Three-phase harmonic watt-hour meter circuit and watt-hour meter

Abstract

The utility model relates to intelligent electric energy meter technical field discloses a kind of three-phase harmonic electric energy meter circuit and electric energy meter, three-phase harmonic electric energy meter circuit includes: sampling module, measurement module, control module and display module, wherein, the input end of sampling module inputs electric signal of electric power line, and the output end of sampling module is connected with the input end of measurement module;The communication end of measurement module is connected with the communication end of control module, and the power supply end of measurement module and the power supply end of control module are all connected with external power supply;The first end of control module is connected with display module, and the communication end of control module is connected with the communication end of measurement module.The electric energy meter circuit of the utility model can display three-phase voltage total harmonic content and current total harmonic content, facilitate user to quickly exclude electric power line fault according to harmonic content data, improve troubleshooting accuracy.

Description

Technical Field

[0001] This utility model relates to the field of smart energy meter technology, specifically to a three-phase harmonic energy meter circuit and energy meter. Background Technology

[0002] Currently available three-phase smart energy digital display meters do not have harmonic measurement functions, which may cause the following problems during use:

[0003] 1. Cover-up of symptoms: When equipment trips, overheats, makes noise, or the control system malfunctions for no reason, ordinary digital displays can only show "normal" or "abnormal" voltage / current values. Since many faults are caused by harmonic pollution, they cannot reveal the root cause of the fault, cannot completely eliminate faults such as waveform distortion, and the troubleshooting is not thorough.

[0004] 2. Troubleshooting difficulties: When maintenance personnel see that the voltage is too high or the current is too large, they cannot determine whether the fault is caused by load changes, power grid fluctuations or harmonics, resulting in extremely low fault diagnosis efficiency and even possible misdiagnosis. Utility Model Content

[0005] In view of this, the present invention provides a three-phase harmonic energy meter circuit and an energy meter to solve the problem that existing energy meter circuits cannot perform harmonic measurement.

[0006] In a first aspect, this utility model provides a three-phase harmonic energy meter circuit, comprising: a sampling module, a metering module, a control module, and a display module. The sampling module receives an electrical signal from a power line at its input terminal, and its output terminal is connected to the input terminal of the metering module. The communication terminal of the metering module is connected to the communication terminal of the control module, and both the power supply terminals of the metering module and the control module are connected to an external power source. The first terminal of the control module is connected to the display module, which controls the metering module to calculate and store energy parameters based on the electrical signal. The display module displays the energy parameters, including the total harmonic content of voltage and the total harmonic content of current.

[0007] The three-phase harmonic energy meter circuit provided by this utility model has the function of displaying the total harmonic content of three-phase voltage and the total harmonic content of three-phase current, so that users can directly observe the changes in harmonic content through the display module. When a power line fault occurs, the harmonic content data can be used as a reference to fundamentally and quickly eliminate the fault. At the same time, the power quality can be analyzed in real time based on the harmonic content, thereby accurately obtaining the current working status of the power line and avoiding the occurrence of faults.

[0008] In one optional implementation, the sampling module includes: a three-phase voltage sampling voltage divider resistor network and a three-phase current sampling transformer, wherein the input terminal of the three-phase voltage sampling voltage divider resistor network is connected in parallel with the power line, and the output terminal of the three-phase voltage sampling voltage divider resistor network is connected to the input terminal of the metering module; the input terminal of the three-phase current sampling transformer is connected in series with the power line, and the output terminal of the three-phase current sampling transformer is connected to the input terminal of the metering module.

[0009] In one optional implementation, the three-phase harmonic energy meter circuit further includes: a switching power supply module, the input terminal of which is connected to an external power supply, and the output terminal of which is connected to the power supply terminals of the metering module and the control module.

[0010] In one optional embodiment, the switching power supply module includes: an input filtering and rectifying unit, a control unit, and a transformer unit. The first terminal of the input filtering and rectifying unit is connected to an external power source; the second terminal of the input filtering and rectifying unit is connected to the first terminal of the control unit and the first terminal of the transformer unit; the third terminal of the input filtering and rectifying unit is connected to the second terminal of the control unit; the third and fourth terminals of the control unit are respectively connected to the second and third terminals of the transformer unit; and the fourth terminal of the transformer unit is connected to the power supply terminal of the metering module.

[0011] In one optional implementation, the display module includes a driving unit and a display screen, wherein the input terminal of the driving unit is connected to the first terminal of the control module, and the output terminal of the driving unit is connected to the input terminal of the display screen.

[0012] In one optional implementation, the three-phase harmonic energy meter circuit further includes: a communication module connected to the second terminal of the control module; the communication module adopts the MODBUS communication protocol.

[0013] In one alternative implementation, the three-phase harmonic energy meter circuit further includes a touch button module connected to the third terminal of the control module.

[0014] In one optional implementation, the three-phase harmonic energy meter circuit further includes a storage module connected to the fourth terminal of the control module; the storage module is a dual-verification dual-backup memory.

[0015] In one alternative implementation, the three-phase harmonic energy meter circuit further includes an energy pulse output module connected to the output terminal of the metering module.

[0016] Secondly, this utility model provides an energy meter, comprising: an energy meter body and a three-phase harmonic energy meter circuit according to the first aspect or any corresponding embodiment. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a circuit diagram of a three-phase harmonic energy meter according to an embodiment of the present invention;

[0019] Figure 2 This is a detailed circuit diagram of the metering module according to an embodiment of the present utility model;

[0020] Figure 3 This is a detailed circuit diagram of the control module according to an embodiment of the present utility model;

[0021] Figure 4 This is a composition diagram of the sampling module according to an embodiment of the present utility model;

[0022] Figure 5 This is a detailed circuit diagram of the sampling module according to an embodiment of the present utility model;

[0023] Figure 6 This is a composition diagram of a switching power supply module according to an embodiment of the present utility model;

[0024] Figure 7 This is a detailed circuit diagram of the switching power supply module according to an embodiment of the present utility model;

[0025] Figure 8 This is a composition diagram of the display module according to an embodiment of the present utility model;

[0026] Figure 9 This is a detailed circuit diagram of the display module according to an embodiment of the present utility model;

[0027] Figure 10 This is a circuit diagram of another three-phase harmonic energy meter according to an embodiment of the present utility model;

[0028] Figure 11 This is a detailed circuit diagram of the communication module and the power pulse output module according to an embodiment of the present utility model;

[0029] Figure 12 This is a detailed circuit diagram of the touch button module according to an embodiment of the present utility model. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0034] This embodiment provides a three-phase harmonic energy meter circuit, such as... Figure 1 As shown, it includes: sampling module 1, metering module 2, control module 3 and display module 4.

[0035] Figure 1 In the process, the input terminal of sampling module 1 receives the electrical signal of the power line, and the output terminal of sampling module 1 is connected to the input terminal of metering module 2.

[0036] Optionally, the sampling module may include voltage transformers, voltage sampling divider resistor networks, current transformers, etc., for collecting voltage and current signals on the power line and sending them to the metering module.

[0037] Figure 1In this system, the communication terminal of metering module 2 is connected to the communication terminal of control module 3, and the power supply terminals of both metering module 2 and control module 3 are connected to an external power source.

[0038] Figure 1 In the middle, the first end of the control module 3 is connected to the display module 4. The control module 3 is used to control the metering module 2 to calculate and store the electrical energy parameters based on the electrical signals.

[0039] Optionally, the electrical energy parameters include the total harmonic content of voltage and the total harmonic content of current. The electrical energy parameters may also include other parameters that can reflect the operating status of the power line, such as voltage, current, power, power factor, frequency, and electrical energy.

[0040] For example, Figure 2 The metering module consists of a metering chip U20 and its peripheral circuitry. Figure 3 It is a control module consisting of the main control chip U21 and its peripheral circuits.

[0041] It should be noted that the control module incorporates various existing and mature electrical energy parameter calculation software programs. This allows the control module to send calculation commands to the metering module via a communication terminal, and the metering module to calculate the corresponding electrical energy parameters based on the collected electrical signals. Those skilled in the art can adjust the types and number of software programs according to actual usage requirements to modify the metering module's ability to calculate various electrical energy parameters.

[0042] Optionally, the main control module is also used for user power data management, rate control, event logging, etc.

[0043] Figure 1 In the middle, display module 4 is used to display electrical energy parameters.

[0044] Optionally, the display module consists of a display screen and a driving circuit. The display screen can be a liquid crystal display (LCD) or an LED digital tube, and the driving circuit can control the display screen to display the electrical energy parameters stored in the control module.

[0045] The three-phase harmonic energy meter circuit provided in this embodiment has the function of displaying the total harmonic content of three-phase voltage and the total harmonic content of three-phase current, so that users can directly observe the changes in harmonic content through the display module. When a power line fault occurs, the harmonic content data can be used as a reference to fundamentally and quickly eliminate the fault. At the same time, the power quality can be analyzed in real time based on the harmonic content, thereby accurately obtaining the current working status of the power line and avoiding the occurrence of faults.

[0046] In some alternative implementations, such as Figure 4As shown, the sampling module 1 includes a three-phase voltage sampling voltage divider resistor network 11 and a three-phase current sampling transformer 12. The input terminal of the three-phase voltage sampling voltage divider resistor network 11 is connected in parallel with the power line, and the output terminal of the three-phase voltage sampling voltage divider resistor network 11 is connected to the input terminal of the metering module 2. The input terminal of the three-phase current sampling transformer 12 is connected in series with the power line, and the output terminal of the three-phase current sampling transformer 12 is connected to the input terminal of the metering module 2.

[0047] Specifically, Figure 5 In the three-phase current sampling transformer, there are transformers U4, U5, and U6, which collect the currents of phases A, B, and C respectively. Resistors R1, R2, and R3 divide the voltage of phase A, resistors R4, R5, and R6 divide the voltage of phase B, and resistors R7, R8, and R9 divide the voltage of phase C.

[0048] Alternatively, voltage transformers can be used to collect voltage on power lines.

[0049] Optionally, when the power line is single-phase, those skilled in the art can adjust the topology of the components in the sampling module according to actual needs.

[0050] In some alternative implementations, such as Figure 6 As shown, the three-phase harmonic energy meter circuit also includes: a switching power supply module 5, the input terminal of which is connected to an external power supply, and the output terminal of which is connected to the power supply terminal of the metering module 2 and the power supply terminal of the control module 3.

[0051] Specifically, Figure 7 In the switching power supply module 5, there are: an input filtering and rectifying unit 51, a control unit 52, and a transformer unit 53. The first end of the input filtering and rectifying unit 51 is connected to an external power supply. The second end of the input filtering and rectifying unit 51 is connected to the first end of the control unit 52 and the first end of the transformer unit 53. The third end of the input filtering and rectifying unit 51 is connected to the second end of the control unit 52. The third and fourth ends of the control unit 52 are respectively connected to the second and third ends of the transformer unit 53. The fourth end of the transformer unit 53 is connected to the power supply end of the metering module 2.

[0052] For example, Figure 7 In the input filter rectifier unit 51, resistors R40 and R41 are used to suppress electromagnetic interference and transient surge voltage or current, protecting the subsequent circuits; the full-bridge rectifier D7 in the input filter rectifier unit 51 is used to convert AC input into unidirectional pulsating DC; the filter capacitor C11 in the input filter rectifier unit 51 is used to smooth the pulsating DC, obtain a more stable DC voltage, and provide primary power supply for the transformer unit 53.

[0053] For example, Figure 7 In the process, the control chip U16 generates pulse width modulation signals to control the power supply and disconnection of the transformer unit 53, thereby achieving voltage regulation and energy transmission.

[0054] For example, Figure 7 In this circuit, T3 is a high-frequency isolation transformer used to achieve energy transfer and electrical isolation from the primary to the secondary winding. It outputs DC voltage to different loads through the secondary windings Ns1 and Ns2. When the energy meter circuit includes a 485 circuit, diode U14 and resistor C7 rectify and filter the AC current induced by Ns2, respectively, to provide a stable DC voltage supply for the 485 circuit.

[0055] Optionally, Figure 7 In the switching power supply module, there may also be a voltage regulator circuit 54 consisting of a voltage regulator U12 and peripheral circuits. This is used to stabilize the input voltage at a 5V output when the energy meter circuit includes a 485 circuit, thereby improving the power supply stability of subsequent circuits.

[0056] In some alternative implementations, such as Figure 8 As shown, the display module 4 includes a driving unit 41 and a display screen 42, wherein the input end of the driving unit 41 is connected to the first end of the control module 3, and the output end of the driving unit 41 is connected to the input end of the display screen 42.

[0057] For example, such as Figure 9 As shown, the driving unit includes a driving chip U1 and its peripheral circuits, and the display screen includes a 16×16 dot matrix display LED1. The driving unit drives the display screen to display characters or simple graphics at corresponding positions based on the power parameters stored in the control module. That is, it controls the voltage of the rows and columns of the dot matrix display LED1 to light up specific LEDs, thereby displaying characters or graphics.

[0058] Optionally, those skilled in the art can adjust the display screen model, dot matrix arrangement, etc., according to actual needs.

[0059] In some alternative implementations, such as Figure 10 As shown, the three-phase harmonic energy meter circuit also includes: a communication module 6 connected to the second terminal of the control module 3 and an energy pulse output module 7 connected to the output terminal of the metering module 2; the communication module 6 adopts the MODBUS communication protocol.

[0060] For example, such as Figure 11 As shown, the communication module 6 includes 485 transceivers U17 and U18, and a transceiver chip U10 for processing 485 signals. The communication module 6 adopts the MODBUS communication protocol and can simultaneously collect three-phase electrical parameters from the primary and secondary sides.

[0061] For example, such as Figure 11As shown, the power pulse output module 7 includes an optocoupler U8, which can isolate input and output signals and prevent electrical interference.

[0062] In some alternative implementations, such as Figure 10 As shown, the three-phase harmonic energy meter circuit also includes a touch button module 8 connected to the third terminal of the control module 3.

[0063] For example, such as Figure 12 As shown, users can perform data addition, subtraction, setting, and confirmation operations on the electricity meter using the data subtraction button U25, the data addition button U26, the setting button U27, and the confirmation button U2.

[0064] In some alternative implementations, such as Figure 10 As shown, the three-phase harmonic energy meter circuit also includes a storage module 9 connected to the fourth terminal of the control module 3; the storage module 9 is a dual-verification dual-backup memory.

[0065] Optionally, the storage module uses electrically erasable programmable read-only memory (EEPROM) to store data, with dual data verification and dual backup. The stored data has its own backup address. When the main data verification fails, the data at the backup address is read, making data storage more secure and reliable.

[0066] This embodiment provides an energy meter, including: an energy meter body and a three-phase harmonic energy meter circuit according to the above embodiment or any corresponding implementation.

[0067] Specifically, the three-phase harmonic energy meter circuit is installed inside the energy meter body. The specific functions and principles of the three-phase harmonic energy meter circuit are the same as those described in the above embodiments, and will not be repeated here.

[0068] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A three-phase harmonic energy meter circuit, characterized in that, include: The system comprises a sampling module, a metering module, a control module, and a display module. The sampling module receives the electrical signal from the power line at its input terminal, and its output terminal is connected to the input terminal of the metering module. The communication terminal of the metering module is connected to the communication terminal of the control module, and the power supply terminals of both the metering module and the control module are connected to an external power source. The first end of the control module is connected to the display module, and the control module is used to control the metering module to calculate and store electrical energy parameters based on the electrical signal; The display module is used to display the electrical energy parameters; The electrical energy parameters include the total harmonic content of voltage and the total harmonic content of current.

2. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, The sampling module includes: a three-phase voltage sampling voltage divider resistor network and a three-phase current sampling transformer, wherein... The input terminal of the three-phase voltage sampling voltage divider resistor network is connected in parallel with the power line, and the output terminal of the three-phase voltage sampling voltage divider resistor network is connected to the input terminal of the metering module. The input terminal of the three-phase current sampling transformer is connected in series on the power line, and the output terminal of the three-phase current sampling transformer is connected to the input terminal of the metering module.

3. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, Also includes: Switching power supply module, The input terminal of the switching power supply module is connected to an external power source, and the output terminal of the switching power supply module is connected to the power supply terminal of the metering module and the power supply terminal of the control module.

4. The three-phase harmonic energy meter circuit according to claim 3, characterized in that, The switching power supply module includes: an input filtering and rectification unit, a control unit, and a transformer unit, wherein... The first end of the input filtering and rectifying unit is connected to the external power supply, the second end of the input filtering and rectifying unit is connected to the first end of the control unit and the first end of the transformer unit, and the third end of the input filtering and rectifying unit is connected to the second end of the control unit. The third and fourth terminals of the control unit are respectively connected to the second and third terminals of the transformer unit; The fourth terminal of the transformer unit is connected to the power supply terminal of the metering module.

5. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, The display module includes: a driving unit and a display screen, wherein... The input terminal of the drive unit is connected to the first terminal of the control module, and the output terminal of the drive unit is connected to the input terminal of the display screen.

6. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, Also includes: The communication module is connected to the second end of the control module; The communication module uses the MODBUS communication protocol.

7. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, Also includes: A touch button module connected to the third end of the control module.

8. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, Also includes: A storage module connected to the fourth terminal of the control module; The storage module is a dual-verification, dual-backup storage device.

9. The three-phase harmonic energy meter circuit according to claim 1, characterized in that, Also includes: An energy pulse output module connected to the output terminal of the metering module.

10. An electricity meter, characterized in that, include: The energy meter body and the three-phase harmonic energy meter circuit according to any one of claims 1 to 9.

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