CA2148146C - Power transmission infrastructure maintenance system - Google Patents
Power transmission infrastructure maintenance systemInfo
- Publication number
- CA2148146C CA2148146C CA002148146A CA2148146A CA2148146C CA 2148146 C CA2148146 C CA 2148146C CA 002148146 A CA002148146 A CA 002148146A CA 2148146 A CA2148146 A CA 2148146A CA 2148146 C CA2148146 C CA 2148146C
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- Canada
- Prior art keywords
- information
- radio relay
- relay unit
- units
- unit
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
- Radio Relay Systems (AREA)
Abstract
A method and apparatus for the maintenance of Power Transmission Infrastructure is disclosed. Power Transmission Infrastructure embodies all physical elements employed directly or indirectly in the conveyance of electricity, for example, cables, conductors, insulators, tower structures, poles, grounding systems, transformers, switches, and surge arrestors.
The apparatus is inventive in that it detects events previously undetected (singularly or as a group). These include leaky arrestor, defective insulator, broken conductor, current faults, sway or galloping cables, corona, transformer degradation, structural integrity of towers and poles.
The method is inventive in that the system's data sources and data consumers communicate using a new protocol which minimizes the number of times a data element. is retransmitted. In its unrestricted form, the protocol will propagate data outward from the point of origin to the extremities of the network.
A plurality of monitor units are located at different tower structures or other structures throughout a power transmission and distribution system and each monitor unit is capable of transmitting its own identifying signal and data information collected from electromagnetic, sound, vibration, and motion sensors. The monitor units are also capable of relaying information originated by other monitor units. A remote station is provided for receiving and processing the identifying signal and data information.
The apparatus is inventive in that it detects events previously undetected (singularly or as a group). These include leaky arrestor, defective insulator, broken conductor, current faults, sway or galloping cables, corona, transformer degradation, structural integrity of towers and poles.
The method is inventive in that the system's data sources and data consumers communicate using a new protocol which minimizes the number of times a data element. is retransmitted. In its unrestricted form, the protocol will propagate data outward from the point of origin to the extremities of the network.
A plurality of monitor units are located at different tower structures or other structures throughout a power transmission and distribution system and each monitor unit is capable of transmitting its own identifying signal and data information collected from electromagnetic, sound, vibration, and motion sensors. The monitor units are also capable of relaying information originated by other monitor units. A remote station is provided for receiving and processing the identifying signal and data information.
Description
~~2-1 4e ~ 4s DESCRIPTION OF THE :PRIOR A:RT
United States Patent 5,343,155 describes a system for detecting electrical current Eault conditions in Power Transmission Infrastructure. The system requires the placement of current sensing devices on ground cables and another current sensing element to be placed at a specific angle to the others. The system includes a plurality of repeats=_rs which converge on a central site. The detection of current faults is one capability of the new apparatus.
Canadian Patent 1,255,359 describes a system for detecting corona. This system detects a broadband radio signal which is fed to a visual indicator for on-site human interpretation. The detection of corona is one capability of the new <~pparatus. Additionally, the new apparatus does not require hurnan operation at each site under study, does not require human corre:iation of the signal sampled to a given problem, and does not employ a single broadband radio signal. The new apparatus is an improvement for the detection of corona.
United States Patent, 4,00!5,410 describes a system for detecting corona.
This system employs a fixed set of preset filters to sample the radio spectrum for frequency components known to be generated by corona. The system consists of one mea:>urement device and is tailored to be (but need not be) operated from an aircraft. The location of measured events is determined by the placing of tick marks on recorded media and/or the superposition of voice data on recorded media to correlate the site under observation with the aircraft position. Whereas, the new apparatus does not require that the single sensing element be flown or carried to the site under test. The new apparatus is an improvement for the detection of corona.
United States Patent 5,343,155 describes a system for detecting electrical current Eault conditions in Power Transmission Infrastructure. The system requires the placement of current sensing devices on ground cables and another current sensing element to be placed at a specific angle to the others. The system includes a plurality of repeats=_rs which converge on a central site. The detection of current faults is one capability of the new apparatus.
Canadian Patent 1,255,359 describes a system for detecting corona. This system detects a broadband radio signal which is fed to a visual indicator for on-site human interpretation. The detection of corona is one capability of the new <~pparatus. Additionally, the new apparatus does not require hurnan operation at each site under study, does not require human corre:iation of the signal sampled to a given problem, and does not employ a single broadband radio signal. The new apparatus is an improvement for the detection of corona.
United States Patent, 4,00!5,410 describes a system for detecting corona.
This system employs a fixed set of preset filters to sample the radio spectrum for frequency components known to be generated by corona. The system consists of one mea:>urement device and is tailored to be (but need not be) operated from an aircraft. The location of measured events is determined by the placing of tick marks on recorded media and/or the superposition of voice data on recorded media to correlate the site under observation with the aircraft position. Whereas, the new apparatus does not require that the single sensing element be flown or carried to the site under test. The new apparatus is an improvement for the detection of corona.
United States Patent 4,095,173 describes a system for detecting the presence of corona :based on sound. Again, this .. Whereas, the new invention does not require that a single sensing element be flown or carried to the site under test.
According to one aspect of the present invention there is provided a maintenance apparatus for a power transmission infrastructure comprising a plurality of monitor units placed in the power transmission infrastructure at different locations and each capable of transmitting its own identifying signal and data information based on measurements of electromagnetic fie:Lds, sound, a structure's attitude, motion, and vibration, as to th<= conditions of at least one power transmission infrastructure elemcant at or near a location; at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to determine the nature and location or locations of a fault or faults and or to forecast the nature and location or locations of a fault or faults.
According to another aspect of the present invention there is provided a method for the conveyance of information comprising a plurality of radio relay units including the steps of (Please note that the media access method is Carrier Sense Multiple Access, a well known method. The logic and meana used to decide when and if a given packet should be relayed is new.) .
1)transmitting infoi:mation from a source connected to at least one radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received at said radio relay unit from another radio relay unit;
According to one aspect of the present invention there is provided a maintenance apparatus for a power transmission infrastructure comprising a plurality of monitor units placed in the power transmission infrastructure at different locations and each capable of transmitting its own identifying signal and data information based on measurements of electromagnetic fie:Lds, sound, a structure's attitude, motion, and vibration, as to th<= conditions of at least one power transmission infrastructure elemcant at or near a location; at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to determine the nature and location or locations of a fault or faults and or to forecast the nature and location or locations of a fault or faults.
According to another aspect of the present invention there is provided a method for the conveyance of information comprising a plurality of radio relay units including the steps of (Please note that the media access method is Carrier Sense Multiple Access, a well known method. The logic and meana used to decide when and if a given packet should be relayed is new.) .
1)transmitting infoi:mation from a source connected to at least one radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received at said radio relay unit from another radio relay unit;
2) receiving, at a given radio relay unit, information from other radio relay units and det~=rmining the relative distance (e. g., very near, near, far, very far) to those radio relay units;
3) utilizing said relative distance information to determine if and when said radio relay unit will relay information received from another radio relay unit;
3) utilizing said relative distance information to determine if and when said radio relay unit will relay information received from another radio relay unit;
4) subsequently uti:Lizing information in packets received from other radio relay units to determine if said radio relay unit will relay information received from another radio relay unit;
5) and transmitting information which was received from another radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received from a respective radio relay unit.
~2~~e~~s BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, with reference to t:he accompanying drawings, in which:-Figure 1 is a diagrammatic representation of an embodiment of the invention in use with a high voltage power transmission and distribution system;
Figure 2 is a block diagrammatic representation of the embodiment of Figure 1;
Figure 3 is a block diagrammatic representation of the remote unit of Figure 2;
Figure 4 is a block diagrammatic representation of a monitor unit for mounting on a tower structure or other structure as shown in Figure 1;
Figure 5 is a block diagrammatic representation showing details of the radio relay unit of Figure 4;
Figure 6 is a block diagrammatic representation of a general form of a detector as shown in Figure 4;
Figure 7 is a block diagrammatic representation of a low frequency detector as shown in Figura_ 4;
Figures 8, 9, and 10 are block diagrammatic representations of 'X', 'Y', and 'Z' plane very .Low frequency detectors respectively within a monitor unit;
Figure 11 is a bloc): diagrammatic representation of the power supply for a monitor unit;
Figure 14 comprises Figure:a 12 and 13 and diagrammatically illustrates a radio relay unit transmission queue structure;
Figure 17 comprises Figures 15 and 16 and diagrammatically illustrates the structure of radio relay unit data transmission packets;
Figure 20 comprises Figure; 18 and 19 and diagrammatically illustrates the structure of radio relay unit control transmission packets;
X21 4g 1 46 Figure 23 comprises Figures 21 and 22 and diagrammatically illustrates the structure of radio relay unit confirmation only packets;
Figures 26, 27, and 38 principally relate to the radio relay unit logic circuit unit 94, of Figure 5 as well as to units 88, 90, 98, 100, and 102 thereon and are to be considered together as they really constitute one flow diagram.
Figure 26 comprises Figures 24 and 25 and is a logic flow diagram depicting the logic employed in a radio unit to handle outgoing packets;
Figure 27 is a logi~~ flow diagram depicting logic employed in a radio unit to manage queue resources therein;
Figure 38 comprises Figures 28 through and 37 and is a logic flow diagram depicting the logic employed in a radio unit to handle incoming packets;
Figure 44 comprises Figures 39 through 43 and is a logic flow diagram depicting the logic employed in a monitor unit to handle data acquisition, gain control, packet assembly, and remote command execution.
~2~~e~~s BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, with reference to t:he accompanying drawings, in which:-Figure 1 is a diagrammatic representation of an embodiment of the invention in use with a high voltage power transmission and distribution system;
Figure 2 is a block diagrammatic representation of the embodiment of Figure 1;
Figure 3 is a block diagrammatic representation of the remote unit of Figure 2;
Figure 4 is a block diagrammatic representation of a monitor unit for mounting on a tower structure or other structure as shown in Figure 1;
Figure 5 is a block diagrammatic representation showing details of the radio relay unit of Figure 4;
Figure 6 is a block diagrammatic representation of a general form of a detector as shown in Figure 4;
Figure 7 is a block diagrammatic representation of a low frequency detector as shown in Figura_ 4;
Figures 8, 9, and 10 are block diagrammatic representations of 'X', 'Y', and 'Z' plane very .Low frequency detectors respectively within a monitor unit;
Figure 11 is a bloc): diagrammatic representation of the power supply for a monitor unit;
Figure 14 comprises Figure:a 12 and 13 and diagrammatically illustrates a radio relay unit transmission queue structure;
Figure 17 comprises Figures 15 and 16 and diagrammatically illustrates the structure of radio relay unit data transmission packets;
Figure 20 comprises Figure; 18 and 19 and diagrammatically illustrates the structure of radio relay unit control transmission packets;
X21 4g 1 46 Figure 23 comprises Figures 21 and 22 and diagrammatically illustrates the structure of radio relay unit confirmation only packets;
Figures 26, 27, and 38 principally relate to the radio relay unit logic circuit unit 94, of Figure 5 as well as to units 88, 90, 98, 100, and 102 thereon and are to be considered together as they really constitute one flow diagram.
Figure 26 comprises Figures 24 and 25 and is a logic flow diagram depicting the logic employed in a radio unit to handle outgoing packets;
Figure 27 is a logi~~ flow diagram depicting logic employed in a radio unit to manage queue resources therein;
Figure 38 comprises Figures 28 through and 37 and is a logic flow diagram depicting the logic employed in a radio unit to handle incoming packets;
Figure 44 comprises Figures 39 through 43 and is a logic flow diagram depicting the logic employed in a monitor unit to handle data acquisition, gain control, packet assembly, and remote command execution.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
A sensor or sensors can be mounted in a single unit, and in Figure 1, monitor units 2 are shown each mounted on a separate tower structure 4, 6, 8, 10, 12 or 14. A monitor unit 2 is also provided at substation 18.
A monitor unit 2 will contain any or all of the following sensors for the detection of the associated list of faults. In some instances different sensors will corroborate each other:
Sensor TypePower' Transmission Infrastructure Faults electro- leaky arrest.or, defective insulator, current fault, magnetic broken conductor sound mechanical resonance (sway) in high tension cables, galloping lines, corona, transformer degradation, vibration structural integrity, transformer degradation attitude/ mechanical resonance (sway) in high tension cables, motion galloping lines, structural integrity Each monitor unit 2 is provided with a transmitting/receiving antenna 20.
A remote unity 28 is at a monitoring station 22, and/or carried in a suitable vehicle :30, or ~aven carried by hand, for example, in the form of a battery powered portable computer.
The remote units 28 ~~re provided with their own radio unit 24 and associated antenna 26.
A unique ident=iffier :is assigned to each monitor unit and the location of each site is correlated to the monitor unit. This correlation is performed within the remote unit 28.
Data collected from f=ach of the sensors is periodically relayed to at least one remote unit 28. Any trend, value, or change in the data i (2148146 reported that signals the onset of a power transmission infrastructure fault is provided to the operator of the remote unit. This would obviate the necessity to have regular inspections by, for example, an operator in a helicopter flying along the transmission line.
Each transmission structure, or other significant element of the power distribution system is provided with a monitor unit 2 having sensors and a radio relay unit comprised of a receiver, transmitter and antenna. The transmissions of each monitor unit include its unique identifier, whereby the remote unit 28 can determine the location of a given fault and sub equently pass this information to an operator.
Figures 17, 20, 23 specify the content of transmitted data packets. Together with these, Figures 14, 26, 27, 38, and 44 describe the new radio relay protocol. The overall effect of the protocol is to provide a topology independent outward progression of monitor unit data along all available Power Transmission Infrastructure avenues. A key feature of the protocol is that it minimizes the number of times that a packet is re-transmitted, thereby maximizing the throughput of the system. Another key feature is the ability to add, modify, move or remove relay units :From a system, without impacting its operation.
The remote unit 28 also automatically accommodates for the presence of localized or broad phenomenon which would mask or otherwise impede the detection of power transmission infrastructure faults. For example, the remote unit can ignore data from an electromagnetic sensor in a particular monitor unit if it is known that local radio broadcasts interfere with said sensor.
The remote un_Lt 28 i:> also equipped to present to its operators the detailed repairs which must be conducted to repair a fault. The remote unit is also equipps~d to organize and schedule maintenance activities.
A sensor or sensors can be mounted in a single unit, and in Figure 1, monitor units 2 are shown each mounted on a separate tower structure 4, 6, 8, 10, 12 or 14. A monitor unit 2 is also provided at substation 18.
A monitor unit 2 will contain any or all of the following sensors for the detection of the associated list of faults. In some instances different sensors will corroborate each other:
Sensor TypePower' Transmission Infrastructure Faults electro- leaky arrest.or, defective insulator, current fault, magnetic broken conductor sound mechanical resonance (sway) in high tension cables, galloping lines, corona, transformer degradation, vibration structural integrity, transformer degradation attitude/ mechanical resonance (sway) in high tension cables, motion galloping lines, structural integrity Each monitor unit 2 is provided with a transmitting/receiving antenna 20.
A remote unity 28 is at a monitoring station 22, and/or carried in a suitable vehicle :30, or ~aven carried by hand, for example, in the form of a battery powered portable computer.
The remote units 28 ~~re provided with their own radio unit 24 and associated antenna 26.
A unique ident=iffier :is assigned to each monitor unit and the location of each site is correlated to the monitor unit. This correlation is performed within the remote unit 28.
Data collected from f=ach of the sensors is periodically relayed to at least one remote unit 28. Any trend, value, or change in the data i (2148146 reported that signals the onset of a power transmission infrastructure fault is provided to the operator of the remote unit. This would obviate the necessity to have regular inspections by, for example, an operator in a helicopter flying along the transmission line.
Each transmission structure, or other significant element of the power distribution system is provided with a monitor unit 2 having sensors and a radio relay unit comprised of a receiver, transmitter and antenna. The transmissions of each monitor unit include its unique identifier, whereby the remote unit 28 can determine the location of a given fault and sub equently pass this information to an operator.
Figures 17, 20, 23 specify the content of transmitted data packets. Together with these, Figures 14, 26, 27, 38, and 44 describe the new radio relay protocol. The overall effect of the protocol is to provide a topology independent outward progression of monitor unit data along all available Power Transmission Infrastructure avenues. A key feature of the protocol is that it minimizes the number of times that a packet is re-transmitted, thereby maximizing the throughput of the system. Another key feature is the ability to add, modify, move or remove relay units :From a system, without impacting its operation.
The remote unit 28 also automatically accommodates for the presence of localized or broad phenomenon which would mask or otherwise impede the detection of power transmission infrastructure faults. For example, the remote unit can ignore data from an electromagnetic sensor in a particular monitor unit if it is known that local radio broadcasts interfere with said sensor.
The remote un_Lt 28 i:> also equipped to present to its operators the detailed repairs which must be conducted to repair a fault. The remote unit is also equipps~d to organize and schedule maintenance activities.
.-2~4a~~s The principle function of each of the constituent sub-units of the remote unit 28 are .summarized as follows:
Sub-unit Name Principal Sub-unit Function Data CommunicationsManage the entry and exit of information from the Unit 36 remote unit 28.
Data Management Manage the storage and retrieval of information Unit 38 within the remote unit 28.
Processing Unit Process data entering the remote unit 28.
Pro<:ess commands invoked by the human interface unit. 42 .
Exex-cise control over and manage the other sub-unity of the remote unit 28.
Human Interface Enable human operation and control of the Unit. power 42 transmission infrastructure maintenance system.
Figure 3 is a slightly expanded block diagrammatic representation of parts of the system shown in Figure 2, and in particular gives further details of t:he processing unit 40.
The purpose of the power transmission infrastructure fault discriminator 52 is to identify only those faults which are of interest to power transmission infrastructure maintenance personnel. It achieves its purpose by reading the data recently supplied by the monitor units (via the data management unit 38 and the data communications unit 36) and comparing it with exist=ing fault signatures to determine or predict the onset of a fault.. Absolute threshold, differential threshold, and relative threshold analysis are applied in comparing the data received to the known fault ;~ignatur_es. The data is also analyzed for long term trends.
Sub-unit Name Principal Sub-unit Function Data CommunicationsManage the entry and exit of information from the Unit 36 remote unit 28.
Data Management Manage the storage and retrieval of information Unit 38 within the remote unit 28.
Processing Unit Process data entering the remote unit 28.
Pro<:ess commands invoked by the human interface unit. 42 .
Exex-cise control over and manage the other sub-unity of the remote unit 28.
Human Interface Enable human operation and control of the Unit. power 42 transmission infrastructure maintenance system.
Figure 3 is a slightly expanded block diagrammatic representation of parts of the system shown in Figure 2, and in particular gives further details of t:he processing unit 40.
The purpose of the power transmission infrastructure fault discriminator 52 is to identify only those faults which are of interest to power transmission infrastructure maintenance personnel. It achieves its purpose by reading the data recently supplied by the monitor units (via the data management unit 38 and the data communications unit 36) and comparing it with exist=ing fault signatures to determine or predict the onset of a fault.. Absolute threshold, differential threshold, and relative threshold analysis are applied in comparing the data received to the known fault ;~ignatur_es. The data is also analyzed for long term trends.
~, ~~
The monitor unit 2 is shown in block diagram format in Figure 4 and it will be seen that there are two main units; a data acquisition unit 58 and a radio relay unit 60. The clock unit 62 provides a local representation of time.
The data acquisition unit 58 includes a plurality of detectors or sensors capable of detecting electromagnetic signals, sound signals, vibration signals, and motion signals.
In use, the outputs from the detector units 64 through 76 are fed to a data sampling cswitch 80 which selectively picks which particular detector and which ;signal from an identified detector will be fed to an A/D (analog to digital) converter unit 82 for conversion into a digitally coded signal which is fed to a data acquisition logic circuit 84. Figure 44 (comprising Figures 39 through 43) is a logic flow diagram which depicts the flow of logic within the data acquisition logic circuit 84 fo:r gathering information from the sensors and subsequently packaging and delivering the sensor data to the radio relay unit 60. Figure 44 <~lso depicts the flow of logic for the interactions between the monitor unit 2 and a remote unit 40.
The monitor unit is also provided with a vibration inducer unit 86 as shown in Figure 4. The vibration detector 74 provides data which indicates, amongst other things, the structural integrity of the power transmission infrastructure element (for example, a pole or tower). In the case of a wooden pole, nature may not conveniently provide enough stimulus to cause the pole to 'reveal its health' through the vibration sensor. In instances such as this, a vibration inducer can be used to stimulate the struct=ure so that its structural signature could be obtained and thereby its structural integrity determined.
In Figure 5, t:he radio relay unit 60 is shown in greater detail.
The antenna 20 for this embodiment serves both the receiver 88 and the transmitter 90 but not simultaneously. When the "tx ptt" control of .. ., Figure 5 is enabled a transmission occurs and the receiver is disconnected from t:he antenna. The transmitter and receiver are shown connected to a radio relay unit logic circuit 94 and a packet discriminator unit 96. The packet discriminator unit receives incoming bits, determines if a sequence of bits forms a packet, and if it does then it passes thes~= packets to an incoming packet temporary holding queue identified as 98. The radio relay unit logic circuit 94 interrogates the in~~oming ;packet temporary holding queue 98 as well as controlling the transmission queue 100 and the control packet queue 102.
The data acquisition unit 58 of Figure 4 is shown in Figure 5 for convenience.
Figures 38, 26, and 27 explain in detail the logical process employed by the sys~~em's Radio Relay Units 60 and Figures 14, 17, 20, and 23 provide supporting descriptive details with respect to said queues and packet constructs. Said figures place particular emphasis on an embodiment of th<a protocol employed among the radio relay units.
Examination of thest=_ figures is required to understand the operation of the Radio Relay Units. In brief:
An incoming packet is detected and the radio relay unit logic circuit 94 reads thc> packet and determines if it is an authorized packet. In other words, the radio relay unit validates the packet as to whether it is a packet that is to be processed by this particular radio relay unit logic circuit. :If it is to be processed and is a control packet from an authorized ;source it is passed to the control packet queue 102 which would be subsequently read and executed by the data acquisition unit 58. Alternatively, the packet would be stored and processed to determine if or when it should be relayed by the radio relay unit. The transmission queue is accessible by both the radio relay unit logic circuit 94 and l~he data acquisition unit 58.
_-,... .r_.__. ___.____..____ -_ The following discussion highlights some of the more salient points of the radio relay 'unit in terms of the advantages which it provides. Where a p:Luralit;y of radio relay units operate, it is advantageous that a failure of one or more units does not diminish the ability of the remaining units to provide communications means between end points in the s_,rstem. 'this can be achieved by ensuring that a radio relay unit is within radio range of greater than one peer radio relay units. Also when a given r~sdio relay unit is within range of greater than one peer radio relay unit it is an advantage that only those radio relay units most di:atant from the source radio relay unit retransmit the packet as this will make for the most efficient system. Further it is an advantage to be able to control which path (where greater than one path exists) is used to convey .information between two or more end points. It is a further advantage to be able to convey information from a single source down all avenues of a network. It is still a further advantage to allow the addition, removal, modification or replacement of radio relay units in a non-disruptive manner. It is still a further advantage to facilitate the operation o:E a plurality of remote units and the mobility of said remote units.
A key feature of the radio relay units is that they are equipped with the capability to detc=_rmine the relative distance between a given transmitter and receiver. ~,larious known means are available to determine the relative distance between a radio transmitter and receiver but these means are also expensive. :Ln this embodiment, a less expensive means is disclosed where a transmitter is made to rapidly decay (via the "TX
decay" control on F_gure 5;1 its output power or the information content therein while sending a string of symbols known to all receivers. (Other embodiments may use different strings of symbols for different sets of receivers.) Each re<:eiver c an then determine the relative distance to the transmitter by counting the number of symbols intelligibly received. Obviously, the farther a receiver is from the transmitter, the fewer the number of symbols that will be received. It is further disclosed in the aforementioned figures that the affects of asymmetry in transmitter-receiver implementations (for example, the receiver in one radio relay unit ma:y be more sensitive than one of its peers which could enable it to hear a transmission from the peer unit while the peer unit could not hear its original packet being retransmitted by the radio relay unit with the more sensitive receiver) are accounted for in the disclosed process. It is also shown that the protocol is effective for complex arrangements of radio relay units.
When a radio :relay unit has determined the relative distance (e. g., very near, near, far, very far) to the source of a transmission it uses this inform<~tion to determine an appropriate retransmission time whereby the farther said radio relay unit is from the source of the transmission, the shorter will be its retransmission time. Radio relay units which hear a :rebroadcast of a packet which is stored in their transmission queue :L00 normally discard the packet. There are logical exceptions to this which a:re detailed in Figures 26, 27, and 38. It will be noted that this eambodiment of the radio relay unit produces and recognizes identity information not only with respect to each monitor unit but also with respect to each associated packet of information.
The " carrier detect" line in Figure 5 is used to alert the radio relay unit logic circuit that another peer radio relay unit is presently transmitting and it is therefore an inappropriate time to transmit.
It is to be noted th<~t the key features of this protocol and the embodiment thereof describe=_d herein make it highly applicable to other applications, most notably, wireless Local Area Networking.
The radio relay unit transmission queue structure is shown in Figure 14, comprising Figures 12 and 13. The different components of this queue will be <:lear from the wording thereon.
_-The radio relay unit data transmission packet is shown in Figure 17, comprising Figures 15 and 16. The different parts making up the packet will be clear from the wording thereon. Note that where a field is identified and described in Figure 17 and subsequently appears in Figures 23 or 20 but without explanation, the definition provided in Figure 17 is suitable. With this in mind the different parts of the radio relay unit confirmation only packet, Figure 23 (comprising Figures 21 and 22) and the :radio relay unit control transmission packet, Figure 20 (comprising Figures 18 and 19) will be clear from the wording thereon and said descriptions from Figure 17.
The operation of the radio relay unit within this embodiment is disclosed through consideration of Figures 14, 17, 23, and 20 together with Figures 26, 27, and 38. Figures 26, 27, and 38 principally relate to the radio relay ,snit logic circuit unit 94, of Figure 5 as well as to units 88, 90, 98, 100, and 102 thereon and are to be considered together as they really constitute one flow diagram.
Instead of packet transmission with radio relay units, the system may, of course, use other methods of communication.
It will be readily apparent to a person skilled in the art that a number of variation:a and modifications can be made without departing from the true spirit. of the invention which will now be pointed out in the appended claims.
The monitor unit 2 is shown in block diagram format in Figure 4 and it will be seen that there are two main units; a data acquisition unit 58 and a radio relay unit 60. The clock unit 62 provides a local representation of time.
The data acquisition unit 58 includes a plurality of detectors or sensors capable of detecting electromagnetic signals, sound signals, vibration signals, and motion signals.
In use, the outputs from the detector units 64 through 76 are fed to a data sampling cswitch 80 which selectively picks which particular detector and which ;signal from an identified detector will be fed to an A/D (analog to digital) converter unit 82 for conversion into a digitally coded signal which is fed to a data acquisition logic circuit 84. Figure 44 (comprising Figures 39 through 43) is a logic flow diagram which depicts the flow of logic within the data acquisition logic circuit 84 fo:r gathering information from the sensors and subsequently packaging and delivering the sensor data to the radio relay unit 60. Figure 44 <~lso depicts the flow of logic for the interactions between the monitor unit 2 and a remote unit 40.
The monitor unit is also provided with a vibration inducer unit 86 as shown in Figure 4. The vibration detector 74 provides data which indicates, amongst other things, the structural integrity of the power transmission infrastructure element (for example, a pole or tower). In the case of a wooden pole, nature may not conveniently provide enough stimulus to cause the pole to 'reveal its health' through the vibration sensor. In instances such as this, a vibration inducer can be used to stimulate the struct=ure so that its structural signature could be obtained and thereby its structural integrity determined.
In Figure 5, t:he radio relay unit 60 is shown in greater detail.
The antenna 20 for this embodiment serves both the receiver 88 and the transmitter 90 but not simultaneously. When the "tx ptt" control of .. ., Figure 5 is enabled a transmission occurs and the receiver is disconnected from t:he antenna. The transmitter and receiver are shown connected to a radio relay unit logic circuit 94 and a packet discriminator unit 96. The packet discriminator unit receives incoming bits, determines if a sequence of bits forms a packet, and if it does then it passes thes~= packets to an incoming packet temporary holding queue identified as 98. The radio relay unit logic circuit 94 interrogates the in~~oming ;packet temporary holding queue 98 as well as controlling the transmission queue 100 and the control packet queue 102.
The data acquisition unit 58 of Figure 4 is shown in Figure 5 for convenience.
Figures 38, 26, and 27 explain in detail the logical process employed by the sys~~em's Radio Relay Units 60 and Figures 14, 17, 20, and 23 provide supporting descriptive details with respect to said queues and packet constructs. Said figures place particular emphasis on an embodiment of th<a protocol employed among the radio relay units.
Examination of thest=_ figures is required to understand the operation of the Radio Relay Units. In brief:
An incoming packet is detected and the radio relay unit logic circuit 94 reads thc> packet and determines if it is an authorized packet. In other words, the radio relay unit validates the packet as to whether it is a packet that is to be processed by this particular radio relay unit logic circuit. :If it is to be processed and is a control packet from an authorized ;source it is passed to the control packet queue 102 which would be subsequently read and executed by the data acquisition unit 58. Alternatively, the packet would be stored and processed to determine if or when it should be relayed by the radio relay unit. The transmission queue is accessible by both the radio relay unit logic circuit 94 and l~he data acquisition unit 58.
_-,... .r_.__. ___.____..____ -_ The following discussion highlights some of the more salient points of the radio relay 'unit in terms of the advantages which it provides. Where a p:Luralit;y of radio relay units operate, it is advantageous that a failure of one or more units does not diminish the ability of the remaining units to provide communications means between end points in the s_,rstem. 'this can be achieved by ensuring that a radio relay unit is within radio range of greater than one peer radio relay units. Also when a given r~sdio relay unit is within range of greater than one peer radio relay unit it is an advantage that only those radio relay units most di:atant from the source radio relay unit retransmit the packet as this will make for the most efficient system. Further it is an advantage to be able to control which path (where greater than one path exists) is used to convey .information between two or more end points. It is a further advantage to be able to convey information from a single source down all avenues of a network. It is still a further advantage to allow the addition, removal, modification or replacement of radio relay units in a non-disruptive manner. It is still a further advantage to facilitate the operation o:E a plurality of remote units and the mobility of said remote units.
A key feature of the radio relay units is that they are equipped with the capability to detc=_rmine the relative distance between a given transmitter and receiver. ~,larious known means are available to determine the relative distance between a radio transmitter and receiver but these means are also expensive. :Ln this embodiment, a less expensive means is disclosed where a transmitter is made to rapidly decay (via the "TX
decay" control on F_gure 5;1 its output power or the information content therein while sending a string of symbols known to all receivers. (Other embodiments may use different strings of symbols for different sets of receivers.) Each re<:eiver c an then determine the relative distance to the transmitter by counting the number of symbols intelligibly received. Obviously, the farther a receiver is from the transmitter, the fewer the number of symbols that will be received. It is further disclosed in the aforementioned figures that the affects of asymmetry in transmitter-receiver implementations (for example, the receiver in one radio relay unit ma:y be more sensitive than one of its peers which could enable it to hear a transmission from the peer unit while the peer unit could not hear its original packet being retransmitted by the radio relay unit with the more sensitive receiver) are accounted for in the disclosed process. It is also shown that the protocol is effective for complex arrangements of radio relay units.
When a radio :relay unit has determined the relative distance (e. g., very near, near, far, very far) to the source of a transmission it uses this inform<~tion to determine an appropriate retransmission time whereby the farther said radio relay unit is from the source of the transmission, the shorter will be its retransmission time. Radio relay units which hear a :rebroadcast of a packet which is stored in their transmission queue :L00 normally discard the packet. There are logical exceptions to this which a:re detailed in Figures 26, 27, and 38. It will be noted that this eambodiment of the radio relay unit produces and recognizes identity information not only with respect to each monitor unit but also with respect to each associated packet of information.
The " carrier detect" line in Figure 5 is used to alert the radio relay unit logic circuit that another peer radio relay unit is presently transmitting and it is therefore an inappropriate time to transmit.
It is to be noted th<~t the key features of this protocol and the embodiment thereof describe=_d herein make it highly applicable to other applications, most notably, wireless Local Area Networking.
The radio relay unit transmission queue structure is shown in Figure 14, comprising Figures 12 and 13. The different components of this queue will be <:lear from the wording thereon.
_-The radio relay unit data transmission packet is shown in Figure 17, comprising Figures 15 and 16. The different parts making up the packet will be clear from the wording thereon. Note that where a field is identified and described in Figure 17 and subsequently appears in Figures 23 or 20 but without explanation, the definition provided in Figure 17 is suitable. With this in mind the different parts of the radio relay unit confirmation only packet, Figure 23 (comprising Figures 21 and 22) and the :radio relay unit control transmission packet, Figure 20 (comprising Figures 18 and 19) will be clear from the wording thereon and said descriptions from Figure 17.
The operation of the radio relay unit within this embodiment is disclosed through consideration of Figures 14, 17, 23, and 20 together with Figures 26, 27, and 38. Figures 26, 27, and 38 principally relate to the radio relay ,snit logic circuit unit 94, of Figure 5 as well as to units 88, 90, 98, 100, and 102 thereon and are to be considered together as they really constitute one flow diagram.
Instead of packet transmission with radio relay units, the system may, of course, use other methods of communication.
It will be readily apparent to a person skilled in the art that a number of variation:a and modifications can be made without departing from the true spirit. of the invention which will now be pointed out in the appended claims.
Claims (11)
1. A maintenance apparatus for a power transmission infrastructure comprising:-(a) a plurality of monitor units placed in the power transmission infrastructure at different locations and each capable of transmitting its own identifying signal and data information relating to the conditions of at least one power transmission infrastructure element at or near a location;
(b) at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to determine the nature and location or locations of a fault or faults; and (c) said monitor units being arranged throughout said power transmission infrastructure for collecting information as to the condition of a power transmission infrastructure element or elements at or near a respective location and sending or relaying to said remote unit or a plurality of remote units said identification signals and said information as to the condition of a power transmission infrastructure element or elements at or near a respective location; and (d) at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to forecast the nature and location or locations of a fault or faults; and (e)locating within each monitor unit a sensor or sensors to measure at least one of the following: electromagnetic fields, sound, structural vibration, structural attitude, structural motion;
(b) at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to determine the nature and location or locations of a fault or faults; and (c) said monitor units being arranged throughout said power transmission infrastructure for collecting information as to the condition of a power transmission infrastructure element or elements at or near a respective location and sending or relaying to said remote unit or a plurality of remote units said identification signals and said information as to the condition of a power transmission infrastructure element or elements at or near a respective location; and (d) at least one remote unit for receiving and storing said identification signal and data information from at least one of said monitor units and processing said information to forecast the nature and location or locations of a fault or faults; and (e)locating within each monitor unit a sensor or sensors to measure at least one of the following: electromagnetic fields, sound, structural vibration, structural attitude, structural motion;
2. A maintenance apparatus for power transmission infrastructure according to claim 1 and also comprising:-(a) the means to detect any combination of the following: leaky arrestors, defective insulators, broken conductors, current faults, motion in cables, galloping lines, corona, transformer degradation, structural integrity.
3. A method for the conveyance of information comprising a plurality of radio relay units including the steps of:-(a) providing the outward progression of information from a given radio relay unit, independent of the arrangement of radio relay units;
(b) moving or allowing radio relay units to move while participating in the conveyance of information; and (c) continuing the conveyance of information in the presence of one or more radio relay unit failures; and (d) discarding in a given radio relay unit packets intended to be forwarded, by confirming that the packet has been successfully relayed past it.
(b) moving or allowing radio relay units to move while participating in the conveyance of information; and (c) continuing the conveyance of information in the presence of one or more radio relay unit failures; and (d) discarding in a given radio relay unit packets intended to be forwarded, by confirming that the packet has been successfully relayed past it.
4. A method for the conveyance of information according to claim 3 also comprising:-The use of received signal strength to control retransmission timers such that optimum throughput is achieved by a relay system.
5. A method for the conveyance of information comprising a plurality of radio relay units including the steps of:-a)transmitting information from a source connected to at least one radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received at said radio relay unit from another radio relay unit;
b) receiving, at a given radio relay unit, information from other radio relay units and determining the relative distance (e. g., very near, near, far, very far) to those radio relay units;
c) utilizing raid relative distance information to determine if and when said radio relay unit will relay information received from another radio relay unit;
d) subsequently utilizing information in packets received from other radio relay units to determine if said radio relay unit will relay information received from another radio relay unit; and e) subsequently transmitting information which was received from another radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received from a respective radio relay unit.
b) receiving, at a given radio relay unit, information from other radio relay units and determining the relative distance (e. g., very near, near, far, very far) to those radio relay units;
c) utilizing raid relative distance information to determine if and when said radio relay unit will relay information received from another radio relay unit;
d) subsequently utilizing information in packets received from other radio relay units to determine if said radio relay unit will relay information received from another radio relay unit; and e) subsequently transmitting information which was received from another radio relay unit when said transmission would not interfere with an ongoing transmission or transmissions being received from a respective radio relay unit.
6. A method for the conveyance of information according to claim 5 also including the steps of:-(a) encapsulating the information to be conveyed in packets;
(b) producing identity information which identifies each information packet originated by a given radio relay unit;
(c) transmitting said packet identity information in radio relay unit transmissions;
(d) determining the identity of information packets produced by other radio relay units which produce said packet identity information;
(e) utilizing said packet identity information in determining if said radio relay units will relay information received from other radio relay units; and (f) utilizing said packet identity information in determining when said radio relay unlit will begin attempting to relay information received from said respective radio relay unit.
(b) producing identity information which identifies each information packet originated by a given radio relay unit;
(c) transmitting said packet identity information in radio relay unit transmissions;
(d) determining the identity of information packets produced by other radio relay units which produce said packet identity information;
(e) utilizing said packet identity information in determining if said radio relay units will relay information received from other radio relay units; and (f) utilizing said packet identity information in determining when said radio relay unlit will begin attempting to relay information received from said respective radio relay unit.
7. A method for the conveyance of information according to claim 5 or 6 including the steps of:
(a) producing identity information which, with a single identifier, identifies each transmission and re-transmission of an identified packet by a given radio relay unit;
(b) transmitting said packet transmission identity information in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the identity of information packet transmissions produced by other radio relay units which produce said packet transmission identity information;
(d) utilizing said packet transmission identity information in determining if said radio relay units will relay information received from other radio relay units; and (e) utilizing said packet transmission identity information in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
(a) producing identity information which, with a single identifier, identifies each transmission and re-transmission of an identified packet by a given radio relay unit;
(b) transmitting said packet transmission identity information in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the identity of information packet transmissions produced by other radio relay units which produce said packet transmission identity information;
(d) utilizing said packet transmission identity information in determining if said radio relay units will relay information received from other radio relay units; and (e) utilizing said packet transmission identity information in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
8. A method for the conveyance of information according to claim 5, 6, or 7 including the steps of:
(a) confirming the progress of information conveyance along the desired or available routes;
(b) transmitting said information at a given radio relay unit where said progress is not confirmed; and (c) ceasing to transmit said information at a given radio relay unit where said progress is not confirmed after completing a set number of transmissions.
(a) confirming the progress of information conveyance along the desired or available routes;
(b) transmitting said information at a given radio relay unit where said progress is not confirmed; and (c) ceasing to transmit said information at a given radio relay unit where said progress is not confirmed after completing a set number of transmissions.
9. A method for the conveyance of information according to claim 5, 6, 7, or 8 including the steps of:
(a) producing, for a given piece of information, priority data;
(b) transmitting said information priority data in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the priority data respecting information produced by other radio relay units which produce said information priority data;
(d) utilizing said information priority data in determining if said radio relay units will relay information received from other radio relay units; and (e) utilizing said information priority data in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
(a) producing, for a given piece of information, priority data;
(b) transmitting said information priority data in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the priority data respecting information produced by other radio relay units which produce said information priority data;
(d) utilizing said information priority data in determining if said radio relay units will relay information received from other radio relay units; and (e) utilizing said information priority data in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
10. A method for the conveyance of information according claim 5, 6, 7, or 8 including the steps of:-including the steps of:-(a) producing, for a given piece of information, priority data;
(b) transmitting said information priority data in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the priority data respecting information produced by other radio relay units which produce said information priority data;
(d) utilizing said information priority data in determining if said radio relay units will relay information received from other radio relay units;
(e) utilizing said information priority data in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
(f) producing, for a given radio relay unit, congestion information;
(g) transmitting said congestion information in radio relay unit transmissions and re-transmissions; and (h) adjusting the volume of information handled by said radio relay unit.
(b) transmitting said information priority data in radio relay unit transmissions and re-transmissions;
(c) determining, for a given radio relay unit, the priority data respecting information produced by other radio relay units which produce said information priority data;
(d) utilizing said information priority data in determining if said radio relay units will relay information received from other radio relay units;
(e) utilizing said information priority data in determining when said radio relay unit will begin attempting to relay information received from said respective radio relay unit.
(f) producing, for a given radio relay unit, congestion information;
(g) transmitting said congestion information in radio relay unit transmissions and re-transmissions; and (h) adjusting the volume of information handled by said radio relay unit.
11. A method for the conveyance of information according to claim 5, 6, 7, 8, 9, or 10 including the step:
Determining the relative distance to the originator of a transmission relative to other radio relay units by:
attenuating, or otherwise altering, at a given radio relay unit transmitter, the strength of the carrier signal or the strength of the information signal carried therein or the strength of both, while transmitting a sequence of symbols known to radio relay unit receivers;
detecting at a given radio relay unit receiver said known sequence of symbols until the sequence ceases to follow its known pattern; and correlating at said radio relay unit receiver the intelligible length of the known sequence of symbols to a relative distance to the transmitting source.
Determining the relative distance to the originator of a transmission relative to other radio relay units by:
attenuating, or otherwise altering, at a given radio relay unit transmitter, the strength of the carrier signal or the strength of the information signal carried therein or the strength of both, while transmitting a sequence of symbols known to radio relay unit receivers;
detecting at a given radio relay unit receiver said known sequence of symbols until the sequence ceases to follow its known pattern; and correlating at said radio relay unit receiver the intelligible length of the known sequence of symbols to a relative distance to the transmitting source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002148146A CA2148146C (en) | 1995-04-28 | 1995-04-28 | Power transmission infrastructure maintenance system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002148146A CA2148146C (en) | 1995-04-28 | 1995-04-28 | Power transmission infrastructure maintenance system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2148146A1 CA2148146A1 (en) | 1996-10-29 |
| CA2148146C true CA2148146C (en) | 1999-12-07 |
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ID=4155746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002148146A Expired - Fee Related CA2148146C (en) | 1995-04-28 | 1995-04-28 | Power transmission infrastructure maintenance system |
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| Country | Link |
|---|---|
| CA (1) | CA2148146C (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITMI20011078A1 (en) * | 2001-05-22 | 2002-11-22 | Microelettrica Scientifica Spa | DEVICE FOR THE DETECTION AND MEASUREMENT OF THE DRIVING CURRENT OF DISCHARGERS FOR HIGH VOLTAGE ELECTRIC NETWORKS AND FOR THE ASSESSMENT |
| CN106526645A (en) * | 2016-11-17 | 2017-03-22 | 北京恒华龙信数据科技有限公司 | Positioning method and positioning device |
| CN110378492A (en) * | 2019-05-28 | 2019-10-25 | 长春电力设计有限公司 | A method of reinforcing the control of distribution net equipment O&M |
-
1995
- 1995-04-28 CA CA002148146A patent/CA2148146C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2148146A1 (en) | 1996-10-29 |
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