Clock power supply switching system for electric energy meter and electric energy meter

Abstract

The invention relates to the technical field of electric energy meters, particularly provides a clock power supply switching system for an electric energy meter and the electric energy meter, and aims to solve the problem of low reliability of a clock power supply scheme of an existing electric energy meter system. The system comprises a main power supply module, a first power supply, a second power supply, a first power supply switching module, a second power supply switching module, a first control module, a second control module and a clock power supply node, the main power supply module is connected with the clock power supply node and is configured to provide a system power supply for the clock power supply node; the first power supply switching module is configured to be switched on or switched off in response to a first control signal output by the first control module; and the second power supply switching module is configured to be switched on or switched off in response to a second control signal output by the second control module. Through hardware logic control among the first power supply switching module, the second power supply switching module, the first control module and the second control module, automatic, rapid and reliable switching of system clock power supply is realized.

Description

Technical Field

[0001] This application relates to the field of electricity meter technology, specifically providing a clock power supply switching system for electricity meters and an electricity meter. Background Technology

[0002] During the use of electricity meters, the continuous power supply to the system clock after a power outage is crucial to ensuring data integrity and compliance. Currently, single-battery solutions for powering the electricity meter system clock pose a risk of single point of failure, while software-based dual-battery switching solutions suffer from slow response and low reliability.

[0003] Accordingly, there is a need in the art for a new clock power switching scheme for electricity meters to solve the above problems. Summary of the Invention

[0004] This application aims to solve the aforementioned technical problem, namely, to address the low reliability of existing clock power supply schemes for electricity meter systems.

[0005] In a first aspect, this application provides a clock power supply switching system for an electricity meter, comprising: a main power supply module, a first power source, a second power source, a first power supply switching module, a second power supply switching module, a first control module, a second control module, and a clock power supply node; wherein the main power supply module is connected to the clock power supply node, and the main power supply module is configured to provide system power to the clock power supply node when the electricity meter is operating; the input terminal of the first power supply switching module is connected to the positive terminal of the first power source, the output terminal of the first power supply switching module is connected to the clock power supply node, the control terminal of the first power supply switching module is connected to the first control module, and the first power supply switching module is configured to... In response to a first control signal output by the first control module, the first power supply is turned on or off to the clock power supply node. The first control signal is used to indicate whether the system power supply is effective. The input terminal of the second power switching module is connected to the positive terminal of the second power supply, the output terminal of the second power switching module is connected to the clock power supply node, and the control terminal of the second power switching module is connected to the second control module. The second power switching module is configured to turn on or off the second power supply node to the clock power supply node in response to a second control signal output by the second control module. The second control signal is used to indicate whether the voltage of the first power supply is less than a first preset threshold.

[0006] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the first power switching module includes a first anti-reverse current unit, a first switching transistor, and a second anti-reverse current unit, wherein the positive terminal of the first power supply is connected to the current input terminal of the first anti-reverse current unit, the current output terminal of the first anti-reverse current unit is connected to the input terminal of the first switching transistor, the output terminal of the first switching transistor is connected to the current input terminal of the second anti-reverse current unit, and the current output terminal of the second anti-reverse current unit is connected to the clock power supply node.

[0007] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the main power supply module includes a main power supply terminal for providing power to the system, and the first control module includes a first pull-up unit and a first pull-down unit; wherein the first pull-up unit is connected between the main power supply terminal and the control terminal of the first power switching module, and is configured to provide a first control signal to the control terminal of the first power switching module indicating that the system power is valid to turn off the first power switching module when the main power supply terminal is normally powered; the first pull-down unit is connected between the control terminal of the first power switching module and ground, and is configured to provide a first control signal to the control terminal of the first power switching module indicating that the system power is invalid to turn on the first power switching module when the main power supply terminal cannot normally power.

[0008] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the main power supply module further includes a functional power supply terminal. The first pull-up unit includes a clamping diode, a second resistor, and a Zener diode. One end of the clamping diode is connected to the main power supply terminal, and the other end of the clamping diode is connected to one end of the Zener diode and the control terminal of the first power switching module via the second resistor. The other end of the Zener diode is connected to the functional power supply terminal. The first pull-down unit includes a third resistor, which is connected between the control terminal of the first power switching module and ground.

[0009] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the first control module further includes a discharge unit. One end of the discharge unit is connected between the Zener diode and the functional power supply terminal, and the other end of the discharge unit is grounded. The discharge unit is used to provide a discharge path to ground for the functional power supply terminal.

[0010] In one technical solution of the above-mentioned clock power supply switching system method for an electricity meter, the second control module includes: a voltage detection unit, wherein both the power input terminal and the voltage detection terminal of the voltage detection unit are connected to the positive terminal of a first power supply, and the output terminal of the voltage detection unit is connected to the control terminal of the second power supply switching module; the voltage detection unit is configured to provide a second control signal to the control terminal of the second power supply switching module indicating that the voltage of the first power supply is less than the first preset threshold to turn on the second power supply switching module when the voltage of the first power supply is less than the first preset threshold; the voltage detection unit is further configured to provide a second control signal to the control terminal of the second power supply switching module indicating that the voltage of the first power supply is greater than or equal to the first preset threshold to turn off the second power supply switching module when the voltage of the first power supply is greater than or equal to the first preset threshold.

[0011] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the second control module further includes a seventh resistor; the seventh resistor is connected between the output terminal of the voltage detection unit and ground, and is used to provide a pull-down path for the control terminal of the second power switching module.

[0012] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the first power source is a lithium battery disposed in the battery compartment of the electricity meter, and the second power source is a lithium battery disposed on the circuit board of the electricity meter.

[0013] In one technical solution of the above-mentioned clock power supply switching system method for electricity meters, the system further includes a first voltage sampling module and a second voltage sampling module, wherein the first voltage sampling module is connected between the positive terminal of the first power supply and ground, and is used to collect the voltage of the first power supply; the second voltage sampling module is connected between the positive terminal of the second power supply and ground, and is used to collect the voltage of the second power supply.

[0014] In a second aspect, an electricity meter is provided, the electricity meter comprising: a system clock module; and a clock power supply switching system as described in the first aspect or any corresponding technical solution above, wherein the clock power supply node is connected to the power input terminal of the system clock module for supplying power to the system clock module.

[0015] In the technical solution of this application, when the system power supply is valid, it supplies power to the clock power supply node. When the first control module detects that the system power supply is invalid, it quickly activates the first power switching module based on the first control signal, using the first power supply to supply power to the clock power supply node. When the second control module detects that the voltage of the first power supply is less than the first preset threshold, it quickly activates the second power switching module based on the second control signal, using the second power supply to supply power to the clock power supply node. This ensures continuous power supply to the system clock when the system power supply is invalid. The entire process is directly controlled by the hardware logic of the first power switching module, the second power switching module, the first control module, and the second control module, without any software intervention. This achieves automatic, fast, and reliable switching of the power supply to the electricity meter system clock, solving the problems of software delay and single point of failure, and improving the reliability of the electricity meter system clock power supply.

[0016] In implementing the technical solution of this application, the clock power supply switching system uses simple and low-cost components, requiring no complex programming or high-performance microcontroller units, making it easy to manufacture and maintain. This clock power supply switching system also integrates a voltage sampling module, which can collect the voltage of the first and second power supplies in real time, thereby achieving the purpose of monitoring the power supply health status for timely maintenance. Attached Figure Description

[0017] The disclosure of this application will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. In the drawings: Figure 1 This is a schematic diagram of the main structure of a clock power supply switching system for an energy meter according to an embodiment of this application; Figure 2 This is a schematic diagram of the circuit connection relationship of a first power switching module according to an embodiment of this application; Figure 3 This is a schematic diagram of the circuit connection relationship of the first control module according to an embodiment of this application; Figure 4 This is a schematic diagram of the circuit connection relationship of the first control module according to another embodiment of this application; Figure 5 This is a schematic diagram of the circuit connection relationship of a second power switching module according to an embodiment of this application; Figure 6 This is a schematic diagram of the circuit connection relationship of the second control module according to an embodiment of this application; Figure 7 This is a schematic diagram of the overall structure of a clock power supply switching system for an energy meter according to an embodiment of this application; Figure 8 This is a schematic diagram of the structure of an electricity meter according to an embodiment of this application. Detailed Implementation

[0018] Some embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0019] In the description of this application, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate medium; a connection within two elements; a wireless connection or a wired connection.

[0020] Furthermore, "module" and "processor" can include hardware, software, or a combination of both. A module can include hardware circuitry, various suitable sensors, communication ports, and memory, and may also include software components such as program code, or a combination of software and hardware. A processor can be a central processing unit, microprocessor, image processor, digital signal processor, or any other suitable processor. A processor has data and / or signal processing capabilities. A processor can be implemented in software, in hardware, or a combination of both. Computer-readable storage media includes any suitable medium capable of storing program code, such as magnetic disks, hard disks, optical disks, flash memory, read-only memory, random access memory, etc.

[0021] In overseas electricity meter market applications, there are specific and critical requirements. Specifically, when an electricity meter loses power, dual lithium batteries are needed to ensure the continuous and stable operation of the system clock. There is a clear priority requirement: the external battery is used first to ensure reliable operation of the system clock under normal circumstances. Simultaneously, considering various conditions during battery use, such as depletion or battery failure, the circuit must have a timely switching function, quickly switching to the internal battery when the external battery fails to provide power, maintaining uninterrupted power to the system clock. This application provides a clock power supply switching system for electricity meters to meet the aforementioned overseas market requirements for reliable power supply to electricity meter system clocks.

[0022] It should be noted that the specific numerical values ​​(including but not limited to the first preset threshold, various voltage values, and resistance values) and the specific ranges formed by these values ​​mentioned in the embodiments of this application are merely illustrative. Those skilled in the art should understand that these values ​​can be adaptively adjusted, selected, and combined according to the actual equipment model and specific reliability requirements, and should not be construed as an undue limitation on the scope of protection of this application.

[0023] See appendix Figure 1 , Figure 1 This is a schematic diagram of the main structure of a clock power supply switching system for an electricity meter according to an embodiment of this application. Figure 1 As shown, the clock power supply switching system mainly includes: main power supply module 0, first power supply 1, second power supply 2, first power supply switching module 3, second power supply switching module 4, first control module 5, second control module 6, and clock power supply node 7.

[0024] The main power supply module 0 is connected to the clock power supply node 7 and is configured to provide system power to the clock power supply node when the energy meter is operating. The input terminal IN1 of the first power switching module 3 is connected to the positive terminal BV1+ of the first power supply 1, and the output terminal OUT1 of the first power switching module 3 is connected to the clock power supply node 7. The control terminal CTR1 of the first power switching module is connected to the first control module 5. The first power switching module 3 is configured to turn on or off in response to a first control signal output by the first control module 5. The first control signal indicates whether the system power supply is in an effective state, such as when the system power supply meets the supply voltage (2.2V-5.5V) requirement of the clock power supply node. Specifically, the first power switching module 3 turns off in response to the first control signal indicating effective system power and turns on in response to the first control signal indicating ineffective system power.

[0025] The input terminal IN2 of the second power switching module 4 is connected to the positive terminal BV2+ of the second power supply 2. The output terminal OUT2 of the second power switching module 4 is connected to the clock power supply node 7. The control terminal CTR2 of the second power switching module 4 is connected to the second control module 6. The second power switching module 4 is configured to turn on or off in response to a second control signal output by the second control module 6. The second control signal indicates whether the voltage of the first power supply is less than a first preset threshold, which can be 2.0V, set according to the actual needs of the electricity meter. Specifically, the second power switching module 4 turns on in response to the second control signal indicating that the voltage of the first power supply is less than the first preset threshold, and turns off in response to the second control signal indicating that the voltage of the first power supply is greater than or equal to the first preset threshold.

[0026] In this embodiment, when the system power supply is valid, it supplies power to the clock power supply node. When the first control module detects that the system power supply is invalid, it quickly activates the first power switching module based on a first control signal, using the first power supply to supply power to the clock power supply node. When the second control module detects that the voltage of the first power supply is less than a first preset threshold, it quickly activates the second power switching module based on a second control signal, using the second power supply to supply power to the clock power supply node. This ensures continuous power supply to the system clock when the system power supply is invalid. The entire process is directly controlled by the hardware logic of the first power switching module, the second power switching module, the first control module, and the second control module, without any software intervention. This achieves automatic, fast, and reliable switching of the power supply to the electricity meter system clock, solving the problems of software delay and single point of failure, and improving the reliability of the electricity meter system clock power supply.

[0027] In one alternative implementation, such as Figure 2 As shown, the first power switching module 3 includes: a first anti-reverse current unit DV1 (non-inverting dual diodes), a first switching transistor QV1 (PMOS transistor), and a second anti-reverse current unit DV2 (diode). The positive terminal BV1+ of the first power supply 1 is connected to the current input terminal of the first anti-reverse current unit DV1. The current output terminal of the first anti-reverse current unit DV1 is connected to the input terminal S of the first switching transistor QV1. The output terminal D of the first switching transistor QV1 is connected to the current input terminal of the second anti-reverse current unit DV2. The current output terminal of the second anti-reverse current unit DV2 is connected to the clock power supply node 7. The control terminal G of the first switching transistor QV1 is connected to the first control module 5. The system power supply MVDD provided by the main power supply module 0 supplies power to the clock power supply node 7 via the second anti-reverse current unit DV2.

[0028] In one optional implementation, the main power supply module includes: a system power supply MVDD, a main power supply terminal SPM, and a functional power supply terminal DVDD. The main power supply terminal SPM (providing +12V voltage) is output from AC power after rectification and filtering, and is connected to the system power supply MVDD and the functional power supply terminal DVDD (providing 3.3V voltage) via a DC-DC chip. The first power source is an external lithium battery (providing 3.6V voltage) located in the battery compartment of the electricity meter, and the second power source is an internal lithium battery (providing 3.6V voltage) located on the circuit board of the electricity meter.

[0029] In one alternative implementation, see Appendix Figure 3The first control module 5 includes a first pull-up unit 50 and a first pull-down unit 51. The first pull-up unit 50 includes a clamping diode DV3, a second resistor RV2, and a Zener diode DV4. One end of the clamping diode DV3 is connected to the main power supply terminal SPM, and the other end of the clamping diode DV3 is connected via the second resistor RV2 to one end of the Zener diode DV4 and the control terminal CTR1 of the first power switching module 3. The other end of the Zener diode DV4 is connected to the functional power supply terminal DVDD. The first pull-down unit 51 includes a third resistor RV3, which is connected between the control terminal CTR1 of the first power switching module 3 and ground GND.

[0030] In one implementation, such as Figure 4 As shown, the first control module 5 further includes a discharge unit 52, which includes a third resistor RV3. One end of the third resistor RV3 is connected between the Zener diode DV4 and the functional power supply terminal DVDD, and the other end of the third resistor RV3 is grounded to GND. The third resistor RV3 is used to provide a discharge path to ground for the functional power supply terminal DVDD.

[0031] For example, when the main power supply is active and the electricity meter is powered on normally, the first control module 5 outputs a high level to CTR1, shutting down the first power switching module. Specifically, when the AC power is normal, the main power supply terminal SPM outputs a stable +12V voltage, and the functional power supply terminal DVDD outputs a stable +3.3V voltage. The +12V voltage of SPM causes the clamping diode DV3 (with a regulated voltage of 5.1V) to reverse-break down, clamping the anode voltage of the clamping diode DV3 at approximately 12V - 5.1V = 6.9V. This voltage is applied to the anode of the Zener diode DV4, i.e., node CTR1, through the second resistor RV2. Since DVDD is +3.3V at this time, the Zener diode DV4 is forward-biased. This clamps the voltage at node CTR1 to a high level of approximately 4.0V. This high-level signal reliably shuts down the first power switching module 3, thereby cutting off the power supply path from the first power supply to the clock power supply node 7. At this time, the clock power supply node is powered by the system power supply MVDD.

[0032] When the main power supply to the energy meter fails, CTR1 outputs a low level, activating the first power switching module. Specifically, assuming the AC power is disconnected, the voltage at the main power supply terminal SPM drops rapidly to 0V. Clamping diode DV3 is cut off due to insufficient voltage across its terminals and no longer provides pull-up current. The voltage at the functional power supply terminal DVDD begins to drop due to the upstream power failure. Discharge unit 52 (RV5, 5.1kΩ) provides a rapid discharge path for DVDD, causing its voltage to drop rapidly to 0V within a short time. This ensures that the forward bias across Zener diode DV4 decreases rapidly and quickly cuts off, making the first pull-down unit 51 (e.g., RV3, 100kΩ) the only effective low-impedance path between the control terminal CTR1 and ground, pulling the voltage at the CTR1 node down to a low level. This low-level signal immediately activates the first power switching module 3, allowing the first power supply 1 to supply power to the clock power supply node 7. It should be noted that in this embodiment, the maximum time required for stable power supply from the main power failure to QV1 being fully activated by BAT1 is less than 1ms.

[0033] In one alternative implementation, such as Figure 5 As shown, the second power switching module 4 includes: a fifth anti-reverse current unit DV5 (non-inverting dual diodes), a second switching transistor QV2 (PMOS transistor), and a sixth anti-reverse current unit DV6 (diode). The positive terminal BV2+ of the second power supply 2 is connected to the current input terminal of the fifth anti-reverse current unit DV5. The current output terminal of the fifth anti-reverse current unit DV5 is connected to the input terminal S of the second switching transistor QV2. The output terminal D of the second switching transistor QV2 is connected to the current input terminal of the sixth anti-reverse current unit DV6. The current output terminal of the sixth anti-reverse current unit DV6 is connected to the clock power supply node 7. The control terminal G of the second switching transistor QV2 is connected to the second control module 6.

[0034] In one alternative implementation, such as Figure 6As shown, the second control module 6 includes a voltage detection unit 60. The voltage detection unit 60 may include a power monitoring chip or a voltage comparison circuit; this embodiment uses a voltage detection unit 60 including a power monitoring chip as an example. Specifically, the power input terminal VDD and the voltage detection terminal VSS of the voltage detection unit 60 are both connected to the positive terminal BV1+ of the first power supply, and the output terminal OUT of the voltage detection unit 60 is connected to the control terminal CTR2 of the second power switching module 4. The voltage detection unit 60 is configured to provide a second control signal to the control terminal CTR2 of the second power switching module 4, indicating that the voltage of the first power supply is less than the first preset threshold, to turn on the second power switching module 4, when the voltage of the first power supply 1 is less than the first preset threshold. Furthermore, the voltage detection unit 60 is also configured to provide a second control signal to the control terminal CTR2 of the second power switching module 4, indicating that the voltage of the first power supply 1 is greater than or equal to the first preset threshold, to turn off the second power switching module 4, when the voltage of the first power supply 1 is greater than or equal to the first preset threshold.

[0035] As an example, when the power monitoring chip detects that the voltage of the first power supply is lower than a preset reference value (i.e., a first preset threshold), the OUT pin outputs a low level, and QV2 is turned on, at which point the second power supply supplies power to the clock power node. In this embodiment, the response time of the power monitoring chip from detecting that the voltage of the first power supply is lower than the first preset threshold to outputting a low level is approximately 60µs, and the built-in hysteresis voltage is approximately 155mV, which can achieve the effects of fast switching and reliable power supply.

[0036] In one embodiment, when the power monitoring chip detects that the voltage of the first power supply is less than the preset reference value of the power monitoring chip, it can prompt the user to replace the first battery through devices such as buzzers and indicator lights inside the energy meter.

[0037] In one embodiment, the second control module 6 further includes a seventh resistor RV7 (100kΩ). The seventh resistor RV7 is connected between the output terminal OUT of the voltage detection unit 60 and ground GND, providing a pull-down path for the control terminal CTR2 of the second power switching module 4. When the external lithium battery voltage is lower than the reference value of the power monitoring chip, it maintains the gate level of the PMOS transistor QV2 at a low level, ensuring reliable conduction of QV2. Furthermore, the voltage detection unit 60 also includes a third capacitor CV3, connected between the positive terminal BV1+ of the first power supply and the voltage detection terminal VSS. This capacitor stabilizes the supply voltage of the voltage detection unit 60, filters out high-frequency noise and transient interference, ensures stable and reliable voltage detection logic, and prevents malfunctions.

[0038] In one implementation, such as Figure 7As shown, the system also includes a first voltage sampling module 80 and a second voltage sampling module 81. VRTC is the clock power supply node 7. The first voltage sampling module 80 includes a first resistor RV1 and a fourth resistor RV4 connected in series between the positive terminal BV1+ of the first power supply and ground GND. The first signal sampling point Battery_1_ADC is connected between the first resistor RV1 and the fourth resistor RV4. A second capacitor CV2 is connected in parallel between the first signal sampling point Battery_1_ADC and ground GND. The second capacitor is used for filtering and decoupling, improving the accuracy and stability of the voltage sampling results. The voltage of BV1 can be calculated using the following formula: Battery_1_ADC measured value × ((RV1+RV4) / RV4).

[0039] Similarly, the second voltage sampling module 81 includes a sixth resistor RV6 and an eighth resistor RV8 connected in series between the positive terminal BV2+ of the second power supply and ground GND. The second signal sampling point Battery_2_ADC is connected between the sixth resistor RV6 and the eighth resistor RV8, and a first capacitor CV1 is connected in parallel between the second signal sampling point Battery_2_ADC and ground GND. The first capacitor is used for filtering and decoupling to improve the accuracy and stability of the voltage sampling results. The voltage of BV2 can be calculated using the following formula: Battery_2_ADC measured value × ((RV6+RV8) / RV8).

[0040] In one implementation, by optimizing the resistance values ​​of RV1, RV4, RV6, and RV8, the power consumption of the first and second power supplies during power-on can be reduced, the power supply life can be extended, and the power supply time can be made longer.

[0041] Another aspect of this application provides an electricity meter. For example... Figure 8 As shown, the energy meter 9 includes a system clock module 90 and a clock power supply switching system as described in any of the above embodiments. The clock power supply node 7 is connected to the power input terminal PWR of the system clock module 90 and is used to supply power to the system clock module 90 of the energy meter.

[0042] In one embodiment, the system clock module 90 can be implemented by a module integrated within the energy meter's microcontroller (MCU). All electronic components of the aforementioned clock power supply switching system (including but not limited to resistors, capacitors, diodes, transistors, and chips contained in the first control module 5, second control module 6, first power switching module 3, second power switching module 4, voltage sampling module 80, etc.) are laid out, wired, and soldered onto the circuit board (PCB) of the energy meter 9. The clock power supply node VRTC is directly connected to the corresponding functional pin of the energy meter's MCU via power traces on the PCB. The first signal sampling point Battery_1_ADC and the second signal sampling point Battery_2_ADC are connected to an analog-to-digital converter input pin of the MCU for monitoring the voltages of the first and second power supplies.

[0043] The energy meter provided in this embodiment supplies power to the clock power supply node when the system power supply is available. When the first control module detects that the system power supply is invalid, it quickly activates the first power switching module based on a first control signal to supply power to the clock power supply node. When the second control module detects that the voltage of the first power supply is less than a first preset threshold, it quickly activates the second power switching module based on a second control signal to supply power to the clock power supply node. This ensures continuous power supply to the system clock when the system power supply is invalid. The entire process is directly controlled by the hardware logic of the first power switching module, the second power switching module, the first control module, and the second control module, without any software intervention. This achieves automatic, fast, and reliable switching of the power supply to the energy meter system clock, solving the problems of software delay and single point of failure, and improving the reliability of the energy meter system clock power supply. It achieves the goal of ensuring continuous and stable operation of the energy meter system clock under any power outage and battery depletion scenarios, which is beneficial to ensuring the integrity and compliance of energy meter data.

[0044] The entire switching system of this energy meter consists of common discrete components (resistors, capacitors, diodes, MOSFETs) and a small number of dedicated chips, resulting in a simple circuit and low cost. All components are integrated on the main PCB of the energy meter, eliminating the need for external complex modules or continuous intervention from a high-performance MCU. This achieves extremely high reliability while maximizing hardware cost and power consumption control, making it highly suitable for large-scale production and widespread adoption. Furthermore, the energy meter can read the voltage of both the primary and secondary power supplies in real time, promptly monitoring their health status. It can also proactively alert users to maintenance when the power supply voltage is too low via local display, indicator lights, or remote communication, greatly improving product maintainability and user satisfaction. In summary, the energy meter of this application, with its highly cost-effective hardware solution, achieves automatic, rapid, and reliable switching of the energy meter system clock power supply, meeting the requirements of domestic and international users for data continuity, operational reliability, and long-term maintenance convenience.

[0045] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A clock power supply switching system for an electricity meter, characterized in that, include: The system includes a main power supply module, a first power supply, a second power supply, a first power supply switching module, a second power supply switching module, a first control module, a second control module, and a clock power supply node. The main power supply module is connected to the clock power supply node, and the main power supply module is configured to provide system power to the clock power supply node when the energy meter is working; The input terminal of the first power switching module is connected to the positive terminal of the first power supply, the output terminal of the first power switching module is connected to the clock power supply node, and the control terminal of the first power switching module is connected to the first control module. The first power switching module is configured to turn on or off the power supply from the first power supply to the clock power supply node in response to a first control signal output by the first control module, wherein the first control signal is used to indicate whether the system power supply is effective. The input terminal of the second power switching module is connected to the positive terminal of the second power supply, the output terminal of the second power switching module is connected to the clock power supply node, and the control terminal of the second power switching module is connected to the second control module. The second power switching module is configured to turn on or off the power supply from the second power supply to the clock power supply node in response to a second control signal output by the second control module, wherein the second control signal is used to indicate whether the voltage of the first power supply is less than a first preset threshold.

2. The clock power supply switching system for an electricity meter according to claim 1, characterized in that, The first power switching module includes a first anti-reverse current unit, a first switching transistor, and a second anti-reverse current unit. The positive terminal of the first power supply is connected to the current input terminal of the first anti-reverse current unit, the current output terminal of the first anti-reverse current unit is connected to the input terminal of the first switching transistor, the output terminal of the first switching transistor is connected to the current input terminal of the second anti-reverse current unit, and the current output terminal of the second anti-reverse current unit is connected to the clock power supply node.

3. The clock power supply switching system for an electricity meter according to claim 1, characterized in that, The main power supply module includes a main power supply terminal for providing power to the system. The first control module includes a first pull-up unit and a first pull-down unit. The first pull-up unit is connected between the main power supply terminal and the control terminal of the first power switching module and is configured to provide a first control signal to the control terminal of the first power switching module when the main power supply terminal is normally powered, indicating that the system power is valid and thus turning off the first power switching module. The first pull-down unit is connected between the control terminal of the first power switching module and ground, and is configured to provide a first control signal to the control terminal of the first power switching module indicating that the system power is invalid so as to turn on the first power switching module when the main power supply terminal cannot supply power normally.

4. The clock power supply switching system for an electricity meter according to claim 3, characterized in that, The main power supply module also includes a functional power supply terminal. The first pull-up unit includes a clamping diode, a second resistor, and a Zener diode. One end of the clamping diode is connected to the main power supply terminal. The other end of the clamping diode is connected to one end of the Zener diode and the control terminal of the first power switching module via the second resistor. The other end of the Zener diode is connected to the functional power supply terminal. The first pull-down unit includes a third resistor, which is connected between the control terminal of the first power switching module and ground.

5. The clock power supply switching system for an electricity meter according to claim 4, characterized in that, The first control module further includes a discharge unit, one end of which is connected between the Zener diode and the functional power supply terminal, and the other end of which is grounded. The discharge unit is used to provide a discharge path to ground for the functional power supply terminal.

6. The clock power supply switching system for an electricity meter according to claim 1, characterized in that, The second control module includes a voltage detection unit, the power input terminal and the voltage detection terminal of the voltage detection unit are both connected to the positive terminal of the first power supply, and the output terminal of the voltage detection unit is connected to the control terminal of the second power switching module. The voltage detection unit is configured to provide a second control signal to the control terminal of the second power switching module, indicating that the voltage of the first power supply is less than the first preset threshold, so as to turn on the second power switching module, when the voltage of the first power supply is less than the first preset threshold; the voltage detection unit is further configured to provide a second control signal to the control terminal of the second power switching module, indicating that the voltage of the first power supply is greater than or equal to the first preset threshold, so as to turn off the second power switching module, when the voltage of the first power supply is greater than or equal to the first preset threshold.

7. The clock power supply switching system for an electricity meter according to claim 6, characterized in that, The second control module also includes a seventh resistor; The seventh resistor is connected between the output terminal of the voltage detection unit and ground, and is used to provide a pull-down path for the control terminal of the second power switching module.

8. The clock power supply switching system for an electricity meter according to any one of claims 1 to 7, characterized in that, The first power source is a lithium battery located in the battery compartment of the electricity meter, and the second power source is a lithium battery located on the circuit board of the electricity meter.

9. The clock power supply switching system for an electricity meter according to any one of claims 1 to 7, characterized in that, The system further includes a first voltage sampling module and a second voltage sampling module, wherein the first voltage sampling module is connected between the positive terminal of the first power supply and ground, and is used to collect the voltage of the first power supply; the second voltage sampling module is connected between the positive terminal of the second power supply and ground, and is used to collect the voltage of the second power supply.

10. An electricity meter, characterized in that, The electricity meter includes: a system clock module; and a clock power supply switching system according to any one of claims 1 to 9, wherein the clock power supply node is connected to the power input terminal of the system clock module for supplying power to the system clock module.

Images