An electric energy meter external power supply power consumption detection device

Abstract

The utility model discloses a kind of electric energy meter external power supply power consumption detection devices, comprising: test power supply, control circuit, power consumption tester, host computer and several to be measured electric energy meters;The test power supply is electrically connected with control circuit and power consumption tester respectively, the control circuit is electrically connected with power consumption tester, host computer and several to be measured electric energy meters respectively, and the power consumption tester is electrically connected with host computer;The control circuit includes MCU chip and several relay switch circuits, and the MCU chip is electrically connected with several relay switch circuits;Several the relay switch circuit includes first control circuit, second control circuit and third control circuit.The utility model solves the technical problem that the existing tooling is complex and low in efficiency to electric energy meter batch power consumption detection mode.

Description

Technical Field

[0001] This utility model relates to the field of electricity meter technology, and in particular to an external power consumption detection device for electricity meters. Background Technology

[0002] Electricity meters are used to measure customer electricity consumption interruptions, undertaking the tasks of electricity data collection, measurement, and transmission. In the power consumption testing of multi-core module electricity meters, requirements are set for different modes of the electricity meter, such as static power consumption without modules and backlight, power consumption under different module combinations, and power consumption under concurrent communication states between modules. Currently, batch testing uses a general-purpose power consumption tester. Patent document CN202411356459.5 discloses a switching power supply circuit, control method, and system for smart electricity meters, including: a main power supply module connected between the grid voltage and the smart electricity meter to provide power to the smart electricity meter; a fault detection module connected between the main power supply module and the auxiliary power supply module to detect faults in the main power supply module and determine whether the main power supply module has failed; and an auxiliary power supply module connected in parallel with the main power supply module between the grid voltage and the smart electricity meter, and connected to the fault detection module to provide power to the smart electricity meter when the main power supply module fails. Therefore, there is an urgent need to propose an external power consumption detection device for electricity meters to solve the technical problems of complex and inefficient batch power consumption detection methods for electricity meters using existing tooling. Utility Model Content

[0003] The main purpose of this invention is to propose an external power consumption detection device for electricity meters, which aims to solve the technical problems of complex and inefficient batch power consumption detection methods for electricity meters using existing tooling.

[0004] To achieve the above objectives, this utility model provides an external power consumption detection device for an electricity meter, wherein the external power consumption detection device for the electricity meter includes:

[0005] The test includes a power supply, control circuit, power consumption tester, host computer, and several energy meters under test.

[0006] The test power supply is electrically connected to the control circuit and the power consumption tester, respectively. The control circuit is electrically connected to the power consumption tester, the host computer, and several energy meters under test, respectively. The power consumption tester is electrically connected to the host computer. The control circuit includes an MCU chip and several relay switch circuits. The MCU chip is electrically connected to several relay switch circuits. Several relay switch circuits include a first control circuit, a second control circuit, and a third control circuit.

[0007] In one preferred embodiment, the first control circuit is connected to phase A of the test power supply, phase A of the energy meter under test, and the MCU chip, respectively; the second control circuit is connected to phase B of the test power supply, phase B of the energy meter under test, and the MCU chip, respectively; and the third control circuit is connected to phase C of the test power supply, phase C of the energy meter under test, and the MCU chip, respectively.

[0008] In one preferred embodiment, the first control circuit includes a relay K19, a diode D21, a resistor RT20, a transistor Q19, a resistor R50, a resistor R52, and a capacitor C28. Pin 1 of the relay K19 is connected to resistor RT20, and the other end of resistor RT20 is connected to phase A of the test power supply. Pin 2 or pin 3 of the relay K19 is connected to phase A of the energy meter under test. Pin 4 of the relay K19 is connected to the power supply terminal. Pin 5 of the relay K19 is connected to the anode of diode D21 and the collector of transistor Q19, respectively. The other end of diode D21 is connected to the power supply terminal. The base of transistor Q19 is connected to capacitor C28, resistor R52, and resistor R50, respectively. The other end of resistor R50 is connected to the MCU chip. The emitter of transistor Q19, the other end of capacitor C28, and the other end of resistor R52 are grounded.

[0009] In one preferred embodiment, the second control circuit includes a relay K20, a diode D22, a resistor RT21, a transistor Q20, a resistor R53, a resistor R54, and a capacitor C29. Pin 1 of the relay K20 is connected to resistor RT21, and the other end of resistor RT21 is connected to phase B of the test power supply. Pin 2 or pin 3 of the relay K20 is connected to phase B of the energy meter under test. Pin 4 of the relay K20 is connected to the power supply terminal. Pin 5 of the relay K20 is connected to the anode of diode D22 and the collector of transistor Q20, respectively. The other end of diode D22 is connected to the power supply terminal. The base of transistor Q20 is connected to capacitor C29, resistor R54, and resistor R53, respectively. The other end of resistor R53 is connected to the MCU chip. The emitter of transistor Q20, the other end of capacitor C29, and the other end of resistor R54 are grounded.

[0010] In one preferred embodiment, the third control circuit includes a relay K21, a diode D23, a resistor RT22, a transistor Q21, a resistor R55, a resistor R56, and a capacitor C30. Pin 1 of the relay K21 is connected to resistor RT22, and the other end of resistor RT22 is connected to phase C of the test power supply. Pin 2 or pin 3 of the relay K21 is connected to phase C of the energy meter under test. Pin 4 of the relay K21 is connected to the power supply terminal. Pin 5 of the relay K21 is connected to the anode of diode D23 and the collector of transistor Q21, respectively. The other end of diode D23 is connected to the power supply terminal. The base of transistor Q21 is connected to capacitor C30, resistor R56, and resistor R55, respectively. The other end of resistor R55 is connected to the MCU chip. The emitter of transistor Q21, the other end of capacitor C30, and the other end of resistor R56 are grounded.

[0011] In one preferred embodiment, the first control circuit, the second control circuit, and the third control circuit are all connected to terminals A, B, and C of the energy meter under test via Phoenix terminals, respectively.

[0012] In one preferred embodiment, the test power supply is electrically connected to a maximum of eight relay switching circuits.

[0013] In one preferred embodiment, the external power consumption detection device for the electricity meter further includes a power conversion circuit; the power conversion circuit includes a voltage regulator U2 and a voltage regulator U3; pin 2 of the voltage regulator U2 is connected to the cathode of resistor R23, capacitor C10, capacitor CP1, and diode D11, respectively; the other end of capacitor CP1 is connected to resistor RP9; the other end of resistor RP9 is connected to the anode of diode D11, resistor RP12, the anode of diode D12, a relay switching circuit, and the MCU chip, respectively; the other end of resistor RP12 is connected to capacitor CP2. The other end of capacitor CP2 is connected to the cathode of diode D12, capacitor C14, resistor R29, and pin 2 of voltage regulator U3. Pin 3 of voltage regulator U3 is connected to the power supply and capacitor C17. Pin 1 of voltage regulator U3, the other end of resistor R29, capacitor C14, and capacitor C17 are all connected to the relay switch circuit, MCU chip, and ground. Pin 3 of voltage regulator U2 is connected to capacitor C11 and the power supply. Pin 1 of voltage regulator U2, capacitor C10, resistor R23, and the other end of capacitor C11 are grounded.

[0014] In one preferred embodiment, the host computer is connected to the power consumption tester and the control circuit via an RS485 circuit.

[0015] In one preferred embodiment, the RS485 circuit includes a 485 chip U20; pin 1 of the 485 chip U20 is connected to pin 4 of optocoupler N13, pin 3 of optocoupler N13 is connected to the power supply, pin 1 of optocoupler N13 is connected to resistor R64 and the power supply, the other end of resistor R64 is connected to the MCU chip and the collector of transistor Q22, the base of transistor Q22 is connected to pin 2 of optocoupler N13 and resistor R63, pins 2 and 3 of the 485 chip U20 are connected to resistor R35 and pin 4 of optocoupler N11, pin 3 of optocoupler N11 is connected to the power supply, pin 2 of optocoupler N11 is connected to the MCU chip, pin 1 of optocoupler N11 is connected to the power supply, pin 4 of the 485 chip U20 is connected to resistor R61 and the collector of transistor Q18, the resistor R65 is connected to the power supply, pin 3 of optocoupler N11 is connected to resistor R65 and the collector of transistor Q18, the resistor R65 is connected to the power supply, pin 4 of optocoupler N20 is connected to resistor R65 ... The other end of pin 1 is connected to the power supply and pin 3 of optocoupler N12. The base of transistor Q18 is connected to pin 4 of optocoupler N12 and resistor R62. Pin 1 of optocoupler N12 is connected to the power supply. Pin 2 of optocoupler N12 is connected to the MCU chip. Pin 6 of 485 chip U20 is connected to the power supply, Zener diode TVS3, Zener diode TVS1, and 485-A terminal. The other end of Zener diode TVS3 is connected to ground, pin 7 of 485 chip U20, Zener diode TVS2, and 485-B terminal. The other end of Zener diode TVS2 is connected to ground and the other end of TVS1. Pin 8 of 485 chip U20 is connected to the power supply. The other end of pin 5 of 485 chip U20, the emitter of transistor Q22, the emitter of transistor Q18, resistor R62, resistor R63, and resistor R35 is grounded.

[0016] In the above-described technical solution of this utility model, the external power consumption detection device for an electricity meter includes: a test power supply, a control circuit, a power consumption tester, a host computer, and several electricity meters under test. The test power supply is electrically connected to the control circuit and the power consumption tester, the control circuit is electrically connected to the power consumption tester, the host computer, and several electricity meters under test, and the power consumption tester is electrically connected to the host computer. The control circuit includes an MCU chip and several relay switch circuits, the MCU chip being electrically connected to the several relay switch circuits. The several relay switch circuits include a first control circuit, a second control circuit, and a third control circuit. The test power supply of this utility model can be connected to several relay switch circuits, and the several relay switch circuits can be connected to several electricity meters respectively, thereby achieving the purpose of simultaneously testing multiple electricity meters and solving the technical problems of complex and inefficient batch power consumption detection methods for electricity meters using existing tooling. Attached Figure Description

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

[0018] Figure 1 This is a schematic diagram of an external power consumption detection device for an electricity meter according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the first control circuit according to an embodiment of the present utility model;

[0020] Figure 3 This is a schematic diagram of the second control circuit according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the third control circuit according to an embodiment of the present utility model;

[0022] Figure 5 This is a schematic diagram of the power conversion circuit according to an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the RS485 circuit according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the MCU chip in an embodiment of the present invention.

[0025] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0028] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0029] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0030] See Figures 1-7 According to one aspect of this utility model, this utility model provides an external power consumption detection device for an electricity meter, wherein the external power consumption detection device for an electricity meter includes: a test power supply, a control circuit, a power consumption tester, a host computer, and a plurality of electricity meters to be tested; the test power supply is electrically connected to the control circuit and the power consumption tester respectively, the control circuit is electrically connected to the power consumption tester, the host computer, and the plurality of electricity meters to be tested respectively, and the power consumption tester is electrically connected to the host computer; the control circuit includes an MCU chip and a plurality of relay switch circuits, the MCU chip being electrically connected to the plurality of relay switch circuits; the plurality of relay switch circuits include a first control circuit, a second control circuit, and a third control circuit.

[0031] Specifically, in this embodiment, the relay switching circuit includes a first control circuit, a second control circuit, and a third control circuit. The first control circuit is connected to phase A of the test power supply, phase A of the energy meter under test, and the MCU chip. The second control circuit is connected to phase B of the test power supply, phase B of the energy meter under test, and the MCU chip. The third control circuit is connected to phase C of the test power supply, phase C of the energy meter under test, and the MCU chip. By connecting the relay switching circuit to phases A, B, and C of the test power supply and the energy meter under test, respectively, and controlling the on / off state of the relay switching circuit through the MCU chip, the purpose of testing the energy meter under different circuit environments can be achieved.

[0032] Specifically, in this embodiment, the first control circuit includes a relay K19, a diode D21, a resistor RT20, a transistor Q19, a resistor R50, a resistor R52, and a capacitor C28. Pin 1 of the relay K19 is connected to resistor RT20, and the other end of resistor RT20 is connected to phase A of the test power supply. Pin 2 or pin 3 of the relay K19 is connected to phase A of the energy meter under test. Pin 4 of the relay K19 is connected to the power supply terminal. Pin 5 of the relay K19 is connected to the anode of diode D21 and the collector of transistor Q19, respectively. The other end of diode D21 is connected to the power supply terminal. The base of transistor Q19 is connected to capacitor C28, resistor R52, and resistor R50, respectively. The other end of resistor R50 is connected to the MCU chip. The emitter of transistor Q19, the other end of capacitor C28, and the other end of resistor R52 are grounded.

[0033] Specifically, in this embodiment, the second control circuit includes a relay K20, a diode D22, a resistor RT21, a transistor Q20, a resistor R53, a resistor R54, and a capacitor C29. Pin 1 of the relay K20 is connected to resistor RT21, and the other end of resistor RT21 is connected to phase B of the test power supply. Pin 2 or pin 3 of the relay K20 is connected to phase B of the energy meter under test. Pin 4 of the relay K20 is connected to the power supply terminal. Pin 5 of the relay K20 is connected to the anode of diode D22 and the collector of transistor Q20, respectively. The other end of diode D22 is connected to the power supply terminal. The base of transistor Q20 is connected to capacitor C29, resistor R54, and resistor R53, respectively. The other end of resistor R53 is connected to the MCU chip. The emitter of transistor Q20, the other end of capacitor C29, and the other end of resistor R54 are grounded.

[0034] Specifically, in this embodiment, the third control circuit includes a relay K21, a diode D23, a resistor RT22, a transistor Q21, a resistor R55, a resistor R56, and a capacitor C30. Pin 1 of the relay K21 is connected to the resistor RT22, and the other end of the resistor RT22 is connected to phase C of the test power supply. Pin 2 or pin 3 of the relay K21 is connected to phase C of the energy meter under test. Pin 4 of the relay K21 is connected to the power supply terminal. Pin 5 of the relay K21 is connected to the anode of the diode D23 and the collector of the transistor Q21, respectively. The other end of the diode D23 is connected to the power supply terminal. The base of the transistor Q21 is connected to the capacitor C30, the resistor R56, and the resistor R55, respectively. The other end of the resistor R55 is connected to the MCU chip. The emitter of the transistor Q21, the other end of the capacitor C30, and the other end of the resistor R56 are grounded.

[0035] Specifically, in this embodiment, the first control circuit, the second control circuit, and the third control circuit are all connected to the A, B, and C terminals of the energy meter under test via Phoenix terminals, respectively.

[0036] Specifically, in this embodiment, the test power supply is a three-phase test power supply or a single-phase test power supply. An electrical connection is established between the energy meter under test and the test power supply. Then, the energy meter under test is powered on and started by the connected test power supply. Next, test items are performed according to the needs of the energy meter under test, such as power consumption in no-load condition. This can be achieved by closing the relay switch of the no-load circuit, connecting the energy meter under test and the no-load circuit, allowing the host computer to further calculate the power consumption based on the electrical signal of the energy meter in no-load condition. Similarly, when testing the performance power consumption of the energy meter, it is only necessary to close the corresponding relay switch and read the corresponding energy meter electrical signal to measure the corresponding power consumption. Multiple energy meters can be tested at once, and after completing one power consumption test, there is no need to rewire; only the relay switch needs to be changed to proceed to the next stage of testing. This solves the problems of low efficiency and long time consumption in traditional batch power consumption testing of energy meters.

[0037] Specifically, in this embodiment, the test power supply is electrically connected to a maximum of 8 relay switching circuits. That is, phase A of the test power supply can be connected to a maximum of 8 first control circuits, phase B of the test power supply can be connected to a maximum of 8 second control circuits, and phase B of the test power supply can be connected to a maximum of 8 third control circuits. The first, second, and third control circuits of the several relay switching circuits are respectively connected to the A, B, and C phases of several energy meters under test, so as to achieve the purpose of testing multiple energy meters simultaneously.

[0038] Specifically, in this embodiment, the host computer is connected to the power consumption tester via an RS485 circuit to receive the measured power consumption data. Simultaneously, it is connected to the control circuit via the RS485 circuit to control the connection or disconnection of each relay switch circuit, ensuring that only one meter is currently connected to the test circuit. The host computer can also be directly connected to the power consumption tester via the RS485 circuit, allowing the power consumption tester to forward control commands from the host computer. This invention does not impose specific limitations; the control circuit can directly receive instructions from the host computer or indirectly receive control commands forwarded from the host computer by the power consumption tester. The current and voltage test data of the energy meter under test can be uploaded via the RS485 communication function of the host computer, and the data can also be output through the host computer interface.

[0039] Specifically, in this embodiment, the RS485 circuit includes a 485 chip U20; pin 1 of the 485 chip U20 is connected to pin 4 of the optocoupler N13; pin 3 of the optocoupler N13 is connected to the power supply terminal through resistor R65; pin 1 of the optocoupler N13 is connected to resistor R64 and the power supply terminal respectively; the other end of resistor R64 is connected to the collector of the MCU chip and transistor Q22 respectively; the base of transistor Q22 is connected to resistor R98 and capacitor C27 respectively; the other end of resistor R98 is connected to the other end of capacitor C27, resistor R63 and pin 2 of optocoupler N13 respectively; the emitter of transistor Q22 and the other end of resistor R63 are connected to... Ground; pins 2 and 3 of the 485 chip U20 are connected to resistor R35 and pin 4 of optocoupler N11, respectively. Pin 3 of optocoupler N11 is connected to the power supply. Pin 2 of optocoupler N11 is connected to the MCU chip through resistor R97. Pin 1 of optocoupler N11 is connected to the power supply. Pin 4 of the 485 chip U20 is connected to resistor R61 and the collector of transistor Q18, respectively. The other end of resistor R61 is connected to the power supply and pin 3 of optocoupler N12. The base of transistor Q18 is connected to resistor R60 and capacitor C25, respectively. The other end of capacitor C25 is connected to pin 4 of optocoupler N12, resistor R62, and the other end of resistor R60, respectively. The emitter of resistor R62 and transistor Q18 is grounded; pin 1 of optocoupler N12 is connected to the power supply, and pin 2 of optocoupler N12 is connected to the MCU chip through resistor R99; pin 6 of 485 chip U20 is connected to resistor R38, Zener diode TVS3, Zener diode TVS1, and resistor RT1 respectively, the other end of resistor RT1 is connected to the 485-A terminal, and the other end of resistor R38 is connected to the power supply; the other end of Zener diode TVS3 is connected to resistor R34, pin 7 of 485 chip U20, Zener diode TVS2, and 485-B respectively, and the other end of Zener diode TVS2 is connected to ground and the other end of TVS1; the 4 Pin 8 of the 85 chip U20 is connected to the power supply. The 485_RE / DE pin of the RS485 circuit is the enable pin of the chip, connected to the MCU chip, and used to control the 485 chip U20 to receive or send signals. The optocoupler N11 controls the on / off state of the CVCC side through the high and low levels of the VCC side, isolating the 485 chip U20 from the MCU chip, thereby protecting the MCU chip. The 485-A and 485-B pins of the 485 circuit are the communication pins with the host computer. The Zener diodes TVS1, TVS2, and TVS3 are used to protect the 485 chip U20. Resistors R34 and R38 are pull-down and pull-up resistors, respectively, to ensure that the electrical signal is not distorted.The 485_TX port is the transmit port of the MCU chip. When the CVCC side of optocoupler N12 is turned on, a voltage is applied to the base of transistor Q18, turning on Q18. The 485_TXD pin is grounded, resulting in a low level. When the CVCC side of optocoupler N12 is not turned on, no voltage is applied to the base of transistor Q18, turning it off. The 485_TXD pin is connected to CVCC, resulting in a high level. Repeating the above steps generates a high / low level signal, which is transmitted to the 485 chip U20. The 485 chip U20 then transmits the signal to the host computer through the 485_A and 485_B ports.

[0040] Specifically, in this embodiment, the external power consumption detection device for the electricity meter further includes a power conversion circuit; the power conversion circuit includes a voltage regulator U2 and a voltage regulator U3; pin 2 of the voltage regulator U2 is connected to resistor R23, capacitor C10, capacitor CP1, and the cathode of diode D11, respectively; the other end of capacitor CP1 is connected to resistor RP9; the other end of resistor RP9 is connected to the anode of diode D11, resistor RP12, the anode of diode D12, a relay switching circuit, and an MCU chip, respectively; the other end of resistor RP12 is connected to capacitor CP2; the other end of capacitor CP2 is connected to... The cathode of transistor D12, capacitor C14, resistor R29, and pin 2 of voltage regulator U3 are connected. Pin 3 of voltage regulator U3 is connected to the power supply and capacitor C17. Pin 1 of voltage regulator U3, the other end of resistor R29, capacitor C14, and capacitor C17 are all connected to the relay switch circuit, the MCU chip, and ground. Pin 3 of voltage regulator U2 is connected to capacitor C11 and the power supply. Pin 1 of voltage regulator U2, capacitor C10, resistor R23, and the other end of capacitor C11 are grounded. The conversion circuit is used to convert the input 12V power supply into the power required by the MCU chip and RS485 circuit.

[0041] Specifically, in this embodiment, the host computer communicates with the MCU chip via an RS485 circuit to control the relay switch circuit to control the meter position. If it is necessary to control the A phase of meter position 1 to be powered on separately, the host computer can control the relay switch of the first control circuit to close and the relay switches of other control circuits to open through the MCU chip, thereby achieving the control purpose. At the same time, the data of the energy meter under test will also be uploaded to the host computer interface for display via the RS485 circuit, which is convenient for technicians to read.

[0042] Specifically, in this embodiment, the external power consumption detection device of the energy meter can be equipped with several control circuits. These control circuits can be expanded by connecting them in parallel to form a network, thereby enabling the expansion of multiple energy meters to be tested. After networking, different control circuits can be distinguished by physical addressing or software address burning.

[0043] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural transformations made based on the inventive concept of this utility model and the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this utility model.

Claims

1. A device for detecting the power consumption of an external power source for an electricity meter, characterized in that, include: The test includes a power supply, control circuit, power consumption tester, host computer, and several energy meters under test. The test power supply is electrically connected to the control circuit and the power consumption tester, respectively. The control circuit is electrically connected to the power consumption tester, the host computer, and several energy meters under test, respectively. The power consumption tester is electrically connected to the host computer. The control circuit includes an MCU chip and several relay switch circuits. The MCU chip is electrically connected to several relay switch circuits. Several relay switch circuits include a first control circuit, a second control circuit, and a third control circuit.

2. The power consumption detection device for an external power supply of an electricity meter according to claim 1, characterized in that, The first control circuit is connected to phase A of the test power supply, phase A of the energy meter under test, and the MCU chip, respectively. The second control circuit is connected to phase B of the test power supply, phase B of the energy meter under test, and the MCU chip, respectively. The third control circuit is connected to phase C of the test power supply, phase C of the energy meter under test, and the MCU chip, respectively.

3. The power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The first control circuit includes a relay K19, a diode D21, a resistor RT20, a transistor Q19, a resistor R50, a resistor R52, and a capacitor C28. Pin 1 of the relay K19 is connected to resistor RT20, and the other end of resistor RT20 is connected to phase A of the test power supply. Pin 2 or pin 3 of the relay K19 is connected to phase A of the energy meter under test. Pin 4 of the relay K19 is connected to the power supply terminal. Pin 5 of the relay K19 is connected to the anode of diode D21 and the collector of transistor Q19, respectively. The other end of diode D21 is connected to the power supply terminal. The base of transistor Q19 is connected to capacitor C28, resistor R52, and resistor R50, respectively. The other end of resistor R50 is connected to the MCU chip. The emitter of transistor Q19, the other end of capacitor C28, and the other end of resistor R52 are grounded.

4. The power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The second control circuit includes a relay K20, a diode D22, a resistor RT21, a transistor Q20, a resistor R53, a resistor R54, and a capacitor C29. Pin 1 of the relay K20 is connected to resistor RT21, and the other end of resistor RT21 is connected to phase B of the test power supply. Pin 2 or pin 3 of the relay K20 is connected to phase B of the energy meter under test. Pin 4 of the relay K20 is connected to the power supply terminal. Pin 5 of the relay K20 is connected to the anode of diode D22 and the collector of transistor Q20, respectively. The other end of diode D22 is connected to the power supply terminal. The base of transistor Q20 is connected to capacitor C29, resistor R54, and resistor R53, respectively. The other end of resistor R53 is connected to the MCU chip. The emitter of transistor Q20, the other end of capacitor C29, and the other end of resistor R54 are grounded.

5. The power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The third control circuit includes a relay K21, a diode D23, a resistor RT22, a transistor Q21, a resistor R55, a resistor R56, and a capacitor C30. Pin 1 of the relay K21 is connected to resistor RT22, and the other end of resistor RT22 is connected to phase C of the test power supply. Pin 2 or pin 3 of the relay K21 is connected to phase C of the energy meter under test. Pin 4 of the relay K21 is connected to the power supply terminal. Pin 5 of the relay K21 is connected to the anode of diode D23 and the collector of transistor Q21, respectively. The other end of diode D23 is connected to the power supply terminal. The base of transistor Q21 is connected to capacitor C30, resistor R56, and resistor R55, respectively. The other end of resistor R55 is connected to the MCU chip. The emitter of transistor Q21, the other end of capacitor C30, and the other end of resistor R56 are grounded.

6. The power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The first control circuit, the second control circuit, and the third control circuit are all connected to the A, B, and C terminals of the energy meter under test via Phoenix terminals, respectively.

7. The power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The test power supply is electrically connected to a maximum of eight relay switching circuits.

8. A power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The external power consumption detection device for the electricity meter also includes a power conversion circuit; the power conversion circuit includes a voltage regulator U2 and a voltage regulator U3; pin 2 of the voltage regulator U2 is connected to resistor R23, capacitor C10, capacitor CP1, and the cathode of diode D11, respectively; the other end of capacitor CP1 is connected to resistor RP9; the other end of resistor RP9 is connected to the anode of diode D11, resistor RP12, the anode of diode D12, a relay switching circuit, and the MCU chip, respectively; the other end of resistor RP12 is connected to capacitor CP2. The other end of capacitor CP2 is connected to the cathode of diode D12, capacitor C14, resistor R29, and pin 2 of voltage regulator U3. Pin 3 of voltage regulator U3 is connected to the power supply and capacitor C17. Pin 1 of voltage regulator U3, the other end of resistor R29, capacitor C14, and capacitor C17 are all connected to the relay switch circuit, MCU chip, and ground. Pin 3 of voltage regulator U2 is connected to capacitor C11 and the power supply. Pin 1 of voltage regulator U2, capacitor C10, resistor R23, and the other end of capacitor C11 are grounded.

9. A power consumption detection device for an external power supply of an electricity meter according to any one of claims 1-2, characterized in that, The host computer is connected to the power consumption tester and the control circuit via an RS485 circuit.

10. The power consumption detection device for an external power supply of an electricity meter according to claim 9, characterized in that, The RS485 circuit includes a 485 chip U20; pin 1 of the 485 chip U20 is connected to pin 4 of optocoupler N13, pin 3 of optocoupler N13 is connected to the power supply, pin 1 of optocoupler N13 is connected to resistor R64 and the power supply, the other end of resistor R64 is connected to the MCU chip and the collector of transistor Q22, the base of transistor Q22 is connected to pin 2 of optocoupler N13 and resistor R63, pins 2 and 3 of the 485 chip U20 are connected to resistor R35 and pin 4 of optocoupler N11, pin 3 of optocoupler N11 is connected to the power supply, pin 2 of optocoupler N11 is connected to the MCU chip, pin 1 of optocoupler N11 is connected to the power supply, pin 4 of the 485 chip U20 is connected to resistor R61 and the collector of transistor Q18, the other end of resistor R61... The power supply terminal is connected to pin 3 of optocoupler N12. The base of transistor Q18 is connected to pin 4 of optocoupler N12 and resistor R62. Pin 1 of optocoupler N12 is connected to the power supply terminal, and pin 2 of optocoupler N12 is connected to the MCU chip. Pin 6 of 485 chip U20 is connected to the power supply terminal, Zener diodes TVS3, TVS1, and 485-A terminal. The other end of Zener diode TVS3 is connected to ground, pin 7 of 485 chip U20, Zener diode TVS2, and 485-B terminal. The other end of Zener diode TVS2 is connected to ground and the other end of TVS1. Pin 8 of 485 chip U20 is connected to the power supply terminal. Pin 5 of 485 chip U20, the emitter of transistor Q22, the emitter of transistor Q18, resistors R62, R63, and R35 are grounded.

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