Research Of The Programmable Power Supply Based On Pulse Current Cathodic Protection System

With the increase of water content in oilfield development,the phenomenon of the corrosion and perforation of the inner wall of the gathering pipeline becomes more and more serious.Impressed current cathodic protection is an effective anti-corrosion method,in which DC power supply is the main equipment of impressed current cathodic protection system.However,when the DC power supply method is applied to the inner wall environment of the pipeline,there are problems such as short protection distance and uneven distribution of protection potential,which cannot achieve full line protection of the pipeline section.Studies have shown that the use of pulse current cathodic protection technology can effectively extend the protection distance in the tube and achieve an even distribution of the protection potential in the tube.Therefore,the programmable power supply based on the pulse current cathodic protection system is studied,and the function of the programmable power supply is tested and realized by designing the pulse current cathodic protection system on the inner wall of the pipeline.It is of great significance to the corrosion protection of the inner wall of oil field gathering pipelines and the popularization and application of pulse current cathodic protection technology.Based on this background,starting from the actual needs of pulse current cathodic protection in the tube,this paper firstly designs the overall structure of the pulse current cathodic protection system on the inner wall of the pipeline,and studies and designs the structure and installation method of the key components flexible anode and reference electrode,And determine the technical solution of cathodic protection dedicated programmable pulse power supply.Secondly,the main circuit structure is designed by using the multi-level conversion idea of full-bridge inverter and DC chopping mode,and related parameters of circuit components are calculated.A multi-level adaptive closed-loop control strategy and related algorithms are used to achieve a reasonable and even distribution of protection potentials and stable and safe power output.A first-order inertial digital filtering algorithm is used to implement ADC sampling filtering.The communication structure with PC as the upper computer and the main control chip as the lower computer is designed.The VB.net software is used to design the human-computer interaction interface to control and monitor the relevant parameters.Finally,based on the above research,the programmable pulse power supply was installed and debugged,and the indoor simulation experiment and field pipeline inner wall pulse current cathodic protection experiment were completed,which verified the rationality and reliability of the programmable pulse power supply design.The experimental results show that the main circuit and control circuit of the programmable pulse power supply are designed reasonably,and the design indexes and functions are realized.The power supply can output square wave pulse current whose duty ratio and frequency can be adjusted intelligently,and the use effect,volume,weight,cost and safety have obvious advantages over traditional anticorrosive power supplies to meet the requirements of on-site use.