Powering Impressed Current Cathodic Protection — Part 2

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 second article of a two-part series published in Inspectioneering Journal, which is intended to provide a basis for understanding the differences between traditional tapped-transformer, fixed voltage type rectifiers, and High Frequency Switched Mode (HFSM) units, as well as highlight some opportunities for optimization provided by HFSM.  In Part 1, published in the July/August 2015 issue, I discussed various power converter technologies, including traditional ICCP systems, closed-loop feedback systems, and high frequency switch mode converters. In Part 2, I will discuss some barriers to adoption of HFSM technology and provide practical solutions to address these obstacles. and will

Barriers to Adopting HFSM Technology

Modern, state-of-the-art HFSM converters are delivering highly reliable performance to a multitude of end markets. When compared to traditional tapped-transformer rectifier type units, they present advantages in numerous areas, including size, weight, cost, modularity, and adaptability to advanced control methods. So the question arises: why hasn’t this technology been aggressively adopted by the ICCP community?

To date, the major obstacles to adoption of this technology include the perception it is overly complex and not rugged enough to provide reliable, long-term performance expected for ICCP applications. In addition, attempts at introducing HFSM technology to the ICCP community thus far have been through niche power supply providers whose cost models result in prohibitive pricing. Finally, the past fifty-plus years have seen development of numerous regulatory requirements designed around the implementation and ongoing operation of TTR based systems. In many cases, the potential advantages provided by HFSM solutions are negated by these regulations.