Mine hoist fault monitoring and diagnosis

One of the problem
    Mine hoist is the underground mine of the "throat" device, in the event of failure, the loss is great. Therefore, we must do a good job maintenance work. The traditional

method of repair is generally two kinds of corrective maintenance and preventive maintenance. Corrective maintenance is repair after failure, maintenance mode is difficult to do

well in advance of this production and maintenance plan, and thus high maintenance costs, impact on production. Preventive maintenance is the device running for some time, check

it regularly, cleaning, maintenance or replacement parts to make repairs to prevent equipment failure and downtime. This repair method does not wait until after the shutdown due

to a fault repair, thus increasing the equipment utilization, reduce maintenance costs. Currently, most of the mining companies mine hoist used for preventive maintenance hot water heat exchanger

approach.
    However, preventive maintenance is based on a predetermined time interval to carry out. Fault repair time deterministic randomness and there was a contradiction between the

actual working equipment is prone ashamed still good maintenance period has come to the "excess repair", the device has not yet reached the hidden but maintenance period "less

repair" and frequently caused by human error removal: To solve these problems more effectively carry out maintenance on the equipment, King rational approach should be based on

the quality of equipment running to schedule maintenance work, this method is called predictive maintenance. And really want to do predictive maintenance, you must create a

microcomputer mine hoist fault monitoring and diagnosis system.
2 mine hoist fault models
    To meet starting, speed, braking, and other static and dynamic characteristics of the requirements of the current mine hoist electric transmission system to use more power

thyristor rectifier DC dual-loop speed control system whose failure can be roughly divided into three categories.
2.1 Emergency stop
    Referred to Class I malfunctions which in the event, disconnect the AC and DC circuit and immediately parking brake. Such failures include:
(1) Over winch hoist two terminals; (2) Hydraulic station motor brake system failure; (3) hoist wrong to run; (4) during the operation of the hoist horizontal cradle steady tank belt conveyor design

actuated; (5 ) two terminal speeding; (6) Main motor failure excitation; (7) protection circuit energized; (8) DC main current passing through; (9) DC main circuit overvoltage;
2.2 Accident Parking
    Referred to as Class Ⅱ malfunctions which in the event, hoisting machine will automatically slow down according to the speed chart, reaching less than 2 m / s when the

automatic brake and stop. Such failures include: (a) brake wheel deformation; (2) tail rope failure; (3) Emergency stop, not zero; (4) Operating limit switch failure; (5)

driving safety door is opened; (6) Zero electrical fault; (7) between the two terminals overdrive.
2.3 Signal Prediction
    Referred to as Class Ⅲ failure, such failure occurs, no parking brake, occurs only audible fault signal prediction. Such failures include: (1) the DC main motor bearings

overheating; (2) DC operating current ground; (3) brake pad wear; (4) oil pressure anomaly; (5) ventilation failure; (6) DC main circuit to ground.
    According to these three fault types, we can set up shown in Figure 1 hoist fault model.


    In order to establish fault monitoring and diagnosis system, you must first carry out the above fault classification numbers, and then in the man-machine dialogue, the

successive input above fault type, name, number, and location, so as to prepare the computer to read and identification purposes.
3 fault monitoring and diagnosis
    According to the above fault model, can be used two computer systems to achieve fault monitoring and diagnosis. The first stage is responsible for operating parameter

display, fault comprehensive, stop fault diagnosis, choose a IBM PC, this machine large memory, fast speed, anti-interference ability, and a better interface extension function,

easy to implement man-machine dialogue; second level is responsible for fault detection and fault handling, optional MCS-51 series of low-power 80C31 microcontroller one;

addition, the configuration 16 A / D board a 32-channel digital input board 5, 32 digital output board 2 and 16 D / A output board 1. Hardware system shown in Figure 2.
    Various fault signal acquisition, after conversion circuit into a standard signal, that is normally a logic "1", the fault is logic "0", input by the digital input board;

various operating parameters such as current, voltage, speed, temperature and upgrade, the conversion circuit, by the A / D input board input; various fault processing signals

from the digital output board and D / A output board output.


    80C31 microcontroller can be programmed in assembly language, using a modular way, even if the program debugging and improve the system's versatility, but also to meet the

pre-start hoist, a variety of atresia, troubleshooting, fault monitoring and diagnosis. IBM PC machine can be intelligent Turbo Prolog programming language, the software should

be designed to meet the operating parameter display, integrated operational failure, accident signal prediction, stop fault diagnosis.