Intelligent high-precision electric energy meter verification circuit

Abstract

The utility model relates to an intelligent high-precision electric energy meter verification circuit. With social and economic development and increase of electric energy requirements, traditional electric energy meters cannot meet the requirements of low-voltage small and micro enterprise users. The technology provides a detection technical means of an in-operation three-phase electric energy meter, and high precision and stability can be kept even in an unstable power grid environment. The technical scheme comprises a driving circuit, a microprocessor module and an interface circuit. The driving circuit adopts a CH340G chip and is matched with a capacitor, a resistor and a triode to realize system circuit driving. The microprocessor STM32 processes current and voltage data, verifies the state of the electric energy meter, and stores verification parameters and historical data. And the interface circuit carries out circuit state debugging by using a JTAG chip. And the LCD liquid crystal display screen or the LED screen is used as a display to provide clear information display. According to the technical scheme, the accuracy and safety of electric energy meter verification are ensured.

Description

Technical Field

[0001] The utility model relates to the field of electric energy detection, in particular to an intelligent high-precision electric energy meter calibration circuit. Background Art

[0002] The electric energy meter is the most basic equipment for metering work. The accuracy of the electric energy meter metering is related to the economic interests of power supply enterprises and power users. With the continuous development and progress of China's social economy and the steady improvement of people's living quality, people's dependence on electric energy is also increasing. Especially for low-voltage small and micro enterprise users, with the continuous expansion of production scale and the increasing annual electricity demand, the original direct-connected three-phase electric energy meter can no longer meet their load requirements. If the direct-connected three-phase electric energy meter operates in a bad environment of overvoltage, undervoltage or overload for a long time, it will not only affect the accuracy of customer electricity metering, but also pose a safety hazard of burning customer-side electrical equipment and the electric energy meter. Therefore, there is an urgent need for a detection technical means for the in-operation three-phase electric energy meter to solve the calibration result of the electric energy meter. Summary of the Invention

[0003] The technical problem to be solved by this technical solution is: to provide a detection technical means for the in-operation three-phase electric energy meter to solve the problem that the calibration result of the electric energy meter can maintain high precision and stability even in an unstable power grid environment.

[0004] To achieve the above purpose, the technical solution adopted by the utility model is: an intelligent high-precision electric energy meter calibration circuit, including: a drive circuit, a microprocessor module and an interface circuit; among them, for the microprocessor module, the PA1 port of the microprocessor STM32 is connected to one end of the resistor R5, and the other end of R5 is connected to one end of the crystal oscillator Y2 and one end of the capacitor C14; the other end of the crystal oscillator Y2 is connected to one end of the capacitor C10, and the other ends of the capacitors C14 and C10 are connected to GND, and the other end of the capacitor C10 is connected to one end of the capacitor C12, one end of the C9, and the VSSA port; the other ends of the capacitors C12 and C9 are connected to one end of the resistor R11 and the VDDA port, and the other end of the resistor R11 is connected to the power supply VCC; the VDD-1 port is connected to the power supply VCC and one end of the capacitor C6, and the other end of the capacitor C6 is connected to the VSS-1 port; the VDD-2 port is connected to the power supply VCC and one end of the capacitor C7, and the other end of the capacitor C7 is connected to the VSS-2 port; the VDD-3 port is connected to the power supply VCC and one end of the capacitor C8, and the other end of the capacitor C8 is connected to the VSS-3 port; the PA2 port is connected to the OUT end of the current and voltage transformer, the VCC port of the current and voltage transformer is connected to the power supply VCC, the OUT port of the current and voltage transformer is connected to one end of the resistor R17, the other end of the resistor R17 is connected to the GND port of the current and voltage transformer and grounded, and the AC-N port and the AC-J port of the current and voltage transformer are connected to the circuit to be detected; the PB0 port is connected to the display.

[0005] The beneficial effects of this technical solution are as follows: Through precise power supply filtering, stable reset control, and a high-performance STM32 microprocessor, this circuit can achieve high-precision power measurement. The microprocessor and current-voltage transformers perform high-precision measurement on the circuit to be measured, obtaining stable power meter measurement results.

[0006] As a further improvement of the above technical solution: For the drive circuit, the drive chip is selected as CH340G. One end of the VCC port of the chip is connected to one end of capacitor C2 and is connected to the power supply VCC. The other end of C2 is connected to GND and is also connected to one end of capacitor C1. The other end of capacitor C1 is connected to the power supply VCC. The GND port of the chip is connected to GND. One end of the V3 port of the chip is connected to one end of capacitor C3, and the other end of C3 is connected to GND. The XO of the chip is connected to one end of crystal oscillator Y1 and one end of capacitor C4. The other end of crystal oscillator Y1 is connected to one end of capacitor C5. The other ends of capacitors C4 and C5 are connected to GND. One end of the DTR# port of the chip is connected to one end of resistor R1. The other end of R1 is connected to the base of npn transistor Q1. The collector of Q1 is connected to the negative electrode of diode D1 and one end of resistor R2. The other end of diode D1 is connected to the RESET port. The other end of resistor R2 is connected to the power supply VCC. The emitter of Q1 is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of pnp transistor Q2. The collector of Q2 is connected to the power supply VCC. The emitter of Q2 is connected to one end of resistor R4. The other end of R4 is connected to the BOOT0 port of the microprocessor STM32.

[0007] The beneficial effects of this technical solution are as follows: The drive chip CH340G is used for interface communication, and power supply filtering is carried out through capacitors C2 and C1. The DTR# port of the chip controls the RESET signal through resistor R1 and npn transistor Q1 to achieve the reset control of the microprocessor.

[0008] As a further improvement of the above technical solution: For the interface circuit, the JTAG chip's VDD port is connected to one end of capacitor C13. The other end of capacitor C13 is connected to the power supply VCC and GND. The GND port is connected to GND. The TRST port is connected to one end of resistor R12 and the JTR port of STM32. The other end of resistor R12 is connected to the power supply VCC. The TD1 port is connected to one end of resistor R13 and the JTD1 port of STM32. The other end of resistor R13 is connected to the power supply VCC. The TMS port is connected to one end of resistor R13 and the JTMS port of STM32. The other end of resistor R13 is connected to the power supply VCC. The TCK port is connected to one end of resistor R14 and the JTCK port of STM32. The other end of resistor R14 is connected to the power supply VCC. The TDO port is connected to one end of resistor R15 and the JTDO port of STM32. The other end of resistor R15 is connected to the power supply VCC. The RESET port is connected to the RESET port of STM32.

[0009] The beneficial effect of this technical solution is that the JTAG interface is used for on-line debugging and programming of the microprocessor, and the JTAG signal is connected to the corresponding port of the STM32 through resistors R12, R13, R14 and R15. The design of this circuit allows users to perform on-line debugging and programming through the JTAG interface, providing high flexibility.

[0010] As a further improvement of the above technical solution, the above display is an LCD liquid crystal display screen or an LED screen.

[0011] The beneficial effect of this technical solution is that the LCD liquid crystal display screen or the LED screen has clear and distinct display. Description of the Drawings

[0012] Figure 1 is the circuit connection schematic diagram of the present utility model;

[0013] Figure 2 is the drive circuit diagram of the present utility model;

[0014] Figure 3 is the interface circuit diagram of the present utility model. Detailed Embodiments

[0015] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description of this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the present invention.

[0016] Embodiment 1:

[0017] An intelligent high-precision electric energy meter verification circuit, comprising:

[0018] A drive circuit, the drive chip is selected as CH340G. One end of the chip vcc port is connected to one end of capacitor C2 and is connected to the power supply VCC. The other end of C2 is connected to GND and is also connected to one end of capacitor C1. The other end of capacitor C1 is connected to the power supply VCC. The chip GND port is connected to GND. One end of the chip V3 port is connected to one end of capacitor C3, and the other end of C3 is connected to GND. The chip XO is connected to one end of crystal oscillator Y1 and one end of capacitor C4. The other end of crystal oscillator Y1 is connected to one end of capacitor C5. The other ends of capacitors C4 and C5 are connected to GND. One end of the chip DTR# port is connected to one end of resistor R1. The other end of R1 is connected to the base of npn transistor Q1. The collector of Q1 is connected to the negative electrode of diode D1 and one end of resistor R2. The other end of diode D1 is connected to the RESET port. The other end of resistor R2 is connected to the power supply VCC. The emitter of Q1 is connected to one end of resistor R3. The other end of resistor R3 is connected to the base of pnp transistor Q2. The collector of Q2 is connected to the power supply VCC. The emitter of Q2 is connected to one end of resistor R4. The other end of R4 is connected to the BOOT0 port of the microprocessor STM32;

[0019] Microprocessor module: One end of resistor R5 is connected to pin PA1 of microprocessor STM32, and the other end of R5 is connected to one end of crystal oscillator Y2 and one end of capacitor C14; the other end of crystal oscillator Y2 is connected to one end of capacitor C10, and the other ends of capacitors C14 and C10 are connected to GND. Moreover, the other end of capacitor C10 is connected to one end of capacitor C12, one end of C9, and port VSSA; the other ends of capacitors C12 and C9 are connected to one end of resistor R11 and port VDDA, and the other end of resistor R11 is connected to power supply VCC; port VDD-1 is connected to power supply VCC and one end of capacitor C6, and the other end of capacitor C6 is connected to port VSS-1; port VDD-2 is connected to power supply VCC and one end of capacitor C7, and the other end of capacitor C7 is connected to port VSS-2; port VDD-3 is connected to power supply VCC and one end of capacitor C8, and the other end of capacitor C8 is connected to port VSS-3; pin PA2 is connected to the OUT end of the current-voltage transformer. The VCC port of the current-voltage transformer is connected to power supply VCC. The OUT port of the current-voltage transformer is connected to one end of resistor R17, and the other end of resistor R17 is connected to the GND port of the current-voltage transformer and grounded. The AC-N port and AC-J port of the current-voltage transformer are connected to the circuit to be detected; pin PB0 is connected to the display.

[0020] Interface circuit: The VDD port of the JTAG chip is connected to one end of capacitor C13, and the other end of capacitor C13 is connected to power supply VCC and GND; the GND port is connected to GND; the TRST port is connected to one end of resistor R12 and the JTR port of STM32, and the other end of resistor R12 is connected to power supply VCC; the TD1 port is connected to one end of resistor R13 and the JTD1 port of STM32, and the other end of resistor R13 is connected to power supply VCC; the TMS port is connected to one end of resistor R13 and the JTMS port of STM32, and the other end of resistor R13 is connected to power supply VCC; the TCK port is connected to one end of resistor R14 and the JTCK port of STM32, and the other end of resistor R14 is connected to power supply VCC; the TDO port is connected to one end of resistor R15 and the JTDO port of STM32, and the other end of resistor R15 is connected to power supply VCC; the RESET port is connected to the RESET port of STM32. In this embodiment, the power supply VCC used is 3.3V, and the display is an LCD liquid crystal display or an LED screen.

[0021] The working principle of this embodiment is that the main function of the driving circuit is to control the reset signal of the microprocessor. The DTR# port of the driving chip CH340G controls the RESET signal through the resistor R1 and the npn transistor Q1. When the DTR# port outputs a high level, the npn transistor Q1 conducts, the RESET port is pulled low, and the microprocessor STM32 is reset. When the DTR# port outputs a low level, the npn transistor Q1 is cut off, the RESET port is pulled high, and the microprocessor STM32 starts to work. The microprocessor STM32 is the core of the entire system and is responsible for processing all calculation and control tasks. STM32 communicates with the current and voltage transformer through the PA2 port to obtain the current and voltage information of the detected circuit, and displays the information on the display screen through the PA1 port. The power supply of STM32 is filtered by capacitors C6, C7 and C8 to ensure the stability of the power supply, thus ensuring the normal operation of the microprocessor. The interface circuit mainly includes a JTAG interface for on-line debugging and programming of the microprocessor. By connecting the JTAG signal to the corresponding port of STM32 through resistors R12, R13, R14 and R15, on-line debugging and programming of STM32 can be realized, providing high flexibility.

[0022] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0023] Specific examples are used in this article to elaborate on the principles and implementation modes of the present invention. The description of the above examples is only used to help understand the method of the present invention and its core idea. The above is only the preferred implementation mode of the present invention. It should be pointed out that due to the limitation of literal expression, objectively there are infinite specific structures. For those of ordinary skill in the art, without departing from the principle of the present invention, several improvements, modifications or changes can be made, or the above technical features can be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, shall all be regarded as the protection scope of the present invention.

Claims

1. An intelligent high-precision electric energy meter calibration circuit, characterized in that: include: The invention relates to a driving circuit, a microprocessor module and an interface circuit; wherein the microprocessor module and the PA1 port of the microprocessor STM32 are connected to one end of a resistor R5, and the other end of R5 is connected to one end of a crystal oscillator Y2 and one end of a capacitor C14; the other end of the crystal oscillator Y2 is connected to one end of a capacitor C10, and the other ends of the capacitors C14 and C10 are connected to GND, and the other end of the capacitor C10 is connected to one end of a capacitor C12, one end of C9, and the VSSA port; the other end of the capacitor C12 and the other end of the capacitor C9 are connected to one end of a resistor R11 and the VDDA port, and the other end of the resistor R11 is connected to the power supply VCC; the VDD-1 port is connected to the power supply VCC and one end of the capacitor C6 , the other end of capacitor C6 is connected to VSS-1 port; VDD-2 port is connected to power supply VCC and one end of capacitor C7, and the other end of capacitor C7 is connected to VSS-2 port; VDD-3 port is connected to power supply VCC and one end of capacitor C8, and the other end of capacitor C8 is connected to VSS-3 port; PA2 port is connected to the OUT end of the current and voltage transformer, the VCC port of the current and voltage transformer is connected to the power supply VCC, the OUT port of the current and voltage transformer is connected to one end of resistor R17, the other end of resistor R17 is connected to the GND port of the current and voltage transformer and grounded, the AC-N port and AC-J port of the current and voltage transformer are connected to the detected circuit; PB0 port is connected to the display.

2. According to the intelligent high-precision electric energy meter calibration circuit described in claim 1, the driving chip of the driving circuit is selected as CH340G, the driving chip Vcc port is connected to one end of the capacitor C2 and connected to the power supply VCC, the other end of C2 is connected to GND and connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the power supply VCC; the chip GND port is connected to GND; the driving chip V3 port is connected to one end of the capacitor C3, and the other end of C3 is connected to GND; the driving chip XO port is connected to one end of the crystal oscillator Y1 and one end of the capacitor C4, the other end of the crystal oscillator Y1 is connected to one end of the capacitor C5, and the capacitors C4 and C5 are connected to the GND port. One end is connected to GND; the DTR# port of the driver chip is connected to one end of the resistor R1, the other end of R1 is connected to the base of the npn transistor Q1, the collector of Q1 is connected to the cathode of the diode D1 and one end of the resistor R2, the other end of the diode D1 is connected to the RESET port, and the other end of the resistor R2 is connected to the power supply VCC; the emitter of Q1 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the base of the pnp transistor Q2, the collector of Q2 is connected to the power supply VCC, the emitter of Q2 is connected to one end of the resistor R4, and the other end of R4 is connected to the BOOT0 port of STM32.

3. According to the intelligent high-precision electric energy meter calibration circuit described in claim 1, the JTAG chip VDD port of the interface circuit is connected to one end of the capacitor C13, and the other end of the capacitor C13 is connected to the power supply VCC and GND; the GND port is connected to GND; the TRST port is connected to one end of the resistor R12 and the JTR port of the STM32, and the other end of the resistor R12 is connected to the power supply VCC; the TD1 port is connected to one end of the resistor R13 and the JTD1 port of the STM32, and the other end of the resistor R13 is connected to the power supply VCC; the TMS port is connected to one end of the resistor R13 and the JTMS port of the STM32, and the other end of the resistor R13 is connected to the power supply VCC; the TCK port is connected to one end of the resistor R14 and the JTCK port of the STM32, and the other end of the resistor R14 is connected to the power supply VCC; the TDO port is connected to one end of the resistor R15 and the JTDO port of the STM32, and the other end of the resistor R15 is connected to the power supply VCC; the RESET port is connected to the RESET port of the STM32.

4. According to the intelligent high-precision electric energy meter calibration circuit of claim 1, the display is an LCD liquid crystal display screen or an LED screen.

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