practical solutions to address them.