Real-time Cathodic Protection For The Seawater Operating Equipment Based On PLC

Metal corrosion problems in the medium has become increasingly serious and global annual waste of resources caused problems also get the attention of more people. So far, at home and abroad this problem have been deep and long-term researched, and a variety method for cathodic protection have been put forward, in which especially impressed current cathodic protection method is the most widely used. Most studies of metal corrosion and impressed current cathodic protection, however, starting from the point of view of the chemical or electrochemical, come down to be chemical or electrochemical problems at last.Conducting impressed current cathodic protection, need to collect many important parameters, and based on these parameters to guide the implementation of the cathodic protection engineering. However, these acquised parameters are essentially electrical parameters, therefore, this article attempts to proceed from the electrical point of view, to analysis and extract circuit components, to get the equivalent circuit model of impressed current cathodic protection, and to explain the reason in different angles that metal corrosion will occur in liquid medium and in which the impressed current cathodic protection can play a role. After acquised the equivalent circuit model,cathodic polarization process of iron in simulated seawater was tested based on the programmable logic controller (PLC) hardware platform and the MATLAB GUI debugging system as a means of disposing of.Followed in the time domain analysis ed the response of the polarization potential of the iron when the excitation voltage was applied, draw response curves and observed the basic trend of the polarization potential for further solve select waiting time in the process of test cathodic polarization curves of iron. In the process of testing cathodic polarization curves of the iron, disconnect incentive power before every polarization potential testing to make the cathodic polarization curve closer to the theoretical definition of the steady-state polarization curves. In this paper, the concept of equivalent circuit node, in order to explain the equivalent model to establish a bridge to the electrical transition from the electrochemical. To further verify the correctness of the extracted equivalent circuit at the same time, used the ALTIUM DESIGNER circuit analysis software to make circuit simulation.In order to organically combine the cathodic protection technology and the automatic control technology, in the opinion of engineering applications, designed the impressed current cathodic protection system based on the PLC.