Electric meter primary energy retention management

Abstract

A utility meter includes a rectifier configured to rectify an AC voltage from a power grid to generate a primary DC voltage source, and a primary hold circuit including a first capacitor coupled to the primary DC voltage rail and configured to store energy from the primary voltage source, a switch coupled to the first capacitor, and a control circuit configured to control the primary hold circuit, wherein the control circuit is configured to determine that a secondary DC voltage of a secondary voltage source is approximately equal to a first specified threshold voltage, and generate a control signal to cause the switch to turn on and cause one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail.

Description

Background Technology

[0001] Unless otherwise stated herein, the materials described in this section are not prior art to the claims of this application and are not acknowledged as prior art by virtue of their inclusion in this section.

[0002] An electricity meter measures the electrical power consumed by a customer of an electricity utility provider. The meter is plugged into a meter socket in a casing installed on a building or other structure and draws its operating power from the distribution network. The meter records energy consumption and transmits this information, along with its own status information, to the utility provider for monitoring and billing. In the event of a power outage, the meter no longer has the ability to communicate with the utility provider.

[0003] To operate the radio components and enable the meter to provide "last gasp" communication to the utility provider during a power outage, the meter may be equipped with a backup power source. This backup power source can supply power to the meter only for a short period sufficient to allow the meter to send the last gasp communication. In some cases, the backup power source may be one or more low-voltage capacitors providing backup power for the operation of the radio components. The capacitors required to store enough energy to operate the radio components for a sufficiently long period can be large and expensive. Summary of the Invention

[0004] Systems and methods for primary energy management of electricity meters can be provided.

[0005] According to various aspects of this disclosure, a utility meter is provided. In some aspects, the utility meter may include: a rectifier configured to rectify an alternating current (AC) voltage from a power grid to generate a primary direct current (DC) voltage source; and a primary holdup circuit. The primary holdup circuit may include: one or more first capacitors coupled to a primary DC voltage rail and configured to store energy from the primary voltage source; a switch coupled to the one or more first capacitors; and control circuitry configured to control the primary holdup circuitry. The control circuitry may be configured to determine that a secondary DC voltage derived from the primary DC voltage source is approximately equal to a first specified threshold voltage; and to generate a control signal to turn on the switch and to cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail.

[0006] According to various aspects of this disclosure, a primary holding circuit is provided. In some aspects, the primary holding circuit may include: one or more first capacitors coupled to a primary DC voltage rail and configured to store energy from a primary voltage source; a switch coupled to the one or more first capacitors; and control circuitry configured to control the primary holding circuit. The control circuitry may be configured to determine that a secondary DC voltage derived from the primary DC voltage source is approximately equal to a first specified threshold voltage; and to generate a control signal to turn on the switch and cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail.

[0007] According to various aspects of this disclosure, a method for operating a utility meter during a power outage is provided. In some aspects, the method may include: determining, by control circuitry, that a power outage has occurred on the AC grid based on sensing that a secondary DC voltage derived from an alternating current (AC) grid is approximately equal to a first specified threshold DC voltage; generating, by control circuitry, a control signal to a primary holding circuit, the primary holding circuit including one or more first capacitors coupled to a primary DC voltage rail and configured to store energy from a primary voltage source, and a switch coupled to the one or more first capacitors. The control signal may cause the switch to turn on and cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail. Attached Figure Description

[0008] Aspects and features of various embodiments will become more apparent from the accompanying drawings, in which:

[0009] Figure 1 This is a simplified diagram illustrating a utility management system according to some aspects of this disclosure;

[0010] Figure 2 This is a simplified block diagram illustrating an electricity meter according to some aspects of this disclosure;

[0011] Figure 3 This is a simplified block diagram of a meter including a primary holding circuit, based on some aspects of this disclosure;

[0012] Figure 4 This is a simplified schematic diagram illustrating a primary holding circuit according to some aspects of this disclosure;

[0013] Figure 5 This is a block diagram illustrating communication between an electricity meter and a head-end system according to some aspects of this disclosure; and

[0014] Figure 6 This is a flowchart illustrating a method for operating an electricity meter during an AC power outage, according to some aspects of this disclosure. Detailed Implementation

[0015] An electricity meter measures the electrical power consumed by a customer of an electricity utility provider. The meter plugs into a meter socket in a casing installed on a building or other structure and provides a connection between the electricity supplied by the utility and the customer. The meter measures and controls the electricity delivered to the customer's home via the power grid. The meter may be combined with a communication module to enable it to communicate with other meters and utilities. The meter may be part of a utility management system.

[0016] Electricity meters can draw power from the alternating current (AC) power source to which they are connected. The AC voltage can be rectified to produce a primary direct current (DC). The meters can also be equipped with a power supply, which can be a switching power supply, also known as an offline switcher, configured to convert the primary DC voltage to a lower secondary DC voltage suitable for operating the meter's components. The offline switcher power supply can also provide electrical isolation (e.g., current isolation) between the circuitry connected to the primary DC voltage and the circuitry connected to the secondary DC voltage.

[0017] During an AC power outage, the meter can no longer draw power from the AC source and requires sufficient stored energy (referred to herein as primary hold-up energy) to operate the offline switch for a short period sufficient to enable the meter to send “last-moment” communications (such as an indication of an AC power outage) during the AC power outage. Last-moment communications can be sent to a receiver, such as a headend system, another utility meter, or a mobile device with an Advanced Metering Infrastructure (AMI) radio component or Automatic Meter Reading (AMR) radio component, such as the meter. In some cases, last-moment communications may require several attempts before successful transmission. Due to power losses in the offline switch, simply providing a set of capacitors across the primary DC voltage rail of the meter to provide the necessary hold-up energy for the offline switch to power the AMI radio component and / or AMR radio component, as well as other AMI or AMR devices, for a long period (e.g., 60 seconds) is impractical.

[0018] Various aspects of this disclosure can improve the efficiency of an offline switch with primary hold-up energy at light secondary loads during extended periods of AC power outages (e.g., 60 seconds or longer). Control circuitry within the meter can turn the offline switch on and off as needed to meet the DC requirements of AMI and / or AMR radio components and other AMI or AMR devices. This control can also improve the efficiency of the offline switch at low secondary loads. Idle losses in the flyback converter can be reduced during AC power outages, allowing the AMI or AMR radio components and other AMI or AMR devices to remain active for extended periods (e.g., greater than 60 seconds).

[0019] While certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of protection. The apparatuses, methods, and systems described herein may be embodied in various other forms. Furthermore, various omissions, substitutions, and changes may be made to the form of the exemplary methods and systems described herein without departing from the scope of protection.

[0020] Figure 1 This is a simplified diagram illustrating a utility management system 100 according to some aspects of this disclosure. (See reference) Figure 1 The utility management system 100 may include an electricity meter 105, a headend system 110, and a storage device 120. Although for ease of explanation... Figure 1 An electricity meter 105 is shown, but those skilled in the art will understand that multiple electricity meters 105 may be included in the disclosed utility management system 100 without departing from the scope of this disclosure.

[0021] Electricity meter 105 can monitor and / or record energy usage at customer home 130 and communicate information about energy usage to headend system 110. For example, electricity meter 105 can continuously monitor and record total energy usage at customer home 130. According to various aspects of this disclosure, electricity meter 105 can monitor and / or record several days of the week and times of the day related to energy usage at customer home 130 and communicate this information to headend system 110. Additionally, electricity meter 105 can function as a sensor to detect and / or record abnormal measurements and / or events, such as, but not limited to, AC power outages. Those skilled in the art will understand that other information can be monitored and communicated by electricity meter 105, such as, but not limited to, average power consumption, peak power, etc.

[0022] Meter 105 can communicate with headend system 110 via wired or wireless communication interfaces known to those skilled in the art, using communication protocols suitable for a specific communication interface. Different wired or wireless communication interfaces and associated communication protocols can be implemented on meter 105 for communication with headend system 110. For example, in some embodiments, a wired communication interface can be implemented, while in others, a wireless communication interface can be implemented for communication between meter 105 and headend system 110. In some embodiments, a wireless mesh network can connect multiple meters 105. Multiple meters 105 can transmit data to a collector (not shown), which communicates with another network to transmit data to headend system 110. Meter 105 can communicate using radio frequency (RF), cellular, or power line communication. In some embodiments, meter 105 can be an Advanced Metering Infrastructure (AMI) meter or an Automatic Meter Reading (AMR) meter, and may include an AMI radio component or an AMR radio component. Other communication methods may be used without departing from the scope of this disclosure.

[0023] The headend system 110 may include a data storage device 120. The data storage device 120 may be, for example, but not limited to, one or more hard disk drives, solid-state storage devices, or other computer-readable storage media. Those skilled in the art will understand that other storage configurations may be used without departing from the scope of this disclosure. A database 125 may be stored on the data storage device 120. The database 125 may store information collected from the meter 105. For example, the database 125 may include days of the week and times of day related to load operation information, such as, but not limited to, average power consumption, peak power consumption, etc. Those skilled in the art will understand that this information is exemplary and other information may be included in the database 125 without departing from the scope of this disclosure.

[0024] The head-end system 110 and meter 105 can be connected to the distribution network 140. The distribution network 140 may include a power plant (not shown) that generates electricity (not shown), a substation (not shown) for raising voltage for transmission or lowering voltage for distribution, high-voltage transmission lines (not shown), and distribution lines (not shown).

[0025] Figure 2 This is a simplified block diagram illustrating an electricity meter 200 according to some aspects of this disclosure. The electricity meter 200 may be, for example... Figure 1 The meter 105. The meter 200 may include a control circuit 205, a communication module 230, various sensors 240, a power supply 260, and a primary holding circuit 270.

[0026] Control circuitry 205 may include processor 210, memory 220, and measurement circuitry 250. Processor 210 may be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic device. Processor 210 may electrically communicate with memory 220, communication module 230, and sensors 240. Processor 210 may control the overall operation of meter 200. Processor 210 may receive data generated by various sensors 240 of meter 200, including but not limited to energy usage, voltage, current, etc., and may perform operations or processing on the data. Processor 210 may communicate with communication module 230 to transmit various operating parameters (e.g., energy usage), diagnostic data (e.g., error conditions), or other meter information (e.g., GPS coordinates) to headend systems and / or other meters via wired or wireless networks.

[0027] Memory 220 may be a storage device such as a solid-state storage device or other storage device, and may be a combination of volatile and non-volatile storage devices or memories. In some embodiments, a portion of the memory may be included in processor 210. Memory 220 may be configured to store instructions executable by processor 210, as well as data generated by various sensors 240 of meter 200, and other applications executable by processor 210.

[0028] Communication module 230 may be a wired or wireless transceiver operable to communicate via various wired or wireless protocols known in the art (e.g., but not limited to the AMI protocol). Communication module 230 may include a processor 235 configured to control the operation of communication module 230. Communication module 230 enables meter 200 to communicate with other meters in a network (e.g., an AMI network) and with a utility provider (e.g., a headend system) controlling the network. Communication module 230 may send data and alarm signals to the utility provider, and receive any of the following: updated program instructions, firmware updates, updates to other settings, or other communications. Communication module 230 may receive capacitor charging and discharging command signals 232 from a headend system (e.g., headend system 110) and may communicate these command signals to processor 210. In some embodiments, communication module 230 may include AMI devices and / or AMR devices, including AMI radio components and / or AMR radio components 237. AMI radio components and / or AMR radio components can use radio frequency (RF) technology or power line communication (PLC) to send data to and receive data from the head-end system.

[0029] Sensor 240 may include, but is not limited to, voltage sensors, current sensors, accelerometers, tilt switches, temperature sensors, and other sensors configured to monitor the electrical and physical characteristics of meter 200.

[0030] Measurement circuit 250 can be interfaced with sensor 240. Measurement circuit 250 may include analog-to-digital (A / D) converter 256, which is configured to measure capacitor voltage and convert capacitor voltage values ​​into digital values. Analog-to-digital (A / D) converter 256 can be configured to receive signals from sensor 240 and convert the signals into digital values ​​that can be operated by processor 210.

[0031] Power supply 260 may be a switching power supply, also referred to herein as an offline switcher. Power supply 260 may be configured to convert a primary DC voltage to a lower secondary DC voltage. Power supply 260 may also include a secondary power supply that converts the secondary DC voltage to a lower voltage suitable for operating the components of the meter.

[0032] The primary holding circuit 270 can supply power to the meter 200 for a period of time immediately after an AC power outage. The capacitor included in the primary holding circuit 270 can be controlled by the control circuit 205 to provide sufficient power to the meter 200 to send a "last moment" message to the headend system via the AMI radio component or AMR radio component 237. The last moment message may include notification of the AC power outage and other information regarding the power loss (e.g., energy usage, error conditions, or other meter information).

[0033] Figure 3 This is a simplified block diagram of a meter 300, including a primary holding circuit 360, based on some aspects of this disclosure. (See also...) Figure 3 The meter 300 may include a first power supply 310, a second power supply 320, a third power supply 325, a control circuit 350, and a primary holding circuit 360. The first power supply 310 (also referred to herein as an offline power supply or offline switch) can operate using an input voltage from the primary DC voltage of the meter 300. The primary DC voltage can be generated based on the AC line voltage rectified by the full-wave rectifier 305. The primary DC voltage can be, for example, 350 volts DC (VDC) or another DC voltage.

[0034] The first power supply 310 may be a switching power supply, such as, but not limited to, a buck-boost power supply or other power supply, operable to convert a primary DC voltage to a lower secondary DC voltage Vsec. The secondary DC voltage Vsec may be, for example, 12VDC or another DC voltage. The first power supply 310 converts the primary DC voltage to the secondary DC voltage Vsec by periodically transferring energy stored in the primary winding of the coupling inductor 315 to the secondary winding of the coupling inductor 315. Electrical isolation (e.g., current isolation) between circuitry connected to the primary DC voltage and circuitry connected to the secondary DC voltage may be provided by the coupling inductor 315. In some embodiments, the coupling inductor 315 may be a transformer. Isolation feedback of the secondary DC voltage Vsec may be provided to the first power supply 310 via an isolation device 312 (e.g., but not limited to, an optocoupler or other isolation device).

[0035] The second power supply 320 can be a switching power supply or another power supply operable to convert the secondary DC voltage Vsec to a lower voltage (e.g., 3.3VDC or another DC voltage). The second power supply 320 can power the control circuit 350 and other circuitry of the meter 300. The third power supply 325 can be a switching power supply or another power supply operable to convert the secondary DC voltage Vsec to a lower voltage (e.g., 3.6VDC or another DC voltage). The second power supply 325 can power the AMI radio component or the AMR radio component 330.

[0036] The primary holding circuit 360 may include a primary holding capacitor 370, a primary holding control switch 375, and a peak detector circuit 380. The primary holding capacitor 370 may be coupled to a primary DC voltage rail 307 and may store energy when powered from an AC source. The primary holding capacitor 370 may include two or more capacitors connected in parallel to provide a specified amount of capacitance. For example, two 220 microfarad (μF) capacitors may be connected in parallel to provide 440 μF of capacitance to store energy from the primary DC voltage rail 307. The primary holding capacitor 370 may be, for example, but not limited to, a set of electrolytic capacitors or other types of capacitors.

[0037] The primary hold control switch 375 is operable to control the discharge of the primary hold capacitor 370 during AC power outages. The primary hold control switch 375 may be, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET). The peak detector circuit 380 may activate or deactivate the primary hold control switch 375 based on a control pulse 356 received from the control circuit 350 via the isolation capacitor 390.

[0038] Control circuit 350 can determine that an AC power outage has occurred by monitoring the secondary voltage Vsec. Control circuit 350 can determine that an AC power outage has occurred when the secondary voltage Vsec is approximately equal to (e.g., within 100mV or another voltage value) a specified threshold voltage (e.g., 3V or another voltage). Control circuit 350 (e.g., a processor of the control circuit (e.g., processor 210)) can also provide a first control signal 352 to enable and disable a third power supply 325 (e.g., a 3.6V power supply) and a second control signal 354 to enable and disable switching circuit 335. Switching circuit 335 can connect power to or disconnect power to auxiliary circuit 340 of meter 300. As used herein, auxiliary circuit refers to any circuit that does not need to operate during an AC power outage. During an AC power outage, control circuit 350 can generate a second control signal 354 to switching circuit 335 to disconnect power to auxiliary circuit 340 of meter 300 that does not need to operate during an AC power outage.

[0039] Figure 4 This is a simplified schematic diagram illustrating the primary holding circuit of a meter 400 according to some aspects of this disclosure. The primary holding circuit may include control circuitry 350, a primary holding capacitor 470, a primary holding control switch 475, and a peak detector circuitry 480. The primary holding capacitor 470 can provide primary holding energy to sustain the operation of the meter 400 and AMI and / or AMR devices (e.g., AMI radio components and / or AMR radio components 330) during AC power outages. The primary holding capacitor 470 may be, for example, but not limited to, a set of electrolytic capacitors or other types of capacitors connected in parallel to provide sufficient capacitance to store energy from the primary DC voltage rail 407.

[0040] The primary hold control switch 475 may be a field-effect transistor (FET) including an intrinsic diode 477. The peak detector circuit 480 may include a capacitor and a resistor connected in parallel, and a resistor R1 connected in series with the reverse bias diode D1. Other configurations of the primary hold control switch and peak detector circuit for controlling the charging and discharging of the primary hold capacitor may be used without departing from the scope of this disclosure.

[0041] During normal operation of the meter 400 powered by AC power, the primary-side capacitor C4 can provide a primary DC voltage on the primary DC voltage rail 407 to operate the offline power supply 410. The primary DC voltage can be, for example, 350VDC or another voltage. The offline power supply 410 can generate a secondary voltage Vsec of approximately 12VDC via the coupling inductor 415 to charge the secondary holding capacitor C5 to its nominal operating voltage of approximately 12VDC. Isolation feedback of the secondary DC voltage Vsec can be provided to the first power supply 410 via an isolation device 412 (e.g., but not limited to, an optocoupler or other isolation device). When the meter 400 is powered by AC power, the primary holding control switch 475 enables the primary holding capacitor 470 to be charged to the primary DC voltage via a path provided by the intrinsic diode 477.

[0042] The secondary holding capacitor C5 can provide only a small portion of the total holding energy for the operation of the meter 400 (especially the AMI radio component and / or AMR radio component) during AC power outages. A larger portion of the holding energy can be stored in the primary holding capacitor 470. Under the control of the control circuitry 350, the energy stored in the primary holding capacitor 470 can be released over a longer period, such as 60 seconds or longer.

[0043] During an AC power outage, the primary holding capacitor 470 is no longer charged from the primary DC voltage. The primary holding control switch 475 can be in the open state, and the intrinsic diode 477 can be reverse biased, thereby preventing the primary holding capacitor 470 from discharging. Therefore, the holding energy stored in the primary holding capacitor 470 can be reserved for later use. In the absence of AC power, the offline power supply 410 can continue to operate based on the primary DC voltage supplied by the primary-side capacitor C4. The offline power supply 410 can continue to operate and continue charging the secondary-side capacitor C5 until the energy stored in the primary-side capacitor C4 is depleted to a point where the primary DC voltage is approximately equal to a specified threshold voltage, which is less than the minimum operating voltage of the offline power supply 410, for example, approximately 60VDC or another voltage. When the primary DC voltage is approximately equal to the specified threshold voltage, the offline power supply 410 can be shut down.

[0044] After the offline power supply 410 is turned off, the secondary-side capacitor C5 can provide the necessary holding energy for the operation of the meter 400 and the AMI or AMR device (e.g., AMI radio component and / or AMR radio component 330). As the energy stored in the secondary-side capacitor C5 is depleted, the secondary voltage Vsec may decrease over time. When the control circuit (e.g., control circuit 350) determines that the secondary voltage Vsec is approximately equal to (e.g., within 100mV or another voltage value) a specified threshold (e.g., approximately 3VDC or another threshold voltage), the control circuit 350 may disable the AMI radio component and / or AMR radio component 330 via a first control signal 352 to the third power supply 325, may enter a low-power mode, and may generate a control pulse 456 to turn on the primary holding control switch 475. For example, the processor of the control circuit 350 (e.g., processor 210) may receive a sensor signal sensing the secondary voltage Vsec (e.g., from sensor 240) and generate the control pulse 456 when it determines that the secondary voltage Vsec is approximately equal to the specified threshold. The control pulse 456 can be a pulse waveform with a specified frequency and duty cycle, and can be coupled to the peak detector circuit 480 via the line isolation capacitor 490. The primary hold control switch 475 can be turned on after a time period determined by the frequency and duty cycle of the control pulse 456.

[0045] The control pulse 456 received by the peak detector circuit 480 can charge the detector capacitor C3 in the peak detector circuit 480. When the voltage on the detector capacitor C3 reaches the turn-on threshold voltage, the primary hold control switch 475 can be turned on, causing the primary hold capacitor 470 to provide a portion of its stored energy to the primary DC voltage rail 407. The energy provided by the primary hold capacitor 470 can increase the voltage on the primary DC voltage rail 407 above the minimum turn-on voltage, thereby turning on the offline power supply 410. The offline power supply 410 can then generate the secondary voltage Vsec again to charge the secondary-side capacitor C5.

[0046] When the voltage Vsec on the secondary-side capacitor C5 exceeds a first specified threshold voltage (e.g., approximately 3VDC or another voltage), the control circuit can wake up and monitor the secondary voltage Vsec. The control circuit can remain idle until it determines that the voltage Vsec on the secondary-side capacitor C5 exceeds a second specified threshold voltage, e.g., approximately 8VDC or another voltage. When the control circuit determines that the secondary voltage Vsec has exceeded the second threshold voltage, the control circuit can enable the AMI radio component and / or the AMR radio component (e.g., via the first control signal 352) and can disable the control pulse. For example, the processor of the control circuit 350 (e.g., processor 210) can receive a sensor signal (e.g., from sensor 240) and disable the control pulse 456 when it determines that the secondary voltage Vsec has exceeded the second specified threshold voltage. The primary holding control switch 475 can remain in the ON state, and the primary holding capacitor 470 can continue to supply energy to the primary DC voltage rail 407 until the charge stored in the detector capacitor C3 decreases to the point where the voltage across the detector capacitor C3 is less than the ON threshold voltage of the primary holding control switch 475.

[0047] When the voltage across detector capacitor C3 discharges (via resistor R3) to below the turn-on threshold voltage of primary hold control switch 475, primary hold control switch 475 can be opened, and primary hold capacitor 470 can no longer supply energy to primary DC voltage rail 407. Opening primary hold control switch 475 conserves energy stored in primary hold capacitor 470. Offline power supply 410 can continue to operate to charge secondary-side capacitor C5 until the energy stored in primary-side capacitor C4 is depleted and the primary DC voltage is again approximately equal to a specified threshold voltage below the minimum operating voltage of offline power supply 410. The charge / discharge cycle can continue until the hold energy previously stored in primary hold capacitor 470 is depleted.

[0048] Various aspects of this disclosure can provide increased power to allow sufficient time for the meter to store and transmit status information to a headend system, another utility meter, or mobile device. During normal operation, the meter can collect status information, including but not limited to voltage and current information, error conditions, etc. During AC power outages, the collected status information can be stored and transmitted to the headend system during "last-minute" communications. In some cases, transmitting last-minute communications may require several attempts. The disclosed embodiments can provide sufficient power to supply the meter to store and transmit information via AMI and / or AMR radio components.

[0049] Figure 5This is a block diagram illustrating communication between an electricity meter and a headend system according to some aspects of this disclosure. (Reference) Figure 5 Meters 510, 520, and 530 can communicate with the headend system 540 via communication link 550 and with each other via communication link 560. The headend system 540 may include a server 545 configured to communicate with meters 510, 520, and 530 via a network (e.g., an Advanced Metering Infrastructure (AMI) network). Each meter 510, 520, and 530 can communicate meter information and data with other meters and with the server 545 in the headend system 540. In some cases, a meter (e.g., meter 520) may be too far from the headend system 540 to communicate directly with it. In this case, meter 520 can communicate with the headend system 540 via another meter (e.g., meter 510). In some cases, meters 510, 520, and 530 can communicate meter information and data with mobile devices 570 (such as mobile phones, laptops, or other mobile devices).

[0050] In some cases, communication between the meter and the headend system can be achieved via an additional network (not shown). Alternatively or additionally, the meter may communicate with one or more edge processing devices located topologically closer to the meter than the headend system. The edge processing devices may have greater processing power than the meter and may provide some of the functionalities typically offered by the headend system.

[0051] Meters 510, 520, and 530 can communicate with each other via communication link 560 to exchange meter information and data. For example, if meter 510 experiences a line voltage drop, meter 510 can communicate with meters 520 and 530 to determine whether the fault is a local fault of meter 510 or a wider fault caused by a common condition. A common condition could be, for example, a fallen power line due to a storm. The common condition can then be reported to the headend system by one or more meters. Additionally or alternatively, an edge processing device can receive data from the meters and determine whether the data indicates a common condition affecting the meters.

[0052] Figure 6 This is a flowchart illustrating a method 600 for operating an electricity meter during an AC power outage, according to some aspects of this disclosure. (See also:) Figure 3 , Figure 4 and Figure 6At box 610, it can be determined whether an AC power outage has occurred. When an AC power outage occurs, the primary power source (e.g., offline power source 310) can stop supplying the secondary voltage Vsec. Control circuitry (e.g., control circuitry 350) can determine that the secondary voltage Vsec is approximately equal to (e.g., within 100mV or another voltage value) a threshold voltage, such as 3VDC or another voltage. In response to determining that no AC power outage has occurred (610-No), the control circuitry can continue monitoring the secondary voltage Vsec.

[0053] In response to determining that an AC power outage has occurred (610-Yes), at block 615, non-essential circuitry in the meter can be disabled. The control circuitry can activate the switching circuitry (e.g., activate the switching circuitry 335 via control signal 354) to disconnect any additional circuitry (e.g., auxiliary circuitry 340) that is not essential for the operation of the meter during an AC power outage.

[0054] At block 620, the control circuitry can disable the AMI radio and / or AMR radio. In some embodiments, the control circuitry can put the AMI radio and / or AMR radio into a "last-minute" mode via a control signal 352 to a third power source 325, which supplies power to the AMI radio and / or AMR radio. In last-minute mode, the radio can send a last-minute message, which may include notification of an AC power outage and other information in the event of power loss (e.g., energy usage, error conditions, or other meter information). In some embodiments, the control circuitry can disable the AMI radio and / or AMR radio via control signal 352. The control circuitry (e.g., the processor 210 of the control circuitry) can transition to a low-power state.

[0055] At block 625, the control circuit can initiate a control pulse (e.g., control pulse 456) to the peak detector circuit (e.g., peak detector circuit 480). The processor of the control circuit 350 (e.g., processor 210) can receive a sensor signal (e.g., from sensor 240) and generate control pulse 456 when it determines that the secondary voltage Vsec is approximately equal to (e.g., within 100mV or another voltage value) a specified threshold voltage. Control pulse 456 can have a specified frequency and duty cycle and can be coupled to peak detector circuit 480 via line isolation capacitor 490.

[0056] At block 630, a primary hold control switch (e.g., primary hold control switch 475) can be turned on. A control pulse received by the peak detector circuit can cause the peak detector circuit to turn on the primary hold control switch. When the primary hold control switch is turned on, the primary hold capacitor (e.g., primary hold capacitor 470) can provide a portion of its stored energy to the primary DC voltage rail (e.g., primary DC voltage rail 407).

[0057] At box 635, it can be determined whether the voltage on the primary DC rail has increased to a level sufficient to operate the first power supply (e.g., offline power supply 410). In response to determining that the voltage on the primary DC rail has not increased to a level sufficient to operate the first power supply (635-No), the primary holding capacitor has depleted its energy, and the process can end (box 640).

[0058] In response to determining that the voltage on the primary DC rail has increased to a level sufficient to operate the first power supply (635-Yes), at block 645, the first power supply can resume operation to supply the secondary voltage Vsec.

[0059] At box 650, it can be determined whether the secondary voltage Vsec exceeds a first specified threshold. In a low-power state, the control circuitry can monitor the secondary voltage Vsec to determine if it exceeds the first specified threshold, such as approximately 3V DC or another voltage. In response to determining that the secondary voltage Vsec has not yet exceeded the first specified threshold (650 - No), the control circuitry can continue monitoring the secondary voltage.

[0060] In response to determining that the secondary voltage Vsec has exceeded a first specified threshold (650-Yes), at block 655, the control circuit can wake up and continue monitoring the secondary voltage Vsec.

[0061] At box 660, it can be determined whether the secondary voltage has exceeded a second specified threshold voltage, such as 8VDC or another voltage. In response to determining that the secondary voltage has not exceeded the second specified threshold voltage (660-No), the control circuit can continue to monitor the secondary voltage.

[0062] In response to determining that the secondary voltage Vsec has exceeded the second specified threshold voltage (660-Yes), at block 665, the control circuitry can cause the AMI radio component and / or the AMR radio component (e.g., AMI radio component and / or AMR radio component 330) to attempt to communicate with the headend system at another last moment.

[0063] At box 670, the control pulse can be turned off. The control circuitry (e.g., processor 210 of the control circuitry) can disable the control pulse to the peak detector circuitry. When the control pulse to the peak detector circuitry is disabled, the primary hold control switch can remain on, and the primary hold capacitor can continue to supply energy to the primary DC voltage rail until the charge stored in the peak detector circuitry decreases and the voltage applied to the primary hold control switch is less than the on-threshold voltage of the primary hold control switch. Disconnecting the primary hold control switch prevents the primary hold capacitor from supplying energy to the primary DC voltage rail and conserves the energy stored in the primary hold capacitor.

[0064] At block 675, the control circuit can continue to monitor the secondary voltage Vsec, and this process can continue at block 610.

[0065] Figure 6 The specific steps shown provide a particular method for operating a meter during an AC power outage according to embodiments of this disclosure. According to alternative embodiments, other sequences of steps may also be performed. For example, alternative embodiments may perform the steps outlined above in a different order. Furthermore, Figure 6 Each step shown can include multiple sub-steps, which can be executed in various orders suitable for each step. Furthermore, additional steps can be added or removed depending on the specific application.

[0066] While examples of electricity meters illustrate and explain aspects of this disclosure, these aspects can be applied to other utility meters, such as, but not limited to, water meters, gas meters, etc., without departing from the scope of this disclosure.

[0067] The examples and embodiments described herein are for illustrative purposes only. Various modifications or variations thereof will be apparent to those skilled in the art. These should be included within the spirit and scope of this application and the appended claims.

Claims

1. A utility meter, comprising: A rectifier, configured to rectify AC voltage from the grid to generate a primary DC voltage source; A radio component configured to transmit communications, including AC power failure notifications, to a receiver; A first power source is coupled to a primary DC voltage rail and configured to convert the primary DC voltage of the primary DC voltage source into a secondary DC voltage. as well as The primary holding circuit includes: One or more first capacitors are coupled to the primary DC voltage rail and configured to store energy from the primary DC voltage source; A switch, coupled to one or more first capacitors; and A control circuit configured to control the primary holding circuit, wherein the control circuit is configured to: The secondary DC voltage is determined to be approximately equal to a first specified threshold voltage; The radio component is disabled when the secondary DC voltage is equal to the first specified threshold voltage; Generate control signals to turn on the switch and to cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail; and The radio component is activated when a portion of the energy stored in the one or more first capacitors is released to the primary DC voltage rail, causing the secondary DC voltage to exceed a second specified threshold voltage.

2. The utility meter of claim 1, wherein the first power supply is further configured to stop operating when the primary DC voltage is approximately equal to a specified threshold voltage, and The first power supply is further configured to resume operation in response to the one or more first capacitors releasing a portion of the energy to the primary DC voltage rail.

3. The utility meter according to claim 2, wherein the control circuit interrupts the control signal when the first power supply resumes operation and causes the secondary DC voltage to exceed a second specified threshold voltage.

4. The utility meter of claim 1 further includes a detector circuit coupled to the switch and configured to control the switch based on the control signal from the control circuit.

5. The utility meter according to claim 4, wherein the control signal is a pulse waveform, and The detector circuit is configured to receive the control signal and turn on the switch after a time period determined by the frequency and duty cycle of the pulse waveform.

6. The utility meter of claim 1, wherein the control circuitry is further configured to generate a signal to the radio component when it is determined that the secondary DC voltage is approximately equal to the first designated threshold voltage, so as to cause the radio component to enter a low-power mode between transmission attempts.

7. The utility meter of claim 1, wherein the receiver comprises a headend system, another utility meter, or a mobile device.

8. The utility meter of claim 1 further includes a switching circuit configured to disconnect an auxiliary circuit of the utility meter based on a signal received from the control circuit. The control circuit is further configured to generate a signal to the switching circuit when it is determined that the secondary DC voltage is approximately equal to the first specified threshold voltage.

9. The utility meter of claim 1, wherein the switch comprises a metal-oxide-semiconductor field-effect transistor.

10. A primary holding circuit for a utility meter, the primary holding circuit comprising: One or more first capacitors are coupled to a primary DC voltage rail and configured to store energy from a primary DC voltage source; A switch, which is coupled to the one or more first capacitors; as well as A control circuit configured to control the primary holding circuit, wherein the control circuit is configured to: The secondary DC voltage obtained by converting the primary DC voltage of the primary DC voltage source from the first power source coupled to the primary DC voltage rail is determined to be approximately equal to a first specified threshold voltage; as well as Generate a control signal to turn on the switch and to cause the one or more first capacitors to release a portion of the energy stored in the one or more first capacitors to the primary DC voltage rail; The control circuit is further configured to: When the secondary DC voltage is equal to the first specified threshold voltage, the radio component of the utility meter is disabled; The radio component is activated when a portion of the energy stored in the one or more first capacitors is released to the primary DC voltage rail, causing the secondary DC voltage to exceed a second specified threshold voltage.

11. The primary holding circuit of claim 10, wherein the control circuit is configured to generate the control signal when an AC voltage failure from the mains is determined, and The control circuit determines the power-off when the secondary DC voltage is approximately equal to the first specified threshold voltage.

12. The primary holding circuit of claim 10, further comprising a detector circuit coupled to the switch and configured to control the switch based on the control signal from the control circuit.

13. The primary holding circuit of claim 12, wherein the control signal is a pulse waveform, and The detector circuit is configured to receive the control signal and turn on the switch after a time period determined by the frequency and duty cycle of the pulse waveform.

14. The primary holding circuit of claim 10, further comprising a switching circuit configured to disconnect the auxiliary circuit from the secondary DC voltage source based on a signal received from the control circuit. The control circuit is further configured to generate the signal to the switching circuit when it is determined that the secondary DC voltage is approximately equal to the first specified threshold voltage.

15. The primary holding circuit of claim 10, wherein the switch comprises a metal-oxide-semiconductor field-effect transistor.

16. A method for operating a utility meter during a power outage, the method comprising: The AC voltage from the power grid is rectified by a rectifier to generate a primary DC voltage source; The primary DC voltage of the primary DC voltage source is converted into a secondary DC voltage by the first power source; The control circuit determines that a power outage has occurred on the AC grid based on the sensing that the secondary DC voltage derived from the AC grid is approximately equal to a first specified threshold DC voltage. The control circuit generates a control signal for a primary holding circuit, the primary holding circuit including one or more first capacitors coupled to a primary DC voltage rail and configured to store energy from a primary voltage source, and a switch coupled to the one or more first capacitors. The control signal causes the switch to release energy from the one or more first capacitors coupled to the primary DC voltage rail; The energy released to the primary DC voltage rail causes the generation of a secondary voltage; The control signal can also be operated to disable radio components; and The method further includes generating a second control signal when the secondary voltage exceeds a second specified threshold voltage, wherein the second control signal is operable to enable the radio component.

17. The method of claim 16, further comprising: When the secondary voltage exceeds the second specified threshold voltage, the control signal is interrupted.

18. The method of claim 16, further comprising: The switching power supply is activated when the voltage on the primary DC voltage rail exceeds a specified threshold voltage generated by the energy released from the one or more first capacitors.

19. The method of claim 16, wherein the control circuit enters a low-power mode before generating the control signal to the primary holding circuit.

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