Claims:WE CLAIM:
1. A system for individually monitoring condition of motors of run-out table and predicting imminent failure of such motors comprising
plurality of current metering means, each operatively interfaced with one of the motors of run-out table;
a field bus communication network establishing a communication between a PLC based controller and the current metering means;
said PLC based controller is configured to control each of the current metering means enabling individualistic continuous monitoring of the current being drawn by each of the motors by the interfaced the current metering means and therefrom determining condition of the motor including prediction of the imminent failure of the motor.

2. The system as claimed in claim 1, wherein each of the motors in the run-out table are supplied current from corresponding inverter via its individual current transformer and individually protected by a motor protection circuit breaker, whereby each of the current transformers is connected to one of the current measuring means enabling said individualistic continuous monitoring of the current being drawn by each of the motors.

3. The system as claimed in claim 1 or 2, wherein the current measuring means is adapted to continuously measure 3 phase current being supplied to the interfaced motor from its corresponding current transformer.

4. The system as claimed in anyone of claims 1 to 3, wherein the current measuring means includes
a current measuring module directly connected to the current transformer to measure the current value being supplied to the interfaced motor; and
a basic evaluation unit having a processor embodying functions related to measurement, control and monitoring the measured values and then transferring the same via the communication network to the PLC based controller;
wherein each motor connecting cable is routed through the current measuring module and current measuring module is connected with basic evaluation unit by flat band cable.

5. The system as claimed in anyone of claims 1 to 4, wherein each of the current measuring means assigned a unique bus address and are interconnected in series with each other forming a network on the master-slave scheme involving the field bus communication network preferably profibus communication in which the master PLC based controller is linked to the slave current measuring means.

6. The system as claimed in anyone of the claims 1 to 5, wherein the PLC based controller includes
a central processing unit forcontrolling all activities like current Monitoring, Fault generation, HMI handling and the current measuring means communication;
communication processors with on board profibus communication port to communicate with the slave current measuring means and Industrial Ethernet communication protocol to drive the HMI interface enabling the user to update about the prevailing condition of the motor and the roll including the overload condition and imminent failure based on the slave current measuring means generated current measurement signal.

7. The system as claimed in anyone of claims 1 to 6, wherein the HMI interface is adapted to associate green colour bars with motor identification indicating that the corresponding motor is drawing normal current and it is in a healthy condition;
wherein the HMI interface is adapted to associate orange colour bars with the motor identification indicating that the corresponding motor is drawing current near to the overloading current and it is in a stressed condition; and
wherein the HMI interface is adapted to associate redcolour bars with the motor identification indicating that the corresponding motor is drawing overloading current as it is in overloaded condition and prone to failure.

Dated this the 31st day of October, 2018
Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)
IN/PA-199
, Description:FIELD OF THE INVENTION:
The present invention relates facilitating operation of Run-out table used for transferring metal strip from finishing mill to down coiler in metal processing plant. More specifically the present invention is directed to develop a system to monitor condition of every motor of the Run-out table and accordingly predict imminent failure of such motors.

BACKGROUND OF THE INVENTION:
The Run-out table is basically a roller table and used for transferring the metal strip from the finishing mill to the down coiler. A typical Run-out table includes multiple rollers wherein each roller is directly coupled with the motor. The motors are placed on operator side of mill. The Run-out table also includes laminar cooling headers through which water is sprayed on running strip to cool it and attend a predefined coiling temperature. Due to such water cooling, the Run-out table area became very harsh because of steam fumes and makes duty life of the roller driving motors very unpredictable even if it is fully enclosed.
Now, if such roller driving motor suddenly stops due to failure, then there is chance of scratch mark on bottom surface of the strip which leads to generation of non-prime product. It is thus there has been a need for developing a technique for predicting imminent failure of every roller driving motors of the Run-out table to avoid the chances of generation of non-prime product

OBJECTS OF THE INVENTION:
It is thus the basic object of the present invention is to develop a system to facilitate operation of the run-out table used for transferring the metal strip from the finishing mill to the down coiler in metal processing plant.

Another object of the present invention is to develop a system which would be adapted to monitor condition of every motor of the Run-out table and accordingly predict imminent failure of such motors.

Yet another object of the present invention is to develop a system which would be adapted to individually measure current drawn by every motor of the Run-out table for monitoring condition of every motor of the Run-out table and accordingly determine motor specific stressed/overload condition.

A still further object of the present invention is to develop a system which would be adapted to individually measure current drawn by every motor of the Run-out table and generate historical data of usage of the current by every motors of the Run-out table.

SUMMARY OF THE INVENTION:
Thus according to the basic aspect of the present invention there is provided a system for individually monitoring condition of motors of run-out table and predicting imminent failure of such motors comprising
plurality of current metering means, each operatively interfaced with one of the motors of run-out table;
a field bus communication network establishing a communication between a PLC based controller and the current metering means;
said PLC based controller is configured to control each of the current metering means enabling individualistic continuous monitoring of the current being drawn by each of the motors by the interfaced the current metering means and therefrom determining condition of the motor including prediction of the imminent failure of the motor.

In a preferred embodiment of the system, each of the motors in the run-out table are supplied current from corresponding inverter via its individual current transformer and individually protected by a motor protection circuit breaker, whereby each of the current transformers is connected to one of the current measuring means enabling said individualistic continuous monitoring of the current being drawn by each of the motors.

In a preferred embodiment of the system, the current measuring means is adapted to continuously measure 3 phase current being supplied to the interfaced motor from its corresponding current transformer.

In a preferred embodiment of the system, the current measuring means includes
a current measuring module directly connected to the current transformer to measure the current value being supplied to the interfaced motor; and
a basic evaluation unit having a processor embodying functions related to measurement, control and monitoring the measured values and then transferring the same via the communication network to the PLC based controller;
wherein each motor connecting cable is routed through the current measuring module and current measuring module is connected with basic evaluation unit by flat band cable.

In a preferred embodiment of the system, each of the current measuring means assigned a unique bus address and are interconnected in series with each other forming a network on the master-slave scheme involving the field bus communication network preferably profibus communication in which the master PLC based controller is linked to the slave current measuring means.

In a preferred embodiment of the system, the PLC based controller includes
a central processing unit forcontrolling all activities like current Monitoring, Fault generation, HMI handling and the current measuring means communication;
communication processors with on board profibus communication port to communicate with the slave current measuring means and Industrial Ethernet communication protocol to drive the HMI interface enabling the user to update about the prevailing condition of the motor and the roll including the overload condition and imminent failure based on the slave current measuring means generated current measurement signal.

In a preferred embodiment of the system, the HMI interface is adapted to associate green colour bars with motor identification indicating that the corresponding motor is drawing normal current and it is in a healthy condition;
wherein the HMI interface is adapted to associate orange colour bars with the motor identification indicating that the corresponding motor is drawing current near to the overloading current and it is in a stressed condition; and
wherein the HMI interface is adapted to associate redcolour bars with the motor identification indicating that the corresponding motor is drawing overloading current as it is in overloaded condition and prone to failure.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1 shows a preferred embodiment of the Run-out table in accordance with the present invention.
Figure 2 shows inverter – motor interfacing involving current measuring means associated with system of the present invention.
Figure 3 shows a snapshot of HMI of the present system indicating condition of each of the motors associated with the present run-out table.
Figure 4 shows the current drawn by the motors associated the run-out table as measured by the current measuring means associated with system of the present invention.
Figure 5 shows enlarged view of an individual motor drawing current for analysis in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING
As stated hereinbefore the present invention discloses system to predict imminent failure of every roller driving motors of the Run-out table by continuously monitoring current of all three phases of all the motors. The failure of the motors can be predicted or even minimized if maintenance team knows the prevailing condition of motor and roll. The current taken by each motor is a very good indicator of physical and electrical condition of motor.
Reference is first invited from the accompanying figure 1 which shows a preferred embodiment of the Run-out table. The complete Run out Table as shown in the figure 1 can be split into five roller table groups [GR1 – GR5], one Coiler-1 Breast Roll [C1 BR], one Roller table Bridge Inverter-1 [RTB], oneCoiler-2 Breast Roll [C2 BR] and one Entry roller Table Operator side motors [ERT].
There are 240 rolls included in the roller table groups [GR1 – GR5] and each roll is driven by a separate AC induction motor. Each roller table group [GR1 – GR5] includes atleast one converter and atleast five inverters and each inverter is feeding atleast 10 motors. The Coiler-1 Breast Roll [C1 BR] includes one inverter which is fed by roller table group-5 converter and it drives atleast 4 motors. The Roller table Bridge drive includes one converter and three inverters, Inverter-1 [RTB1] feeds seven motors, Inverter-2 [RTB2] feeds seven motors and Inverter-3 Coiler-2 Breast Roll [C2 BR] feeds four motors. The Entry Roller Table [ERT] drive includes one converter and one inverter and [ERT] inverter is feeding 14 motors.
The inverter – motor interfacing is shown in the accompanying figure 2. As shown in the figure 2, each of the motor supplied current from the corresponding inverter and individually protected by a MPCB (motor protection circuit breaker). The 3 phase driving current is supplied to each of the motor through its individual current transformer. Now according to the preferred embodiment of the present system, each of the current transformers is connected to individual current measuring means (SIMOCODE) to continuously measure the 3 phase current being drawn by the corresponding motor.

Thus each of the roller table group [GR1 – GR5] as shown in the figure 1 will include at least 10 numbers of current metering means for individually measuring the current being drawn by the at least 10 motors associated with the roller table group.
Similarly for other components like[C1 BR] 4, [RTB] 14, [C2 BR] 4, and [ERT] 14 separate current metering means are used for individually measuring the current being drawn by motors of these groups.
Now, according to a preferred embodiment, the current metering means [Simocode] comprises two components: one is current measuring module which is connected straight through the transformer to measure the current value being supplied to the interfaced motor and other one is basic evaluation unit having a processor embodying functions related to measurement, control and monitoring the measured values and then transferring the same via the communication network to the PLC based controller. The each motor connecting cable is routed through the current measuring module and current measuring module is connected with basic evaluation unit by flat band cable.
As shown in the figure 1, the current metering means of theroller table group [GR1 – GR5] and the components [C1 BR], [RTB], [C2 BR], [ERT] are operatively connected to via a Profibus communication link. PROFIBUS (Process field bus) is a protocol for field bus communication in automation technology. Profibus links automation controllers with decentralized field devices such as sensors and actuators it uses single bus cable of two cores. The transmission rate in the present case is 187.5Kbps as distance of cable from the current measuring means to controller is less than 150 meter. Each current measuring meanshas been assigned a unique bus address and are interconnected in series with each other. The network works on the master-slave scheme in which a master (CPU) passes the token with its slaves (current measuring means) and then to next station in a closed system.
The present system also comprises a PLC based controller operating as the master (CPU) having at least four operational layers viz. CPU 315-2DP, CP 342-5(1), CP 342-5 (2) and CP 342-5 (3) for controlling thecurrent measuring means of theroller table group [GR1 – GR5] and the components [C1 BR], [RTB], [C2 BR], [ERT]. The CPU 315-2 DP is central processing unit for S7-300 programmable logic controller (PLC) and is used for controlling all activities like current Monitoring, Fault generation, HMI handling and Simocode Communication through execution of application and system software programme. CPU 315-2 DP has on board profibus communication port through which it Communicate with 56 numbers of DP slaves (current measuring means). The CP 342 -5 (1), (2), (3) is the communication processor and are used for communication with other current measuring means. Each CP 342-5 can communicate maximum 124 no. of DP slaves (current measuring means). In this architecture CP 342-5 (1) is connected with 112 DP slaves, CP 342-5(2) is connected with 93 DP Slaves and CP 342-5 (3) is connected with 14 DP slaves.
The PLC based controller further includes operational layer CP 343-1 board to drive an interface (HMI) enabling the user to update about the prevailing condition of the motor and the roll including the overload condition and imminent failure based on the current measuring means generated signal. The CP 343-1 communications processor is designed for operation in an S7-300 programmable logic controller (PLC). It allows the S7-300 PLC to communicate on Industrial Ethernet communication protocol. The HMI system WinCC communicates with PLC using this interface. The HMI exchanges data using standard communication blocks configured at both ends, i.e. PLC side and WinCC side.
Reference is now invited from the accompanying 3 which shows a snapshot of the HMI indicating condition of each of the motors associated with the present run-out table. The Green Colour Bars associated with the motor identification are the indication that the corresponding motor is drawing normal current and it is in a healthy condition. The Orange Colour Bars associated with the motor identification are the indication that the corresponding motor is drawing current near to the overloading current and it is in a stressed condition. The Red Colour Bars associated with the motor identification are the indication that the corresponding motor is drawing overloading current as it is in overloaded condition and prone to failure.
As illustrated in the accompanying figure 3, the colour based motor condition indication in conjunction with the motor identification effectively reduced the overloaded/stressed motor searching time across the run-out table.
The accompanying figure 4 shows the current drawn by the motors associated the run-out table as measured by the current measuring means. The graph under the figure 4 shows the individual motor current in a selected time period. Each of the motor current is shown in different colours. The Facility is available to even select only one motor current. This helps in analysis during repeated tripping of motor. This current drawing trend can be stored in memory elements associated with the present system for post analysisof the motor condition.
The current trend graph helps in identification of number of times motor tripped and highest current taken during entire month.
The accompanying figure 5 shows enlarged view of an individual motor drawing current for analysis. The marked portion of the graph corresponds to overload or near overload current drawing by the motor.