The Research And Design Of Cathodic Protection Power Supply On Substation Grounding Grids

Substation grounding grids is an important part of power system, is to ensure the personal safety and the power equipment reliable operation. However, because buried in the soil, soil erosion by perennial role which led to uneven thickness or broken, so Grounding resistance increases. When the power system is shorted to ground fault, grounding resistance will cause an increase in the potential of the ground line ends abnormally high. When the potential difference exceeds the safety threshold, it will cause harm to the physical and electrical equipment. Therefore, anti-corrosion measures substation grounding grids is an important guarantee reliable operation of the power system.Cathodic protection is an essential tool for corrosion protection of grounding grids. Currently widely used methods are the sacrificial anode or thyristor potentiostat which belong to enforce current law. Because of its large volume, low efficiency, low reliability, has been unable to meet the current needs of the power system. Based on the status quo, we study and design a high-frequency soft switching digital control cathodic protection power.This paper discussed the full bridge converter soft switch technology firstly. Analyze the principle, feasibility, advantages and disadvantages of two soft switch technology(ZVS PWM full-bridge converter and ZVZCS PWM full-bridge converter). And give several implementations of ZVZCS PWM full-bridge converter topologies. Finally, select the topology design as the subject of a power circuit is relatively easy to achieve, and make a simulation to test and verify.Secondly, the design of cathodic protection power supply for a detailed hardware and software design, including EMI filters, main circuit soft start, high-frequency transformer, snubber circuit, IGBT drive circuit, control and auxiliary circuits. Master chip is currently more advanced digital signal processor core TMS320F28335. It also highlights the shift control program design and digital PID designed to achieve digital control.Finally, in the lab to build a set of cathodic protection power experimental platform for the relevant simulation experiments carried out to test its various functions, and its feasibility has been verified.