Electric energy meter with harmonic monitoring function

Abstract

The utility model provides an electric energy meter with a harmonic monitoring function. The electric energy meter comprises an electric energy meter main body structure, a harmonic measurement module, a data processing unit, an alarm module and a heat dissipation module. The basic sampling circuit is connected with the harmonic measurement module, the display screen is connected with the data processing unit, the harmonic measurement module is connected with the data processing unit, and the data processing unit is connected with the alarm module; the harmonic measurement module is used for accurately measuring the harmonic content of each order of voltage and current, and transmitting the measured data to the data processing unit; the data processing unit is used for receiving the data uploaded by the harmonic measurement module, analyzing and processing the data in real time, and transmitting an analysis result to the display screen for displaying; and the alarm module is used for giving out a sound-light alarm when the data processing unit detects that the harmonic content exceeds a preset threshold value. According to the technical scheme, the problem that an existing electric energy meter cannot accurately measure and monitor harmonic waves in real time is solved.

Description

Technical Field

[0001] This utility model relates to the field of electrical energy metering technology, and in particular to an electrical energy meter with harmonic monitoring function. Background Technology

[0002] In power systems, harmonic problems are becoming increasingly prominent. Harmonics increase the current in power lines, leading to overheating, accelerated aging, and increased line losses. They also exert thermal, mechanical, and chemical effects on electrical equipment, causing performance degradation and shortened lifespan. Furthermore, harmonics can interfere with nearby communication systems, affecting communication quality. Therefore, the detection and mitigation of harmonics are crucial for ensuring the stable operation of power systems. However, most existing electricity meters can only measure fundamental frequency energy and cannot accurately measure and monitor harmonics in real time. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide an energy meter with harmonic monitoring function, which aims to solve the problem that existing energy meters cannot accurately measure and monitor harmonics in real time.

[0004] To achieve the above objectives, this utility model adopts the following technical solution: an energy meter with harmonic monitoring function, comprising an energy meter main structure, a harmonic measurement module, a data processing unit, an alarm module, and a heat dissipation module; the energy meter main structure includes an energy meter housing, a basic sampling circuit, and a display screen; the basic sampling circuit is connected to the harmonic measurement module, the display screen is connected to the data processing unit, the harmonic measurement module is connected to the data processing unit, and the data processing unit is connected to the alarm module; the harmonic measurement module is used to accurately measure the harmonic content of voltage and current, and transmit the measurement data to the data processing unit; the data processing unit is used to receive the data uploaded by the harmonic measurement module, perform real-time analysis and processing, and transmit the analysis results to the display screen for display; the alarm module is used to issue an audible and visual alarm when the data processing unit detects that the harmonic content exceeds a preset threshold.

[0005] In a preferred embodiment, the harmonic measurement module is connected to an external circuit input interface to acquire circuit voltage and current information of the line, and converts the sampled signal into a digital signal and outputs it to the data processing unit. Specifically, the three-phase input voltage is connected to a voltage transformer for conversion and then input to the analog input interface of the harmonic measurement module to acquire voltage data; the three-phase input current is connected to a converter and then connected to a current transformer for conversion and input to the input interface of the harmonic measurement module to acquire current data; after analog-to-digital conversion by the harmonic measurement chip, the digital signal is transmitted to the data processing unit.

[0006] In a preferred embodiment, the harmonic measurement module includes a chip U1 and a first inductor bead L1, a second inductor bead L2, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7. The first pin of chip U1 is externally connected to an analog power supply circuit, the second pin of chip U1 is externally connected to an analog ground circuit, and the third, fourth, and fifth pins of chip U1 are connected to the data processing unit for oversampling mode selection. The sixth pin of chip U1 is a serial / parallel output selection port connected to the data processing unit. The eighth pin of chip U1, the analog input range port, is connected to the data processing unit; the ninth pin of chip U1, the conversion start input A port, is connected to the data processing unit; the tenth pin of chip U1, the conversion start input B port, is connected to the data processing unit; the 11th pin of chip U1, the RESET port, is connected to the data processing unit; the twelfth pin of chip U1, the serial clock input port, is connected to the data processing unit; the thirteenth pin of chip U1, the chip select signal port, is connected to the data processing unit; the fourteenth pin of chip U1 is connected to the data processing unit, which outputs the busy signal of the module.

[0007] In a preferred embodiment, pin 15 of chip U1 is connected to the data processing unit; pins 24 and 25 of chip U1 are connected to the data processing unit to receive serial output data from the harmonic measurement module; pin 33 of chip U1 is connected to the data processing unit to receive serial output data from the harmonic measurement module; pin 48 of chip U1 is connected to a 3.3V power supply; pin 34 of chip U1 is connected to an external reference voltage of 3.3V; pins AIN_V1-AIN_V8 of chip U1 are the 8-channel synchronous analog input channels of chip U1, introducing voltage and current analog signals; pins V1GND-V8GND are grounded.

[0008] In a preferred embodiment, the data processing unit includes a chip U2, an eighth capacitor C8, a ninth capacitor C9, and a crystal oscillator unit X1. The first pin of chip U2 is connected to a 3.3V backup power supply. The fifth and sixth pins of chip U2 are connected to a crystal oscillator circuit composed of the eighth capacitor C8, the ninth capacitor C9, and the crystal oscillator unit X1. The seventh pin of chip U2 is connected to a RESET button. The eighth pin of chip U2 is grounded. The ninth pin of chip U2 is connected to a 3.3V power supply. Pins 10 to 17 of chip U2 are connected to a display screen to transmit data. Pins 18 to 20 of chip U2 are connected to a harmonic measurement module for oversampling mode selection. Pin 21 of chip U2 is connected to the harmonic measurement module to receive the module's busy signal. Pin 22 of chip U2 is connected to the harmonic measurement module... Connections: Pin 24 of chip U2 is connected to a 3.3V power supply; pins 25 and 26 of chip U2 are connected to the harmonic measurement module to receive serial output data from the harmonic measurement module; pin 27 of chip U2 is connected to the harmonic measurement module to receive serial output data from the harmonic measurement module; pin 22 of chip U2 is connected to the START button; pin 22 of chip U2 is connected to the display screen; pin 23 of chip U2 is grounded; pin 24 of chip U2 is connected to a 3.3V voltage; pin 29 of chip U2 is connected to the chip select interface of the display screen; pin 30 of chip U2 is connected to the command signal port of the display screen; pin 31 of chip U2 is connected to the write signal port of the display screen; pin 32 of chip U2 is connected to the read signal port of the display screen; pin 33 of chip U2 is connected to the reset signal port of the display screen.

[0009] In a preferred embodiment, pin 34 of chip U2 is connected to the BEEP port of the alarm circuit; pin 35 of chip U2 is grounded; pin 36 of chip U2 is connected to a 3.3V power supply; pin 37 of chip U2 is connected to the G-LED port of the alarm circuit; pin 38 of chip U2 is connected to the R-LED port of the alarm circuit; pin 39 of chip U2 is connected to the serial / parallel output selection port of the harmonic measurement module; pin 40 of chip U2 is connected to the analog input range port of the harmonic measurement module; pin 41 of chip U2 is connected to the A port of the harmonic measurement module; pin 42 of chip U2 is connected to the B port of the harmonic measurement module; pin 43 of chip U2 is connected to the RESET port of the harmonic measurement module; pin 45 of chip U2 is connected to the serial clock input port of the harmonic measurement module; pin 46 of chip U2 is connected to the chip select signal port of the harmonic measurement module; pin 47 of chip U2 is grounded; and pin 48 of chip U2 is connected to a 3.3V power supply.

[0010] In a preferred embodiment, the alarm circuit includes a sound alarm circuit and a light alarm circuit; when the harmonic exceeds the threshold, the data processing unit outputs an alarm signal to the sound and light alarm circuit; the sound alarm circuit includes a first resistor R1, an NPN transistor Q1, and a buzzer; the light alarm circuit includes a second resistor R2, a third resistor R3, a first LED, and a second LED; the G-LED connector of the light alarm circuit is connected to the data processing unit, and the R-LED is connected to the data processing unit.

[0011] In a preferred embodiment, the display screen includes an LCD display chip. The first pin of the LCD display chip is connected to the chip select signal port, the second pin is connected to the command port, the third pin is connected to the write signal port, the fourth pin is connected to the read signal port, and the fifth pin is connected to the reset signal port. The sixth to thirteenth pins of the LCD display chip are connected to the data processing unit for data input and receiving data information displayed on the display screen. The twenty-third and twenty-fourth pins of the LCD display chip are connected to a 3.3V power supply, and the twenty-sixth pin is grounded.

[0012] In a preferred embodiment, the power supply circuit supplies power to the harmonic measurement module, the data processing unit, the display screen, and the alarm circuit. The P1 terminal block of the power supply circuit is connected to a 5V voltage and outputs a 5V voltage. The 3.3V power supply circuit includes chip U3, tenth capacitor C10, and eleventh capacitor C11. The third pin of chip U3 is connected to a 5V voltage, and the second and third pins of chip U3 output a 3.3V voltage.

[0013] In a preferred embodiment, the heat dissipation module consists of heat sinks that are attached to the back of the electricity meter.

[0014] Compared with the prior art, the present invention has the following advantages: when the harmonic content is detected to exceed the preset threshold, it can issue an audible and visual alarm to remind maintenance personnel to handle it in a timely manner, and can accurately measure and monitor harmonic signals in real time. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the electricity meter according to a preferred embodiment of the present invention;

[0016] Figure 2 This is a wiring diagram of the overall circuit principle of the electricity meter according to a preferred embodiment of this utility model;

[0017] Figure 3 This is a circuit diagram of the harmonic measurement module according to a preferred embodiment of the present invention.

[0018] Figure 4 The circuit diagram of the data processing unit of the preferred embodiment of this utility model is shown below.

[0019] Figure 5 The circuit diagram of the alarm circuit of the preferred embodiment of this utility model is shown below.

[0020] Figure 6 This is a circuit diagram of the display screen according to a preferred embodiment of the present invention.

[0021] Figure 7 The circuit diagram of the power supply circuit of the preferred embodiment of this utility model is shown below.

[0022] Figure 8 This is a schematic diagram of the heat dissipation module structure according to a preferred embodiment of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application; as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise; furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] like Figure 1 As shown, an energy meter with harmonic monitoring function includes a main structure of the energy meter, which includes: an energy meter housing, a basic sampling circuit, and a screen; the energy meter housing is used for external encapsulation; the basic sampling circuit is used to collect data such as voltage, current, frequency, power factor, and energy meter events of the external circuit; the screen is used to display the collected data and harmonic monitoring data.

[0027] The electricity meter also includes a harmonic measurement circuit, a data processing unit, an alarm module, and a heat dissipation module.

[0028] The harmonic measurement circuit is used to accurately measure the harmonic content of voltage and current, and transmit the measurement data to the data processing unit.

[0029] The data processing unit is used to receive data uploaded by the harmonic measurement module, perform real-time analysis and processing, and transmit the analysis results to the display screen for display.

[0030] The alarm module is used to issue an audible and visual alarm when the data processing unit detects that the harmonic content exceeds a preset threshold.

[0031] The heat dissipation module includes a heat sink attached to the back of the circuit board to improve the heat dissipation performance of the electricity meter.

[0032] like Figure 2 The diagram shows the overall circuit connection of the harmonic monitoring system of this utility model, which includes: 1. Harmonic measurement module; 2. Data processing unit; 3. Alarm module; 4. Power supply circuit; 5. Display screen.

[0033] The harmonic measurement module is connected to an external circuit input interface to acquire the circuit voltage and current information of the line, convert the sampled signal into a digital signal, and output it to the data processing unit. Specifically, it includes: connecting the three-phase input voltage to a voltage transformer for conversion, and inputting it to the analog input interface of the harmonic measurement module for voltage data acquisition; connecting the three-phase input current to a converter and then to a current transformer for conversion, and inputting it to the input interface of the harmonic measurement module for current data acquisition; the harmonic measurement chip performs analog-to-digital conversion and transmits the digital signal to the data processing unit through relevant pins.

[0034] The data processing unit receives data uploaded by the harmonic measurement module, performs real-time analysis and processing using relevant algorithms, and outputs the analysis results to the screen. Specifically, after receiving the digital signal from the harmonic measurement module, the data processing unit performs a Fourier transform on the digital signal to obtain the fundamental amplitude and the content of each harmonic, determining whether each harmonic exceeds the limit. When a harmonic limit violation occurs, the data processing unit transmits the information to the alarm module and the screen via the corresponding pins.

[0035] The alarm module can issue an audible and visual alarm when the data processing unit detects that the harmonic content exceeds the preset threshold, reminding maintenance personnel to handle it in a timely manner; the power supply circuit is used to power the harmonic measurement module, data processing unit, alarm circuit and display screen; the display screen circuit receives the harmonic monitoring results data output by the data processing unit and displays them.

[0036] like Figure 3As shown, the harmonic measurement module consists of chip U1, inductors L1 and L2, and capacitors C1, C2, C3, C4, C5, C6, and C7. Pin 1 of the harmonic measurement module is connected to an external analog power supply circuit, pin 2 is connected to an external analog ground circuit, and pins 3-5 are connected to pins 18-20 of the data processing unit for oversampling mode selection. Pin 6, the serial / parallel output selection port of the harmonic measurement module, is connected to pin 39 of the data processing unit. Pin 8, the analog input range port of the harmonic measurement module, is connected to pin 40 of the data processing unit. Pin 9, the start input A port of the harmonic measurement module, is connected to pin 41 of the data processing unit. Pin 10, the start input B port of the harmonic measurement module, is connected to pin 42 of the data processing unit. Pin 11, the RESET port of the harmonic measurement module, is connected to pin 42 of the data processing unit. Pins 43, 12 (serial clock input) of the harmonic measurement module, and 45 (data processing unit) are connected. Pin 13 (chip select) of the harmonic measurement module and 46 (data processing unit) are connected. Pin 14 of the harmonic measurement module and 21 of the data processing unit are connected, outputting the module's busy signal. Pin 15 of the harmonic measurement module and 22 of the data processing unit are connected. Pins 24-25 of the harmonic measurement module and 25-26 of the data processing unit are connected, receiving the serial output data from the harmonic measurement module. Pin 33 of the harmonic measurement module and 27 of the data processing unit are connected, receiving the serial output data from the harmonic measurement module. Pin 48 is connected to a 3.3V power supply. Pin 34 is connected to an external 3.3V reference voltage. Pins AIN_V1-AIN_V8 are the 8-channel synchronous analog input channels of chip U1, introducing voltage and current analog signals. Pins V1GND-V8GND are grounded.

[0037] like Figure 4As shown, the data processing unit includes chip U2, capacitors C8 and C9, and crystal oscillator unit X1. Pin 1 of the data processing unit is connected to a 3.3V backup power supply. Pins 5 and 6 are connected to a crystal oscillator circuit consisting of capacitors C8 and C9 and crystal oscillator unit X1. Pin 7 is connected to the RESET button. Pin 8 is grounded. Pin 9 is connected to a 3.3V power supply. Pins 10-17 are connected to pins 6-13 of the display screen to transmit data to the display screen chip. Pins 18-20 are connected to pins 3-5 of the harmonic measurement module for oversampling mode selection. Pin 21 is connected to pin 14 of the harmonic measurement module to receive the module's busy signal. Pin 22 is connected to pin 15 of the harmonic measurement module. Pin 24 is connected to a 3.3V power supply. Pins 25-26 are connected to pins 24-25 of the harmonic measurement module to receive the serial output data from the harmonic measurement module. Pin 27 is connected to pin 33 of the harmonic measurement module to receive the serial output data from the harmonic measurement module. Pin 22 is connected to the START button and corresponds to pin 3 of the display screen. Pin 23 is grounded. Pin 24 is connected to a 3.3V voltage. Pin 29 is connected to pin 1 of the display screen chip. Select the interface: pin 30 connects to the display screen's pin 2 command signal port; pin 31 connects to the display screen's pin 3 write signal port; pin 32 connects to the display screen's pin 4 read signal port; pin 33 connects to the display screen's pin 5 reset signal port; pin 34 connects to the alarm circuit's BEEP port; pin 35 is grounded; pin 36 connects to the 3.3V power supply; pin 37 connects to the alarm circuit's G-LED port; pin 38 connects to the alarm circuit's R-LED port; pin 39 connects to the harmonic measurement module's pin 6 serial / parallel output selection port; pin 40 connects to the harmonic measurement module's pin 8 analog input range port; pin 41 connects to the harmonic measurement module's pin 9 conversion start input port A; pin 42 connects to the harmonic measurement module's pin 10 conversion start input port B; pin 43 connects to the harmonic measurement module's pin 11 RESET port; pin 45 connects to the harmonic measurement module's pin 12 serial clock input port; pin 46 connects to the harmonic measurement module's pin 13 chip select signal port; pin 47 is grounded; and pin 48 connects to the 3.3V power supply.

[0038] like Figure 5 As shown, the alarm circuit includes a sound alarm circuit. When the harmonic exceeds the threshold, the data processing unit outputs an alarm signal to the sound and light alarm circuit. The sound alarm circuit includes a resistor R1, an NPN transistor Q1, and a buzzer 1. The light alarm circuit includes resistors R2 and R3, LED 1, and LED 2. The G-LED connector of the light alarm circuit is connected to pin 37 of the data processing unit, and the R-LED is connected to pin 38 of the data processing unit. When the harmonic exceeds the threshold, the alarm circuit emits a sound and light alarm.

[0039] like Figure 6As shown, the display screen pin 1 chip select signal port is connected to the data processing unit pin 29; the LCD display screen pin 2 command port is connected to the data processing unit pin 30; the display screen pin 3 write signal port is connected to the data processing unit pin 31; the display screen pin 4 read signal port is connected to the data processing unit pin 32; and the display screen pin 5 reset signal port is connected to the data processing unit pin 33. Display screen pins 6-13 are connected to the data processing unit pins 10-17 for data input and receiving data information displayed on the display screen. Pins 23 and 24 are connected to a 3.3V power supply, and pin 24 is grounded.

[0040] like Figure 7 As shown, the power supply circuit supplies power to the harmonic measurement module, data processing unit, display screen, and alarm circuit. The P1 terminal block is connected to a 5V voltage and can output a 5V voltage. The 3.3V power supply circuit includes chip U3, capacitor C10, and capacitor C11; pin 3 is connected to a 5V voltage, and pins 2 and 3 output a 3.3V voltage.

[0041] like Figure 8 As shown, the heat dissipation module consists of heat sinks, which are attached to the back of the electricity meter's PCB board to enhance the electricity meter's heat dissipation performance.

Claims

1. An energy meter with harmonic monitoring function, characterized in that... The device includes a main structure for an electricity meter, a harmonic measurement module, a data processing unit, an alarm module, and a heat dissipation module. The main structure includes a meter housing, a basic sampling circuit, and a display screen. The basic sampling circuit is connected to the harmonic measurement module, the display screen is connected to the data processing unit, the harmonic measurement module is connected to the data processing unit, and the data processing unit is connected to the alarm module. The harmonic measurement module accurately measures the harmonic content of voltage and current and transmits the measurement data to the data processing unit. The data processing unit receives the data uploaded by the harmonic measurement module, performs real-time analysis and processing, and transmits the analysis results to the display screen for display. The alarm module issues an audible and visual alarm when the data processing unit detects that the harmonic content exceeds a preset threshold.

2. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The harmonic measurement module connects to an external circuit input interface to acquire circuit voltage and current information, converts the sampled signals into digital signals, and outputs them to the data processing unit. Specifically, the three-phase input voltage is connected to a voltage transformer for conversion and then input to the analog input interface of the harmonic measurement module to acquire voltage data. The three-phase input current is connected to a converter and then to a current transformer for conversion and input to the input interface of the harmonic measurement module to acquire current data. After analog-to-digital conversion by the harmonic measurement chip, the digital signal is transmitted to the data processing unit.

3. An energy meter with harmonic monitoring function according to claim 2, characterized in that, The harmonic measurement module includes chip U1, a first inductor bead L1, a second inductor bead L2, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, and a seventh capacitor C7. The first pin AVCC of chip U1 is connected to an external analog power supply circuit, and the second pin AGND of chip U1 is connected to an external analog ground circuit. The third pin OS0, fourth pin OS1, and fifth pin OS2 of chip U1 are connected to the data processing unit for oversampling mode selection. The sixth pin PAR of chip U1 is connected to the data processing unit, and the eighth pin R of chip U1... The ANGE analog input range port is connected to the data processing unit. Pin 9 of chip U1, CONVSTA, is connected to the data processing unit. Pin 10 of chip U1, CONVSTB, is connected to the data processing unit. Pin 11 of chip U1, RESET, is connected to the data processing unit. Pin 12 of chip U1, RD#SLCK, is connected to the data processing unit. Pin 13 of chip U1, CS#, is connected to the data processing unit. Pin 14 of chip U1, BUSY, is connected to the data processing unit and outputs the busy signal of the module.

4. An energy meter with harmonic monitoring function according to claim 3, characterized in that, Pin 15 FRSTDATA of chip U1 is connected to the data processing unit; pins 24 DB7 and 25 DB8 of chip U1 are connected to the data processing unit to receive serial output data from the harmonic measurement module; pin 33 DB15 of chip U1 is connected to the data processing unit to receive serial output data from the harmonic measurement module; pin 48 AVCC of chip U1 is connected to a 3.3V power supply; pin 34 REFSELECT of chip U1 is connected to an external reference voltage of 3.3V; pins AIN_V1-AIN_V8 of chip U1 are the 8-channel synchronous analog input channels of chip U1, introducing voltage and current analog signals; pins V1GND-V8GND are grounded.

5. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The data processing unit includes chip U2, eighth capacitor C8, ninth capacitor C9, and crystal oscillator unit X1. Pin VBAT of chip U2 is connected to a 3.3V backup power supply. Pins PD0 and PD1 of chip U2 are connected to a crystal oscillator circuit composed of the eighth capacitor C8, ninth capacitor C9, and crystal oscillator unit X1. Pin NRET of chip U2 is connected to the RESET button. Pin VSSA of chip U2 is grounded. Pin VDDA of chip U2 is connected to a 3.3V power supply. Pins PA0 to PA7 of chip U2 are connected to the display screen to transmit data. Pins PB0 to PB2 of chip U2 are connected to the harmonic measurement module for oversampling mode selection. Pin PB10 of chip U2 is connected to the harmonic measurement module to receive the module's busy signal. Pin PB11 of chip U2 is connected to the harmonic measurement module... Module Connections: Pin 24 (VDD-1) of chip U2 is connected to a 3.3V power supply; pins 25 (PB12) to 26 (PB13) of chip U2 are connected to the harmonic measurement module to receive serial output data from the harmonic measurement module; pin 27 (PB14) of chip U2 is connected to the harmonic measurement module to receive serial output data from the harmonic measurement module; pin 22 (PB11) of chip U2 is connected to the START button and correspondingly connected to the display screen; pin 23 (VSS-1) of chip U2 is grounded; pin 29 (PA8) of chip U2 is connected to the chip select interface of the display screen; pin 30 (PA9) of chip U2 is connected to the command signal port of the display screen; pin 31 (PA10) of chip U2 is connected to the write signal port of the display screen; pin 32 (PA11) of chip U2 is connected to the read signal port of the display screen; and pin 33 (PA12) of chip U2 is connected to the reset signal port of the display screen.

6. An energy meter with harmonic monitoring function according to claim 5, characterized in that, Pin 34 (BEEP) of chip U2 is connected to the BEEP port of the alarm circuit; pin 35 (GND) of chip U2 is grounded; pin 36 (VCC) of chip U2 is connected to the 3.3V power supply; pin 37 (G-LED) of chip U2 is connected to the G-LED port of the alarm circuit; pin 38 (R-LED) of chip U2 is connected to the R-LED port of the alarm circuit; pin 39 (PB3) of chip U2 is connected to the serial / parallel output selection port of the harmonic measurement module; pin 40 (PB4) of chip U2 is connected to the analog input range port of the harmonic measurement module; pin 41 (PB5) of chip U2 is connected to the A port of the harmonic measurement module; pin 42 (PB6) of chip U2 is connected to the B port of the harmonic measurement module; pin 43 (PB7) of chip U2 is connected to the RESET port of the harmonic measurement module; pin 45 (PB8) of chip U2 is connected to the serial clock input port of the harmonic measurement module; pin 46 (PB9) of chip U2 is connected to the chip select signal port of the harmonic measurement module; pin 47 (GND) of chip U2 is grounded; and pin 48 (VDD) of chip U2 is connected to the 3.3V power supply.

7. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The alarm circuit includes a sound alarm circuit and a light alarm circuit. When the harmonics exceed the threshold, the data processing unit outputs an alarm signal to the sound and light alarm circuit. The sound alarm circuit includes a first resistor R1, an NPN transistor Q1, and a buzzer. The light alarm circuit includes a second resistor R2, a third resistor R3, a first LED, and a second LED. The G-LED connector of the light alarm circuit is connected to the data processing unit, and the R-LED is also connected to the data processing unit.

8. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The display screen includes an LCD display chip. The first pin (CS) of the LCD display chip is connected to the data processing unit. The second pin (RS) of the LCD display chip is connected to the data processing unit. The third pin (WR) of the LCD display chip is connected to the data processing unit. The fourth pin (RD) of the LCD display chip is connected to the data processing unit. The fifth pin (RST) of the LCD display chip is connected to the data processing unit. The sixth pin (PA0) to the thirteenth pin (PA7) of the LCD display chip are connected to the data processing unit for data input and receiving data information displayed on the display screen. The twenty-third pin (BL) and the twenty-fourth pin (VDD) of the LCD display chip are connected to a 3.3V power supply. The twenty-sixth pin (GND) of the LCD display chip is grounded.

9. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The power supply circuit supplies power to the harmonic measurement module, data processing unit, display screen and alarm circuit. The P1 terminal block of the power supply circuit is connected to 5V voltage and outputs 5V voltage. The 3.3V power supply circuit includes chip U3, tenth capacitor C10 and eleventh capacitor C11. The third pin IN of chip U3 is connected to 5V voltage, and the second pin OUT and the fourth pin OUT of chip U3 output 3.3V voltage.

10. An energy meter with harmonic monitoring function according to claim 1, characterized in that, The heat dissipation module consists of heat sinks, which are attached to the back of the electricity meter.

Images