Emergency power supply management circuit and single-phase three-phase electric meter

Abstract

The present invention provides an emergency power supply management circuit for a single three-phase electric meter and a single three-phase electric meter. The circuit includes a power management chip, including an LDO constant current charging module, a boost module and a diode D2; a voltage stabilizing unit, including capacitors C4 and C5, for stabilizing the LDO output voltage; a supercapacitor, for storing the energy required for emergency power supply; and an MCU, which is the power consumption end of the emergency power supply management circuit and is used for controlling and monitoring the electric meter. The present invention can effectively provide a stable voltage output when the power supply is interrupted, ensuring the stable operation and rapid response of the system in an emergency.

Description

Technical Field

[0001] The present invention relates to the technical field of power system auxiliary equipment and power supply management, and more specifically, to an emergency power supply management circuit for a single-phase or three-phase electric meter. Background Art

[0002] In the existing power system, single-phase three-phase meters are key metering devices, and their stable operation is crucial to the accuracy of power supply and metering. However, the instability of the main power supply and sudden power outages may cause the meter to fail to work properly, thus affecting the reliability of the power system and the user's power experience. Existing emergency power supply solutions usually rely on bulky battery systems or complex circuit designs, which are not only costly, but also have problems such as large size, slow response speed, and difficult maintenance in actual applications.

[0003] In the process of implementing the embodiments of the present invention, the inventors found that there are at least the following problems or defects in the prior art: traditional emergency power supply systems often lack sufficient flexibility and adaptability, and it is difficult to respond quickly to power outages; the battery system has a limited life and needs to be replaced regularly, which increases maintenance costs; at the same time, complex circuit design may lead to poor system stability, making it difficult to maintain efficient operation in various environments. Summary of the invention

[0004] The invention provides an emergency power supply management circuit for a single three-phase electric meter and a single three-phase electric meter.

[0005] In a first aspect of the present invention, there is provided an emergency power supply management circuit for a single three-phase electric meter, comprising:

[0006] The power management chip includes an LDO constant current charging module with current limiting function, a boost module and a diode D2;

[0007] Voltage stabilizing unit, one end of the voltage stabilizing unit is connected to the output end of the boost module, and the other end is directly connected to GND, which is used to stabilize the BOOST output voltage;

[0008] The supercapacitor C3 is used to store the energy required for emergency power supply; the positive electrode of the supercapacitor C3 is connected to the input end of the boost module, and the negative electrode is directly connected to GND;

[0009] MCU is the power consumption end of the emergency power supply management circuit, which is used for controlling and monitoring the electric meter. The power input end of the MCU is connected to the output end of the LDO constant current charging module of the power management chip through a diode D2;

[0010] Lithium battery module for powering the MCU

[0011] As a further improvement of the present application, the LDO constant current charging module of the power management chip provides 5V power to the MCU in the first phase and charges the super capacitor C3 at the same time. The anode of the diode D2 is connected to the output end of the LDO constant current charging module, and the cathode is connected to the power input end of the MCU.

[0012] As a further improvement of the present application, in the second phase, when the 5V power supply disappears, the boost module uses the supercapacitor C3 to provide 3.8V power supply for the MCU. The boost module is connected to the supercapacitor C3 through the inductor L1, one end of the inductor L1 is connected to the positive electrode of the supercapacitor C3, and the other end is connected to the input end of the boost module.

[0013] As a further improvement of the present application, the lithium battery module includes a lithium battery E1 and a diode D1. In the third phase, the lithium battery E1 provides a 3.6V power supply to the MCU through the diode D1. The positive electrode of the lithium battery E1 is connected to the power input terminal of the MCU through the diode D1, and the negative electrode is directly connected to GND; wherein, the anode of the diode D1 is connected to the positive electrode of the lithium battery E1, and the cathode is connected to the power input terminal of the MCU. The diode D1 is used to prevent the current of the lithium battery E1 from flowing back into the voltage stabilizing unit or the power management chip.

[0014] As a further improvement of the present application, the voltage stabilizing unit includes a capacitor C4 and a capacitor C5 connected in parallel, one end of the capacitor C4 and the capacitor C5 are both connected to the output end of the boost module, and the other end are directly connected to GND.

[0015] As a further improvement of the present application, the capacity range of the supercapacitor C3 is 3.3F to 10F, the withstand voltage is 3V or 2.7V, and the negative electrode thereof is directly connected to GND.

[0016] As a further improvement of the present application, the capacity of capacitor C4 is 4.7uF and the rated voltage is 16V;

[0017] The capacity of capacitor C5 is 1uF and the rated voltage is 16V.

[0018] As a further improvement of this application, the GND connection method is:

[0019] The ground terminal of the power management chip is connected to GND;

[0020] The ground terminal of the voltage stabilizing unit is connected to GND;

[0021] The negative pole of supercapacitor C3 is directly connected to GND;

[0022] The ground terminal of MCU is connected to GND to form a common ground.

[0023] As a further improvement of the present application, the inductor L1 of the boost module has a nominal value of 2.2uH and a package of 0805, and is connected to the input end of the boost module;

[0024] Inductor L1 is connected in series between supercapacitor C3 and boost module, and is used to provide stable 3.8V power supply to MCU through boost module when 5V power supply disappears in the second phase;

[0025] One end of the inductor L1 is connected to the positive electrode of the supercapacitor, and the other end is connected to the input end of the boost module, forming a part of the boost circuit to achieve voltage conversion and stable output. In the second aspect of the present invention, a single three-phase electric meter is provided, comprising: the emergency power supply management circuit described in any one of the first aspects above, used to ensure that the electric meter can work stably in different power supply stages.

[0026] According to the above embodiment of the present invention, at least the following beneficial effects are achieved: the emergency power supply management circuit of the present invention can realize stable power supply to a single three-phase electric meter when the main power supply is interrupted through a carefully designed power management unit and an energy storage unit. The LDO constant current charging module and the boost BOOST module in the power management unit work together to ensure that the supercapacitor can efficiently store and release energy, thereby quickly switching to the emergency power supply mode when the power supply is interrupted. The addition of the MCU control unit can improve the intelligence level of the system, and can monitor and control the working state of the power management unit in real time, as well as accurately monitor and manage the system state. In addition, the setting of the first control unit and the second control unit can further enhance the control ability of the charging process and the boost BOOST module. Through the coordinated use of the voltage monitoring circuit and the diode, the reverse flow of current can be effectively prevented, and the charging safety of the supercapacitor and the stable operation of the circuit can be guaranteed. The parallel use of capacitors C4 and C5, and the parallel design of diodes D2, can improve the stability and anti-interference ability of the circuit. On the whole, the emergency power supply management circuit of the present invention is not only small in size and low in cost, but also has the characteristics of fast response, high reliability and easy maintenance, which can improve the emergency handling ability of the electric meter when facing power outages. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background technology, the drawings required for use in the embodiments of the present invention or the background technology will be described below.

[0028] Figure 1 A schematic diagram of a module of an emergency power supply management circuit for a single-phase three-phase electric meter provided in one embodiment of the present invention;

[0029] Figure 2A circuit diagram of an emergency power supply management circuit for a single three-phase electric meter provided in one embodiment of the present invention;

[0030] Figure 3 An output characteristic curve diagram of an LDO constant current charging module provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the technical means, creative features, objectives and effects achieved by the embodiments of the present invention easy to understand, the embodiments of the present invention are further described below in combination with diagrams and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention.

[0032] Those skilled in the art know that the embodiments of the present invention can be implemented as a system, device, apparatus, method or computer program product. Therefore, the present invention can be specifically implemented in the following forms, namely: complete hardware, complete software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0033] It should be noted that any number of elements in the drawings is for illustration rather than limitation, and any naming is only for distinction and does not have any limiting meaning.

[0034] Reference below Figure 1 , Figure 1 The module diagram of the emergency power supply management circuit for a single three-phase electric meter provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, an emergency power supply management circuit for a single three-phase electric meter includes:

[0035] The power management chip 101 includes an LDO constant current charging module with a current limiting function, a boost module and a diode D2;

[0036] The voltage stabilizing unit 102 includes a capacitor C4 and a capacitor C5, and is used to stabilize the BOOST output voltage;

[0037] Super capacitor 103, used to store energy required for emergency power supply;

[0038] MCU104 is the power consumption end of the emergency power supply management circuit and is used for controlling and monitoring the electric meter.

[0039] It should be noted that the power management chip is responsible for the conversion and distribution of electric energy. The LDO constant current charging module is part of the power management chip, which provides a stable charging current for the super capacitor C3; the boost module provides the necessary voltage conversion when the power supply voltage drops to ensure the power supply demand of the MCU; the diode D2 is used to ensure the power flow and prevent reverse current; the voltage stabilization unit is composed of capacitors C4 and C5, which work together to stabilize the voltage output by BOOST; the super capacitor C3, as an energy storage unit, provides the necessary energy reserve for emergency power supply; the MCU is the control center of the entire circuit, responsible for the control and monitoring of the meter. The parameters of capacitors C4 and C5 can be selected according to actual needs. For example, if higher voltage stability is required, a capacitor with larger capacity or higher rated voltage can be selected. The capacity and withstand voltage of the super capacitor C3 are also determined according to the emergency power supply demand of the meter. The capacity range of 3.3F to 10F and the withstand voltage of 3V or 2.7V are to ensure sufficient energy storage and safe use.

[0040] Furthermore, the power management chip integrates an LDO constant current charging module and a boost module. The LDO module provides a stable 5V power supply to the MCU in the first phase, and is connected to the MCU through a diode D2, while charging the supercapacitor C3. Diode D2 ensures that the current flows in one direction to prevent reverse current from damaging the power management chip.

[0041] More specifically, the selection of MCU can be determined according to the specific control requirements of the meter. For example, if complex data processing and communication functions are required, an MCU with high processing power and rich communication interfaces can be selected. In the configuration of the power management chip, the output voltage and current of the LDO can be set by programming to meet the charging requirements of different supercapacitors C3. In addition, the selection of diode D2 should also consider its maximum current carrying capacity and forward voltage drop to ensure efficient operation of the circuit. In practical applications, the circuit design can also be appropriately adjusted and optimized according to the specific use environment and power supply conditions of the meter.

[0042] like Figure 2 As shown, the power management chip provides 5V power to the MCU through D2 in the first phase, and the LDO charges the super capacitor C3.

[0043] It should be noted that the LDO module in the power management chip is responsible for converting the input voltage into a stable 2.5V output for charging the supercapacitor C3. Diode D2 plays a unidirectional role here, ensuring that the power can only flow from the power management chip to the MCU to avoid reverse current from damaging the circuit. The charging current of the LDO module can be set according to the capacity of the supercapacitor C3 and the required charging time to ensure charging efficiency and battery life. The first phase refers to the operation stage under normal supply of the main power supply. In this stage, the power management chip directly provides the 5V main power supply to the MCU through an integrated diode D2 to ensure its normal operation. At the same time, the LDO constant current charging module is also activated, using the main power supply to charge the supercapacitor C3 to prepare for possible power outages.

[0044] like Figure 3 As shown. Furthermore, the LDO module has a current limiting function, thereby providing a stable power supply for the MCU of the electric meter. When the output current of the LDO is lower than the set limit value, it maintains a constant output voltage. In some embodiments, the typical constant output voltage is 2.5V. This constant voltage mode is suitable for the MCU to work under low load, which can ensure the stability of the power supply and the reliable operation of the MCU.

[0045] When the output current reaches the current limit due to the increase in load, the typical current limit in this example is 50mA, and the LDO enters the current limit mode. In the current limit mode, the output voltage is no longer constant, but is dynamically adjusted according to the actual output current and load resistance. This adjustment ensures that the circuit will not be damaged due to excessive current even under high load conditions, thereby improving the safety and reliability of the entire power system.

[0046] The output voltage of the LDO is adjusted based on the load resistance and the current limit, as shown in the following formula:

[0047] ;

[0048] in, is the output voltage of the LDO, is the current limiting current, is the load resistance.

[0049] Preferably, the output voltage of the BOOST module can be accurately set by adjusting its internal feedback resistor to meet the power supply requirements of the MCU. The selection of diode D2 should take into account its maximum current carrying capacity to adapt to the possible maximum load situation. In addition, in order to improve the reliability of the system, an overcurrent protection circuit can be added between diode D2 and the MCU to prevent excessive current from damaging the MCU under abnormal conditions.

[0050] More specifically, an adjustable charging current, such as 50mA, can be set for the LDO module to accommodate supercapacitors C3 of different capacities. At the same time, Schottky diodes can be selected as D2 because they have low forward voltage drop and fast switching characteristics, which are suitable for high-efficiency power conversion circuits. In practical applications, a power management chip with overcurrent protection function can also be considered to reduce the complexity of external circuit design. In addition, a power monitoring circuit can be designed at the power input end of the MCU to monitor the power status in real time and take corresponding protection measures when the power supply is abnormal.

[0051] In some embodiments, in the second phase, when the 5V power supply disappears, the BOOST module uses the super capacitor C3 to provide 3.8V power supply for the MCU.

[0052] It should be noted that when the 5V power supply disappears, the boost module uses supercapacitor C3 to provide 3.8V power to the MCU. This is an emergency power supply mechanism in the circuit design, which ensures that the meter can still maintain basic operation when the main power supply fails. The second phase occurs when the main power supply is no longer available. At this time, the power management chip switches to the boost module and uses the energy stored in supercapacitor C3 to provide the required 3.8V power to the MCU. The role of the boost module is to increase the voltage of supercapacitor C3 to a voltage level at which the MCU can work normally after the power supply is interrupted, thereby achieving seamless power switching and ensuring that the meter continues to operate.

[0053] In the second phase, when the 5V power supply is unavailable, the boost module starts, using the energy stored in the supercapacitor C3 to provide 3.8V power to the MCU through the inductor L1. The inductor L1 is connected in series with the supercapacitor C3, with one end connected to the positive electrode of the supercapacitor C3 and the other end connected to the input of the boost module, forming a boost circuit to achieve voltage conversion and stable output.

[0054] Specifically, the boost module is an important component of the power management chip. Its main function is to increase the voltage to the required level through the cooperation of inductor L1 and switching elements when the input voltage is lower than the output voltage. Supercapacitor C3 plays a key energy buffering role in this process. It stores energy when the power supply is working normally and quickly releases energy when the power supply fails to maintain the power supply of the MCU. 3.8V is the operating voltage required by the MCU when there is no 5V power supply. This voltage value is determined according to the power supply specification of the MCU.

[0055] Preferably, the design of the boost module can adopt a high-efficiency topology, such as SEPIC or a non-isolated boost converter, to reduce losses during energy conversion. The parameter selection of the inductor L1 needs to consider its nominal value, package size, and the degree of matching with the supercapacitor C3. For example, the nominal value of the inductor L1 can be 2.2uH and the package is 0805. Such a choice can ensure a fast response to power changes in the second phase while maintaining a small volume. In addition, in order to further improve the reliability of the system, it is possible to consider adding overcurrent protection and short-circuit protection mechanisms to the boost module to prevent the supercapacitor C3 from damaging the circuit under abnormal circumstances.

[0056] More specifically, the power management interface of the MCU can be designed to accept an input voltage of 3.8V and automatically switch to the power provided by the boost module when the power supply is unstable. In practical applications, it is also possible to consider adding a voltage monitoring circuit to monitor the MCU's power supply voltage in real time. Once the voltage is detected to be lower than the preset threshold, the boost module is immediately started. In addition, in order to improve the flexibility and adaptability of the system, it is possible to consider designing a multi-level voltage conversion solution. For example, when the supercapacitor C3 is fully charged, a more efficient boost solution is used; when the power is insufficient, switch to a less efficient but more stable solution to ensure the continuous operation of the MCU.

[0057] In some embodiments, in the third phase, the lithium battery E1 provides a 3.6V power supply to the MCU through the diode D1.

[0058] It should be noted that the boost module is an important component of the power management chip. It can provide stable power through boost conversion when the input voltage is lower than the required output voltage. Supercapacitor C3 plays the role of energy buffer here. It stores energy when the power is normal and quickly releases energy when the power is gone to maintain the operation of the MCU. 3.8V is the power supply voltage required by the MCU in this particular case. This value is determined according to the operating voltage requirements of the MCU.

[0059] In some embodiments, the third phase is started after the second phase when the super capacitor C3 is exhausted and can no longer provide sufficient voltage to the MCU. If the circuit design includes an additional power source, such as a lithium battery E1, then at this stage, the lithium battery E1 provides a 3.6V power supply to the MCU through a diode D1. Diode D1 here ensures that the current flows in one direction, prevents power backflow, and protects the lithium battery. This stage is the last line of defense of the circuit design to ensure that the MCU can maintain basic operation after all other power options are exhausted.

[0060] The lithium battery E1 provides 3.6V power to the MCU through the diode D1 in the third phase. The anode of the diode D1 is connected to the positive electrode of the lithium battery E1, and the cathode is connected to the power input terminal of the MCU to prevent the current from flowing back into the voltage stabilizing unit or the power management chip.

[0061] Preferably, the design of the boost module can use an efficient boost converter, such as a chip with high switching frequency and high conversion efficiency, to reduce energy loss and improve power supply stability. The selection of supercapacitor C3 should take into account its capacity, withstand voltage, and charge and discharge rate to ensure that the required energy can be quickly provided when the power disappears. For example, a supercapacitor C3 with a capacity of 5F and a withstand voltage of 2.7V can be selected to meet the needs of fast discharge and large energy output. In addition, the working state of the MCU under a 3.8V power supply can be optimized through software programming to ensure that it can operate stably under low voltage conditions. As an alternative, other types of energy storage elements, such as lithium-ion batteries or nickel-metal hydride batteries, can be considered, but this will require additional circuit design to manage the battery charging and discharging process.

[0062] In some embodiments, the capacitor C4 and the capacitor C5 of the voltage stabilizing unit are:

[0063] Capacitor C4, capacity is 4.7uF, rated voltage is 16V;

[0064] Capacitor C5, capacity is 1uF, rated voltage is 16V;

[0065] The two are connected in parallel at the BOOST output to stabilize the output voltage.

[0066] It should be noted that capacitors C4 and C5 are key components of the voltage stabilization unit. They are connected in series at the BOOST output end and work together to stabilize the output voltage. The capacity of capacitor C4 is 4.7uF and the rated voltage is 16V, while the capacity of capacitor C5 is 1uF and the rated voltage is also 16V. The capacity (uF) indicates the ability of the capacitor to store charge, while the rated voltage (V) is the maximum voltage that the capacitor can withstand. Exceeding this voltage may cause damage to the capacitor. Parallel connection means that the capacitance of the two capacitors will be added, but the total current remains unchanged, which can improve the ability of the entire circuit to suppress voltage fluctuations.

[0067] The voltage stabilizing unit is composed of capacitors C4 and C5, which are connected in parallel at the output end of the boost module to stabilize the output voltage of the boost module. The capacity of capacitor C4 is 4.7uF and the rated voltage is 16V; the capacity of capacitor C5 is 1uF and the rated voltage is also 16V.

[0068] Preferably, the selection of capacitor C4 and capacitor C5 can be adjusted according to the needs of the actual circuit. For example, if a higher energy storage capacity is required, a capacitor with a larger capacity can be selected; if the circuit has higher requirements for voltage stability, a capacitor with a higher rated voltage can be selected to provide a larger safety margin. In addition, there are many options for capacitor types, such as ceramic capacitors, electrolytic capacitors, etc., each type has its specific characteristics and application scenarios. In actual design, it is also possible to consider using multiple capacitors in parallel to further optimize the performance of the circuit, such as by connecting multiple capacitors of the same or different capacities in parallel to achieve a smoother voltage response and higher energy density. At the same time, it is also possible to consider using capacitors with higher withstand voltage ratings to cope with possible voltage spikes, thereby improving the reliability and stability of the circuit.

[0069] In some embodiments, the capacity of the super capacitor C3 ranges from 3.3F to 10F, and the withstand voltage is 3V or 2.7V.

[0070] It should be noted that the capacity range and withstand voltage value of the supercapacitor C3 are key parameters to ensure that the electric meter can work normally under emergency power supply conditions.

[0071] Specifically, the capacity range of supercapacitor C3 refers to the amount of charge it can store. The larger the capacity, the more energy it can store. Accordingly, the meter can maintain normal operation for a longer time in the event of a power outage. The withstand voltage value refers to the maximum voltage that supercapacitor C3 can withstand. Selecting an appropriate withstand voltage value can prevent supercapacitor C3 from being damaged during charging or power supply. During design, the capacity of supercapacitor C3 can be determined based on the power consumption of the meter and the expected power-off time, and the withstand voltage value of supercapacitor C3 can be determined based on the LDO output voltage of the power management chip.

[0072] Preferably, the capacity of supercapacitor C3 can be set between 3.3F and 10F, which can meet the emergency power supply requirements of most single-phase three-phase meters. The withstand voltage value can be selected as 3V or 2.7V, depending on the output voltage of the power management chip and the charging voltage of supercapacitor C3. For example, if the LDO output voltage of the power management chip is 2.5V, then a supercapacitor C3 with a withstand voltage of 3V can be selected to ensure sufficient safety margin during the charging process. In addition, the selection of supercapacitor C3 should also consider factors such as its charging and discharging efficiency, life and environmental adaptability.

[0073] More specifically, during the implementation process, the capacity and withstand voltage value of the supercapacitor C3 can be fine-tuned according to the actual situation and usage environment of the electric meter. For example, if the usage environment of the electric meter is relatively harsh, it may be necessary to select a supercapacitor C3 with a higher withstand voltage value to improve the reliability of the system. At the same time, the total energy storage capacity can be increased by increasing the number of supercapacitors C3 to cope with longer power outages. When selecting supercapacitors C3, their volume and weight can also be considered to ensure that they can adapt to the physical space limitations of the electric meter. In addition, a hybrid energy storage solution using supercapacitors C3 and lithium batteries can also be considered to further improve the flexibility and reliability of the system.

[0074] In some embodiments, the diode D1 is used to prevent the current of the lithium battery E1 from flowing reversely into the voltage stabilizing unit or the power management chip.

[0075] It should be noted that the role of the diode D1 in the circuit is to prevent the current of the lithium battery E1 from flowing back into the voltage stabilizing unit or the power management chip, which ensures the safety and stability of the circuit.

[0076] Specifically, diode D1 plays the role of current direction control here, which only allows current to flow from lithium battery E1 to MCU, but not to flow in the opposite direction. This unidirectional conductivity is the basic function of the diode, which is essential for protecting other components in the circuit from damage caused by reverse current. As a power supply option for the circuit, lithium battery E1 usually has a voltage of about 3.6V, and diode D1 needs to be able to withstand a voltage of 5V and have sufficient current carrying capacity.

[0077] Preferably, the selection of diode D1 should take into account parameters such as its forward voltage drop, maximum current carrying capacity, and reverse recovery time. For example, Schottky diodes can be selected because they have low forward voltage drop and fast switching characteristics. In practical applications, a diode with a corresponding rating can be selected based on the output current and voltage characteristics of the lithium battery E1. In addition, in order to further improve the safety of the circuit, an overcurrent protection circuit can be added between the diode D1 and the lithium battery E1 to prevent excessive current from damaging the circuit under abnormal conditions.

[0078] More specifically, the forward voltage drop of diode D1 should be as low as possible to reduce energy loss; the maximum current carrying capacity should be higher than the maximum current that may appear in the circuit to ensure that the diode does not become a bottleneck for current flow under any circumstances. When selecting a diode, you can also consider its package size to accommodate the space layout requirements of the circuit board. As an alternative, you can consider using MOSFET as an electronic switch to control the direction of current, which may be more appropriate when more precise control of the current flow is required.

[0079] In some embodiments, the GND connection is:

[0080] The ground terminal of the power management chip is connected to GND;

[0081] The ground terminal of the voltage stabilizing unit is connected to GND;

[0082] The negative pole of supercapacitor C3 is directly connected to GND;

[0083] The ground terminal of MCU is connected to GND to form a common ground.

[0084] It should be noted that the ground terminal of the power management chip is connected to GND, which ensures that the reference point of the power management chip is consistent with the ground potential of the entire circuit system, thereby ensuring the stability and safety of the power supply. The ground terminal of the voltage stabilizing unit is also connected to GND, ensuring the stability of the output voltage of the voltage stabilizing unit. The negative pole of the supercapacitor C3 is directly connected to GND, which is to quickly and effectively transfer energy to the circuit during the discharge process. The ground terminal of the MCU is connected to GND to form a common ground, which helps to reduce noise and interference during signal transmission.

[0085] Preferably, the design of the ground wire (GND) should take into account minimizing impedance and maximizing current carrying capacity to ensure the stability of the circuit under high current load. In actual circuit design, this can be achieved by using thick copper wire or multiple parallel thin copper wires. In addition, in order to reduce electromagnetic interference, the ground wire should be as short and direct as possible to avoid forming loops. In some cases, it may also be necessary to use a ground plane or ground grid to improve the grounding effect of the circuit.

[0086] More specifically, the ground connection between the power management chip and the MCU can be achieved by star grounding or multi-point grounding to reduce mutual interference between ground lines. The connection between the negative electrode of the supercapacitor C3 and GND can use highly conductive materials, such as copper foil, to ensure a fast response during discharge. In addition, the connection between the ground terminal of the voltage stabilizing unit and GND can further stabilize the voltage by using appropriate decoupling capacitors, which can be placed near the power management chip and MCU to provide local voltage stability. In some applications, isolation technology can also be considered to further improve the safety and anti-interference ability of the circuit.

[0087] In some embodiments, the boost module includes an inductor L1, with a nominal value of 2.2uH and a package of 0805, connected to the input end of the boost module;

[0088] Inductor L1 is connected between supercapacitor C3 and BOOST module to provide stable 3.8V power supply to MCU through boosting BOOST module in the second phase when 5V power supply disappears;

[0089] One end of the inductor L1 is connected to the positive electrode of the supercapacitor C3, and the other end is connected to the input end of the boost module, forming a part of the boost circuit to achieve voltage conversion and stable output.

[0090] It should be noted that the boost module is a key part of the emergency power supply management circuit, which is used to ensure that the MCU can obtain a stable 3.8V power supply in the second phase, that is, when the 5V power supply disappears.

[0091] Specifically, the boost module consists of an inductor L1, a boost controller, and necessary capacitors and diodes. Inductor L1 is the core component of the boost circuit, which is connected to the positive electrode of the supercapacitor C3 to provide the necessary energy conversion and voltage stability. The nominal value of the inductor L1 is 2.2uH, and the package is 0805. These parameters determine the current carrying capacity and volume of the inductor. One end of the inductor L1 is connected to the positive electrode of the supercapacitor C3, and the other end is connected to the input end of the boost module, in order to form a complete boost circuit to achieve voltage conversion and stable output.

[0092] Preferably, the selection of inductor L1 can be determined based on the discharge characteristics of the supercapacitor C3 and the power supply requirements of the MCU. For example, if the discharge curve of the supercapacitor C3 is steeper, an inductor with a higher current carrying capacity may be required. The selection of the boost controller is also very important. It needs to be able to accurately control the charging and discharging process of the inductor to ensure the stability of the output voltage. In addition, the boost BOOST module may also include some auxiliary capacitors and diodes to filter out noise and improve efficiency. The nominal value of inductor L1 is 2.2uH, the package is 0805, and it is connected to the input of the boost BOOST module to ensure that when the 5V power supply disappears, a stable 3.8V power supply can be provided to the MCU.

[0093] More specifically, the parameters of the inductor L1 can be optimized based on the capacity of the supercapacitor C3 and the power consumption requirements of the MCU to ensure that after the 5V power supply disappears, it can quickly switch to the 3.8V output and maintain a stable power supply. In practical applications, the parameter settings of the boost controller can also be adjusted to adapt to different load changes and power supply conditions to ensure the reliability and efficiency of the circuit. If necessary, other types of inductors or boost modules can also be considered to meet specific design requirements or cost considerations.

[0094] The above-mentioned embodiments of the present invention have the following beneficial effects: Through the emergency power supply management circuit of the present invention, continuous and stable power supply to a single three-phase electric meter can be achieved when the main power supply is interrupted. In the circuit design, the combined use of the LDO constant current charging module and the boost BOOST module, as well as the supercapacitor C3 as an energy storage unit, can ensure that it can quickly switch to the backup power supply in an emergency and maintain the continuous operation of the electric meter. The addition of the MCU control unit can improve the intelligence level of the system, monitor and control the working state of the power management unit in real time, and accurately monitor and manage the system state. In addition, through the carefully designed voltage monitoring and control logic, the circuit can automatically activate the boost BOOST module when the voltage of the supercapacitor C3 is lower than the set threshold to ensure the stability of the output voltage. The parallel use of capacitors C4 and C5, and the reasonable layout of diodes D1 and D2, can further improve the stability and safety of the circuit. In addition, the emergency power supply management circuit of the present invention has a high degree of integration and reliability. The LDO, boost BOOST module and diode D2 are integrated in a compact DFN1.5×1.5-6 package, which can reduce external connections and interference and simplify the layout and manufacturing process of the circuit. The reasonable connection method of GND can provide a stable reference potential and working voltage for the entire system, and the careful selection of the capacity and withstand voltage level of supercapacitor C3 can meet the requirements of energy density and withstand voltage in different application scenarios. These designs can not only improve the emergency handling capability of the meter in the face of power outages, but also reduce maintenance costs, extend the service life of the equipment, and provide users with an efficient and reliable power metering solution.

[0095] Another embodiment of the present invention provides a single three-phase electricity meter, which includes an emergency power supply management circuit in any of the above embodiments, used to ensure that the electricity meter can work stably in different power supply stages.

[0096] It is understandable that the modules recorded in the single three-phase meter are consistent with the reference Figure 1 , Figure 2 Therefore, the operations, features and beneficial effects described above for the emergency power supply management circuit for single-phase and three-phase electricity meters are also applicable to single-phase and three-phase electricity meters and the modules contained therein, and will not be repeated here.

[0097] The above descriptions are only some preferred embodiments of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the embodiments of the present invention is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the embodiments of the present invention.

Claims

1. An emergency power supply management circuit for a single three-phase electric meter, characterized in that: The circuit comprises: The power management chip includes an LDO constant current charging module with current limiting function, a boost module and a diode D2; Voltage stabilizing unit, one end of the voltage stabilizing unit is connected to the output end of the boost module, and the other end is directly connected to GND, which is used to stabilize the BOOST output voltage; The supercapacitor C3 is used to store the energy required for emergency power supply; the positive electrode of the supercapacitor C3 is connected to the input end of the boost module, and the negative electrode is directly connected to GND; MCU is the power consumption end of the emergency power supply management circuit, which is used for controlling and monitoring the electric meter. The power input end of the MCU is connected to the output end of the LDO constant current charging module of the power management chip through a diode D2; Lithium battery module, used to power the MCU; Among them, the LDO constant current charging module of the power management chip provides 5V power for the MCU in the first phase and charges the super capacitor C3 at the same time. The anode of the diode D2 is connected to the output end of the LDO constant current charging module, and the cathode is connected to the power input end of the MCU; in the second phase, when the 5V power disappears, the boost module uses the super capacitor C3 to provide 3.8V power for the MCU. The boost module is connected to the super capacitor C3 through the inductor L1. One end of the inductor L1 is connected to the positive electrode of the super capacitor C3, and the other end is connected to the input end of the boost module; the lithium battery module includes a lithium battery E1 and a diode D1. In the third phase, the lithium battery E1 provides a 3.6V power supply for the MCU through the diode D1. The positive electrode of the lithium battery E1 is connected to the power input end of the MCU through the diode D1, and the negative electrode is directly connected to GND; wherein, the anode of the diode D1 is connected to the positive electrode of the lithium battery E1, and the cathode is connected to the power input end of the MCU. The diode D1 is used to prevent the current of the lithium battery E1 from flowing back into the voltage stabilizing unit or the power management chip.

2. The emergency power supply management circuit according to claim 1, characterized in that: The voltage stabilizing unit includes a capacitor C4 and a capacitor C5 connected in parallel. One end of the capacitor C4 and the capacitor C5 are both connected to the output end of the boost module, and the other end are both directly connected to GND.

3. The emergency power supply management circuit according to claim 2, characterized in that: The capacity range of the super capacitor C3 is 3.3F to 10F, the withstand voltage is 3V or 2.7V, and the negative electrode thereof is directly connected to GND.

4. The emergency power supply management circuit according to claim 3, characterized in that: The capacity of capacitor C4 is 4.7uF and the rated voltage is 16V; The capacity of capacitor C5 is 1uF and the rated voltage is 16V.

5. The emergency power supply management circuit according to claim 4, characterized in that: GND connection method is: The ground terminal of the power management chip is connected to GND; The ground terminal of the voltage stabilizing unit is connected to GND; The negative pole of supercapacitor C3 is directly connected to GND; The ground terminal of MCU is connected to GND to form a common ground.

6. The emergency power supply management circuit according to claim 5, characterized in that: The inductor L1 of the boost module has a nominal value of 2.2uH and a package size of 0805, and is connected to the input end of the boost module; Inductor L1 is connected in series between supercapacitor C3 and boost module, and is used to provide stable 3.8V power supply to MCU through boost module when 5V power supply disappears in the second phase; One end of the inductor L1 is connected to the positive electrode of the supercapacitor, and the other end is connected to the input end of the boost module, forming a part of the boost circuit to achieve voltage conversion and stable output.

7. A single three-phase electric meter, characterized in that: The emergency power supply management circuit comprising any one of claims 1 to 6 is used to ensure that the electric meter can operate stably in different power supply stages.

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