Photovoltaic powered regulated cathodic protection system

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Solar Energy (Journal of Solar Energy Science and Engineering); (United States)

DOI:https://doi.org/10.1016/0038-092X(94)90484-7· OSTI ID:6811110

Anis, W R; Alfons, H A ^[1]

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1. Ain Shams Univ., Cairo (Egypt)

The cathodic protection (CP) system objective is to protect metallic structures against corrosion caused by chemical reaction between metallic structures and surrounding mediums, such as soil or water. To overcome such a problem, a sacrificing anode is connected to the protected structure (which acts as a cathode) through a DC power supply. As a result, a current passes from the sacrificing anode to the protected cathode. This leads to anode corrosion rather than causing the cathode (protected structure) corrosion. To stop the corrosion, the protected structure requires a constant current determined by structure metal, area, and the surrounding medium. The major difficulty in achieving this condition is the variation of surrounding medium resistivity due to climatic condition changes. For example, rains as well as humidity decrease soil resistivity, and as a result the DC current increases and a harmful overprotection may take place. Both corrosion and overprotection are harmful for the metallic structure. Conventional CP systems resolve this problem by manual adjustment of DC voltage periodically to obtain a constant current. Such adjustment depends on the personal experience of the technician and the accuracy of the measuring equipment used. Accordingly, the adjustment is subject to personal and measuring equipment errors. Moreover, if the internal between two successive adjustment is relatively long, structure corrosion becomes significant, which may have drastic consequences. To overcome the aforementioned difficulties associated with the conventional CP system, an automatically regulated CP system is discussed in this article. The proposed system senses the variations of the surrounding medium resistivity and adjusts the DC voltage of the system automatically so that the DC current is kept constant at the required level. The design of a solar photovoltaic system to supply the CP system by the required DC power is also discussed.

• OSTI ID: 6811110
• Journal Information: Solar Energy (Journal of Solar Energy Science and Engineering); (United States), Journal Name: Solar Energy (Journal of Solar Energy Science and Engineering); (United States) Vol. 53:2; ISSN 0038-092X; ISSN SRENA4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
140909 -- Solar Thermal Utilization-- Miscellaneous Solar Applications-- (1980-)
CATHODIC PROTECTION
CORROSION PROTECTION
DC SYSTEMS
ELECTRONIC EQUIPMENT
ENERGY SYSTEMS
EQUIPMENT
FEASIBILITY STUDIES
PHOTOVOLTAIC POWER SUPPLIES
POWER SUPPLIES
POWER SYSTEMS
SOLAR EQUIPMENT
SOLAR-ASSISTED POWER SYSTEMS
VOLTAGE REGULATORS