BACKGROUND OF THE INVENTION The present invention relates to a control system and method, to operate a switching device, and in particular, to a control system and method to selectively connect a power supply to a load.

DESCRIPTION OF THE PRIOR ART

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Whist this invention is primarily for use in hazardous and dangerous underground mining environments, it is not limited to that particular field of use. The present invention is suitable for most electrically powered loads such as motors, cables, machines, transformers and the like in both underground, above ground mining, and other

applications.

It is commonly known that high power electrical equipment such as motors and transformers are typically connected to a power source via switchgear. This switchgear is in general set up for a particular piece of equipment so that once certain predetermined load characteristics vary sufficiently the power will be disconnected to prevent any potentially hazardous conditions which may result in the loss of equipment or life. Any set up or adjustment of the switchgear is typically manually performed which, due to operator fatigue or inadvertence, may result in incorrect adjustment.

In underground mining applications, the switchgear is typically located within a protective housing, to ensure that any sparks generated during switching are not available to ignite flammable gases such as methane which may be present.

Such housings include walls formed from thick steel plate and are accessible through an opening which is closed by a door. Such doors are generally attached about their periphery to an adjacent wall by a plurality of spaced apart bolts. Accordingly, to set up or adjust the switchgear for a particular piece of equipment necessitates the opening of the steel door by removing all the bolts, the setting of the switchgear, and the subsequent replacement of the door. Following this procedure testing should be conducted to ensure safe operation. If the switqhgear is not correctly set this must be repeated. Accordingly, and reconfiguration is both time consuming and labour intensive.

Australian Patent No. 704930 describes a 'load control module' for controlling switch gear. The 'load control module' of Australian Patent No. 704930 operates by having a sensor unit associated with the load. The sensor unit provides a signal which transmits load protection data from the load to a controller. The controller then provides a signal, dependent upon the signal from the sensor unit, to isolate the load from the power source when, during operation, the load does not comply with the load protection data. Whilst the 'load control module' of Australian Patent No. 704930 suffices to 'sense' a particular load during operation to determine whether it complies with predetermined load protection data, it has a number of inherent disadvantages and shortcomings.

The device of Australian Patent No. 704930 relies on the transmission of the load protection data from a remote location at the load back to the 'load control module'.

This therefore identifies a need to provide an alternative device for controlling the operation of a switching device, which overcomes the disadvantages of the prior art. SUMMARY OF THE INVENTION

The present invention seeks to provide a system and method to operate a switching device, which overcomes the disadvantages , or at least provides an alternative to, prior art switching devices.

The present invention also seeks to provide a system and method to operate a switching device, whereby the data protection settings are provided local to the switching device, rather than at a remote location of a load.

The present invention also seeks to provide a system and method to operate a switching device whereby the data protection settings are not required to be sensed at a load, but rather, a reader is used to read a name plate or the like to identify the load, and this identification information only is then transmitted back to the controller.

The present invention also seeks to provide a system and method to operate a switching device whereby a memory device, capable of storing data protection settings of a plurality of potential loads, is provided.

In one broad form, the present invention provides a control system to operate a switching device to selectively connect a power supply to a load, said control system including:

a reader, to read an identification plate of a load or store load identification, and, transmit an identification signal of an identified load;

a controller, including:

a memory device, having a repository of protocol settings pertaining to a plurality of identified loads; and,

a processor, to receive said identification signal, to communicate with said memory device to selectively obtain protocol settings associated with said identified load, and, to provide a control signal to operate said switching device according to said protocol settings. In a further broad form, the present invention provides a method of operating a switching device to selectively connect a power supply to a load, said method including the steps of:

reading an identification of a load;

transmitting an identification signal of said load;

selecting protocol setting associated with said load from a memory device, the memory device including a repository of protocol settings pertaining to a plurality of identified loads; and

operating said switching device according to said protocol settings to thereby connect said power supply to said load.

Preferably, said reader operates using any one or combination of:

optical character recognition;

bar code reader/scanner;

configured memory.

Also preferably, said identification signal is transmitted by any one or combination of:

infra-red, Bluetooth or other wireless communications;

wire, cable, fibre-optics or the like.

In a preferred form, said controller is provided in a protective housing formed of steel plate or the like.

In a preferred embodiment, said controller includes a data communications port for setup and monitoring via a communications protocol device, including a PLC, a PC or a human interface screen.

Preferably, said memory device stores energy consumption, history, earth leakage protection settings, overload protection settings, etc. In a preferred form, the system/method further includes a monitoring device. Preferably, said monitoring device is adapted to monitor any one or combination of:

arc flash protection;

power;

certified SIL level;

harmonic protection.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the following detailed description of a preferred but non-limiting embodiment thereof, described in connection with the accompanying drawings, wherein:

Figure 1 illustrates a block diagram of the basic components of the control system in accordance with the present invention, showing how the system controls the operation of a switching device to connect a power supply to a load; and,

Figure 2 details various component features of the controller and the reader.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated.

As shown in Fig. 1, the control system, generally designated by the numeral 1 is adapted to operate a switching device 2 to selectively connect a power supply 3 to a load 4. The load 4 may include but is not limited to a motor, machine, transformer, or other load. The load may be utilised, but is not limited to use in underground or above ground mining environments, or any other environment. The device of the present invention is particularly suitable for use in hazardous conditions whereby, any incorrect adjustment of the switching device may result in a dangerous situation. The control system of the present invention includes a reader 5, and a controller 6.

The reader 5 is adapted to read name plate details or other identification details of a load 4, identified by numeral 7, and then transmit an identification signal 8 identifying the load 4 to the controller 6* and in particular, to a processor 9 of the controller 6.

The processor 9 receives the identification signal 8 then communicates via communication channel 10 with a memory device 1 1.

The memory device 11 includes a repository of protocol settings pertaining to a plurality of potential loads 4. As a result of receipt of signal 8, the processor 9 determines from interrogating the memory device 11 the relevant protocols settings pertaining to the connected load 4 and thereby provides a control signal 12 to the switching device 2 to thereby operate the switching device 2 such that the power supply 3 is either connected or disconnected to the load 4. Ongoing connection or disconnection of the power supply 3 to the load 4 is determined by the protocol settings in the memory device 1 1 pertaining to the identified load 4.

It will be appreciated by persons skilled in the art that the provision of a reader 5 to read identification details of a load 4 is unique to the present invention; The reader 5 may operate in a variety of manners including but not limited to any one or combination of utilising optical character recognition to read a name plate associated with load 4, or, by utilising a bar code reader or scanner to read an appropriate bar code provided on load 4. Other forms of reader 5 appropriate to this purpose will become apparent to persons skilled in the art, and these readers should be considered to fall within the scope of this invention.

The reader 5 may utilise any one or combination of infra-red, Bluetooth or other wireless or communication means or, a hard wired cable or fibre-optic pathway to transmit the information from the load 4 to the reader 5 and from the reader 5 to the processor 9.

The controller 6 is preferably provided in a protective housing suitable for use in a hazardous environment. This may include, but is not limited to being formed of steel plate or the like such that it may be fire proof, explosion proof, and the like. Other suitable materials for provision of the housing of the controller will become apparent to persons skilled in the art. The controller 6 may include a data communications port, a human interface, or any other form of interface 13 for set up and monitoring of the communication protocols. Suitable human interfaces may include a PLC, a PC, or any other human interface screen. The memory device 1 1 may optionally store other information pertaining to the load, including, but not limited to energy consumption information, other history information, earth leakage protection settings, overload protection settings, etc.

The control system of the present invention may further include a monitoring device for ongoing monitoring of the load 4 during operation. Any one or combination of , the following may be monitored

Arc flash protection;

power;

certified SIL level;

harmonic protection.

In Fig. 2 is shown various component locks of the present invention, which are hereinafter described.

Description of Major Items

SD - Sensing Device Typically a stainless steel device complete with internally mounted electronics. Live line indication, overload CT's, contactor control, EL toroid connection, fibre optic interface and frozen contactor flag relay.

Approximately 250 mm wide by 250mm high and 200mm deep. Bolted or quick connect installation.

APMD - Automated Protection and Monitoring Device

Typically an aluminum device complete with internally mounted electronics. LED indication, earth continuity connection, circuit breaker control, human interface

connection, fibre optic interface and memory module data connection.

Approximately 100mm wide by 100mm high and 100mm deep. Din rail mounted for quick installation.

PRD - Plant Recognition Device

Typically a stainless steel device complete with internally mounted electronics.

LED indication, earth continuity connection, temperature connections, analog/vibration connections, human interface connection, fibre optic interface and data connection.

Approximately 100mm wide by 100mm high and 50mm deep. Magnetic or Din rail mounted for quick installation.

MM - Memory Module Device

Typically an aluminum device complete with internally mounted electronics. LED indication, restricted control interlock, fibre optic interface, Ethernet connection and

APMD data connection.

Approximately 100mm wide by 100mm high and 100mm deep. Din rail mounted for quick installation.

Centralized repository of protection parameters

- Either per groups of outlets, or common to multiple groups. HI - Human Interface Device

Typically a colour touch screen device complete with internally mounted electronics and APMD data connection.

Approximately 120mm wide by 100mm high and 50mm deep. Surface mounted and rated at IP56 or better. CPD - Communications Protocol Device

Typically an industrial PLC or PC that allows remote monitoring and setup of the Memory Module (MM). Typically protocol is Ethernet, also allows connection of an industrial screen or human interface via Ethernet. Principals of Operation

1. Automated Set Up.

la. The Automated Protection + Monitoring Device (APMD) is connected to the remote plant including a plant recognition device.

lb. The Plant Recognition Device (PRD) identifies the plant via a single data communications wire.

lc. The Automated Protection + Monitoring Device (APMD) reads the plant recognition and communicates with the Memory Module (MM), to determine the required protection settings, energy consumption and history.

2. Programming Protection Settings

The Memory Module (MM) is complete with a data communication's port that allows setup and monitoring via standard communications protocol devices, including but not limited to: PLC's, Industrial PC's and human interface screens.

Set up of the Memory Module (MM) may alternatively be monitored and configured via a local human interface screen, connected to the Automated Protection + Monitoring Device (APMD).

3. Earth Leakage

Earth leakage protection settings are stored in the Memory Module (MM) and are compared to the levels sensed by the sensoring device. Based on algorithm excessive values will result in an interruption of power to the plant. 4. Overload

Overload protection settings are stored in the Memory Module (MM) and are compared to the levels sensed by the sensonng device, based on the algorithm excessive values will result in an interruption of power to the plant.

Characteristics of load and automated adaption of protection parameters and techniques by analysis of current draw - with guarantee of meeting 'fixed trips'. 5. Instantaneous

Overload protection settings are stored in the Memory Module (MM) and are compared to the levels sensed by the sensoring device, based on the algorithm excessive values will result in an interruption of power to the plant. 6. Earth Fault Lock Out

Prior to allowing the remote plant to be energized, the connected cable and plant are tested for leakage to earth via injected DC voltage. Excessive levels of leakage will prevent the energization of the remote plant and cable.

Analysis of voltage and current across all outlets of (e.g.) a DCB, to do on-line ductor testing, and be able to discriminate between high resistance in individual outlet circuits and the normal feeder impedance. This would mitigate hot joints and therefore things like insulators failing due to temperature and all the resultant hazards. Identifying cables in some way to allow trending of individual cables regardless of how they are moved around between outlets and machines.

7. Earth Continuity

The single data communication wire connecting the Automated Protection + Monitoring Device (APMD) to the Plant Recognition Device (PRD) is used to monitor the continuity of bonding to earth at the remote load, in the event the bond to earth is of a high resistance than power to the remote plant is interrupted or prevented from energizing. Pilot Communications

Data transfer using pilot conductor

Operates concurrently with protection functionality that uses pilot

Allows connection of additional devices at ends

Redundancy of transfer of data

Automatic variation of technique used to transfer data, dependent on condition of pilot

Increased safety by use of multiple safety checking techniques on single pilot Characterization of properties of power conductors of cable by use of pilot.

8. Frozen Contactor

The sensoring device monitors voltage which is compared to the controlled switch status if voltage is detected when the controlled switch should be open. The Automated Protection + Monitoring Device (APMD) will provide a signal to interrupt power at a higher level.

9. Miscellaneous Protection Functions

The invention provides additional protection functions, including but not limited to: Phase Loss

Asymmetry

Under Voltage

High Voltage Breakdown Insulation.

Acoustic arc-flash detection

UV arc-flash detection

10. Start Up Process

1. The Automated Protection + Monitoring Device (APMD) is connected to the Plant Recognition Device (PRD).

2. The Plant Recognition Device (PRD) communicates to the Automated Protection + Monitoring Device (APMD) the plant recognition.

3. The Automated Protection+ Monitoring Device (APMD) reads the Memory Module (MM) to determine required protection settings and functions.

4. A start signal is initiated.

5. The earth continuity status is monitored (continuously)

6. The sensoring device performs an earth fault lock out test.

7. If the earth continuity and earth fault lock out test continue to be healthy, a high voltage insulation test is performed.

8. If all the tests are healthy the Automated Protection + Monitoring Device (APMD) will allow the switching device to close.

9. The Automated Protection + Monitoring Device (APMD) will continue to monitor the protection functions of the device. If a trip status is detected the switching devices controlled so as to interrupt power to the remote plan

11. Segregation

Segregation of protection system functionality using non-electrical medium (prevents dangerous voltages invading otherwise ELV area)

'Power' area (dangerous, voltages, etc.) electrically separated from 'control' area.

12. Parallel Feeder Protection

Parallel Feeder System

Phase transposal detection

Detect effective phase-phase short-circuit via parallel feeders prior to energization.

Feeder impedance imbalance detection

Impedance imbalance results in unequal load sharing between feeders. 13. Harmonic Protection

Harmonic trip if protected hazard (earth inductance = touch potential at high frequency).

Includes wideband measurement of earth leakage current.

Includes wideband measurement of earth impedance. VARIATIONS AND MODIFICATIONS TO THE CONTROL SYSTEM AND METHOD

It will be appreciated that the present invention has been hereinbefore described with reference to particular examples. Persons skilled in the art will appreciate that numerous variations and modifications will become apparent thereto. All such variations and modifications should be considered to fall within the scope of the invention as broadly hereinbefore described, and as hereinafter claimed.