Electricity meter and method for cold load start-up management

Abstract

Systems and methods for managing connections of cold loads to an electrical distribution network are disclosed. A disclosed system for managing a connection of a cold load to a power distribution network includes an electricity meter configured to detect a power recovery after a power failure and, in response to detecting the power recovery after the power failure, restart operation and enter a service restriction mode. The electricity meter remains in a service restriction mode for a predetermined period of time. When in the service restriction mode, the electricity meter accumulates power and compares the accumulated power to a threshold to determine whether to control the service switch to connect or disconnect the one or more loads from the distribution network. After another predetermined period of time, the electricity meter may reconnect the one or more loads to the distribution network and return to normal operation.

Description

Technical Field

[0001] The present disclosure generally relates to management of connection of loads to a power distribution network following a power outage. Background Art

[0002] The distribution network consists of many interconnected devices over a large geographic area. The interconnected devices are typically used to monitor and distribute power to customer premises and may include power assets such as transformers, protection devices (such as switches), line sections, and meters associated with customer premises.

[0003] Distribution networks are typically optimized to handle nominal or typical steady loads. Therefore, distribution networks may be susceptible to sudden atypical increases in demand. Sudden increases in demand may stress or damage equipment on the distribution network, which may result in a power outage. In the event that a power outage is widespread and occurs over an extended period of time, restarting the distribution network risks stressing equipment on the distribution network due to cold load pick-ups. Cold load pick-ups occur when a load that has lost power (e.g., a cold load) is reconnected to the distribution network. The connection of a cold load to the distribution network causes an influx of current. Surge currents may damage power assets and other equipment on the distribution network. Sudden demands from large loads such as electric heating, electric water heaters, etc. may overburden the distribution network and result in further power outages. Therefore, a management system is needed to control the connection of loads to the distribution network. Summary of the invention

[0004] The present disclosure includes an electric meter that can be connected to a power distribution network. The electric meter includes a meter for measuring power from the power distribution network, a processing unit for determining whether a power outage has occurred and whether power has been restored, and an optional communication module for communicating with a central system. In some embodiments, the electric meter may also include one or more service switches, a controller, and a memory that can store operating parameters of the electric meter.

[0005] In one example of a method for operating an electric meter, in response to detecting restoration of power following a power outage, the electric meter resumes operation and enters a service limit mode. The electric meter remains in the service limit mode for a predetermined period of time. While in the service limit mode, the electric meter monitors power from the distribution network to the premises through the electric meter and accumulates the power during a service limit demand period. The accumulated power for the service limit demand period is compared to a service limit threshold, and when the accumulated power for the service limit demand period is within the service limit threshold, the electric meter controls the service switch so that the premises remains connected to the distribution network. While in the service limit mode, the electric meter may also determine an amount of time that has elapsed since entering the service limit mode, and when the amount of time that has elapsed since entering the service limit mode meets or exceeds a predetermined amount of time, the electric meter exits the service limit mode and enters a normal operating mode.

[0006] In other examples, when the cumulative power of the service limit demand period exceeds the service limit threshold, the meter controls the service switch to disconnect the premises from the distribution network.Then, the meter may wait for a second predetermined period of time before controlling the service switch to connect the premises to the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] These and other features, aspects and advantages of the present disclosure may be better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0008] Figure 1 is a flow chart illustrating an exemplary method of operation of an electric meter in a service restriction mode.

[0009] Figure 2 is a flow chart illustrating an exemplary method of operation of an electric meter transitioning between a service restriction mode and a normal operating mode.

[0010] Figure 3 is a block diagram illustrating components of an exemplary electricity meter.

[0011] Figure 4 is a block diagram illustrating a portion of an exemplary power distribution network.

[0012] Figure 5 is a block diagram illustrating an exemplary communication network for a power distribution network. DETAILED DESCRIPTION

[0013] Aspects of the present disclosure relate to a system for managing the connection of a house to an electrical distribution network after experiencing a power outage event. A house may include multiple loads. When a house is disconnected from the electrical distribution network, the load associated with the house may become a cold load. A cold load is a load that has lost power for a period of time long enough to cause the load to reach a power outage or low power state. Reconnecting a house with a cold load may cause the house to experience a cold load startup problem. When initially connected to the electrical distribution network, the power demand of the cold load is typically higher. In the instance of a power outage event, where individual houses may have lost power for a period of time long enough to have a cold load, the connection of the house to the electrical distribution network may result in a higher demand than the electrical distribution network is typically configured to provide, which may cause stress or damage to the electrical distribution network, thereby causing further power outages.

[0014] Cold load start management is the ability of a utility provider to manage the sudden demand placed on the distribution network as a result of a property with a cold load receiving power. The meter can be used to manage cold load starts at a property by limiting service to the property so that the demand does not exceed the capacity of the distribution network. Once power is restored, the meter can assist in cold load start management by limiting demand. In some examples, the meter can manage demand by controlling the on / off state of a service switch so that the meter can connect and disconnect the property associated with the meter from the distribution network when the distribution network restores power after an outage.

[0015] When the meter detects that power is restored after a power outage, the meter determines whether the length of the outage is likely to be sufficient to cause the property to have a cooling load. In the event that the outage is momentary, the property may not have a cooling load and the meter may resume normal metering operation, however when the outage is long enough to cause the property to have a cooling load, the meter may enter a service limiting mode. Service limiting mode is an operating mode of the meter in which the meter manages power to the property.

[0016] The meter may rely on parameters of the meter, such as timer values ​​and thresholds, to determine whether to connect or disconnect the premises from the distribution network. For example, when the service limit mode is enabled, the meter may start a cold load start timer. While the cold load start timer is running, the meter may accumulate demand at the premises and compare the demand to a threshold, such as a service limit threshold. The service limit threshold may be a preset threshold that represents the amount of electricity allocated by the utility provider for use at the premises when the meter is in the service limit mode.

[0017] When the demand at the premises is less than the threshold, the service switch may remain closed. If the demand at the premises exceeds the service limit threshold, the meter may open the service switch to disconnect the premises from the distribution network for a predetermined amount of time. After the predetermined amount of time has passed, the meter closes the service switch to reconnect the premises to the distribution network. Once the cold load start delay timer expires, the meter may transition from the service limit mode to the normal operation mode, in which the meter resumes normal metering operation.

[0018] The timers and thresholds may vary between meters. The parameters of the meter may be based on the location of the meter in the distribution network, the type of premises or loads at the premises, account options associated with the premises, etc. These values ​​may be preset at the meter by the utility provider or a central system. A further description of the parameters and operation of the meter is discussed below.

[0019] Exemplary Operation Methods

[0020] Figure 1 and Figure 2 is a flow chart showing an illustrative method for operation of an electric meter. In some examples, Figure 1 and Figure 2 Some steps in the flowchart of are implemented as program codes executed by a processor of the electric meter. In some examples, Figure 1 and Figure 2 The steps shown in may be performed in a different order, or one or more steps may be skipped. Alternatively, in some examples, the steps may be performed Figure 1 and Figure 2 Additional steps not shown.

[0021] Figure 1 and Figure 2 It is shown that the electric meter monitors the electric power consumed from the electric distribution network, and determines to connect or disconnect the house to the electric distribution network based on the monitored electric power information.

[0022] Exemplary method of operating an electric meter in a service restriction mode

[0023] Figure 1 1 is a flow chart illustrating an exemplary method 100 of operating an electric meter that controls the connection of a load to an electric distribution network. The method begins at step 102, where the electric meter detects restoration of power after a power outage. In response to detecting restoration of power after a power outage, the electric meter resumes operation and enters a service restriction mode for a predetermined period of time (step 104).

[0024] Service limit mode is an operating mode in which the meter can allow the amount of electricity distributed to one or more loads at the premises. When the prescribed amount of electricity is exceeded, the meter can disconnect the premises from the distribution network.

[0025] The meter monitors power from the distribution network to the premises through the meter (step 106), and accumulates the power during a service limit demand period (step 108). The service limit demand period is a predetermined time period in which the meter determines whether the demand of the load exceeds a service limit threshold. The service limit threshold is a preset value set at the meter by the utility provider that represents the allocated amount of power from the distribution network that can be used at the premises.

[0026] In step 110, the electric meter compares the cumulative power of the service limit demand period with the service limit threshold. Based on the comparison of the cumulative power with the service limit threshold, the electric meter controls the service switch of the electric meter so that the premises remains connected to the distribution network when the cumulative power or the service limit demand period is within the service limit threshold (step 112).

[0027] The electric meter determines an amount of time that has elapsed since entering the service restriction mode (step 114 ), and exits the service restriction mode when the amount of time that has elapsed meets or exceeds a predetermined amount of time (step 116 ).

[0028] After exiting the service limit mode, the electric meter may enter a normal operation mode (step 118). While in the normal operation mode, the electric meter does not control the service switch based on the service limit threshold.

[0029] Exemplary method of operating an electric meter when power is restored

[0030] Figure 2 is a flow chart illustrating an exemplary method 200 of operation of an electric meter that connects and disconnects a premises from an electric distribution network.

[0031] The method begins at step 202 when the electric meter detects an outage event. The electric meter may be configured to measure power associated with the power distribution network, and when the electric meter detects the absence of power or the power drops below a predetermined power threshold for an amount of time greater than an outage identification time, the electric meter may determine that the power distribution network is experiencing an outage event (step 204). The outage identification time is a predetermined time period that may be set by a utility provider.

[0032] When the electric meter determines that the power outage event has not lasted longer than the power outage identification time, the method continues to step 218, where the electric meter operates in a normal operating mode. When in the normal operating mode, the electric meter performs normal metering operations.

[0033] When the electric meter determines that a power outage event has occurred and lasts longer than the power outage identification time, the method proceeds from step 204 to step 206, where the electric meter records the power outage event. The electric meter can record the power outage event in a memory at the electric meter, or can send a record of the power outage event to an edge computing device or a central system.

[0034] When power is restored (step 207), the meter determines whether the outage event lasted for an amount of time greater than a cold load start delay trigger (step 208). The cold load start delay trigger is a predetermined time period set at the meter to determine whether the outage event lasted for a long enough period of time to cause the premises to have a cooling load.

[0035] When the outage event does not persist for a period greater than the cold load start delay trigger, the meter resumes normal metering operation (step 218). When the outage event persists for a period greater than the cold load start delay trigger, the meter enters a service limitation mode (step 210). The service limitation mode is an operating mode of the meter in which the meter manages the power demand of the premises on the distribution network. The meter can manage power demand by connecting or disconnecting the premises.

[0036] When entering the service limited mode, the meter starts the cold load start delay timer (step 212). The cold load start delay timer is a timer that specifies how long the meter will remain in the service limited mode.

[0037] The meter determines whether the cold load start delay timer has expired (step 214). When the meter determines that the cold load start delay timer has expired, the meter disables the service restriction mode (step 216) and transitions to the normal operation mode, wherein the meter resumes normal metering operation (step 218).

[0038] When the meter determines that the cold load start timer has not expired, the meter starts the service limit command timer (step 220). While the service limit demand timer is running, the meter may accumulate the demand of the load associated with the meter (step 222). When the service limit demand timer expires, the meter determines whether the demand for electricity from the load during the service limit demand period exceeds the service limit threshold (step 226). The service limit threshold is a preset value set at the meter that represents the amount of allocated electricity that can be used by the premises during the service limit demand period. When the demand of the load does not exceed the service limit threshold, the meter proceeds to step 214.

[0039] When the demand of the load exceeds the service limit threshold, the meter opens the service switch (step 228). The service switch is a switch configured to connect or disconnect the premises to the distribution network. The service switch may be located at the meter. Once the service switch is opened (step 228), the meter starts an open switch timer (step 230). The open switch timer tracks the amount of time the service switch has been open (step 232). When the open switch timer expires, the meter closes the service switch (step 234) and returns to step 214.

[0040] In some examples, the meter may receive a restart command while in service restricted mode. Upon receiving the restart command, the meter resumes normal metering operation. If the service switch is open when the restart command is received, the meter turns off the service switch. The restart command may be a command received from an input at the meter, such as by pressing a button, pulling a lever, or adjusting a switch. The restart command may also be a command sent by an edge computing device or a central system.

[0041] Example Electricity Meter

[0042] The above description shows that the electric meter performs various functions, including metering function, processing function and communication function. In some embodiments, these functions can be performed by different components. Figure 3 An electric meter 300 is depicted, which includes two service switches 302, a metering component 304, a processing unit 306, parameters 308, a controller 310, and an optional communication module 312. The electric meter 300 is connected to a premises 314, which may include one or more loads (not shown). The electric meter can be configured to connect to single-phase power or multi-phase power. Figure 3 In the case of a two-phase meter, there is a service switch for each phase.

[0043] One or more service switches 302 are configured to connect and disconnect the premises to an electricity distribution network (not shown). The service switch 302 may also be connected to a controller 310 and a metering component 304. In some examples, the service switch 302 is controlled by the controller 310, which may send a control signal configured to adjust the on and off state of the service switch 302.

[0044] In other examples, the electric meter may control one or more load control switches instead of the service switch during the service restriction mode.The load switches may be located external to the electric meter and may be associated with one or more loads.

[0045] The metering component 304 can measure the voltage, current, power, or other characteristics of the distribution network. The processing unit 306 can process the measurements made by the metering component 304 to determine whether a power outage event has occurred. The processing unit 306 (e.g., a processor or other processing device) can also include preset parameters 308. The parameters 308 can be stored in a memory located at the processing unit 306, or stored in a memory at another location at the meter 300. In some examples, the parameters 308 are set and / or modified by a central system such as a head-end system. The parameters 308 can also be preset at the time of manufacture or installation, or set or modified during configuration of the meter 300. The parameters 308 can include values ​​related to timers or thresholds, such as Figure 1 and Figure 2For example, the parameters may include the outage identification time, the cold load start delay trigger, the service limit demand period, and the value of the service limit threshold.

[0046] When the electric meter 300 is in the normal operating mode, the optional communication module 312 can receive information, instructions, and messages from the central system to adjust the parameters 308. For example, when the electric meter is in the normal operating mode, the central system can send information to the optional communication module 312 to adjust the parameters 308. The optional communication module 312 can also send parameter 308 information (e.g., measurements and parameters 308 of the electric meter 300) to the central system, which can store the parameter 308 information in a database or other data management system. In other examples, a field service technician can adjust the parameters 308 of the electric meter 300 in the field. In other examples, the service limit mode parameters 308 of the electric meter 300 can vary based on the location of the electric meter 300 in the distribution network.

[0047] The electric meter may also include additional components. For example, the memory may be a separate component or may be included in one or more of the metering component 304, the processing unit 306, the controller 310, or the communication module 312. The processor or processing unit 306 may be included in any component. The processor may execute computer-readable instructions to configure the processor to perform the functions of the electric meter, including the metering functions, processing functions, and communication functions described herein. The instructions may be stored in a computer-readable medium.

[0048] Exemplary Implementation in Power Distribution Networks

[0049] Figure 4 465 represents an exemplary power distribution network. The power distribution network includes a generator 410 , which may be a power generation facility or a generator at a power generation facility. The generator 410 may generate 3-phase alternating current (AC) power and transmit the power to a substation 420 via a transmission line 465 .

[0050] Substation 420 includes transformer 430 to reduce the voltage for consumption by customers. The reduced voltage electricity is transmitted by transmission lines 440a, 440b and 440c to transformers 450 and 455, which further reduce the voltage for consumption by customers.

[0051] Transformers 450 and 455 may deliver single-phase or multi-phase power to customer premises through meters 460 and 462. The meters may monitor characteristics such as current, voltage, and power, and may be multi-phase meters. Additionally, other power assets besides those depicted may also be included in the distribution network.

[0052] The electric meters 460 and 462 can operate differently in the service limit mode based on their location on the distribution network. For example, one or more values ​​of the cold load start delay trigger, the cold load start delay timer, the service limit demand timer, and the service limit threshold can vary based on the location of the electric meters 460, 462 within the distribution network or the premises associated with the electric meters 460, 462.

[0053] In some embodiments, the electric meter 460, 462 can be configured to have a cold load start delay timer or an open switch timer, which is a shorter amount of time compared to the electric meter 460, 462 at other locations. By shortening the cold load start delay timer, the electric meter 460, 462 can remain in the service restriction mode for a shorter period of time, thereby allowing the electric meter 460, 462 to return to the normal operation mode to resume normal operation faster than other electric meters 460, 462. In some embodiments, this can allow some houses to be prioritized over other houses. For example, a hospital or other critical infrastructure can have an electric meter 460, 462 that has a shorter cold load start delay timer that will allow the hospital to return to normal metering operation faster than a residence. In other examples, the cold load start delay timer can vary based on the location of the electric meter 460, 462 on the distribution network or relative to other power assets within the distribution network. For example, due to the distance of the electric meters 460 , 462 from the generator 410 , the electric meters 460 , 462 may have different cold load start delay timer values.

[0054] Exemplary Communication Network

[0055] The central system 504 can be Figure 5 The communication network shown is in communication with an electric meter 560 . Figure 5 It is a wireless mesh network 540 that allows meters 560 to communicate with other meters 560 and the central system 504. Meters 560 can send information to other meters 560 to reach their respective root nodes 554. Meters 560 can communicate with each other through various wireless and wired communication technologies, including: RF, WiSUN, satellite, 3g, 4g, UHB, WiFi and other communication technologies.

[0056] The root node can be a personal area network coordinator, a gateway, a border router, or other device capable of communicating with the central system 504 and other devices on the mesh network. In addition, the root node 564 can forward the information 522 to the central system 504 through the network 550.

[0057] The information sent over the communication network may include parameters of the meter 560, such as threshold and timer information. In some embodiments, the central system 504 may send information to the meter 560 to update the parameters of the meter 560. In other examples, the central system 504 may also query the information from the meter 560.

[0058] Additional Examples

[0059] In some examples of electric meters, parameters of the electric meters, such as timers and thresholds, may vary between electric meters based on a priority system set by a utility provider. For example, based on a customer at the first premises paying for an enhanced level of service, a service limit threshold at a first premises may be set to a higher value than a service limit threshold at a second premises.

[0060] In other examples, the meter may send information to the central system when entering the normal operating mode from the service limit mode. While in the normal operating mode, the meter may send information to the central system, such as information collected during the time the meter was operating in the service limit mode. The information may include whether a service limit threshold was exceeded, the amount of power accumulated during the service limit mode, or the number of times the service limit threshold was exceeded during a single service limit demand period. The information may be received by the central system and recorded in a database.

[0061] In another example, the electric meter can be configured to communicate with individual loads. In order to reduce the demand of the premises so that the demand is within the service limit threshold, in addition to controlling the service switch of the electric meter, the electric meter can also communicate with individual loads at the premises to power off or operate in a low power mode.

[0062] Although the subject matter has been described in detail with respect to specific aspects of the subject matter, it should be understood that those skilled in the art, after obtaining an understanding of the foregoing, can easily generate substitutions, changes and equivalents to these aspects. Therefore, it should be understood that the present disclosure has been presented for the purpose of illustration and not limitation, and does not exclude the inclusion of such modifications, changes and / or additions to the subject matter, which are obvious to those of ordinary skill in the art.

Claims

1. A method for operating an electric meter, comprising: Detecting power restoration after a power outage; in response to detecting restoration of power following said power outage, restarting operation and entering a service limited mode for a predetermined amount of time; When in the described service restriction mode: monitoring electricity from the distribution network to the premises via said electricity meter; accumulating said electricity during a service limited demand period; comparing the accumulated power during the service limit demand period to a service limit threshold; When the accumulated power in the service limit demand period is within the service limit threshold, controlling the service switch of the electric meter so that the house remains connected to the power distribution network; determining an amount of time that has elapsed since entering said service restriction mode; as well as exiting the service restriction mode when the amount of time that has elapsed since entering the service restriction mode meets or exceeds the predetermined amount of time; and Enter normal operating mode.

2. The method according to claim 1, comprising: When in the service limit mode, the service switch is controlled to disconnect the premises from the power distribution network when the cumulative power during the service limit demand period exceeds the service limit threshold.

3. The method according to claim 1, further comprising: detecting the power outage; in response to detecting the power outage, controlling the service switch to disconnect the premises from the power distribution network; as well as In response to detecting restoration of power following the power outage, the service switch is maintained in an open state until a second predetermined time period expires or a restart command is received.

4. The method according to claim 2, comprising: receiving a restart command via a wireless network; as well as The service switch is controlled to connect the premises to the power distribution network.

5. The method according to claim 1, wherein: The predetermined amount of time for the service restriction mode is based on one or more of: a location of the electric meter within the electric distribution network, a demand of a load associated with the electric meter, and input from a utility provider.

6. The method according to claim 1, comprising: In response to entering the service limitation mode, controlling a premises to prevent the premises from receiving power from the power distribution network while the electric meter is operating in the service limitation mode.

7. The method according to claim 1, comprising: In response to entering the normal operating mode, a message is caused to be sent to the remote system.

8. A system for restoring power to one or more loads, comprising: An electric meter, wherein the electric meter is configured to: detecting restoration of power following a power outage, and in response to detecting restoration of power following the power outage, restarting operation and entering a service restriction mode for a predetermined amount of time, wherein the predetermined amount of time is based on connection of the electric meter to one or more electric assets of the electric distribution network; When in the described service restriction mode: monitoring electricity from the distribution network to the premises via said electricity meter; accumulating said electricity during a service limited demand period; comparing the accumulated power during the service limit demand period to a service limit threshold; When the accumulated power or the service limit demand period is within the service limit threshold, controlling the service switch of the electric meter so that the house remains connected to the power distribution network; determining an amount of time that has elapsed since entering said service restriction mode; and exiting the service restriction mode when the amount of time that has elapsed since entering the service restriction mode meets or exceeds the predetermined amount of time; and Enter normal operating mode.

9. The system of claim 8, wherein when in the service limit mode, the electric meter controls the service switch to disconnect the premises from the power distribution network when the cumulative power during the service limit demand period exceeds the service limit threshold.

10. The system of claim 8, wherein the electric meter detects the power outage and, in response to detecting the power outage, controls the service switch to disconnect the premises from the power distribution network; and In response to detecting restoration of power following the power outage, the service switch is maintained in an open state until a second predetermined time period expires or a restart command is received.

11. The system of claim 10, wherein the electric meter receives the restart command via a wireless network; and The service switch is controlled to connect the premises to the power distribution network.

12. The system of claim 10, wherein the electric meter determines that the second predetermined time period has expired; and The service switch is controlled to connect the premises to the power distribution network.

13. The system of claim 8, wherein in response to entering the service limitation mode, the electric meter controls a premises to prevent the premises from receiving power from the power distribution network while the electric meter is operating in the service limitation mode.

14. The system of claim 8, wherein in response to entering the normal operating mode, the electric meter causes a message to be sent to a remote system.

15. A method for operating an electric meter, comprising: entering a service restriction mode wherein the meter restricts power to the premises; When in the described service restriction mode: determining needs associated with said housing; comparing the demand to a threshold value; When the demand of the house exceeds the threshold, setting the service switch to an on state; when the demand is within the threshold, setting the service switch to an off state and determining an amount of time that has elapsed since entering the service restriction mode; as well as exiting the service restriction mode when the amount of time that has elapsed since entering the service restriction mode meets or exceeds a predetermined amount of time; and Enter normal operating mode.

16. The method of claim 15, wherein the threshold value varies based on a location of the electric meter within a power distribution network.

17. The method of claim 15, wherein the predetermined amount of time is based on a location of the electric meter within an electric distribution network.

18. The method of claim 15, wherein the predetermined amount of time or the threshold is preset at the electric meter by a utility provider.

19. The method according to claim 15, further comprising: When the electric meter enters a normal operating mode, a message is sent to a remote system.

20. The method of claim 19, wherein the electric meter enters a service limitation mode upon detecting that power has been restored from a power outage event that lasted longer than a predetermined period of time.

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