CN203433041U - An electric energy meter provided with a communication function - Google Patents

Abstract

An electric energy meter with a communication function relates to the electric energy meter. Provides a power meter with communication function that has a communication interface and can transmit signals to the PC in real time, so that the PC can collect and monitor signals in real time. A current and voltage acquisition module, a metering chip, a microprocessor, a communication module, a display module, and an EEPROM are provided; the current and voltage acquisition module includes an A-phase current and voltage acquisition module, a B-phase current and voltage acquisition module, and a C-phase current and voltage acquisition module; The output ends of the A-phase current and voltage acquisition module, the B-phase current and voltage acquisition module, and the C-phase current and voltage acquisition module are respectively connected to the input ends of the metering chip, the metering chip is connected to the microprocessor, and the processing signal output ends of the microprocessor are respectively connected to the communication The input terminals of the module, the display module and the EEPROM are connected. It has the function of anti-stealing electricity, which can prevent electricity theft behaviors such as short-circuit theft, external magnetic field, and tilting the meter.

Description

An electric energy meter with communication function

technical field

The utility model relates to an electric energy meter, in particular to an electric energy meter with a communication function.

Background technique

With the continuous development of communication technology and smart grid "informatization, automation, and interactive" construction, the limitations of traditional manual meter reading are becoming more and more obvious. We hope to obtain data in real time on the PC and monitor the equipment in real time. In this way, we need the energy meter to have a communication function and be able to interconnect with the PC.

In order to realize the design of this energy meter with communication function, it is necessary to have the knowledge of the principle and design of intelligent instruments and communication technology.

At present, the existing electric energy meters on the market mainly solve the measurement of single-phase and three-phase electric energy; the display of electric energy readings on the LCD of the electric energy meter; single-phase plug-in power measurement and display. Without the SPI communication function, it is impossible to read data to the computer for processing in real time.

Chinese patent CN202393826U discloses a single-phase electronic energy meter. The electric energy meter can measure single-phase electric energy and LED display electric energy. It has the advantages of high precision, wide load, low power consumption and reliable operation. But it can only measure single-phase electric energy and has no communication function.

Chinese patent CN202404135U discloses a three-phase four-wire remote monitoring electric energy meter. The energy meter uses GPRS communication, which can transmit signals remotely, has the advantages of long signal transmission distance and wide coverage. But it occupies the GPRS channel, the cost is high, and the scope of application is narrow.

Chinese patent CN202362374U discloses a three-phase four-wire electronic active energy meter. The watt-hour meter can measure active power, and LED can display electric energy data. It has the advantages of low power consumption and easy installation. However, it has no communication function and cannot transmit data to a computer for analysis in real time.

Contents of the invention

The purpose of this utility model is to provide a communication interface, which can transmit signals to the PC in real time, so that the PC can collect signals and monitor signals in real time. An electric energy meter with communication function.

The utility model is provided with a current and voltage acquisition module, a metering chip, a microprocessor (MCU module), a communication module, a display module and an EEPROM;

Described current and voltage acquisition module comprises A phase current and voltage acquisition module, B phase current and voltage acquisition module and C phase current and voltage acquisition module; The output of A phase current and voltage acquisition module, B phase current and voltage acquisition module and C phase current and voltage acquisition module The terminals are respectively connected to the input terminals of the metering chip, the metering chip is connected to the microprocessor (MCU module), and the processing signal output terminal of the microprocessor (MCU module) is respectively connected to the input terminals of the communication module, the display module and the EEPROM.

The metering chip is provided with a voltage and current analog signal sampling module, a DSP metering module, a pulse generator, an SPI communication interface, a clock control circuit, a temperature sensor, a reference voltage module and a power management module; the input terminal of the voltage and current analog signal sampling module The output terminals of the A-phase current and voltage acquisition module, the B-phase current and voltage acquisition module and the C-phase current and voltage acquisition module, the output terminals of the voltage and current analog signal sampling module are connected to the input terminals of the DSP metering module, and the output terminals of the DSP metering module are respectively connected to pulses The generator is connected to the input terminal of the SPI communication interface, the clock control circuit is connected to the crystal oscillator circuit, the SPI communication interface is connected to the microprocessor (MCU module), the output terminal of the temperature sensor is connected to the voltage and current analog signal sampling module, and the reference voltage module is connected to the voltage The current analog signal sampling module is connected to the temperature sensor, and the power management module provides power for the chip.

The utility model has the following technical effects:

The utility model provides an electric energy meter with a communication function. The electric energy meter with a communication function is a basic part of all remote meter reading or control systems. The line interface transmits data, and it is full-duplex communication, which does not require addressing operations, making communication simpler and more efficient.

The utility model well realizes the centralized collection of data by the computer, real-time monitoring of the electric energy of the equipment, and at the same time, the installation location of the electric meter is more flexible, and the data collection is more accurate. To a large extent, it saves the installation cost and reduces the human and financial loss of manual meter reading. In addition, the utility model has the function of anti-stealing electricity, which can prevent electricity theft behaviors such as short-circuit theft, external magnetic field, and tilting the electric meter.

Description of drawings

Fig. 1 is a structural composition block diagram of an embodiment of the utility model.

Fig. 2 is a block diagram of the structure and composition of the metering chip of the embodiment of the present invention.

Detailed ways

The utility model will be described in detail below in conjunction with the accompanying drawings, so that the advantages and features of the utility model can be more easily understood by those skilled in the art, so as to define the protection scope of the utility model more clearly.

Referring to Figures 1 and 2, the embodiment of the utility model is provided with a current and voltage acquisition module 1, a metering chip 2, a microprocessor (MCU module) 3, a communication module 4, a display module 5 and an EEPROM6.

Described current and voltage acquisition module 1 comprises A phase current and voltage acquisition module 11, B phase current and voltage acquisition module 12 and C phase current and voltage acquisition module 13; A phase current and voltage acquisition module 11, B phase current and voltage acquisition module 12 and C phase The output ends of the current and voltage acquisition module 13 are respectively connected to the input ends of the metering chip 2, the metering chip 2 is connected to the microprocessor (MCU module) 3, and the processing signal output ends of the microprocessor (MCU module) 3 are respectively connected to the communication module 4, The input terminal of display module 5 and EEPROM6 is connected.

The metering chip 2 is provided with a voltage and current analog signal sampling module 21, a DSP metering module 22, a pulse generator 23, an SPI communication interface 24, a clock control circuit 25, a temperature sensor 26, a reference voltage module 27 and a power management module 28; The input terminal of the current analog signal sampling module 21 is connected to the output terminals of the A-phase current and voltage acquisition module 11, the B-phase current and voltage acquisition module 12 and the C-phase current and voltage acquisition module 13, and the output terminal of the voltage and current analog signal sampling module 21 is connected to the DSP measurement The input end of the module 22 and the output end of the DSP metering module 22 are respectively connected to the input end of the pulse generator 23 and the SPI communication interface 24, the clock control circuit 25 is connected to the crystal oscillator circuit 7, and the SPI communication interface 24 is connected to the microprocessor (MCU module) 3 connections, the output terminal of the temperature sensor 26 is connected to the voltage and current analog signal sampling module 21, the reference voltage module 27 is respectively connected to the voltage and current analog signal sampling module 21 and the temperature sensor 26, and the power management module 28 provides power for the chip.

In addition to the selection of the chip, it is also necessary to design the peripheral circuit. The peripheral circuit includes the design of the voltage divider and the shunt. The function of the voltage divider and the shunt is to convert the AC voltage and current into the voltage and current of the small signal. Simultaneously isolate grid voltage and current. The pulse generator is mainly used to complete the calculation of power, integration, frequency calculation and other functions.

Regarding the design of the communication interface, the utility model adopts the SPI bus interface. The SPI bus system is a synchronous serial peripheral interface, which can enable the MCU to communicate with various peripheral devices in a serial manner to exchange information.

Calibrating the electric energy meter through software can effectively improve its accuracy.

Sampling voltage input can convert voltage into current by using resistive voltage divider, and then convert current into voltage through current transformer. Connect the neutral line to the reference voltage output to facilitate superimposing the sampling signal on the bias DC. Connect the neutral wire to the chip ground for power sampling autotransformer applications. Current sampling is done through current transformers.

The design of the power circuit is related to the electromagnetic compatibility of the product. Including that the power supply voltage should be kept within the specified error range, the appropriate filter capacitor should be selected at the output end, and the filter resistor, varistor and capacitor should be arranged reasonably to ensure a good filter effect and electromagnetic compatibility.

Regarding the design of the SPI interface, the SPI communication line should be as short as possible, so that the interference of the transmission signal line is as small as possible, and a low-pass filter circuit is added at the input end to eliminate high-frequency interference, and a suitable decoupling capacitor is selected to increase the anti-interference of the circuit ability. The microcontroller must monitor the SPI port to ensure measurement accuracy.

Program writing for SPI communication.

SPI write timing:

The calibration of the electric energy meter adopts a pure software calibration method, including two parts: the ratio difference calibration and the angle difference calibration. The ratio difference calibration is to correct the ratio difference of the transformer, and the angle difference calibration is to verify the angular difference of the transformer. Both methods are carried out in sections.

Through the above implementation steps, the design of a power meter with communication function can be realized. The power meter with communication function can transmit the power information to the computer for analysis in real time. The utility model is also the basic equipment of some remote metering systems. , has a wide range of uses and practical significance.

Claims (2)

1. with an electric energy meter for communication function, it is characterized in that being provided with current/voltage acquisition module, computation chip, microprocessor, communication module, display module and EEPROM;

Described current/voltage acquisition module comprises A phase current voltage acquisition module, B phase current voltage acquisition module and C phase current voltage acquisition module; The output terminal of A phase current voltage acquisition module, B phase current voltage acquisition module and C phase current voltage acquisition module connects respectively the input end of computation chip, computation chip is connected with microprocessor, and the processing signals output terminal of microprocessor is connected with the input end of communication module, display module and EEPROM respectively.

2. a kind of electric energy meter with communication function as claimed in claim 1, is characterized in that described computation chip is provided with electric current and voltage simulating signal sampling module, DSP metering module, pulse producer, SPI communication interface, clock control circuit, temperature sensor, reference voltage module and power management module, the input termination A phase current voltage acquisition module of electric current and voltage simulating signal sampling module, the output terminal of B phase current voltage acquisition module and C phase current voltage acquisition module, the input end of the output termination DSP metering module of electric current and voltage simulating signal sampling module, the output terminal of DSP metering module connects respectively the input end of pulse producer and SPI communication interface, clock control circuit is connected with crystal oscillating circuit, SPI communication interface is connected with microprocessor, the output termination electric current and voltage simulating signal sampling module of temperature sensor, reference voltage module is connected with temperature sensor with electric current and voltage simulating signal sampling module respectively, power management module provides power supply for chip.

Images