Motor control system and method for water treatment engineering

Abstract

The invention provides a motor control system for water treatment engineering. The motor control system comprises an MCC low-voltage cabinet, a PLC / DCS controller and a spot operation box, wherein thePLC / DCS controller comprises a signal input module and a signal output module; the signal input module is connected with the MCC low-voltage cabinet; the motor control system furthermore comprises acontactor which is located on the MCC low-voltage cabinet and is used for controlling the ON / OFF of a motor main circuit; a coil of the contactor is connected with a motor control loop and is controlled through the signal output module of the PLC / DCS controller; an intermediate relay is connected with two ends of a coil loop of the contactor in parallel; when a manual / automatic switching switch isswitched to a contact corresponding to an automatic control manner, the intermediate relay is closed; the intermediate relay is connected with the signal input module of the PLC / DCS controller; and an opening or closing state signal of the intermediate relay serves as an automatic control manner signal and is transferred to a weak current digital input end of the signal input module of the PLC / DCS controller.

Description

technical field [0001] The invention relates to the field of equipment control in the field of water treatment, in particular to a motor control system and a control method for water treatment engineering. Background technique [0002] In the design of water treatment engineering, in order to meet the standard discharge, the process profession needs to configure a large number of various process equipment to complete the treatment functions of sewage (waste) water treatment such as lifting, backflow, stirring, blast aeration, dosing, and sludge disposal. Usually, multiple types of motors such as electric motors are configured as a transmission power source in a set. [0003] According to the requirements of the process control conditions, the electrical major usually adopts two control modes of manual / automatic for the motor and realizes the function through the corresponding control circuit. The on-site button box (or operation column) is set on the equipment site to comple...

AI Technical Summary

Problems solved by technology

[0005] The manual / automatic signal passes through the motor control cable connected to the field button box. According to the design specifications, it is usually designed that the motor control cable and the power cable are laid in the same cable trench or bridge, so that during the transmission process, the motor control cable has many problems due to the laying environment. Various current or voltage changes (inverter use, load changes, equipment start-stop, etc.) and other complex electromagnetic environments with strong interference will generate induction electricity, and the electromagnetic interference will react to the control system cabinet, causing some automatic control signal circuits to induce voltage or It can reach more than 100 volts of AC, causing the control system to be disordered, malfunctioning or unable to work normally, affecting its reliable operation and standard discharge. The automatic control system is disordered or cannot return to normal for a long time, which will force the sewage plant to enter the manual operation control mode, increasing the sewage plant. Labor cost

Images