Auxiliary power supply for testing metering device

Abstract

The invention belongs to the technical field of electric power metering device testing, and discloses a metering device testing auxiliary power supply which comprises a power supply shell, a charging wire interface, a switch, an electric power metering device wiring port and a touch screen, the power supply shell is provided with a charging circuit; the charging circuit comprises a charging module connected with the charging wire interface and a lithium battery connected with the charging module; the alternating current output circuit is connected with the lithium battery and an alternating current electric power metering equipment wiring port; the direct current output circuit is connected with the lithium battery and a direct current metering equipment wiring port; and a central processor control unit connected with the alternating current output circuit, the direct current output circuit and the touch screen is also arranged in the power supply shell. The auxiliary power supply for testing the metering device provides an AC / DC power supply for the detection of the electric power metering equipment, so that the functions of the electric power metering equipment can be conveniently detected, the problem of electricity meter checking and reading obstacles in the equipment account cancellation process is solved, and the auxiliary power supply has good practical value.

Description

Technical Field

[0001] The invention relates to the technical field of electric power metering device testing, and in particular to a metering device testing auxiliary power supply. Background Art

[0002] In today's context of increasingly tight resources, energy conservation and emission reduction are particularly important. In order to promote the effective use of power metering equipment, some power metering materials need to be reused and identified and tested. However, due to the lack of necessary power supply devices in the bureau (station), some basic functions cannot be tested, which hinders the status assessment of electronic metering equipment. The following is a detailed analysis of the problems existing in the current work: 1. There is a problem with the terminal When using electricity metering equipment, performance problems are often discovered only after installation, such as damage or malfunctions that may have occurred during transportation. This delay leads to waste in the following aspects: Waste of human resources: Since it is impossible to thoroughly test the function of the equipment before installation, technicians need to conduct secondary debugging or replace the meter after discovering the problem. This not only increases labor costs, but also prolongs the period of equipment commissioning.

[0003] Equipment idleness and repetitive work: For every problem that occurs, the technical team needs to re-inspect and re-debug. This repetitive work impairs the effective use of resources and time.

[0004] 2. Problems with reading the meter code during the account cancellation process During the cancellation process of the meter, the customer needs to return the old meter to the sales department to complete the cancellation process. However, there are some problems in the actual operation, especially when the meter code is required during the cancellation process: Difficulty in obtaining meter codes: For some meters, such as 3100V and 357.7V models, if the battery of the meter is dead, the meter code cannot be read normally. This makes it impossible to carry out the account cancellation process smoothly without backup power or repair.

[0005] Inefficient process: Failure to read the meter code in time means delays in the account cancellation process, which may lead to customer complaints and dissatisfaction, thus affecting the company's image and customer relationships. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a metering device test auxiliary power supply, which provides AC and DC power for power metering equipment detection, so as to detect the function of the power metering equipment.

[0007] The technical solution adopted by the present invention is: A metering device testing auxiliary power supply, the metering device testing auxiliary power supply comprising a power supply housing, a charging line interface, a switch, a power metering device connection port, and a touch screen located on the power supply housing; The power supply housing is provided with a charging circuit, which includes a charging module connected to the charging line interface and a lithium battery connected to the charging module; the power supply housing is also provided with an AC output circuit connected to the lithium battery and the AC power metering device wiring port, and a DC output circuit connected to the lithium battery power and the DC metering device wiring port; The power supply housing is also provided with a central processor control unit connected with the AC output circuit, the DC output circuit and the touch screen.

[0008] Furthermore, the charging line interface receives an AC / DC 220V voltage input by inserting a charging line to charge the lithium battery.

[0009] Furthermore, the lithium battery is a 48V lithium battery.

[0010] Furthermore, the AC output circuit includes an inverter module connected to the lithium battery, a step-up transformer connected to the inverter module, and an AC output line connected between the step-up transformer and a wiring port of an AC power metering device; the AC output line includes four AC output lines ABCN, and relays are provided on the three AC output lines ABC; the wiring port of the AC power metering device includes an ABCN wiring port compatible with the four AC output lines ABCN.

[0011] Furthermore, the AC output circuit also includes an LCL filter; the LCL filter is located between the inverter module and the AC output line, and the LCL filter is connected to the inverter module and the step-up transformer respectively.

[0012] Furthermore, the inverter module is a three-phase inverter bridge, which is connected to the central processor control unit; the central processor control unit includes an MCU, an inverter output sinusoidal voltage measurement circuit and an inverter output AC current measurement circuit connected to the MCU and the three-phase inverter bridge, a liquid crystal screen interface circuit connected to the MCU and the touch screen, and a gate drive circuit connected to the lithium battery.

[0013] Furthermore, the DC output circuit includes a resonant bridge main circuit connected to the lithium battery, and a DC output full-wave rectifier circuit connected between the resonant bridge main circuit and a DC power metering device wiring port; the DC power metering device wiring port includes two wiring ports adapted to the DC output full-wave rectifier circuit.

[0014] Furthermore, the resonant bridge main circuit is connected to the MCU of the central processor control unit, and the resonant bridge main circuit also includes a resonant network composed of a plurality of inductors, capacitors and diodes.

[0015] Furthermore, the charging module is connected to the MCU of the central processor control unit, and includes a battery voltage measurement circuit and a battery current measurement circuit.

[0016] A method for detecting an electric power metering device, the method for detecting an electric power metering device testing an auxiliary power supply based on the above-mentioned metering device, comprises the following steps: Step 1: connect the power metering device to the power metering device connection port of the auxiliary power supply for the metering device test; if the power metering device uses an AC power supply, connect it to the AC power metering device connection port; if the power metering device uses a DC power supply, connect it to the DC power metering device connection port; Step 2: Insert the charging cable into the charging cable interface of the auxiliary power supply of the metering device to enter the AC / DC 220V voltage input to charge the lithium battery, ensure that the battery is fully charged, and enter a normal working state; Step 3: Select the appropriate AC or DC output mode on the touch screen and set the AC or DC output voltage according to the power metering and detection requirements; Step 4, the processor control unit of the metering device tests the auxiliary power supply and issues a control instruction to the AC output circuit or the DC output circuit based on the AC or DC output voltage setting parameters; wherein the control instruction issued by the processor control unit is to generate an SVPWM modulation wave according to a three-phase vector space synthesis algorithm; Step 5, the AC output circuit is based on the SVPWM modulation wave, and drives the three-phase bridge circuit through the gate drive circuit to output the three-phase power-driven SVPWM, and then passes through the LCL filter of the output stage to obtain a three-phase sine wave. The line voltage effective value of the sine wave is designed to be 30V, and then passes through a △ / Y-connected step-up transformer to filter the third harmonics and step up to 380V or 220V, and then output to the AC power metering equipment wiring port; The DC output circuit adjusts the switching timing of each switch tube in the resonant bridge main circuit based on the SVPWM modulation wave to form an alternating pulse width modulation PWM waveform, and converts DC power into a high-frequency signal through the resonance characteristic. After the high-frequency signal is output, the DC output full-wave rectifier circuit rectifies the high-frequency signal into a stable DC voltage and outputs it to the DC power metering equipment wiring port; Step 6, the power metering device performs various functional tests based on the AC or DC voltage provided by the auxiliary power supply tested by the metering device; Step 7, if the AC output voltage is set according to the power metering detection needs, during the various function tests of the power metering equipment, the processor control unit detects the output AC voltage value and current value in real time through the inverter output sinusoidal voltage measurement circuit and the inverter output AC current measurement circuit, and displays them through the touch screen.

[0017] Beneficial effects of the present invention: The above-mentioned metering device testing auxiliary power supply device has the following beneficial effects: Multifunctional power supply: The device can provide stable AC and DC power supply to meet the diverse needs of power metering equipment, enabling comprehensive functional testing.

[0018] Efficient Charging: The built-in charging circuit and lithium battery design ensure fast charging when not in use, improving the convenience of using the device.

[0019] Flexibility and portability: With a lightweight housing design and touch screen operation, users can easily set up and monitor, greatly improving operational efficiency during the test process.

[0020] Accurate measurement: Using the processor control unit, the device can measure the output voltage and current in real time, provide accurate values, and help users to judge the working status of the power metering equipment in time.

[0021] Ensure safety: The relays and LCL filters in the design can effectively prevent overload and voltage fluctuations, improving the safety and reliability of the entire equipment.

[0022] Simplify the test process: The integrated design reduces the complexity of external connections, making the test process simpler and more systematic, suitable for use in a variety of environments such as on-site and laboratory.

[0023] Intelligent monitoring: The integrated touch screen and processing unit can perform intelligent management and monitoring, providing users with a good operating interface and feedback information.

[0024] Support for multiple metering devices: The device is designed to be compatible with different types of power metering devices, which increases the applicability of the device and meets the needs of different industries.

[0025] In summary, the metering device for testing the auxiliary power supply not only improves the testing and use efficiency of power metering equipment, but also ensures safety and convenience. It is an important tool in the field of power detection.

[0026] The above-mentioned power metering equipment detection method has the following beneficial effects: Accurate testing: This method generates AC and DC outputs through SVPWM modulation waves, which can provide stable and high-quality voltage signals, thereby improving the test accuracy of power metering equipment.

[0027] Flexibility: Able to support a variety of power metering devices, whether AC or DC devices, can be tested through appropriate wiring and settings, enhancing the applicability of the detection equipment.

[0028] Real-time monitoring: The processor control unit can detect the output voltage and current values ​​in real time and display them on the touch screen, so that the operator can grasp the equipment status at any time, improving the convenience and safety of the test process.

[0029] High efficiency: The use of LCL filter and step-up transformer can effectively filter harmonics, achieve efficient power conversion and transmission, reduce power loss, and improve test efficiency.

[0030] Battery Management: The lithium battery is charged through the charging cable interface to ensure that the device has sufficient power during the test, thus avoiding test interruptions or inaccurate results caused by insufficient power.

[0031] Ensure design safety: Through strict parameter settings and control instructions, ensure that the output voltage and current are within the safe range, protecting the device under test and the test equipment itself.

[0032] Multi-function test support: The device can perform multiple functional tests during the test process, such as measurement accuracy, response time, etc., to meet the needs of different users and improve service levels.

[0033] Cost-effectiveness: This detection method integrates multiple functions, reducing the complexity and number of equipment, thereby reducing software and hardware costs.

[0034] In summary, this power metering equipment detection method can effectively improve the test quality and efficiency of power metering equipment and promote technological progress in the field of power metering. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0036] Figure 1 The overall circuit diagram for testing the auxiliary power supply for the invented metering device; Figure 2 A circuit diagram of a three-phase inverter bridge of a DC output circuit of the present invention; Figure 3 A circuit diagram of an output LCL filter and a boost transformer of a DC output circuit of the present invention; Figure 4 A gate drive circuit diagram of a DC output circuit of the present invention; Figure 5 The battery voltage and current measurement circuit diagram of the charging module of the present invention; Figure 6The inverter output sinusoidal voltage measurement circuit diagram of the processor control unit in the present invention; Figure 7 The inverter output AC current measurement circuit diagram of the processor control unit in the present invention; Figure 8 A circuit diagram of the MCU of the processor control unit in the present invention; Fig. 9 It is a circuit diagram of the LCD interface of the MCU of the processor control unit in the present invention; Fig.10 It is the main circuit diagram of the resonant bridge of the DC output circuit of the present invention; Fig.11 This is an output full-wave rectification circuit diagram of the DC output circuit of the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention. Example

[0038] In view of the problem of testing and identifying power metering equipment in the absence of power supply, this embodiment provides a metering device for testing auxiliary power supply, such as Figure 1 As shown, the metering device for testing the auxiliary power supply includes a power supply housing, a charging line interface, a switch, a power metering device connection port, and a touch screen located on the power supply housing.

[0039] Among them, Figure 1 As shown, the power supply housing is provided with a charging circuit, which includes a charging module connected to the charging line interface and a lithium battery connected to the charging module; the lithium battery is a 48V lithium battery. Charging line interface: used to connect an external power source to charge the lithium battery; the charging line interface enters the AC and DC 220V voltage input by inserting the charging line to charge the lithium battery.

[0040] The power supply casing also includes an AC output circuit connected to the lithium battery and the AC power metering device wiring port, and a DC output circuit connected to the lithium battery power and the DC metering device wiring port; the power supply casing also includes a processor control unit connected to the AC output circuit, the DC output circuit and the touch screen.

[0041] When in use, according to the needs of power metering test and identification, it is connected to the wiring port of the power metering equipment, the auxiliary power supply of the metering device test is started, and the voltage parameters required for the power metering test and identification are set through the touch screen; the auxiliary power supply of the metering device test can output AC and DC voltages of corresponding levels through the corresponding AC output circuit or DC output circuit, thereby providing power for power metering test and identification.

[0042] Further, in order to facilitate understanding of the voltage output function of the metering device for testing the AC output circuit or DC output circuit of the auxiliary power supply, the following explanation is provided: 1. AC output circuit: like Figure 1 As shown, the AC output circuit in this embodiment includes an inverter module connected to a lithium battery, a step-up transformer connected to the inverter module, and an AC output line connected between the step-up transformer and a connection port of an AC power metering device; wherein the inverter module is a three-phase inverter bridge connected to a central processor control unit; the central processor control unit includes an MCU, an inverter output sinusoidal voltage measurement circuit and an inverter output AC current measurement circuit connected to the MCU and the three-phase inverter bridge, a liquid crystal interface circuit connected to the MCU and the touch screen, and a gate drive circuit connected to the lithium battery.

[0043] Three-phase inverter bridge circuit: Figure 1 and Figure 2 As shown in the figure, the three-phase inverter bridge circuit is the core part of the inverter, which is responsible for converting the DC power provided by the lithium battery into three-phase AC power. The three-phase inverter bridge circuit directly affects the output voltage and waveform quality.

[0044] Step-up transformer circuit: Figure 1 and Figure 3 As shown, the step-up transformer circuit is responsible for increasing the three-phase output voltage to the required 380V or 220V. The step-up transformer circuit is a key component to ensure that the output voltage meets the application requirements.

[0045] Gate drive circuit: Figure 4 As shown in the figure, the gate drive circuit is used to control the power switch devices in the inverter bridge to realize the generation and output of the SVPWM modulation waveform. Although the gate drive circuit is not directly related to the measurement, it is the basis for the MCU to control the three-phase inverter bridge circuit.

[0046] Inverter output sinusoidal voltage measurement circuit: After setting the voltage parameters required for power metering test and identification through the touch screen, in order to facilitate real-time monitoring of the voltage waveform output by the inverter and ensure the quality of the output voltage, the inverter output sinusoidal voltage measurement circuit is set. Inverter output sinusoidal voltage measurement circuit, such as Figure 6As shown in the figure, the inverter output sinusoidal voltage measurement circuit provides feedback information to the MCU, which then pushes the AC voltage output value to the touch screen, so that the operator can intuitively understand the AC voltage output value.

[0047] Inverter output AC current measurement circuit: After setting the voltage parameters required for power metering test and identification through the touch screen, monitor the AC current output by the inverter so that the system can adjust the output in real time to adapt to load changes. Therefore, the inverter output AC current measurement circuit is set. Inverter output AC current measurement circuit, such as Figure 7 As shown in the figure, the inverter output AC current measurement circuit provides feedback information to the MCU, which then pushes the output AC voltage value to the touch screen, so that the operator can intuitively understand the AC current output value.

[0048] like Figure 1 and Figure 3 As shown, the AC output lines include four AC output lines ABCN, and relays are provided on the three AC output lines ABC; the AC power metering equipment wiring port includes an ABCN wiring port adapted to the four AC output lines ABCN.

[0049] In addition, if Figure 1 and Figure 3 As shown, the AC output circuit in this embodiment also includes an LCL filter; the LCL filter is located between the inverter module and the AC output line, and the LCL filter is connected to the inverter module and the step-up transformer respectively. LCL filter: used to suppress harmonics in the output current and provide a smoother sinusoidal wave output, which is an important part to ensure that the output waveform meets the power quality requirements.

[0050] Based on the above AC output circuit, after setting the voltage parameters required for power metering test and identification through the touch screen, the AC output circuit is based on the SVPWM modulation wave, and drives the three-phase bridge circuit through the gate drive circuit to output the three-phase power-driven SVPWM, and then passes through the LCL filter of the output stage to obtain the three-phase sine wave. The effective value of the line voltage of the sine wave is designed to be 30V, and then passes through a △ / Y-connected step-up transformer to filter the third harmonics and step up to 380V or 220V, and then output to the AC power metering equipment wiring port.

[0051] Second, DC output circuit: like Figure 1 As shown, the DC output circuit in this embodiment includes a resonant bridge main circuit connected to a lithium battery, and a DC output full-wave rectifier circuit connected between the resonant bridge main circuit and a wiring port of a DC power metering device; at the same time, a switch is provided on the connection line between the resonant bridge main circuit and the lithium battery, and a switch is provided on the connection line between the DC output full-wave rectifier circuit and the wiring port of the DC power metering device.

[0052] Resonant bridge main circuit: Fig.10 As shown in the figure, the DC output circuit adopts a phase-shifted ZVS soft-switching full-bridge topology scheme with an auxiliary resonant network, which greatly improves the efficiency and reliability of the regulated power supply. This topology is easier to achieve soft switching of the lagging arm than the traditional ZVS phase-shifted full-bridge; the DC output circuit adjusts the switching timing of each switch tube in the main circuit of the resonant bridge based on the SVPWM modulation wave to form an alternating pulse width modulation PWM waveform, and converts DC power into a high-frequency signal through the resonance characteristics.

[0053] In addition, the main circuit of the resonant bridge also includes a resonant network composed of several inductors, capacitors and diodes. Fig.10 As shown, the resonant network includes an inductor La, capacitors Ca1, Ca2, and diodes Da1, Da2. The auxiliary resonant network does not interfere with the main power conversion and is not affected by the load current. The principle is: when the lower tube M4 of the lagging arm is turned off, the auxiliary inductor current and the primary current flow into the node between M2 and M4 at the same time, and when the upper tube M2 of the lagging arm is turned off, they flow out of the node at the same time. That is, the two currents discharge the parallel capacitors at the same time, and can drain the charge in the parallel capacitors before M2 or M4 is turned on under various load currents, especially light load or no load, and smoothly achieve ZVS.

[0054] DC output full-wave rectifier circuit: Fig.11 As shown in the figure, after the high-frequency signal is output, the high-frequency signal is rectified into a stable DC voltage through a rectifier circuit composed of a diode, a capacitor, and an inductor. During the rectification process, the full-wave rectifier circuit integrates the pulse signals in two directions to form a stable DC output and effectively filter out the high-frequency components.

[0055] like Figure 1 and Fig.11 As shown, the DC power metering device connection port includes two connection ports adapted to the DC output full-wave rectifier circuit. In terms of control, the resonant bridge main circuit in the DC output circuit is connected to the MCU of the processor control unit.

[0056] Based on the above DC output circuit, after setting the voltage parameters required for power metering test and identification through the touch screen; the DC output circuit adjusts the switching timing of each switch tube in the resonant bridge main circuit based on the SVPWM modulation wave to form an alternating pulse width modulation PWM waveform, and converts DC power into a high-frequency signal through the resonance characteristics. After the high-frequency signal is output, the DC output full-wave rectifier circuit rectifies the high-frequency signal into a stable DC voltage and outputs it to the DC power metering equipment wiring port.

[0057] Further, such as Figure 1As shown, in this embodiment, the charging module is connected to the MCU of the processor control unit, which includes a basic short-circuit protection circuit, a battery voltage measurement circuit, and a battery current measurement circuit, as shown in FIG. Figure 5 As shown; when the charging line interface is connected to an external power supply to charge the lithium battery, and when the metering device tests the auxiliary power supply, the charging module detects the voltage and current of the lithium battery in real time through the battery voltage measurement circuit and the battery current measurement circuit, and transmits them to the MCU of the central processor control unit, and the MCU displays the lithium battery voltage and current values ​​through the touch screen.

[0058] Furthermore, the circuit diagram of the MCU of the processor control unit in this embodiment is as follows: Figure 8 As shown, since the MCU of the processor control unit is connected to the touch screen; therefore, it also includes a liquid crystal interface circuit, the liquid crystal interface circuit is as shown in FIG. Fig. 9 As shown. The MCU of the processor control unit adopts the STM32F4RCT6 microcontroller, which is a single-chip microcomputer based on the ARM Cortex-M4 core; STM32F4RCT6 is usually used as the core control unit of the system, used to process data, control peripherals and realize various functions; the MCU of the processor control unit cooperates with the AC output circuit composed of the three-phase inverter bridge, LCL filter, step-up transformer, etc., and cooperates with the DC output circuit composed of the resonant bridge main circuit, DC output full-wave rectifier circuit, etc., to form a pure intelligent digital power supply system, and then a touch LCD screen is used to realize the human-computer interaction page.

[0059] In summary, the test auxiliary power supply of the metering device can provide AC and DC power to meet the test requirements of different types of power metering equipment, and enhance the flexibility and comprehensiveness of the test. The use of charging modules and lithium batteries ensures that the power supply device can be charged quickly and prolongs the use time of the equipment, especially in an environment without a stable power supply. The inverter module, step-up transformer and LCL filter are equipped to ensure the high quality of the output AC power, reduce the impact of power fluctuations on the test results, and improve the accuracy of the test. The application of the processor control unit can realize the intelligent management and monitoring of the power supply, implement automated testing, and improve the test efficiency. The use of relays and monitoring circuits improves the safety of the power supply device, prevents safety hazards such as overload and short circuit, and ensures the safety of equipment and personnel. The test auxiliary power supply of the metering device provides a reliable and efficient test solution for the detection of power metering equipment. Example

[0060] Based on the metering device provided in Example 1 to test the auxiliary power supply, this embodiment provides a method for detecting an electric power metering device, specifically comprising the following steps: Step 1: Connect the power metering device to the power metering device connection port of the auxiliary power supply for the metering device test; if the power metering device uses an AC power supply, connect it to the AC power metering device connection port; if the power metering device uses a DC power supply, connect it to the DC power metering device connection port.

[0061] Through step 1, ensure that the power metering equipment is connected to the auxiliary power supply for metering device testing, and correctly select the AC or DC access mode to provide the necessary power input for subsequent testing.

[0062] Step 2: Insert the charging cable into the charging cable interface of the auxiliary power supply of the metering device to enter the AC / DC 220V voltage input to charge the lithium battery, ensure that the battery is fully charged, and enter normal working state.

[0063] Through step 2, the lithium battery of the auxiliary power supply for the metering device test is charged to ensure that the device has sufficient power supply during the test and avoid test interruption due to insufficient power.

[0064] Step 3: Select the appropriate AC or DC output mode on the touch screen and set the AC or DC output voltage according to the power metering and detection requirements.

[0065] Through step 3, the user selects the appropriate output mode and voltage setting through the touch screen to ensure that the test conditions meet the performance requirements of the power metering equipment, thereby obtaining accurate test results.

[0066] Step 4, the processor control unit of the metering device tests the auxiliary power supply and issues control instructions to the AC output circuit or the DC output circuit based on the AC or DC output voltage setting parameters; wherein the control instructions issued by the processor control unit are to generate SVPWM modulation waves according to the three-phase vector space synthesis algorithm.

[0067] Through step 4, the processor control unit generates an SVPWM modulation wave according to the set output parameters to control the operation of the AC or DC output circuit. This operation ensures that the output voltage is accurately adjusted to meet the test requirements.

[0068] Step 5, the AC output circuit is based on the SVPWM modulation wave. The gate drive circuit drives the three-phase bridge circuit to output the three-phase power-driven SVPWM, and then passes through the LCL filter of the output stage to obtain a three-phase sine wave. The line voltage effective value of the sine wave is designed to be 30V. After passing through a △ / Y-connected step-up transformer to filter the third harmonics and boost it to 380V or 220V, it is output to the AC power metering equipment wiring port.

[0069] The DC output circuit adjusts the switching timing of each switch tube in the resonant bridge main circuit based on the SVPWM modulation wave to form an alternating pulse width modulation PWM waveform, and converts DC power into a high-frequency signal through the resonance characteristics. After the high-frequency signal is output, the DC output full-wave rectifier circuit rectifies the high-frequency signal into a stable DC voltage and outputs it to the DC power metering equipment wiring port.

[0070] Step 5: Achieve efficient power conversion and output through SVPWM modulation wave; wherein, the AC output circuit: provides high-quality three-phase sine waves to meet the test requirements of AC power metering equipment. The DC output circuit: stably outputs high-frequency rectified DC voltage for performance testing of DC power metering equipment.

[0071] In step 6, the power metering device performs various functional tests based on the AC or DC voltage provided by the auxiliary power supply tested by the metering device.

[0072] Through step 6, the power metering equipment is functionally tested under the provided AC or DC voltage to evaluate whether its performance meets the design parameters and technical specifications.

[0073] Step 7, if the AC output voltage is set according to the power metering detection needs, during the various function tests of the power metering equipment, the processor control unit detects the output AC voltage value and current value in real time through the inverter output sinusoidal voltage measurement circuit and the inverter output AC current measurement circuit, and displays them through the touch screen.

[0074] Step 7 monitors and displays the output voltage and current values ​​in real time through the inverter output voltage and current measurement circuit. This process can help users quickly identify the performance of the power metering equipment during the test and ensure the accuracy and reliability of the test.

[0075] In summary, the power metering equipment detection method supports the access of AC and DC power metering equipment, can meet the test requirements of different equipment, and improves the applicability of the equipment. By charging the lithium battery, the test equipment is ensured to be carried out in normal working state, which improves the reliability of the test. The SVPWM modulation wave generated by the three-phase vector space synthesis algorithm improves the stability and accuracy of the output voltage and ensures the quality of the output signal. Harmonic filtering is performed through the LCL filter and the step-up transformer, which significantly reduces the harmonic components in the output signal and improves the test accuracy of the power metering equipment. The processor control unit detects the output voltage and current values ​​in real time and displays them on the touch screen, which is convenient for users to obtain the device status in time and improve the test efficiency. It supports multiple functional tests to meet the performance verification requirements of different power metering equipment, and improves the detection range and comprehensive testing capabilities. This method performs well in accuracy, stability and user experience, providing strong technical support for power metering testing.

[0076] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A metering device for testing an auxiliary power supply, characterized in that: The metering device test auxiliary power supply includes a power supply housing, a charging line interface, a switch, a power metering device connection port, and a touch screen located on the power supply housing; The power supply housing is provided with a charging circuit, which includes a charging module connected to the charging line interface and a lithium battery connected to the charging module; the power supply housing is also provided with an AC output circuit connected to the lithium battery and the AC power metering device wiring port, and a DC output circuit connected to the lithium battery power and the DC metering device wiring port; The power supply housing is also provided with a central processor control unit connected with the AC output circuit, the DC output circuit and the touch screen.

2. The metering device test auxiliary power supply according to claim 1, characterized in that: The charging line interface receives an AC / DC 220V voltage input by inserting a charging line to charge the lithium battery.

3. The metering device test auxiliary power supply according to claim 1, characterized in that: The lithium battery is a 48V lithium battery.

4. The metering device test auxiliary power supply according to claim 1, characterized in that: The AC output circuit includes an inverter module connected to the lithium battery, a step-up transformer connected to the inverter module, and an AC output line connected between the step-up transformer and a wiring port of an AC power metering device; the AC output line includes four AC output lines ABCN, and relays are provided on the three AC output lines ABC; the wiring port of the AC power metering device includes an ABCN wiring port adapted to the four AC output lines ABCN.

5. The metering device test auxiliary power supply according to claim 4, characterized in that: The AC output circuit also includes an LCL filter; the LCL filter is located between the inverter module and the AC output line, and the LCL filter is connected to the inverter module and the step-up transformer respectively.

6. The auxiliary power supply for testing a metering device according to claim 4, characterized in that: The inverter module is a three-phase inverter bridge, which is connected to the central processor control unit; the central processor control unit includes an MCU, an inverter output sinusoidal voltage measurement circuit and an inverter output AC current measurement circuit connected to the MCU and the three-phase inverter bridge, a liquid crystal screen interface circuit connected to the MCU and the touch screen, and a gate drive circuit connected to the lithium battery.

7. The metering device test auxiliary power supply according to claim 1, characterized in that: The DC output circuit includes a resonant bridge main circuit connected to a lithium battery, and a DC output full-wave rectifier circuit connected between the resonant bridge main circuit and a DC power metering device wiring port; the DC power metering device wiring port includes two wiring ports adapted to the DC output full-wave rectifier circuit.

8. The metering device test auxiliary power supply according to claim 7, characterized in that: The resonant bridge main circuit is connected to the MCU of the central processor control unit, and the resonant bridge main circuit also includes a resonant network composed of a plurality of inductors, capacitors and diodes.

9. The metering device test auxiliary power supply according to claim 1, characterized in that: The charging module is connected to the MCU of the central processor control unit, and comprises a battery voltage measurement circuit and a battery current measurement circuit.

10. A method for detecting an electric power metering device, the method for detecting an electric power metering device is based on the metering device according to any one of claims 1 to 9 to test an auxiliary power supply, characterized in that: The following steps are involved: Step 1, connecting the power metering device to the power metering device connection port of the auxiliary power supply of the metering device test; If the power metering device uses an AC power supply, connect it to the AC power metering device wiring port; if the power metering device uses a DC power supply, connect it to the DC power metering device wiring port; Step 2: Insert the charging cable into the charging cable interface of the auxiliary power supply of the metering device to enter the AC / DC 220V voltage input to charge the lithium battery, ensure that the battery is fully charged, and enter a normal working state; Step 3: Select the appropriate AC or DC output mode on the touch screen and set the AC or DC output voltage according to the power metering and detection requirements; Step 4, the processor control unit of the metering device tests the auxiliary power supply and issues a control instruction to the AC output circuit or the DC output circuit based on the AC or DC output voltage setting parameters; wherein the control instruction issued by the processor control unit is to generate an SVPWM modulation wave according to a three-phase vector space synthesis algorithm; Step 5, the AC output circuit is based on the SVPWM modulation wave, and drives the three-phase bridge circuit through the gate drive circuit to output the three-phase power-driven SVPWM, and then passes through the LCL filter of the output stage to obtain a three-phase sine wave. The line voltage effective value of the sine wave is designed to be 30V, and then passes through a △ / Y-connected step-up transformer to filter the third harmonics and step up to 380V or 220V, and then output to the AC power metering equipment wiring port; The DC output circuit adjusts the switching timing of each switch tube in the resonant bridge main circuit based on the SVPWM modulation wave to form an alternating pulse width modulation PWM waveform, and converts DC power into a high-frequency signal through the resonance characteristic. After the high-frequency signal is output, the DC output full-wave rectifier circuit rectifies the high-frequency signal into a stable DC voltage and outputs it to the DC power metering equipment wiring port; Step 6, the power metering device performs various functional tests based on the AC or DC voltage provided by the auxiliary power supply tested by the metering device; Step 7, if the AC output voltage is set according to the power metering detection needs, during the various function tests of the power metering equipment, the processor control unit detects the output AC voltage value and current value in real time through the inverter output sinusoidal voltage measurement circuit and the inverter output AC current measurement circuit, and displays them through the touch screen.

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