The purpose of operation is design of the automation device of which is intended for automatic control, the control technological process of coal transportation from a fresh seam to a skip shaft of mine, and also for the account and the analysis of information streams from sensors of technological processes with improvement of separate elements of automation system concerning concrete conditions of operation and emergency operation.
As emergency operation it is observed emergency conveyor line stall. It will be observed to a basis in following cases:
- At proslipping a belt concerning a head pulley more than on 10 % from its nominal frequency of rotation;
- At proslipping a belt on 6 % should move the signal for a belt tension regulation;
- At lowering of a belt speed of the conveyor on 25 % from its rating value;
- At lowering of frequency of rotation for a driving pulley during operation more than on 15 %;
- At overflow of frequency of rotation for a driving pulley more than on 8 % (for cargo-passenger conveyors);
- At long start-up of conveyors (more than 60 sec.);
- During inflow of a control word on switching-off from automatic means of revealing and clearing of fires.
On the basis of mathematical models design dependences of a current stator I1=f (t), the electromagnetic moment of motor M=f (t), angular speed of a rotor w2=f (t), voltage and frequencies on clips stator U1=f (t) and f1=f (t) for operating modes are received: start-up in a course, operation under loading, short circuit. The analysis of character of transient in asynchronous motor at characteristic modes will allow improving system of emergency switching-off at a stop of working body. These all dependences are presented in figure 1.
Figure 1. Dependence of a current stator I1=f (t), the electromagnetic moment of motor M=f (t), angular speed of a rotor w2=f (t), voltage and frequencies on clips stator U1=f (t) and f1=f (t) for operating modes: start-up in a course, operation under loading, short circuit.
On the basis of mathematical models of system a pulley - belt is received a picture of a thermal field at belt slippage - proslipping depending on geometrical model with a grid of end elements (a hollow or whole pulley).
2. Model of a pulley - belt system: geometrical model with a grid of end elements (the pulley is presented by the whole metal cylinder); a picture of a thermal field at belt slippage - proslipping.
Figure 3. Model of a pulley - belt system: geometrical model with a grid of end elements (the pulley is presented by the hollow metal cylinder); a picture of a thermal field at belt slippage - proslipping.
