埋地钢质管道防腐数字高频恒电位仪的设计与研究

【作者】 胡雷；

【导师】 黄琦；

【作者基本信息】 电子科技大学 ， 检测技术及自动化装置， 2011， 硕士

【摘要】 埋地钢质管道通常采用外加电流阴极保护来防止电化学反应的发生,以达到防止管道腐蚀的目的。恒电位仪是外加电流阴极保护系统的关键设备,其功能、性能和稳定可靠性很大程度决定了阴极保护的效果、恒电位的智能性和测量的准确度。本文运用电力电子等先进技术研究设计了数字高频恒电位仪,主控制器使用数字信号处理器TMS320F28015,主功率拓扑采用全桥DC/DC整流器,控制策略运用移相PWM方法。本文结合阴极保护电源恒电位仪的发展方向和先进阴极保护有效性评价的方法、标准,设计了恒电位仪的实现框图及各功能模块的实现的方法思路。首先论述了恒电位仪的软开关技术,包括实现ZVS开关的电路拓扑、控制策略、实现条件等,并针对实际运用中滞后桥臂难于实现ZVS的客观事实,通过添加辅助网络以实现滞后桥臂实现ZCS的目标。其次对高功率因素AC/DC整流器进行了研究,通过建立电压、电流双闭环的PFC控制器和主电路的数学模型和分析,给出了电压环PI参数的计算方法。用MATLAB工具搭建了仿真模型,通过电压外环采用PI控制、电流内环采用滞环控制方法,实现了功率校正,且功率因素达99%以上。然后设计实现了数字高频恒电位仪的硬件系统,包括DSP控制器、功率电路、防雷电路等,并完成的软件代码的编写。最后在实验室进行了模拟试验,能准确的采样参比电位、输出电流等信息,并能根据采样的参比电位值和设定值的差值来调节输出,实现恒电位的功能。并能实现自动通断功能等相关功能。更多还原

【Abstract】 Usually the buried pipelines use the method of impressed current cathodic protection to prevent the occurrence of electrochemical reaction, in order to achieve the purpose of preventing pipe corrosion. Potentiostat is the key equipment of impressed current cathodic protection system, its function, performance, reliability and stability importantly determine the effect of cathodic protection, constant potential of intelligence and measurement accuracy. In this paper, use the power electronics and other advanced technology to design high-frequency digital potentiostat: the host controller using digital signal processor TMS320F28015, and the main power with full-bridge topology DC / DC converter, phase-shifted PWM control strategy for the use of methods.This paper designed the block diagram and the ideas of functional modules based on the cathodic protection power potentiostat direction and reference to theadvanced evaluation of the effectiveness of cathodic protection methods, standard. Firstly discussed the method of soft-switching technology, including the realization of ZVS switching circuit topology, control strategy, to achieve conditions, and adding support network to achieve the lagging leg achieve ZCS goals for the objective facts of practical using the lagging leg is difficult to achieve ZVS.Secondly, the high power factor AC / DC converter has been studied. Introduce the method of calculating voltage loop PI parameter through the establishment and analysis of voltage and current double closed loop of the PFC controller and the main circuit of the mathematical model. The simulation achieved the power factor correction and power factor up to 99%, using MATLAB tools to built the simulation model, and the outer voltage loop use PI control method with inner current loop using hysteresis loop control methodAnd then design and implement the hardware of digital and high frequency potentiostat systems, including DSP controller, power circuit, lightning circuits, and complete the preparation of software code.Finally, a simulated test in laboratory proved that it can accuratly sample the reference potential, the output current and other information, and according to the difference of the sampling of the reference value and set the value of potential to adjust the output, to realize the function constant potential. And also can realize automatic on/off function and other related functions.更多还原