The present invention relates to energy measurement systems and methods and, in particular, to systems and methods that facilitate the measurement of parameters and recording of data associated with secondary voltage systems.
Utility companies operate extensive networks of power distribution equipment connected by power lines. The power distribution equipment and power lines are often located in remote locations, and it is not feasible to continuously monitor such distribution equipment and power lines.
In particular, the power distribution equipment typically includes transformers located throughout an electrical distribution system (grid) as required by the loads serviced by the electrical distribution system. To allow the electrical distribution system to operate efficiently, the transformers forming a part of the electrical distribution system should be efficiently loaded. Factors such as power theft may result in inefficient loading of transformers and thus inefficient operation of the electrical distribution system.
The need thus exists for energy measurement systems for secondary voltage systems that facilitate the efficient operation of power distribution equipment such as transformers forming a part of an electrical distribution system.
The present invention may be embodied as a measurement device for generating measurement data associated with at least first and second conductors of an electrical distribution system comprising at least first and second tap assemblies and at least one cable. The first and second tap assemblies each comprising a clamp assembly comprising a brace defining a bolt opening, a piercing member supported relative to the brace, a clamp member defining an anchor surface, and a bolt member defining a shaft portion and a head portion. The shaft portion of the bolt member extends through the bolt opening and engages the anchor surface such that axial rotation of the bolt member displaces the clamp member towards and away from the piercing member. The at least one cable operatively connects the first and second tap assemblies. At least portions of the first and second conductors are arranged between the clamp member and the piercing member of the first and second tap assemblies, respectively. Accordingly, displacement of the clamp member of the first tap assembly towards the piercing member of the first tap assembly causes the piercing member of the first tap assembly to engage the first conductor. Similarly, displacement of the clamp member of the second tap assembly towards the piercing member of the second tap assembly causes the piercing member of the second tap assembly to engage the second conductor.
The present invention may also be embodied as a tap assembly for a measurement device for generating measurement data associated with at least one conductor of an electrical distribution system comprising a clamp base, a main assembly, a piercing member, a clamp member, and a bolt member. The clamp base comprises a brace portion defining a bolt opening. The main assembly comprises a contact plate. The piercing member is supported by the contact plate. The clamp member defines an anchor surface. The bolt member defines a shaft portion and a head portion. The clamp base is attached to the main assembly to define a clamp notch, where the contact plate is adjacent to the clamp notch. The shaft portion of the bolt member extends through the bolt opening and engages the anchor surface such that axial rotation of the bolt member displaces the clamp member towards and away from the piercing member. At least a portion of the conductor is arranged within the clamp notch between the clamp member and the piercing member such that displacement of the clamp member towards the piercing member causes the piercing member to engage the conductor.
The present invention may be embodied as a method of generating measurement data associated with at least one conductor of an electrical distribution system comprising the following steps. A clamp base comprising a brace portion defining a bolt opening is provided. A main assembly comprising a contact plate is provided. A piercing member is supported on the contact plate. A clamp member defining an anchor surface is provided. A bolt member defining a shaft portion and a head portion is provided. The clamp base is attached to the main assembly to define a clamp notch, where the contact plate is adjacent to the clamp notch. The shaft portion of the bolt member is extended through the bolt opening. The shaft portion of the bolt member is engaged with the anchor surface. At least a portion of the conductor is arranged within the clamp notch between the clamp member and the piercing member. The bolt member is axially rotated to displace the clamp member towards the piercing member to cause the piercing member to engage the conductor.
Referring initially to
The first example measurement system 20 comprises an electrical portion 30 and a mechanical portion 32. The example electrical portion 30 is a circuit board or module that generates measurement data associated with parameters of the electrical distribution system 26. The measurement data is typically converted to digital form and stored for subsequent downloading.
The example electrical portion 30 thus comprises components that form a signal conditioning system 40, a measurement processing system 42, a control processing system 44, a radio module 46, and a power supply 48. An example circuit diagram that may be used to implement the electrical portion 30 is depicted in
The signal conditioning system 40 generates raw data based on analog signals associated with the electrical distribution system 26; the raw data is binary data suitable for processing and possibly storage by the measurement processing system 42. The control processing system 44 arranges the raw data as processed data and stores the processed data for subsequent downloading.
The control processing system 44 further runs an integrated software program incorporating the logic necessary to transmit the processed data to an access device 50 when directed. The control processing system 44 and the access device 50 communicate using the radio module 46, although the processed data may be directly downloaded from the control processing system 44 using an electrical connector (not shown) in a conventional fashion. The example access device 50 contains a remote processor 60, a radio module 62, and a user interface 64. The remote processor 60 runs a remote software program that cooperates with the integrated software program running on the control processing system 44 to transmit data between the example measurement system 20 and the access device 50.
The power supply 48 supplies electrical power to the signal conditioning system 40, measurement processing system 42, control processing system 44, and radio module 46 as will be described in further detail below.
The mechanical portion 32 of the first example measurement system 20 is depicted in further detail in
The example tap assemblies 120 and 122 are or may be mechanically the same. The electrical portion 30 of the measurement system 20 is mounted in one or both of the tap assemblies 120 and 122. In particular, the example electrical portion 30 is mounted within the first tap assembly 120, and the cable 124 allows communication of analog signals from second tap assembly 122 to the electrical portion 30 mounted within the first tap assembly 120. As an alternative example, only the measurement processing system 42, control system 44, and radio module 46 may be mounted within the first tap assembly 120. In this case, the signal conditioning system 40 may be arranged partly within the first tap assembly 120 and partly within the second tap assembly 122. As yet another example, it may be possible to duplicate entire electrical portion 30 in each of the tap assemblies 120 and 122, in which case the duplicated electrical portions 30 may each communicate directly with the access device 50 and with each other using the radio modules.
Referring now to
As perhaps best shown in
The example main housing 140 is generally rectangular and defines a housing notch region 160 and, in the example first tap assembly 120, three mounting holes 162. The example main housing 140 further defines a sister board opening 164 through which the sister board 138 extends. When the piercing member 144 is attached to the contact plate 142, the piercing points 152 and 154 extend into the housing notch region 160 defined by the main housing 140 as shown in
Referring now to
The base plate 230 defines a plate notch region 240, and, in the example tap assembly 120, three mounting openings 236 are formed in the base plate 230. The plate notch region 240 is bounded by an end wall 250 and opposing clamp side walls 252. As with the end wall 166 described above, the example end wall 250 is generally shaped to correspond to an external surface of the conductor 70. And like the opposing housing side walls 168, the clamp side walls 252 are spaced from each other to allow the conductor 70 to be arranged substantially adjacent to at least a portion of the end wall 166. The example end wall 166 is semi-circular to accommodate a typical conductor, with a diameter of the circle defining the end wall 166 being slightly larger than a diameter of the conductor 170. Like the housing side walls 168, the spacing between clamp side walls 252 is slightly greater than a diameter of the conductor 170. In addition, the end wall 250 defines a contact notch 256 as will be described in further detail below.
The brace portion 232 defines a bolt opening 260. The example bolt opening 260 is located on the opposite side of the contact notch 256 from the cover portion 234 in the example base plate 230.
The example engaging assembly 222 comprises a clamp member 270 defining an anchor opening 272 and an anchor insert 274 secured within at least a portion of the anchor opening 272. The anchor insert 274 is internally threaded. The clamp member 270 further defines a clamp surface 276 and a cover wall portion 278. The example clamp member 270 is integrally formed of plastic of sufficient rigidity to perform the clamping function as described herein. The example clamp surface 276 is textured and shaped with a concave V-shaped shape to guide the conductor 70 against the piercing member 144 as will be described in further detail below.
The example clamp bolt assembly 224 comprises a bolt member 280 and a bolt head 282. The example bolt member 280 is integrally formed of steel and defines a head portion 284 and a shaft portion 286. The shaft portion 286 is externally threaded. The bolt head 282 facilitates axial rotation of the bolt member 280 as described below.
The example bolt head 282 defines a base portion 290, a first drive portion 292, and a second drive portion 294. The base portion 290 defines a head chamber 296 sized and dimensioned to accommodate the bolt head portion 284. An optional relief portion 298 separates the first and second drive portions 292 and 294. The example bolt head 282 is integrally formed of plastic of sufficient rigidity to transfer rotational loads applied to the drive portions 292 and 294 to the base portion 290 and thus to the head portion 284 of the bolt member 280. The relief portion 298 may be used to prevent over-torqueing of the bolt head 282 by allowing the second drive portion 294 to break away from the first drive portion 292 when excessive torque is applied to the second drive portion 294.
To assemble the clamp assembly 132, the shaft portion 286 of the bolt member 280 is inserted through the bolt opening 260 and at least partly into the threaded anchor insert 274. The bolt opening 260 is oversized to allow free axial rotation of the shaft portion 286 relative to the brace portion 232. However, the example bolt opening 260 is smaller than the head portion 284 of the bolt member 280 and/or the bolt head 282. The clamp member 270 may thus rotate between an open position as shown in
With the clamp assembly so formed, the three mounting screws 134 are passed through the mounting openings 236 and threaded into the mounting holes 162 to secure the clamp base 220 to the main housing 140. With the clamp base 220 secured to the main housing 140, the plate notch region 240 defined by the base plate 230 substantially corresponds to the dimensions of the housing notch region 160 described above. The plate notch region 240 and housing notch region 160 define a clamp region 320 when the clamp base 220 is secured to the main housing 140. In addition, the contact notch 256 defined by the end wall 250 is sized and dimensioned to accommodate the contact plate 142 and the piercing member 144 as perhaps best shown in
To use the example first tap assembly 120, the clamp member 270 is arranged in the unclamped and open configurations as shown in
The conductor 70 is next arranged such that the conductor 70 is within the clamp notch 320. In particular, the clamp region 320 defines a clamping plane 322 as perhaps best shown in
The clamp member 270 is then pivoted about the bolt axis 326 from the open position as shown in
The bolt member 280 is then axially rotated to displace the clamp member 270 towards the brace portion 232 from the unclamped position shown in
At this point, the piercing member 144 and contact plate 142 electrically connect the electrical portion 30 to the conductor portion 80 of the conductor 70. The piercing member 144 thus allows the electrical portion to detect a voltage signal associated with the conductor 70. Further, the electrical portion 30 contains a current transformer or the like (not shown) that is mounted within the main assembly 130 to detect a current signal associated with the conductor 70. In practice, a current transformer will be mounted in each of the tap assemblies 120 and 122. The detection of voltage and current signals by the electrical portion 30 is or may be conventional and will not be described herein in further detail. However, the present invention is of particular significance when the current sensing device is a variant of a Rogowski coil, and the example electrical portion 30 preferably employs a variant of a Rogowski coil.
The electrical portion 30 thus is capable of measuring and storing data values associated with the voltage and current signals and transferring these data values to a remote device such as the access device 50 at a later point in time. The first example measurement system 20 of the present invention thus integrates a non-contact current sensor and an insulation-piercing electrical contact with an electronic circuit for measurement, recording, time/date stamping, and communication for use on conductors in secondary voltage (typically 100-600 VAC) systems with a mechanism that automatically positions the tap assemblies 120 and 122 on the conductor or conductors being measured and which provides a controlled clamping force.
Referring now to
The second example measurement system 420 comprises an electrical portion 430 and a mechanical portion 432. The example electrical portion 430 is a circuit board or module comprising components that form a signal conditioning system 440, a measurement processing system 442, a control processing system 444, a radio module 446, and a power supply 448. The signal conditioning system 440 generates raw data based on analog signals associated with the electrical distribution system 426; the raw data is typically binary data suitable for processing by the measurement processing system 442. The control processing system 444 arranges the raw data as processed data and stores the processed data.
The control processing system 444 further runs an integrated software program incorporating the logic necessary to transmit the processed data to an access device 450 when directed. The control processing system 444 and the access device 450 communicate using the radio module 446, although the processed data may be directly downloaded from the control processing system 444 using an electrical connector (not shown) in a conventional fashion. The example access device 450 contains a remote processor 460, a radio module 462, and a user interface 464. The remote processor 460 runs a remote software program that cooperates with the integrate software program running on the control processing system 444 to transmit
The power supply 448 supplies electrical power to the signal conditioning system 440, measurement processing system 442, control processing system 444, and radio module 446 as will be described in further detail below.
The mechanical portion 432 of the second example measurement system 420 is depicted in further detail in
The example tap assemblies 520, 522, 524 are or may be mechanically the same as each other, and any one of these tap assemblies 520, 522, and 524 may be the same as one or both of the tap assemblies 120 and 122 described above. The cables 530, 532, and 534 are interconnected to allow measurement of voltage signals as generally described above.
The electrical portion 430 of the measurement system 420 is mounted in any one or more of the tap assemblies 520, 522, and 524. In particular, the example electrical portion 430 is mounted within the first tap assembly 520, and the cables 530, 532, and 534 allow communication of analog signals from second and third tap assemblies 522 and 524 to the electrical portion 430 mounted within the first tap assembly 520. As an alternative example, only the measurement processing system 442, control system 444, and radio module 446 may be mounted within the first tap assembly 520. In this case, the signal conditioning system 440 may be arranged partly within the first tap assembly 520, partly within the second tap assembly 522, and partly within the third tap assembly 524. As yet another example, it may be possible to replicate the entire electrical portion 430 in each of the tap assemblies 520, 522, and 524, in which case the duplicated electrical portions 430 may each communicate directly with the access device 450 and with each other using the radio modules.
Like the first example measurement system 20 of the present invention, the second example measurement system 42 integrates a non-contact current sensor and an insulation-piercing electrical contact with an electronic circuit for measurement, recording, time/date stamping, and communication for use on conductors in secondary voltage (typically 100-600 VAC) systems with a mechanism that automatically positions the tap assemblies 520, 522, and 524 on the conductor or conductors being measured and which provides a controlled clamping force.
In the foregoing examples, the first and second example measurement systems 20 and 420 were described in the context of the insulated conductors 70, 72, 470, 472, and 474 that are typically suspended above-ground. The principles of the present invention may be applied to other types and uses of conductors, including uninsulated conductors, rigid conductors, and conductors located underground.
When applied to uninsulated conductors, the piercing member need only penetrate the conductor and need not pierce an insulator. The voltage contact thus is in direct contact with the conductor. The clamping mechanism otherwise operates as described above with respect to the tap assemblies described herein.
Rigid electrical connectors may form the conductor. Rigid electrical connectors may be insulated or uninsulated. In particular, some electrical equipment, such as transformers, employ rigid connectors, which may or may not be insulated, and the measurement systems of the present invention could be used directly on the connector rather than on the conductors attached to the connector.
In underground applications, the voltage contact and the flexible conductor, rigid connector, or other on which the measurement systems are connected may requires a water-tight seal. The measurement systems of the present invention as described above may be extended to such underground applications by using or incorporating any sealing components that may be required to form the water-tight seal.
This application claims benefit of U.S. Provisional Application Ser. No. 61/867,507 filed Aug. 19, 2013, the contents of which are incorporated herein by reference.
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