System for removing induction voltage in coal conveyor program control circuit

Abstract

The invention relates to a system for removing induction voltage in a coal conveyor program control circuit. Each instruction isolation relay comprises a relay contact and a relay winding coil. Each control cabinet comprises a feedback isolation relay and a DCS controller. An equipment feedback and protection circuit is connected with each feedback isolation relay to form a feedback protection circuit through a non-shielding signal cable, wherein power supply is achieved for the feedback protection loop through a 48VDC direct-current power source. When early warning happens to one device of acoal conveyor, the device transmits feedback signals to the feedback isolation relays through dry node signals via the equipment feedback and protection circuits in component control boxes, and the feedback isolation relays transmit the feedback signals to the DCS controllers. The DCS controllers are connected with the relay winding coils through non-shielding signal cables, and an instruction conveying loop is formed. The isolation relay adding manner is adopted, 220VAC power in cables is removed, and accordingly the alternating current induction voltage is removed.

Description

technical field [0001] The invention belongs to the technical field of electric power systems, and in particular relates to a system for eliminating induced voltage in a program-controlled circuit of a coal conveyor. Background technique [0002] The coal handling control system of the thermal power plant works in the way that the bucket wheel or impeller coal feeder loads coal to the raw coal bunker, and the system operates according to the principle of reverse start and stop. The operating site environment of coal handling equipment is relatively harsh, with serious rain, dust, humidity, vibration, noise, and electromagnetic interference, and the control of the entire coal handling system is scattered, with long coverage distances, many equipment in the coal handling system, and complicated interlocking, especially The signal line (weak current) and the control line (strong current) of the coal transportation system use the same cable, resulting in a large induction voltag...

AI Technical Summary

Problems solved by technology

In normal operation, when any one of the equipments running in chain fails and shuts down, the rest of the equipment should stop running in the direction of coal flow according to the chain stop relationship, and at the same time send out an alarm signal. Therefore, the defect of any one equipment means that the entire process can't go on

[0004] Because the existing technology cannot solve the problem of eliminating the induced electricity of the coal transportation control system of the thermal power plant at low cost under the harsh environment, first of all, the existing technology has a large control range of the coal transportation control system, which makes the construction difficult and the transformation cost high; In the presence of alternating current, due to the harsh operating environment of coal handling equipment, the cables cannot be reliably grounded, so it is impossible to fundamentally eliminate the induced electricity of the coal handling control system of the thermal power plant.

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