The Design Of Ballast Water Treatment Automation System With Electrolytic Disinfection On The Basis Of PLC

The harmful invasive aquatic organisms carried by ships ballast water will pose a threat to the stability of local original bioroenosis and ecosystem.Meanwhile,it will also do harm to global ocean health.The paper designs a set of ballast water treatment automation system with electrolytic disinfection using PLC, referring to Guidelines for Apprival of BW Management Systems.This paper chooses the electrode material and calculates the total current and current density of electrolyzer, the size and gap of electrode as well as the tank voltage.The tank voltage contains theory decomposition voltage,overpotential of positive and negative electrodes,electrolyte resisitance voltage,matallic conductors and contact resistance voltage.On the basis of the result of tank voltage calculation and the principle analysis of Phase-shaft Full-bridge ZVS PWM DC-DC Convertor,this paper designs the main circuit,control circuit and compensating network of switching power supply used in ballast water treatment system,and then calculate the relevant paramenters.To discuss the control performance of switch control system designed in this paper,builds the small signal model of DC-DC convertor as well as frequency and time domain model by using MATLAB/Simulink.After designing the pipeline structure of BWTS,use SIEMENS PLC and Win CC flexible to achieve auaomatic control and HMI of system so that it can realize the automatic control,online monitoring and remote operation.This paper uses MATLAB/Simulink to test and verify the switching power supply system model.The results showd that the switching power supply designed in this paper can realize ZVS and the control performance,output voltage and current of system can satisfy the requirements.For the whole ballast water treatment system,this paper uses simulation software PLCSIM and WinCC flexible Runtime to debug the system to online simulate the actual effect when system is operating.