System and method for verifying and maintaining the accuracy of metrology equipment

Abstract

A system for identifying an uncalibrated meter and a control method thereof include: obtaining power measurement values ​​of each of a plurality of metering devices in a hierarchy of metering devices; calculating virtual metering points of a candidate metering device using metering devices connected upstream and / or downstream of the candidate metering device; and identifying the candidate metering device as uncalibrated by utilizing the virtual metering points and specifications of the candidate metering device.

Description

Technical Field

[0001] The present invention generally relates to systems and methods for determining meters in a hierarchy of meters that require calibration. Background Art

[0002] A single line diagram is used to analyze the flow of power from the source to the load throughout the power distribution system. Power meters in such a distribution system may experience drift in accuracy over time. Current methods for determining meter accuracy focus on individual metering devices. Summary of the invention

[0003] Various aspects and embodiments are directed to a method of identifying an out of calibration meter, the method comprising the following acts: obtaining a power measurement value of each metering device in a plurality of metering devices arranged in a hierarchical structure, the hierarchical structure comprising a plurality of levels, wherein at least one metering device in the plurality of metering devices is in each of the plurality of levels; selecting a candidate metering device from one of the plurality of levels of the plurality of metering devices; calculating a plurality of comparison values ​​for the candidate metering device based on power measurement values ​​of at least two metering devices in the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level in the hierarchical structure than the candidate metering device, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices in the plurality of metering devices; calculating a difference between the power measurement value of the candidate metering device and a first comparison value in the plurality of comparison values; and identifying the candidate metering device as out of calibration based on the difference.

[0004] In one example, the method further includes calculating the comparison value by summing power measurements of at least two metering devices of the plurality of metering devices.

[0005] In another example, the method further includes obtaining a new power measurement value for each metering device in the plurality of metering devices in the hierarchy in response to determining that the difference is within the tolerance.

[0006] In one example, identifying the candidate metering device as uncalibrated based on the difference includes calculating an additional difference between the power measurement value of the candidate metering device and an additional comparison value of the plurality of comparison values.

[0007] In another example, the method further includes determining whether the difference value and the additional difference value are positive or negative; and in response to determining that the difference value and the additional difference value are both positive or both negative, identifying an increased likelihood that the candidate metrology device is out of calibration.

[0008] In one example, identifying the candidate metrology device as uncalibrated based on the calculated difference value includes: calculating an uncertainty value of the candidate metrology device based on an accuracy value of the candidate metrology device and a power measurement value of the candidate metrology device; and calculating an uncertainty value of the comparison value.

[0009] In another example, the uncertainty value of the comparison value is calculated by calculating a sum of squares of a plurality of uncertainty values ​​including the uncertainty value of the comparison value.

[0010] In one example, the method further includes: calculating a plurality of difference values ​​including the difference value; calculating a plurality of uncertainty values ​​including the uncertainty value of the comparison value; wherein identifying the candidate metrology device as uncalibrated based on the difference value includes: determining whether a minimum difference value among the plurality of difference values ​​exceeds a maximum uncertainty value among the plurality of uncertainty values; and based on the determination, calculating an adjustment to a calibration constant of the candidate metrology device.

[0011] In another example, the method further includes adjusting a calibration constant of the candidate metrology device in response to identifying the candidate metrology device as uncalibrated.

[0012] In one example, the method further includes issuing a calibration warning in response to identifying the candidate metrology device as uncalibrated.

[0013] Various aspects and embodiments are directed to a system for identifying an uncalibrated meter, the system comprising a plurality of metering devices arranged in a hierarchical structure, the hierarchical structure comprising a plurality of levels, wherein at least one metering device of the plurality of metering devices is in each of the plurality of levels; and a controller configured to: obtain a power measurement value of each metering device of the plurality of metering devices; select a candidate metering device from one of the plurality of levels of the plurality of metering devices; calculate a plurality of comparison values ​​of the candidate metering device based on power measurement values ​​of at least two metering devices of the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level in the hierarchical structure than the candidate metering device, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices of the plurality of metering devices; calculate a difference between the power measurement value of the candidate metering device and a first comparison value of the plurality of comparison values; and identify the candidate metering device as uncalibrated based on the difference.

[0014] In one example, the controller is further configured to calculate the comparison value by summing power measurement values ​​of at least two metering devices among the plurality of metering devices.

[0015] In another example, the controller is further configured to obtain a new power measurement value for each metering device in the plurality of metering devices in the hierarchy in response to determining that the difference is within the tolerance.

[0016] In one example, the controller is further configured to calculate an additional difference between the power measurement value of the candidate metering device and an additional comparison value of the plurality of comparison values.

[0017] In another example, the controller is further configured to determine whether the difference value and the additional difference value are positive or negative; and in response to determining that the difference value and the additional difference value are both positive or both negative, identifying that the candidate metrology device is out of calibration has an increased likelihood.

[0018] In one example, the controller is further configured to calculate an uncertainty value of the candidate metrology device based on the accuracy value of the candidate metrology device and the power measurement value of the candidate metrology device; and calculate the uncertainty value of the comparison value.

[0019] In another example, the uncertainty value of the comparison value is calculated by calculating a sum of squares of a plurality of uncertainty values ​​including the uncertainty value of the comparison value.

[0020] In one example, the controller is further configured to calculate a plurality of difference values ​​including the difference value; calculate a plurality of uncertainty values ​​including the uncertainty value of the comparison value; determine whether a minimum difference value among the plurality of difference values ​​exceeds a maximum uncertainty value among the plurality of uncertainty values; and based on the determination, calculate an adjustment to a calibration constant of the candidate metrology device.

[0021] In another example, the controller is further configured to, in response to identifying the candidate metrology device as uncalibrated, adjust a calibration constant of the candidate metrology device; or, in response to identifying the candidate metrology device as uncalibrated, issue a calibration warning.

[0022] Aspects and embodiments are directed to a non-transitory computer-readable medium storing a sequence of instructions executable by at least one processor, the sequence of instructions instructing the at least one processor to perform a process of identifying an uncalibrated meter, the sequence of instructions causing the at least one processor to perform operations including the following steps: obtaining a power measurement value of each metering device in a plurality of metering devices arranged in a hierarchical structure, the hierarchical structure comprising a plurality of levels, wherein at least one metering device in the plurality of metering devices is in each of the plurality of levels; selecting a candidate metering device from one of the plurality of levels of the plurality of metering devices; calculating a plurality of comparison values ​​of the candidate metering device based on power measurement values ​​of at least two metering devices in the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level in the hierarchical structure than the candidate metering device, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices in the plurality of metering devices; calculating a difference between the power measurement value of the candidate metering device and a first comparison value in the plurality of comparison values; and identifying the candidate metering device as uncalibrated based on the difference.

[0023] Other aspects, embodiments and advantages of these exemplary aspects and embodiments are discussed in detail below. In accordance with at least one principle disclosed herein, the embodiments disclosed herein may be combined with other embodiments in any manner, and references to "embodiments", "some embodiments", "alternative embodiments", "various embodiments", "one embodiment", etc. are not necessarily mutually exclusive and are intended to indicate that the specific features, structures or characteristics described may be included in at least one embodiment. The appearance of these terms here does not necessarily refer to the same embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various aspects of at least one embodiment are discussed below with reference to the accompanying drawings, which are not intended to be drawn to scale. The accompanying drawings are included to provide illustration and further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of the specification, but are not intended to be used as a definition of limitations of the present invention. In the accompanying drawings, each identical or nearly identical component shown in different figures is represented by the same number. For clarity, not every component may be labeled in every figure. In the drawings:

[0025] Figure 1 is a block diagram of a power meter monitor in communication with a plurality of power meters installed in a facility in accordance with aspects described herein;

[0026] Figure 2 is a block diagram of a hierarchy of connected power meters according to aspects described herein;

[0027] Figure 3is a flow chart for identifying metrology equipment requiring calibration according to various aspects described herein; and

[0028] Figure 4 is a block diagram of a system upon which various embodiments of the invention may be implemented. DETAILED DESCRIPTION

[0029] The examples of the methods and systems discussed herein are not limited in application to the details of the construction and arrangement of the components set forth in the following description or shown in the accompanying drawings. These methods and systems can be implemented in other embodiments and can be practiced or performed in various ways. The examples of specific implementations provided herein are merely for illustrative purposes and not for limitation. Specifically, the actions, components, elements, and features discussed in conjunction with any one or more examples are not intended to be excluded from similar roles in any other examples.

[0030] In addition, the wording and terminology used here are for the purpose of description and should not be considered as limiting. Any reference to the examples, embodiments, components, elements or actions of the system and method cited here in the singular may also cover embodiments including multiple embodiments, and any reference to any embodiment, component, element or action in the plural may also cover embodiments including only the singular. References in singular or plural form are not intended to limit the currently disclosed system or method, their components, actions or elements. "Including", "comprising", "having", "including", "involving" and its variants used here mean to include the items listed thereafter and their equivalents and additional items. References to "or" may be interpreted as inclusive, so that any term described using "or" may represent any of the single, more than one and all of the terms described. In addition, if the term usage between this document and the document incorporated herein by reference is inconsistent, the term usage in the incorporated reference document is a supplement to this document; for irreconcilable inconsistencies, the term usage in this document shall prevail.

[0031] The distribution network can be arranged in a hierarchical structure so that the grid feeds power to one or more distribution centers, each of which in turn distributes power to lower-level feeders. At any node in such a hierarchy, except for the lowest node, the amount of power at that node is ideally equivalent to the sum of all direct child nodes. For example, in an ideal situation, if 100 watts of power is measured at the grid, and two child nodes with loads are connected to the grid, it can be understood that a certain percentage of the 100 watts is consumed by the load at one child node, and the remaining percentage of the 100 watts is consumed by the load at the other child node.

[0032] In order to monitor the power usage at any node in this hierarchy, power meters are installed to report the measurements to another device over the network. Each power meter is calibrated to obtain accurate readings. The problem is that although the power meter is initially calibrated, over time, the power meter becomes uncalibrated (e.g., the accuracy drifts) to such an extent that the error between its measurement reading and the actual value is too large to be used. The user may not want to take the meter out of service for calibration. A solution is needed to determine the specific power meter that needs to be calibrated among the hierarchy of power meters. The embodiments described herein provide a self-verification system for monitoring the accuracy of the meter and provide warnings of the long-term drift characteristics of the meter point.

[0033] Figure 1 A power meter monitor 100 is shown, which communicates with each power meter 110 of a plurality of power meters 110 within a facility 102. One or more loads 111 (e.g., motors) are electrically coupled to each power meter 110. Therefore, the power measurement of one power meter 110 can be associated with more than one load 111, so that the power meter 110 is configured to monitor one or more loads 111. In some examples, each power meter 110 is connected in a hierarchical structure as described above. In order to obtain one or more power measurements from each power meter 110, a controller (not shown) is configured to receive the one or more power measurements and retain them for further processing. In some examples, the controller is located within the power meter monitor 100. In other examples, the controller is located within the facility 102. In order to communicate remotely with the power meter 110, in some examples, the controller is located outside both the power meter monitor 100 and the facility 102. Additional examples include that the controller is connected to meters in a plurality of facilities (e.g., facility 102). According to certain aspects, one or more power measurements from the power meter 110 are received at the controller directly from the power meter 110, or indirectly (e.g., through a gateway between the power meter 110 and the controller). In one embodiment, the front end or master meter receives or collects data from the power meter 110 downstream of the master meter, and the master meter provides the received or collected data to the controller.

[0034] Figure 2 A hierarchy of power meters, generally designated 200, is shown (e.g., similar to the hierarchy of power meters 110 described above). The hierarchy includes three levels, including a top level 202, a middle level 204, and a bottom level 206. The top level includes a top node A0, which includes a power meter that measures power of a power grid. Figure 2As shown, the top node A0 is the only node in the top level in the hierarchical structure 200. The second level 204 includes a plurality of nodes B0, B1, B2 and B3, each of which has a power meter. The bottom level 206 of the hierarchical structure includes nodes C0, C1, C2, C3, C4, C5 and C6, each of which has a power meter. In the bottom level 206 of the hierarchical structure 200, nodes C0 and C1 are both connected to B0, nodes C2 and C3 are connected to node B1, node C4 is coupled to B2, and nodes C5 and C6 are coupled to B3. It should be understood that the hierarchical structure 200 is one of many possible hierarchical structures of power meters, and other hierarchical structures can be expected, wherein there are different numbers of power meters located at each level and connected to each node. In addition, it should be understood that each of the nodes of the hierarchical structure 200 can have one or more loads (e.g., similar to load 111) electrically coupled to the node, so that the power meter at the node is configured to monitor one or more of the coupled loads.

[0035] In order to determine which meter among the multiple meters in the hierarchy 200 needs to be recalibrated, the dependency properties between the parent nodes and the child nodes in the hierarchy 200 are exploited to generate multiple calculations for the same power measurement at a given node. In one example, at a given moment, a power measurement is obtained from each node in the hierarchy 200. Although simply obtaining a power reading from the meter at node B0 is one way to determine the amount of power at node B0, relying on B0's own meter is prone to accuracy drift, resulting in unreliable readings. Additional calculations can be performed to more accurately determine the amount of power at B0 using other nodes directly connected to B0. Each ideal equivalent measurement value of B0 (e.g., A0-(B1+B2+B3)) is considered a virtual metering point or comparison value in the hierarchy 200, and can be used to verify the measurement accuracy of B0.

[0036] To study the hierarchy 200, each available node reading is obtained. Next, multiple comparison values ​​are calculated for each reading, thereby creating multiple virtual measurements of each node reading. For each comparison value, an error or difference is calculated with its corresponding node reading. Using the hierarchy 200 as an example, the first comparison value of B1 is: B1 comp1 =(A0–(B0+B2+B3)). The second comparison value is B1 comp2 =C2+C3. The first difference of B1 is: (B1 comp1 -B1) / (B1). The second comparison value of B1 is: (B1 comp2 -B1) / (B1). This process is repeated for each node in the hierarchical structure 200.

[0037] Figure 3A logic flow for identifying a metering device that needs recalibration, generally designated 300, is shown, including a plurality of actions of action 302, action 304, action 306, action 314, action 316, action 318, and action 322, and a plurality of conditions of condition 308, condition 310, condition 312, condition 314, and condition 320. According to certain aspects, each action and condition of the logic flow 300 is performed by one or more processors. The one or more processors can remotely implement the logic flow 300 by communicating with a hierarchy of power meters over a network.

[0038] Logic flow 300 begins with act 302, in which power measurements / readings are obtained for each available metering device / node in a hierarchy of power meters (e.g., similar to hierarchy 200). In some examples, each of these measurements is obtained simultaneously. In other examples, each measurement is obtained over a predetermined time period. Further, other examples include obtaining a time average of multiple measurements for each meter over a predetermined time period. In one example, these measurements are obtained when the hierarchy of power meters has reached a steady state or stable condition. It should be understood that each power measurement obtained in act 302 can be associated with more than one load, which is electrically coupled to the corresponding meter that provided the power measurement.

[0039] After each available power measurement is obtained in act 302, in act 304, multiple virtual measurements of a given power reading are performed for the metering devices in the hierarchy by generating multiple virtual metering points or comparison values ​​using different equations that are theoretically equivalent to each other in a perfect, error-free and lossless system.

[0040] In act 306, for a given metering device, the plurality of comparison values ​​are analyzed by calculating the error or difference between each comparison value and the corresponding power measurement. In one example, the reading of a given metering device is 100.0 Watts, the first comparison value of the metering device is 100.2 Watts, and the second comparison value of the metering device is 100.1 Watts. Thus, the error of the first comparison value is 0.2%, and the error of the second comparison value is 0.1%. This process is repeated for each virtual metering point.

[0041] To determine whether further analysis is required, in condition 308, each comparison value is checked to see if it is within the tolerance of the reading of the corresponding meter. In keeping with the above example, if the tolerance for the comparison value of a given metering device described in action 306 is specified to be within 0.3% of the reading of the meter, condition 308 will indicate "yes". One example of determining the tolerance includes analyzing the measurement uncertainty of the meters contributing to each virtual metering point of a given metering device (discussed in more detail below), where a larger measurement uncertainty indicates a larger tolerance and a smaller measurement uncertainty indicates a smaller tolerance. According to certain aspects, each level in the hierarchy has a different tolerance. In one example, the tolerance increases as the level moves away from the highest node. In another example, the tolerance for each node is based on the load(s) at that node.

[0042] Having determined that a meter device in the hierarchy may need calibration (i.e., condition 308 indicates "no"), in condition 310, the errors analyzed in action 306 are processed to determine whether a single candidate node in the hierarchy has an out-of-spec error (i.e., a positive or negative error) in the same direction for all virtual meter points that use the single node in their calculations. According to certain aspects of condition 308, all such virtual meter points that report a different value from the reading of the single node (as well as any other requirements) indicate "yes". Using Figure 2 As an example, and assuming that node B1 is potentially out of specification and requires calibration, the comparison values ​​for B1 using the nodes in the top level 202 and bottom level 206 connected to B1 are examined. In this example, B0 reads 50.25 watts, the first comparison value is 50 watts (e.g., A0 - (B0 + B2 + B3)), and the second comparison value is 49 watts (e.g., A0 - (C0 + C1 + C4 + C5 + C6)). The difference in the first comparison value is -0.50%, which is negative. The difference in the second comparison value is -2.49%, which is negative. Therefore, the comparison values ​​for B1 are in the same direction.

[0043] Before further analysis, measurement uncertainty needs to be considered. The above example shows that B1 has a difference in the same direction for all virtual meter points that are directly connected to the node that uses B1 in the calculation. The differences between the directly connected nodes and B1 are evaluated to see if these differences exceed the measurement uncertainty of each node. Measurement uncertainty is related to the specifications of the individual meters / nodes. In one example, for a given metering device, the specifications indicate an accuracy of ±.2% at 500 watts. Therefore, the metering device has an uncertainty of 1 watt or an uncertainty of 0.2%. If the metering device is the only node used in the comparison value calculation, the uncertainty value is calculated as described above. However, if a comparison value uses multiple meter readings, the value of each reading is considered. Using the hierarchy 200 as an example, nodes A0, B1, B2, and B3 have uncertainty values ​​of 0.1%, 0.2%, 0.2%, and 0.2%, respectively, and the comparison value of B0 is: A0–(B1+B2+B3). Therefore, the uncertainty value of the comparison value of B0 is: √((.001^2)+(.002^2)+(.002^2)+(.002^2))=.36% (i.e., add the squares of all uncertainties). If the maximum uncertainty value among all comparison values ​​of B0 is less than the minimum difference value, condition 310 indicates "yes". If no node meets the condition, condition 310 indicates "no". Any repeated uncertainty value or difference value is considered a single value for comparison purposes.

[0044] In condition 312, a node that successfully passes condition 310 is further evaluated. If the node is at the lowest level of the hierarchy (e.g., Figure 2 206 in level 206), then the logic process 300 proceeds to action 318 and the measurement is recorded for future use because there is no node below it to verify its measurement and potentially increase the likelihood that the node does need to be recalibrated. Figure 2 For example, since B1 is not at the lowest level, condition 312 will be "yes".

[0045] In condition 314, the nodes connected downstream of the given node that passed condition 312 (i.e., "No") are processed. Among these downstream nodes, specific patterns are sought. If the given node may need to be recalibrated, the virtual metering points of the downstream nodes that use the actual readings of the given node should show significant differences or errors. As an example, a possible comparison value of C2 from the hierarchical structure 200 is calculated as: B1-C3. If the comparison value is 0.00% or substantially close to 0.00%, condition 314 indicates "No" and the error is recorded for future use. In one example, the significant difference of the downstream node is at least as large (for positive errors) or as small (for negative errors) as the difference of the given node.

[0046] In action 316, the adjustment required to move the node processed in action 314 from its out-of-specification error to within an acceptable tolerance is calculated. The known error of the node is calculated by taking the difference between the reading of the node and the closest comparison value that takes into account the measurement uncertainty. In one example, the power of the node is 50.25 watts. The closest comparison value is 48 watts, which has a measurement uncertainty of ±.2%. From a visual perspective, the measurement uncertainty value provides an "error bar" around the measurement value. In this example, the value of the error bar to the right of the comparison value is 48.10 watts. Therefore, the known error is +2.15 watts or +4.28% of the node reading.

[0047] In action 318, the measured data and corresponding comparison value data of the node are recorded for further use. If the logic process 300 reaches condition 316, then in condition 320, the node is likely to need calibration, and in action 322, the known error calculated from action 316 is used to adjust the calibration constant of the node to improve its accuracy, and / or issue a calibration warning. The calibration constant (i.e., calibration factor) is the percentage of the full-scale response of a specific power meter. In some examples, for a specific meter, the calibration constant changes from about 80% to about 100%. If the logic process 300 determines in condition 320 that among one or more loads at a given node, the power meter that performs power measurement at the given node is fully out of specification, then adjust its calibration constant accordingly, to bring the power meter back to an acceptable range based on the known error in the power meter. In the embodiment here, it is expected that other parameters (e.g., voltage) other than power will be analyzed in the logic flow 300 to verify and maintain the accuracy of the metering device.

[0048] Qualify events include confidence determinations that calibration is required or strongly recommended. In some examples, the user does not want to recalibrate any meter before approving the change. Therefore, only a calibration warning is issued, while in other examples, calibration is automatically initiated. In the example of calibrating a node, the power calibration constant of the node is reduced or increased by a percentage of a known error. In one example, if the metering device is adjusted by +1.0%, the 100 watt reading will then be adjusted according to: (calibration constant) * (node ​​reading), in which case the node reading of 1*100 watts is adjusted to 1.01*100 watts, i.e. 101 watts. In some embodiments, condition 320 determines whether the same node has reached action 316 a predetermined number of times before indicating "yes", thereby increasing the confidence or probability of the calibration decision.

[0049] In some embodiments, a particular gain stage in the metering device being analyzed is determined to require calibration. According to certain aspects, after sufficient data or multiple measurement points are recorded for the metering device / node during a time interval, and assuming that the average power consumed at the node is constant for the time interval, the number and type of voltage gain stages and current gain stages in the metering device are determined. In one example, the metering device has a switch point in its gain stages at 5 amps. If the recorded data indicates that the metering device needs to be recalibrated, and the current conducted by the metering device during the interval is greater than 5 amps, the higher current gain stage is calibrated, thereby avoiding calibration of other gain stages that do not need calibration.

[0050] To increase the likelihood or confidence of deciding in condition 320 that the meter is to be calibrated, some embodiments include obtaining voltage, current, and / or power factor measurements in addition to the power measurements in action 302, and then recording or logging these measurements in action 318. In one example, a qualifying event includes determining in condition 310 that the meter has a disqualifying error, and additionally determining that the meter has had a stable voltage measurement over a period of time or several samples. In one example, a stable voltage measurement includes a plurality of voltage measurements from the meter that are within tolerance. In one example, a stable voltage measurement is indicated by a plurality of voltage measurements, wherein the plurality of voltage measurements deviate from an average value of the voltage measurements of the meter by less than 1% of the average value. The average value is calculated over the period of time, several samples, or different ranges of values.

[0051] According to certain aspects, condition 320 includes determining whether a predetermined period of time (or a predetermined number of samples) without meter measurements has occurred for a given meter. In one example, the predetermined period of time is a planned interruption of metering. In one example, the planned interruption is a firmware upgrade. In another example, the lack of meter measurements within the predetermined period of time is caused by a power outage affecting the given meter. In response to determining that no meter measurements were obtained for the given meter within the predetermined period of time, or that less than a predetermined number of meter measurements were obtained, an average of the most recent virtual measurements for the given meter is calculated to record the measurement data when the given meter was offline, thereby replacing the missing data. In one example, the time period between the most recent measurement until the point in time when the given meter was offline includes a time length at least the same as the predetermined period of time.

[0052] Figure 4An example block diagram of computing components forming a system 400 is shown, which can be configured to implement one or more aspects disclosed herein. For example, the system 400 can be communicatively coupled to a controller (e.g., similar to the controller described above) or included within a controller. The system 400 can also be configured to operate a power meter monitor (e.g., similar to the power meter monitor 100) and / or implement the logic flow 300 as processor executable instructions. In some embodiments, the logic flow process 300 is fully automated.

[0053] System 400 may include, for example, a computing platform such as a computing platform based on an Intel Pentium processor, a Motorola PowerPC, a SUN UltraSPARC, a Texas Instruments DSP, a HP PA-RISC processor, or any other type of processor. System 400 may include specially programmed dedicated hardware, such as an application specific integrated circuit (ASIC). System 400 may also include a field programmable gate array (FPGA). Various aspects of the present disclosure may be implemented in a processor such as a processor. Figure 4 Dedicated software executing on the system 400 is shown.

[0054] The system 400 may include a processor / ASIC 406 connected to one or more memory devices 410, such as a disk drive, memory, flash memory, or other device for storing data. The memory 410 may be used to store programs and data during the operation of the system 400. The components of the computer system 400 may be coupled by an interconnection mechanism 408, which may include one or more buses (e.g., between components integrated in the same machine) and / or networks (e.g., between components residing on different machines). The interconnection mechanism 408 enables communications (e.g., data, instructions) to be exchanged between the components of the system 400. The system 400 also includes one or more input devices 404, which may include, for example, a keyboard or a touch screen. The system 400 includes one or more output devices 402, which may include, for example, a display. In addition, as a supplement to the interconnection mechanism 408 or as a substitute for the interconnection mechanism 408, the computer system 400 may include one or more interfaces (not shown) that may connect the computer system 400 to a communication network.

[0055] The system 400 may include a storage device system 412, which may include a non-transitory computer-readable medium in which a signal may be stored to provide a program to be executed by a processor, or to provide information stored on or in the medium to be processed by a program. The non-transitory computer-readable medium may be, for example, a disk or flash memory, and in some examples may include RAM or other non-volatile memory, such as EEPROM. In some embodiments, the processor may read data from the non-volatile medium into another memory 410, which allows the processor / ASIC to access information faster than the medium. The memory 410 may be a volatile random access memory, such as a dynamic random access memory (DRAM) or a static memory (SRAM). It may be located in the storage device system 412 or the memory system 410. The processor 406 may manipulate the data within the integrated circuit memory 410 and then copy the data to the storage device 412 after the processing is completed. A variety of mechanisms are known for managing data movement between the storage device 412 and the integrated circuit memory element 410, and the present disclosure is not limited thereto. The present disclosure is not limited to a specific memory system 410 or storage device system 412.

[0056] System 400 may include a computer platform that can be programmed using a high-level computer programming language. System 400 may also be implemented using specially programmed dedicated hardware (e.g., ASIC). System 400 may include processor 406, which may be a commercially available processor, such as the well-known Pentium class processor obtained from Intel Corporation. Many other processors are also available. Processor 406 may execute an operating system, which may be, for example, a Windows operating system available from Microsoft Corporation, a MAC OS system X available from Apple Computer, a Solaris operating system available from SUN Microsystems, or UNIX and / or LINUX available from various sources. Many other operating systems may be used.

[0057] The processor and the operating system together can form a computer platform for which applications in high-level programming languages ​​can be written. It should be understood that the present disclosure is not limited to a specific computer system platform, processor, operating system, or network. In addition, it is apparent to those skilled in the art that the present disclosure is not limited to a specific programming language or computer system. In addition, it should be understood that other suitable programming languages ​​and other suitable computer systems may also be used.

[0058] Current power meters used in hierarchical configurations may require regular calibration, especially lower cost meters. There is an increasing need to rely on measurement data from low cost meters to allocate electricity costs to groups of loads or individual loads. In many cases, frequent calibrations are used to ensure valid measurements. If the meter is operating within specifications, these frequent calibrations may be unnecessary in many cases, and they may cause the meter to shut down. This is a technical problem. In at least one embodiment described herein, the metering control system includes an improvement to an existing system and is intended to solve the technical problem by reducing the number of calibrations required and at the same time improving the overall accuracy of the metering control system. This technical solution is not conventional or customary. The technical solution is a practical application of a power meter, which solves the aforementioned technical problems and constitutes an improvement in the technical field.

[0059] At least one embodiment described herein provides additional advantages. By effectively identifying meters that need recalibration, a self-checking metering system is provided that stores and tracks calibration events over time, providing data for advanced analysis of hierarchical power systems. Such data is useful for supplementing and enhancing other power monitoring systems.

[0060] Thus, having described several aspects of at least one embodiment of the present invention, it will be appreciated that various changes, modifications and improvements will readily occur to those skilled in the art. Such changes, modifications and improvements are intended to be a part of this disclosure and are intended to fall within the spirit and scope of the present invention. Therefore, the foregoing description and accompanying drawings are intended only as examples.

Claims

1. A method for identifying an uncalibrated meter, comprising the following actions: obtaining a power measurement value for each metering device of a plurality of metering devices arranged in a hierarchy, the hierarchy comprising a plurality of levels, wherein at least one metering device of the plurality of metering devices is in each level of the plurality of levels; selecting a candidate metrology device from one of the plurality of classes of the plurality of metrology devices; calculating a plurality of comparison values ​​for the candidate metering device based on power measurement values ​​of at least two metering devices of the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level than the candidate metering device in the hierarchy, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices of the plurality of metering devices; calculating a difference between a power measurement value of the candidate metering device and a first comparison value of the plurality of comparison values; as well as The candidate metering device is identified as uncalibrated based on the difference by: calculating additional differences between the power measurement value of the candidate metering device and additional comparison values ​​of the plurality of comparison values, determining whether the difference and the additional difference are positive or negative; and in response to determining that the difference and the additional difference are both positive or both negative, identifying that the candidate metering device is uncalibrated with an increased likelihood, wherein the additional comparison value is a comparison value other than the first comparison value of the plurality of comparison values.

2. The method according to claim 1, further comprising: The comparison value is calculated by summing power measurement values ​​of at least two metering devices among the plurality of metering devices.

3. The method according to claim 1, further comprising: In response to determining that the difference is within a tolerance, a new power measurement value is obtained for each metering device in the plurality of metering devices in the hierarchy.

4. The method of claim 1 , wherein identifying the candidate metrology device as uncalibrated based on the calculated difference comprises: calculating an uncertainty value of the candidate metrology device based on an accuracy value of the candidate metrology device and a power measurement value of the candidate metrology device; as well as An uncertainty value for the comparison value is calculated.

5. The method according to claim 4, wherein: The uncertainty value for calculating the comparison value includes: The sum of squares of a plurality of uncertainty values ​​is calculated, wherein the plurality of uncertainty values ​​are uncertainty values ​​of a metrological device used to calculate the comparison value.

6. The method according to claim 4, further comprising: calculating a plurality of difference values ​​including the difference value; calculating a plurality of uncertainty values ​​including the uncertainty value of the comparison value; Wherein identifying the candidate metrology device as uncalibrated based on the difference comprises: determining whether a minimum difference value among the plurality of difference values ​​exceeds a maximum uncertainty value among the plurality of uncertainty values; as well as Based on the determination, an adjustment to a calibration constant of the candidate metrology device is calculated.

7. The method according to claim 6, further comprising: In response to identifying the candidate metrology device as uncalibrated, a calibration constant of the candidate metrology device is adjusted.

8. The method according to claim 1, further comprising: In response to identifying the candidate metrology device as uncalibrated, a calibration warning is issued.

9. A system for identifying an uncalibrated meter, comprising: a plurality of metering devices arranged in a hierarchy, the hierarchy comprising a plurality of levels, wherein at least one metering device of the plurality of metering devices is in each of the plurality of levels; as well as The controller is configured as: obtaining a power measurement value for each metering device in the plurality of metering devices; selecting a candidate metrology device from one of the plurality of classes of the plurality of metrology devices; calculating a plurality of comparison values ​​for the candidate metering device based on power measurement values ​​of at least two metering devices of the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level than the candidate metering device in the hierarchy, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices of the plurality of metering devices; calculating a difference between a power measurement value of the candidate metering device and a first comparison value of the plurality of comparison values; as well as The candidate metering device is identified as uncalibrated based on the difference by: calculating additional differences between the power measurement value of the candidate metering device and additional comparison values ​​of the plurality of comparison values, determining whether the difference and the additional difference are positive or negative; and in response to determining that the difference and the additional difference are both positive or both negative, identifying that the candidate metering device is uncalibrated with an increased likelihood, wherein the additional comparison value is a comparison value other than the first comparison value of the plurality of comparison values.

10. The system of claim 9, wherein the controller is further configured to: The comparison value is calculated by summing power measurement values ​​of at least two metering devices among the plurality of metering devices.

11. The system of claim 9, wherein the controller is further configured to: In response to determining that the difference is within a tolerance, a new power measurement value is obtained for each metering device in the plurality of metering devices in the hierarchy.

12. The system of claim 9, wherein the controller is further configured to: calculating an uncertainty value of the candidate metrology device based on the accuracy value of the candidate metrology device and the power measurement value of the candidate metrology device; and An uncertainty value for the comparison value is calculated.

13. The system according to claim 12, wherein: The uncertainty value for calculating the comparison value includes: The sum of squares of a plurality of uncertainty values ​​is calculated, wherein the plurality of uncertainty values ​​are uncertainty values ​​of a metrological device used to calculate the comparison value.

14. The system of claim 12, wherein the controller is further configured to: calculating a plurality of difference values ​​including the difference value; calculating a plurality of uncertainty values ​​including the uncertainty value of the comparison value; determining whether a minimum difference value among the plurality of difference values ​​exceeds a maximum uncertainty value among the plurality of uncertainty values; as well as Based on the determination, an adjustment to a calibration constant of the candidate metrology device is calculated.

15. The system of claim 14, wherein the controller is further configured to: In response to identifying the candidate metrology device as uncalibrated, adjusting a calibration constant of the candidate metrology device; or In response to identifying the candidate metrology device as uncalibrated, a calibration warning is issued.

16. A non-transitory computer readable medium storing a sequence of instructions executable by at least one processor, the sequence of instructions instructing the at least one processor to perform a process of identifying an uncalibrated gauge, the sequence of instructions causing the at least one processor to perform operations comprising: obtaining a power measurement value for each metering device of a plurality of metering devices arranged in a hierarchy, the hierarchy comprising a plurality of levels, wherein at least one metering device of the plurality of metering devices is in each level of the plurality of levels; selecting a candidate metrology device from one of the plurality of classes of the plurality of metrology devices; calculating a plurality of comparison values ​​for the candidate metering device based on power measurement values ​​of at least two metering devices of the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level than the candidate metering device in the hierarchy, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices of the plurality of metering devices; calculating a difference between a power measurement value of the candidate metering device and a first comparison value of the plurality of comparison values; as well as The candidate metering device is identified as uncalibrated based on the difference by: calculating additional differences between the power measurement value of the candidate metering device and additional comparison values ​​of the plurality of comparison values, determining whether the difference and the additional difference are positive or negative; and in response to determining that the difference and the additional difference are both positive or both negative, identifying that the candidate metering device is uncalibrated with an increased likelihood, wherein the additional comparison value is a comparison value other than the first comparison value of the plurality of comparison values.

17. A method of identifying an uncalibrated meter, comprising the following actions: obtaining a power measurement value for each metering device of a plurality of metering devices arranged in a hierarchy, the hierarchy comprising a plurality of levels, wherein at least one metering device of the plurality of metering devices is in each level of the plurality of levels; selecting a candidate metrology device from one of the plurality of classes of the plurality of metrology devices; calculating a plurality of comparison values ​​for the candidate metering device based on power measurement values ​​of at least two metering devices of the plurality of metering devices excluding the candidate metering device, wherein at least one metering device of the at least two metering devices is located in a different level than the candidate metering device in the hierarchy, and the plurality of comparison values ​​are calculated based on at least two different sets of one or more metering devices of the plurality of metering devices; calculating a difference between a power measurement value of the candidate metering device and a first comparison value of the plurality of comparison values; as well as The candidate metrology device is identified as uncalibrated based on the difference value by: calculating an uncertainty value for the candidate metrology device based on an accuracy value for the candidate metrology device and a power measurement value for the candidate metrology device; and calculating the uncertainty value of the comparison value, wherein calculating the uncertainty value of the comparison value comprises: calculating the sum of squares of a plurality of uncertainty values, wherein the plurality of uncertainty values ​​are uncertainty values ​​of a metrological device used to calculate the comparison value, and the method further comprises: calculating a plurality of difference values ​​including the difference value; calculating a plurality of uncertainty values ​​including the uncertainty value of the comparison value; Wherein identifying the candidate metrology device as uncalibrated based on the difference comprises: determining whether a minimum difference value among the plurality of difference values ​​exceeds a maximum uncertainty value among the plurality of uncertainty values; and Based on the determination, an adjustment to a calibration constant of the candidate metrology device is calculated.

18. The method according to claim 17, further comprising: In response to identifying the candidate metrology device as uncalibrated, a calibration constant of the candidate metrology device is adjusted.

19. The method according to claim 17, further comprising: In response to identifying the candidate metrology device as uncalibrated, a calibration warning is issued.

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