High-integration-level low-power-consumption micro-miniature electric meter

Abstract

The utility model relates to a high-integration-level low-power-consumption microminiature electric meter, and belongs to the field of electric energy metering. The electric meter adopts the SoC chip design, integrates an analog circuit and a digital circuit, and has a plurality of low-power-consumption modes. An analog circuit of the SoC chip comprises an on-chip power management module, a programmable gain amplifier (PGA) and a Delta-Sigma ADC, and an operational amplifier tube of the analog circuit works in a sub-threshold region to reduce power consumption. The digital circuit of the SoC chip comprises a storage unit, a calculation unit and an I2Camp; and the SPI module and the state register are used for controlling the working mode of the electric meter and communicating with external equipment. The utility model provides a high-integration low-power consumption microminiature electric meter, which has the advantages of low power consumption, small volume, easiness in installation and the like, is suitable for various electric energy metering scenes, and is particularly suitable for use scenes such as fields, remote areas and the like which are inconvenient to maintain.

Description

Technical Field

[0001] The utility model belongs to the field of electric energy metering and relates to a highly integrated low-power micro-meter. Background Technique

[0002] At present, with the development of smart electric energy meters, traditional induction electric energy meters are gradually replaced by rail-mounted smart meters because they require a large space for installation and are restricted by factors such as time and space during installation. The rail-mounted electric energy meter has a more flexible and convenient installation method. It can be installed through a rail, which can greatly save space and installation costs compared with traditional meters. For places where electrical equipment using single-phase electric energy meters is concentrated, such as some units with a large number of people and communities with centralized installation of electric meters, reducing the installation complexity and saving space better meet the user's needs. Although the volume of the rail-mounted electric energy meters on the market has been reduced and the level of intelligence has been increased, the power consumption of the vast majority of current single-phase rail-mounted electric energy meters is about 3W - 5W. Although the power consumption is lower than that of traditional meters, it is not conducive to the protection of the interests of users and power enterprises when facing large-scale use and centralized management. In addition, due to the increasing number of household appliances and high-power equipment, the power consumption of the electric energy meter itself will affect the accurate measurement of electric energy. And the power consumption of the electric energy meter itself will seriously affect some outdoor usage scenarios. For example, in the usage scenario where it is not convenient to perform offline meter reading in the wild, the excessive power consumption of the electric energy meter will seriously limit the service life of the backup battery, and it is not convenient for meter installation and modulation and data transmission and maintenance of the electric energy meter after the power grid power failure. Content of the Utility Model

[0003] In view of this, the purpose of the utility model is to provide a highly integrated low-power micro-meter. This electric energy meter not only occupies a small space and is easy to install, but also can perform electric energy metering work with low power consumption. While ensuring accurate measurement, it can achieve lower power consumption, and the designed low-power mode can extend the service life of the backup battery in usage scenarios where maintenance is not convenient.

[0004] To achieve the above purpose, the utility model provides the following technical solutions:

[0005] A highly integrated low-power micro-meter, comprising:

[0006] SoC chip, the SoC chip includes an analog circuit and a digital circuit, the analog circuit includes a programmable gain amplifier (PGA), on-chip power management, and a Delta-Sigma ADC. The operational amplifier transistors of the PGA and the Delta-Sigma ADC operate in the subthreshold region. The digital circuit includes a storage unit, a computing unit, an I2C & SPI module, and a status register. The storage unit, the computing unit, the I2C & SPI module, and the status register are all connected to the analog circuit; the storage unit is connected to the computing unit, and the I2C & SPI module and the status register are both connected to the storage unit;

[0007] Signal acquisition module 2, the signal acquisition module is used to acquire current signals and voltage signals. The signal acquisition module passes through the PGA and the Delta-Sigma ADC in sequence;

[0008] RS485 communication module 4, the RS485 communication module 4 is connected to the RS485 communication module driver module 17;

[0009] RS485 communication module driver module 17, the RS485 communication module driver module is connected to the RS485 communication module and the storage module;

[0010] Display panel, the display panel is used to display power metering information, and the display panel is connected to the digital circuit;

[0011] Magnetic latching relay 6, the magnetic latching relay is used to control the on and off of the power supply. The magnetic latching relay is connected to the power supply and the relay driver.

[0012] Further, the analog circuit of the SoC chip further includes an internal driver operational amplifier, and the internal driver operational amplifier adopts a Class AB structure.

[0013] Further, the power management module includes three power management modules, which are respectively used to supply power to the relay driver, the analog circuit of the SoC chip, and the digital circuit.

[0014] Further, the display panel is an LCD display panel.

[0015] The beneficial effects of the present utility model are as follows: It realizes the low-power design of the electricity meter. In full voltage loss mode 1, the effective current value is calculated to detect the full voltage loss situation. In full voltage loss mode 2, a preliminary judgment of the full voltage loss current value is carried out. After the power grid power failure, it can automatically switch to the sleep mode powered by the backup power supply, with only the SPI and AVCC power supply monitoring working, while closing other circuits to minimize power consumption as much as possible. Therefore, users can use this electricity meter to complete low-power electricity metering work. Even in the event of a power grid power failure, it can rely on a variety of low-power working modes to operate and calculate for a period of time, making the electricity meter more suitable for diverse and complex usage environments and enhancing the stability of the electricity meter's operation in the case of power failure. It provides a solution for the debugging and detection of electricity meters installed in the wild.

[0016] Other advantages, objectives, and features of the present utility model will be elaborated to some extent in the subsequent description, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present utility model. The objectives and other advantages of the present utility model can be achieved and obtained through the following description. Brief Description of the Drawings

[0017] In order to make the objectives, technical solutions, and advantages of the present utility model clearer, the present utility model will be described in detail and preferably in conjunction with the accompanying drawings, where:

[0018] Figure 1 It is the structural block diagram of the SoC system used in the electricity meter;

[0019] Figure 2 It is the schematic diagram of the low-power mode;

[0020] Figure 3 It is the structural block diagram of the electricity meter.

[0021] Reference numerals: signal acquisition module 2, on-chip power management module 3, RS485 communication module 4, magnetic latching relay 6, relay drive circuit 7, metering module 9, I2C & SPI module 10, status register 11, storage module 12, HPLC module 13, LCD drive module 14, temperature compensation module 15, LCD display panel 16, RS485 communication module drive module 17, Bluetooth module 18, first power management module 31, second power management module 32, third power management module 33. Detailed Embodiment

[0022] The following describes the implementation manners of the present utility model through specific examples. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present utility model in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0023] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams rather than actual diagrams, and should not be construed as a limitation to the present utility model; in order to better illustrate the embodiments of the present utility model, some components in the drawings will be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0024] In the drawings of the embodiments of the present utility model, the same or similar reference numerals correspond to the same or similar components; in the description of the present utility model, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation to the present utility model. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0025] The technical solution adopted by the present utility model is a low-power micro-miniature electric energy meter. Low-power design is adopted in the design of the meter SoC chip, and three low-power modes are designed for different situations of the power grid. The structure block diagram of the SoC used in the present utility model is as Figure 1 shown. Among them, the main energy-consuming core is the metering module, and the power consumption of the analog circuit in the metering module is the largest. In order to reduce the power consumption in the metering state, the present utility model adopts low-power technology to design the analog part: the amplification tubes of the programmable gain amplifier PGA and the operational amplifier in the Delta-Sigma ADC work in the subthreshold region to obtain the maximum gain under the same current; the internal driver operational amplifier adopts a Class AB structure to reduce its static power consumption. Finally, the current consumed by the analog circuit part of the metering chip is 3 mA.

[0026] A highly integrated low-power micro-miniature electric meter, comprising:

[0027] SoC chip, the SoC chip includes an analog circuit and a digital circuit, the analog circuit includes an on-chip power management 3, an RS485 communication module driving module 17, an LCD driving 14, a temperature compensation 15 and a metering module 9, the metering module includes a programmable gain amplifier PGA, and a Delta-Sigma ADC, the amplifier tubes of the PGA and the Delta-Sigma ADC operational amplifiers operate in the subthreshold region, the digital circuit includes an I2C & SPI module 10, a status register 11, a storage module 12, a Bluetooth module 18, an HPLC module 13;

[0028] A signal acquisition module 2, the signal acquisition module 2 is used to acquire current signals and voltage signals, and the signal acquisition module 2 passes through the metering module and the storage module in sequence;

[0029] A first power management module 31, connected to an external power supply, supplies power to the relay driving circuit and the second power management module; a second power module 32 supplies power to the on-chip power management module 3, the metering module 9, the temperature compensation module 15, the RS485 communication module driving module 17 and a third power management module, and a third power module 33 supplies power to the I2C & SPI module 10, the status register 11, the storage module 12, the HPLC module 13 and the Bluetooth module 18. The RS485 communication module driving module 17, the LCD driving module 14, the I2C & SPI module 10, the Bluetooth module 18, and the HPLC module 13 are all connected to the storage module 12 to receive the data inside the storage module. The status register 11 is respectively connected to the I2C & SPI module 10 and the metering module 9, and the purpose is to configure the status register 11 through the I2C & SPI module 10, thereby modifying the internal settings of the metering module 9;

[0030] An RS485 communication module 4, the RS485 communication module 4 is connected to the RS485 communication module driving module 17;

[0031] An RS485 communication module driving module 17, the RS485 communication module driving module is connected to the RS485 communication module and the storage module;

[0032] An LCD display panel 16, used to display power metering information, the LCD display panel 16 is connected to the digital circuit;

[0033] A magnetic latching relay 6, the magnetic latching relay is used to control the on and off of the power supply, the magnetic latching relay is connected to the first power management module 31; the magnetic latching relay 6 is connected to the relay driving circuit 7;

[0034] Among them, the SOC chip has a full voltage loss mode 1, and the full voltage loss mode 1 is used to calculate the effective value of the current in the case of a full grid voltage loss;

[0035] Among them, the SOC chip has a full power failure mode 2, and the full power failure mode 2 is used to predict the full power failure current under the condition of full power failure of the power grid;

[0036] Among them, the SOC chip has a sleep mode, and the sleep mode is used for the operation mode powered by a backup power supply after the power grid power failure;

[0037] Among them, the I2C&SPI module of the SOC chip is used to control the SOC chip to switch between different low-power modes.

[0038] The three low-power modes are: full power failure mode 1, which realizes the measurement of the effective value of the low-power current; full power failure mode 2, which realizes the prediction of the low-power full power failure current; sleep mode, which is used for the operation mode of the electric meter powered by a backup battery after the power grid power failure. By transmitting a control signal to the digital circuit and turning off most of the digital circuits, low power consumption is achieved. The working block diagrams of the three modes are as Figure 2 shown. The user can configure the electric energy meter to work in the full power failure mode 1. The chip starts to calculate the effective value of the current, and the result is within the range of 800:1, and the non-linear error is less than 0.5%. When the voltage is lower than the critical voltage of the electric energy meter, the used DC correction register is used to replace the high-pass filter to eliminate the offset error, reduce the energy consumption, and the stable time of the full power failure effective value measurement is 60ms. After the value in the current effective value register is stable, the user can read the current effective value register to make a full power failure judgment. An interrupt is generated after the calculation is completed, and it is only valid in the full power failure mode 1. The current of the electric energy meter in the full power failure mode is 1.5mA, achieving power consumption reduction.

[0039] After the full power failure mode 1 interrupt is generated, the full power failure mode 2 starts to work, predicts the full power failure current, reduces the power consumption by extending the current calculation time, and only its dedicated comparator and part of the digital circuit in the circuit work, and the working current of the circuit is 120uA. In the working state of the full power failure mode 2, a current comparison is started once every 60s, the comparison result is stored in the corresponding register, and compared with the threshold value, then it is judged as a power failure situation, an interrupt is generated, and the circuit switches to the sleep mode.

[0040] In the sleep mode, only the SPI and AVCC power supply monitoring modules work, which is the lowest power consumption mode of the electric meter, and no longer accepts the off-chip reset signal. The user can read and write the full power failure mode 1, full power failure mode 2, and system configuration and status registers through SPI, and the working current is 5uA. Under the condition of enabling the write of the status register, after the working mode switches to the metering mode, the chip switches to the normal working mode, and when the power grid is powered, it realizes the measurement and metering functions of various power parameters.

[0041] Such as Figure 3As shown in the figure, the utility model discloses a single-phase rail type energy meter with low power consumption. The functions of the entire energy meter are realized by three power management modules, a magnetic latching relay and its driver, a signal acquisition module, an RS485 communication module, an LCD display panel, and an SoC chip. Among them, the first power management module 31 converts 220V alternating current into 12V direct current to supply the relay drive module, which is used to ensure the normal operation of the signal acquisition module. The second power management module 32 is used to supply power to the power management module inside the SoC chip. It is mainly responsible for providing a clean and low-noise power supply for the analog circuits inside the SoC, such as circuits sensitive to noise like PGA and Delta-Sigma ADC, to ensure the high precision of the metering module. The third power management module 33 is for the digital circuits inside the SoC chip, such as the storage module. Bluetooth and broadband power line carrier communication are integrated inside the SoC chip, which can support multiple communication modes of wireless and wired, and adapt to various working environments, such as the wild, unit power distribution rooms, and personal residences, etc. The SoC chip adopts the SoC chip XL7501, which integrates an HPLC module 13 and an LCD drive and temperature compensation module 14 to realize functions such as metering function, LCD drive, and temperature compensation. In addition, the on-chip power management module 3 further processes the noise in the power supply to provide the accuracy of the metering module.

[0042] For low-power design, in addition to adopting low-power design during the design, there are also various logical judgments for the low-power mode in the chip, such as Figure 3 As shown in the figure, the energy meter switches to the full voltage-loss mode 1 at intervals, and at the same time, the chip starts to calculate the effective current value. The non-linear error of the effective current value within the range of 800:1 is less than 0.5%. In this mode, a DC correction register is used instead of a high-pass filter to eliminate the offset error and reduce energy consumption. The stable time of the full voltage-loss effective value measurement is 60ms. After the value of the effective current register is stable, the user can read the effective current register to make a full voltage-loss judgment. When an interruption occurs, the working mode is converted to the full voltage-loss mode 2. To detect and pre-judge the current with lower power consumption, in the full voltage-loss mode 2, the chip starts a current value comparison every 60s, compares the comparison result with the threshold value in the register. If the effective current value is lower than 5% of the rated current, it is judged as a power-off situation, an interruption is generated, and the circuit switches to the sleep mode. In the sleep mode, only the SPI and AVCC power supply monitoring work, which can save a large amount of energy. It is the lowest power consumption mode for the electric meter to be powered by the backup power supply and no longer accepts off-chip reset signals. The user can read and write the full voltage-loss mode 1, the full voltage-loss mode 2, and the system configuration and status register through the SPI. Under the condition of enabling the write of the status register, after writing the metering mode command to the working mode switching register, the chip switches to the normal working mode. When powered by the power grid, it realizes the measurement and metering functions of various power parameters.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A highly integrated low-power micro-miniature electric meter, characterized in that: including: SoC chip, the SoC chip includes an analog circuit and a digital circuit, the analog circuit includes a programmable gain amplifier (PGA), on-chip power management, and a Delta-Sigma ADC. The operational amplifier transistors of the PGA and the Delta-Sigma ADC operate in the subthreshold region. The digital circuit includes a storage unit, a computing unit, an I2C & SPI module, and a status register, the storage unit, the computing unit, the I2C & SPI module, and the status register are all connected to the analog circuit; the storage unit is connected to the computing unit, and both the I2C & SPI module and the status register are connected to the storage unit; a signal acquisition module (2), which is used to acquire current signals and voltage signals. The signal acquisition module passes through the PGA and the Delta-Sigma ADC in sequence; a power management module group (31 - 33), including: a first power management module (31), which is used to convert an external power supply into 12V DC power and supply power to the relay drive circuit; a second power management module (32), which supplies power to the analog circuit of the SoC chip; a third power management module (33), which supplies power to the digital circuit of the SoC chip; an RS485 communication module (4), which is connected to the storage unit; a display panel (16), which is an LCD display panel and is connected to the digital circuit; a magnetic latching relay (6), which is connected to the first power management module (31) and controls the power on and off through a relay drive circuit (7); wherein, the setting mode of the power management module group (31 - 33) is: the first power management module (31) is connected to an external power supply, the second power management module (32) is connected to the output end of the first power management module (31), and the third power management module (33) is connected to the output end of the second power management module (32).

2. The highly integrated low-power micro-miniature electric meter according to claim 1, characterized in that: The analog circuit of the SoC chip further includes an internal driver operational amplifier, and the internal driver operational amplifier adopts a Class AB structure.

3. A highly integrated low-power micro-miniature electric meter according to claim 1, characterized in that: The communication module includes a Bluetooth module (18), a broadband power line carrier module (13), and an RS485 communication module (4).

4. A highly integrated low-power micro-miniature electric meter according to claim 1, characterized in that: The display panel is an LCD display panel.

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