CN220773166U

CN220773166U - Three-phase four-wire CTVT type intelligent ammeter

Info

Publication number: CN220773166U
Application number: CN202322221281.0U
Authority: CN
Inventors: 姚国伟; 费鑫杰; 严忠明
Original assignee: Zhejiang Yongtailong Electronic Co ltd
Current assignee: Zhejiang Yongtailong Electronic Co ltd
Priority date: 2023-08-17
Filing date: 2023-08-17
Publication date: 2024-04-12
Anticipated expiration: 2033-08-17

Abstract

The utility model provides a three-phase four-wire CTVT type intelligent ammeter which solves the problems of poor high-voltage isolation effect and the like of an electric energy meter. The utility model has the advantages of high safety, stable structure and the like.

Description

Three-phase four-wire CTVT type intelligent ammeter

Technical Field

The utility model belongs to the technical field of three-phase electric meters, and particularly relates to a three-phase four-wire CTVT intelligent electric meter.

Background

The three-phase intelligent ammeter is based on a single-phase intelligent ammeter, can be simply regarded as two or three intelligent ammeters, is provided with two or three groups of electromagnetic elements by sharing one rotating shaft by a plurality of parts, can measure three-phase current parameters in a power grid by adopting an alternating current sampling technology, calculates various active/reactive electric energy, has the functions of event recording, communication, data display, storage/transmission and the like, and is widely applied to various prepayment management systems and energy consumption monitoring systems, thus being an ideal product for metering electric quantity by a power supply department. However, in the practical process, the existing three-phase ammeter has poor isolation effect on high voltage and is easy to fail and damage.

In order to solve the defects existing in the prior art, long-term exploration is performed, and various solutions are proposed. For example, chinese patent literature discloses a three-phase digital smart meter [201210542219.5] that includes an input-output module, a minimum system module, a man-machine interface module, and a communication module; the input and output module, the man-machine interface module and the communication module are respectively connected with the minimum system module; the minimum system module comprises a power supply module, a reset unit, a microprocessor and a storage unit; the power module is provided with a lightning protection circuit and a switching power supply, external alternating current generates two paths of isolated 5V direct current voltages after passing through the lightning protection circuit and the switching power supply, one path is used for supplying power to the communication module, and the other path is used for supplying power to the input/output module, the microprocessor, the storage unit and the human-computer interface module.

The scheme solves the problem of ammeter data monitoring and recording to a certain extent, but the scheme still has a plurality of defects, such as poor high-voltage isolation effect and the like.

Disclosure of Invention

The utility model aims to solve the problems and provides a three-phase four-wire CTVT type intelligent ammeter with reasonable design and voltage.

In order to achieve the above purpose, the present utility model adopts the following technical scheme: the utility model provides a three-phase four-wire CTVT formula smart electric meter, includes MCU module, and MCU module is connected with communication module and display module, and MCU module is connected with input module and storage module, and MCU module is equipped with metering module, and metering module and MCU module are connected with power module, and metering module has independent current transformer and voltage transformer.

In the three-phase four-wire CTVT type intelligent ammeter, the MCU module selects the main control chip U1 of the RN8318 signal.

In the three-Phase four-wire CTVT type intelligent ammeter, the power module takes A-Phase, B-Phase, C-Phase and N-GND as power input, and comprises a power chip IC1, a power chip IC5 and a power chip IC15; the power chip IC1 is connected with a voltage stabilizer IC2 and a voltage stabilizer IC3; the power chip IC5 is connected with a voltage stabilizer IC6; the power supply chip IC15 is connected to the voltage regulator IC14.

In the three-phase four-wire CTVT type intelligent ammeter, the power chip IC1 is selected from the ETA8113 type, and the voltage stabilizer IC2 and the voltage stabilizer IC3 are selected from the 7533 type; the power chip IC5 is of model KIA78R, and the voltage stabilizer IC6 is of model 7805; the power chip IC15 is PN8143T type, and the voltage stabilizer IC14 is 7533 type.

In the three-phase four-wire CTVT type intelligent ammeter, the input module comprises a key input module, a magnetic field detection module, a cover opening and meter box door detection module; the input module comprises a Hall magnetic sensor IC8 and a Hall magnetic sensor IC11, and the Hall magnetic sensor IC8 and the Hall magnetic sensor IC11 are of the type S-5712ACDL 1.

In the above three-phase four-wire CTVT intelligent ammeter, the metering module includes a metering chip IC13, and the metering chip IC13 adopts RN8302 model.

In the three-phase four-wire CTVT type intelligent ammeter, the storage module comprises an EEP memory IC10 and a FLASH memory IC7, wherein the EEP memory IC10 is of an FM24C512A model, and the FLASH memory IC7 is of a W25Q80 model.

In the three-phase four-wire CTVT type intelligent ammeter, the communication module comprises an infrared communication module, a 485 communication module and a GPRS or PLC module; the communication module comprises a communication chip IC9 and a communication chip IC4, and is provided with a PLC module JP2 and an interface J4; the communication chip IC9 is of RY485 type, the communication chip IC4 is of MAX3232 type, and the interface J is of CON8 type.

In the three-phase four-wire CTVT type intelligent ammeter, the display module comprises an LCD display module and an LED display module.

In the three-phase four-wire CTVT type intelligent ammeter, the LED display module is provided with an active pulse lamp, a reactive pulse lamp, an ammeter door warning lamp and an overvoltage warning lamp; the LCD display module is a Duan Ma LCD display screen with 8COM multiplied by 18 SEG.

Compared with the prior art, the utility model has the advantages that: the current transformer and the voltage transformer adopt a separated structure, and only the current transformer and the voltage transformer are connected to a tested circuit, so that the circuit is not required to be changed; the safety performance is extremely high, because the mutual inductor has an isolation effect on high voltage, the occurrence of electric shock accidents can be effectively avoided, and meanwhile, the influence on a power system caused by ammeter faults or damage can be prevented; the communication module adopts the form of three communication channels of infrared, 485 and PLC or GPRS, is compatible with the PLC and GPRS communication, can be plugged in and pulled out, can select a proper communication module according to the needs and the service environment, carries out remote reading and management on the ammeter, and greatly improves the working efficiency and applicability of meter reading and charging.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic circuit diagram of the MCU module of the present utility model;

FIG. 3 is a schematic circuit diagram of a power module of the present utility model;

FIG. 4 is a schematic circuit diagram of an input module of the present utility model;

FIG. 5 is a schematic circuit diagram of a metering module of the present utility model;

FIG. 6 is a circuit schematic of a memory module of the present utility model;

FIG. 7 is a schematic circuit diagram of a communication module according to the present utility model;

FIG. 8 is a schematic circuit diagram of a display module of the present utility model;

in the figure, an MCU module 1, a communication module 2, a display module 3, an input module 4, a storage module 5, a metering module 6 and a power module 7.

Detailed Description

The utility model will be described in further detail with reference to the drawings and the detailed description.

As shown in fig. 1-8, a three-phase four-wire CTVT type intelligent ammeter comprises an MCU module 1, wherein the MCU module 1 is connected with a communication module 2 and a display module 3, the MCU module 1 is connected with an input module 4 and a storage module 5, the MCU module 1 is provided with a metering module 6, the metering module 6 and the MCU module 1 are connected with a power supply module 7, and the metering module 6 is provided with an independent current transformer and a voltage transformer.

Specifically, the MCU module 1 selects the main control chip U1 of the RN8318 signal. ARM Cortex-M0 kernel, 512KB Flash, 32KB SRAM and independent power supply hardware temperature compensation RTC are integrated. Under typical conditions, the voltage range of 2.3V-5.5V ensures the normal work of the CPU, the voltage range of 2.7V-5.5V ensures the precision of the RTC, and the perpetual calendar time of the voltage range of 1.8V-5.5V is kept. The RTC pulse per second error is less than 10ppm in the full temperature range (-40-85 degrees), the accuracy of pulse per second is still guaranteed under the condition of battery power supply, the hardware is automatic in temperature compensation, the accuracy and the power consumption required by the standard are met, and the temperature compensation does not need CPU participation.

The main control chip U1 communicates with the metering module 6 through SPI, and pins are SCLK1, SDO1, SDI1 and SCSN1 respectively; the UART is communicated with the PLC module or the GPRS module, and the pins are TX and RX respectively; infrared communication is carried out through a UART, and pins are OPT_TX and OPT_RX respectively; RS485 communication is carried out through a UART, and pins are 485_TX, 485_RX and 485_R/D respectively; the integrated liquid crystal driving port is connected with the LCD liquid crystal screen, and pins are COM0-COM7 and SEG0-SEG17 respectively; software simulation IIC is connected with EEP memory through I/O port, and pins are EEP_ WP, SCL, SDA respectively; software simulates SPI to connect FLASH memory through I/O port, pins are CS2, MISO2, MISI2, CLK2; the cover opening and the meter box door detection module are connected through an I/O port, and pins are respectively OPEN2, OPEN1, KAIMEN-IN1 and KAIMEN-IN2; the input is connected with the key through an I/O port, and pins are PAGE1 and PAGE2 respectively; the pins are Huo Er1 and Huo Er2, and are connected with the magnetic field detection module through an I/O port; the output of the LEDs 2 and 3 is controlled through I/O, and pins are POWER and TAMP; the power supply is provided by V33L.

In depth, the power module 7 takes A-Phase, B-Phase, C-Phase and N-GND as power inputs, and the power module 7 comprises a power chip IC1, a power chip IC5 and a power chip IC15; the power chip IC1 is connected with a voltage stabilizer IC2 and a voltage stabilizer IC3; the power chip IC5 is connected with a voltage stabilizer IC6; the power supply chip IC15 is connected to the voltage regulator IC14.

Further, the power chip IC1 is selected from ETA8113 model, and the voltage stabilizer IC2 and the voltage stabilizer IC3 are selected from 7533 model; the power chip IC5 is of model KIA78R, and the voltage stabilizer IC6 is of model 7805; the power chip IC15 is PN8143T type, and the voltage stabilizer IC14 is 7533 type. After the ammeter is normally electrified, the power supply module 7 mainly takes networks of 'A-Phase', 'B-Phase', 'C-Phase', 'N-GND' as power supply input of the whole scheme, one path of the power supply module is 3.3V for supplying power to the metering module after rectification, filtering, voltage reduction and voltage stabilization, and the other path of the power supply module VDD1 is voltage-stabilized to generate 12V-PLC, V5 and V33H. The 12V-PLC mainly provides working voltage for the PLC module, the V5 mainly provides working voltage for the GPRS module and the 485 module, and the V33H provides working voltage for the main control chip and other modules.

When the power is lost, the battery power EVCC is input and output V33L is regulated, and when the external power is lost, the main control chip U1 and other partial circuits can continue to work in a low power consumption mode.

Further, the input module 4 includes a key input module, a magnetic field detection module, a cover opening and table door detection module; the input module 4 comprises a Hall magnetic sensor IC8 and a Hall magnetic sensor IC11, and the Hall magnetic sensor IC8 and the Hall magnetic sensor IC11 are selected from the model S-5712ACDL 1. The key input module uses two keys: PAGE2 is used for PAGE-backward and display mode switching; page1 was used for PAGE forward and manual settlement. Strong magnets may deactivate the current sensor of the transformer or current transformer in the power supply, resulting in a user's electricity charge being lower than they should actually pay. The magnetic field detection module utilizes the Hall sensor to induce an external magnetic field for display and event recording, thereby realizing detection of magnetic tampering and warning. Some electricity larceny needs to be realized by changing wiring or internal devices of an ammeter, and the states of a side cover, an upper cover, an ammeter door 1, an ammeter door 2 and the like are respectively judged by a cover opening and ammeter door detection module through an OPEN2, an OPEN1, a KAIMEN-IN1 and a KAIMEN-IN2, so that an alarm can be sent out when an electricity larceny OPENs the ammeter door, the side cover and the upper cover, and the alarm can be stored IN the storage module 5 IN an event record mode.

Besides, the metering module 6 comprises a metering chip IC13, and the metering chip IC13 adopts the model RN8302, can provide full-wave and fundamental wave active electric energy, has nonlinear error less than 0.1% in a dynamic range of 5000:1, and meets 0.5S and 0.2S; a metering module 6 power metering solution is provided for the present application. The metering module 6 adopts an isolated sampling design: the current transformer performs current sampling and the voltage transformer performs voltage sampling. SCLK, SDO, SDI, SCSN is responsible for SPI communication with the main control chip U1; the CF1 outputs an electric energy metering active pulse to directly drive an active pulse LED4, and the CF2 outputs an electric energy metering reactive pulse to directly drive a reactive pulse LED5.

Meanwhile, the memory module 5 comprises an EEP memory IC10 and a FLASH memory IC7, wherein the EEP memory IC10 is of an FM24C512A model, and the FLASH memory IC7 is of a W25Q80 model. The cost and the service life are considered, and meanwhile, the requirement of the ammeter for storing a large amount of data is met.

The communication module 2 comprises an infrared communication module, a 485 communication module, a GPRS or a PLC module; the communication module 2 comprises a communication chip IC9 and a communication chip IC4, and the communication module 2 is provided with a PLC module JP2 and an interface J4; the communication chip IC9 is of RY485 type, the communication chip IC4 is of MAX3232 type, and the interface J is of CON8 type. The communication module 2 comprises three communication channels: the infrared communication module is used for an Infrared (IR) channel for communicating with a PC end, the 485 communication module is a multi-point RS-485 channel which is completely isolated, and the communication module is also based on a PLC module or a GPRS module. The PLC module or the GPRS module adopts an external pluggable module, one type of module can be selected when the module is used, and a corresponding communication mode is selected by using an upper computer through infrared or 485. The HES can read the ammeter at any time through the PLC or GPRS, and the ammeter can report at any time when detecting an alarm event.

It is apparent that the display module 3 includes an LCD display module and an LED display module.

Preferably, the LED display module has an active pulse lamp, a reactive pulse lamp, a door warning lamp, and an overvoltage warning lamp; the LCD display module is a Duan Ma LCD display screen with 8COM multiplied by 18 SEG. The LED4 is an active pulse lamp and is directly output by the metering module; the LED5 is a reactive pulse lamp and is directly output by the metering module; the LED2 is a warning lamp of the table door, and the warning is normally lighted once the opening of the table door is detected; the LED3 is an overvoltage warning lamp, and when an overvoltage is transmitted, a warning is always lighted. The data such as various real-time metering parameters, electric quantity and the like of the ammeter can be displayed by matching with the key input module; the coordination metering module 6 and other modules can display battery conditions, communication conditions, magnetic field interference, uncapping and meter box door states.

The specific embodiments described herein are offered by way of example only to illustrate the spirit of the utility model. Those skilled in the art may make various modifications or additions to the described embodiments or substitutions thereof without departing from the spirit of the utility model or exceeding the scope of the utility model as defined in the accompanying claims.

Although the terms MCU module 1, communication module 2, display module 3, input module 4, storage module 5, metering module 6, power module 7, etc. are used more herein, the possibility of using other terms is not precluded. These terms are used merely for convenience in describing and explaining the nature of the utility model; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present utility model.

Claims

1. The three-phase four-wire CTVT type intelligent ammeter comprises an MCU module (1), wherein the MCU module (1) is connected with a communication module (2) and a display module (3), the MCU module (1) is connected with an input module (4) and a storage module (5), and the intelligent ammeter is characterized in that the MCU module (1) is provided with a metering module (6), the metering module (6) and the MCU module (1) are connected with a power supply module (7), and the metering module (6) is provided with an independent current transformer and an independent voltage transformer; the power module (7) takes A-Phase, B-Phase, C-Phase and N-GND as power inputs, and the power module (7) comprises a power chip IC1, a power chip IC5 and a power chip IC15; the power supply chip IC1 is connected with a voltage stabilizer IC2 and a voltage stabilizer IC3; the power supply chip IC5 is connected with a voltage stabilizer IC6; the power supply chip IC15 is connected to the voltage regulator IC14.

2. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the MCU module (1) is a main control chip U1 with RN8318 signals.

3. The three-phase four-wire CTVT type intelligent ammeter according to claim 1, wherein the power chip IC1 is ETA8113 type, and the voltage stabilizer IC2 and the voltage stabilizer IC3 are 7533 type; the power chip IC5 is of the model KIA78R, and the voltage stabilizer IC6 is of the model 7805; the power chip IC15 is of PN8143T type, and the voltage stabilizer IC14 is of 7533 type.

4. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the input module (4) comprises a key input module, a magnetic field detection module, a cover opening and meter box door detection module; the input module (4) comprises a Hall magnetic sensor IC8 and a Hall magnetic sensor IC11, wherein the Hall magnetic sensor IC8 and the Hall magnetic sensor IC11 are of the type S-5712ACDL 1.

5. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the metering module (6) comprises a metering chip IC13, and the metering chip IC13 is of RN8302 type.

6. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the memory module (5) comprises an EEP memory IC10 and a FLASH memory IC7, wherein the EEP memory IC10 is of FM24C512A type, and the FLASH memory IC7 is of W25Q80 type.

7. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the communication module (2) comprises an infrared communication module, a 485 communication module, a GPRS or PLC module; the communication module (2) comprises a communication chip IC9 and a communication chip IC4, and the communication module (2) is provided with a PLC module JP2 and an interface J4; the communication chip IC9 is of RY485 type, the communication chip IC4 is of MAX3232 type, and the interface J4 is of CON8 type.

8. The three-phase four-wire CTVT intelligent ammeter according to claim 1, wherein the display module (3) comprises an LCD display module and an LED display module.

9. The three-phase four-wire CTVT intelligent ammeter according to claim 8, wherein the LED display module comprises an active pulse lamp, a reactive pulse lamp, an ammeter door warning lamp and an overvoltage warning lamp; the LCD display module is a Duan Ma type LCD display screen with 8COM multiplied by 18 SEG.