Automatic detection device for storage battery load meter

Abstract

The utility model discloses an automatic detection device for a storage battery load meter, which comprises a voltage regulation conversion module, a rectification filtering module and a main control module, the AC voltage regulation conversion module at least comprises a three-phase self-coupling voltage regulator and a three-phase isolation transformer, and the AC rectification filtering module at least comprises a three-phase rectification filter. The alternating current main control module is configured to acquire the output voltage, current and discharge capacity of the rectification filter module in real time and adjust the three-phase self-coupling voltage regulator to stabilize the output voltage of the automatic detection device at a target voltage value, and the main control module is electrically connected with the control end of the three-phase self-coupling voltage regulator and the output end of the three-phase rectification filter. And star-to-triangle conversion is carried out between the input end and the output end of the three-phase isolation transformer so as to reduce the output voltage of the three-phase isolation transformer and reduce the input current of the three-phase self-coupling voltage regulator. By adopting the automatic detection device provided by the utility model, the power supply condition of an existing laboratory modified from an office does not need to be changed.

Description

TECHNICAL FIELD

[0001] The utility model relates to load instrument detection field, concretely relates to a battery load instrument automatic detection device. BACKGROUND

[0002] In the DC system of the power substation, the battery group as the key backup power, its stable and reliable performance is directly related to the safe operation of the power system. Therefore, the battery load instrument emerges as the times require and becomes one of the indispensable tools for maintaining and monitoring these batteries. The battery load instrument is a kind of equipment specially used for detecting the discharge performance of the battery, and the voltage, current and other parameters of the battery during discharge are measured by simulating the actual load condition, so as to evaluate the performance of the whole group and each individual battery in the battery group.

[0003] The battery load instrument needs to be detected / calibrated by a detection device with higher accuracy level, and the automatic detection device can realize the automatic test thereof. The automatic detection device can detect the voltage, current, discharge capacity and other measurement data of the battery load instrument in real time, process and analyze the measurement data, and form a report certificate and the like. In this way, not only the test efficiency can be improved, but also the human error can be reduced, and the accuracy and reliability of the detection result can be ensured. Moreover, the automatic detection device meets the technical requirements of JJF2039-2023 calibration specification, can meet the calibration and detection requirements of most in-service and newly produced battery load instruments, has the characteristics of standard device, equipment replaceability, low power supply requirement, convenient maintenance and the like.

[0004] However, in practice, some laboratories are rebuilt from ordinary offices, and the power supply capacity of the office is usually small, and a 25A air switch is usually used. The design index of the automatic detection device is that the output voltage is DC 220V or DC 110V, the output rated current is 60A, and the 120% capacity margin. When the automatic detection device works at the rated current, the current passing through the existing three-phase self-coupled voltage regulator (15kVA, 16A) will exceed the rated current of the three-phase self-coupled voltage regulator. However, changing the original circuit of the office needs to consider the compatibility of new and old circuits, wiring space, electrical safety, building specifications and cost and other problems, which has great difficulties.

[0005] Therefore, a new automatic detection device is needed, which can meet the requirements of the existing equipment and power supply environment of the automatic detection device without increasing equipment, cost and time, and can use the existing equipment and reduce the power supply requirement. UTILITY MODEL CONTENTS

[0006] The utility model at least overcomes one of the deficiencies of the existing production site and equipment, and provides a battery load instrument automatic detection device.

[0007] To solve the above technical problems, the utility model adopts the technical scheme as follows:

[0008] The application provides an automatic detection device for a battery load instrument, comprising a voltage-regulating conversion module, a rectification filtering module and a main control module, the voltage-regulating conversion module comprises at least one three-phase self-coupled voltage regulator and one three-phase isolation transformer, the three-phase self-coupled voltage regulator is configured to regulate the input AC voltage to an AC voltage within a preset fluctuation range based on a target voltage value, and the three-phase isolation transformer is configured to regulate the input AC voltage to an AC target voltage value; the rectification filtering module comprises at least one three-phase rectification filter, the three-phase rectification filter is configured to output a DC voltage after rectification and filtering of the input AC voltage; the main control module is configured to collect the output voltage, output current and discharge capacity of the rectification filtering module in real time, and adjust the three-phase self-coupled voltage regulator to stabilize the output voltage of the automatic detection device at the target voltage value; wherein the output voltage, output current and discharge capacity of the rectification filtering module are the output voltage, output current and discharge capacity of the automatic detection device for the battery load instrument, and the output voltage, output current and discharge capacity of the automatic detection device for the battery load instrument are used as the input voltage, input current and discharge capacity of the battery load instrument; the output end of the three-phase self-coupled voltage regulator is electrically connected to the input end of the three-phase isolation transformer, the output end of the three-phase isolation transformer is electrically connected to the input end of the three-phase rectification filter, the output end of the three-phase rectification filter is electrically connected to the input end of the battery load instrument, and the main control module is electrically connected to the control end of the three-phase self-coupled voltage regulator and the output end of the three-phase rectification filter respectively, star-to-delta conversion is performed between the input end and the output end of the three-phase isolation transformer to reduce the output voltage of the three-phase isolation transformer and the input current of the three-phase self-coupled voltage regulator.

[0009] Optionally, the star-to-delta conversion between the input end and the output end of the three-phase isolation transformer comprises:

[0010] The ends of each phase coil of the input end of the three-phase isolation transformer are connected together to realize star connection, and the neutral point of the input end is left hanging;

[0011] The end of each phase coil of the output end of the three-phase isolation transformer is connected to the start of the adjacent phase coil to form a closed-loop delta connection to realize delta connection, and the neutral point of the output end is left hanging.

[0012] Optionally, the main control module comprises a measuring unit and a control unit, the measuring unit is configured to collect output voltage, output current and discharge capacity of the rectification filter module in real time, and the control unit is configured to obtain a control signal by comparing the output voltage value of the automatic detection device with a target voltage value, and automatically adjust the output voltage of the three-phase self-coupled voltage regulator according to the control signal, so as to realize that the output voltage of the automatic detection device is stabilized at the target voltage value.

[0013] Optionally, the control unit controls the synchronous motor through an operational amplifier comparator circuit to realize comparison of the output voltage value of the automatic detection device and the target voltage value, and then obtain the control signal.

[0014] Optionally, the target voltage value is set by the control unit, and the target voltage value is direct current 220V or direct current 110V.

[0015] Optionally, the control unit adjusts the brush position and the fluctuation range of the output voltage of the three-phase self-coupled voltage regulator according to the control signal, so as to realize that the direct current voltage output by the three-phase self-coupled voltage regulator is stabilized at 90%-110% of the target voltage value.

[0016] Optionally, the automatic detection device of the battery load instrument further comprises an auxiliary module, the auxiliary module comprises a temperature monitoring unit, a radiator fan control unit, a voltage monitoring unit and a current monitoring unit,

[0017] The temperature monitoring unit is configured to monitor and control the temperature of other modules;

[0018] The radiator fan control unit is configured to control the rotating speed and / or on-off state of the radiator fan according to the data provided by the temperature monitoring unit, so as to adjust the temperature inside the automatic detection device;

[0019] The voltage monitoring unit is configured to monitor the three-phase alternating current input voltage of the automatic detection device, the three-phase alternating current output voltage of the voltage regulation conversion module and the direct current voltage of the output loop of the rectification filter module in real time;

[0020] The current monitoring unit is configured to monitor the three-phase input current of the automatic detection device, the three-phase output current of the voltage regulation conversion module and the direct current of the output loop of the rectification filter module in real time.

[0021] Optionally, the measuring unit comprises a digital multimeter, a PC used for controlling the digital multimeter and processing measurement data, the digital multimeter and the PC realize transmission of measurement data through a USB interface, the digital multimeter measures the rectification filter module to obtain measurement data of the rectification filter module, and the measurement data at least comprises output voltage, output current and discharge capacity of the rectification filter module.

[0022] Optionally, the digital multimeter is used to measure at least one of AC voltage, AC current, DC voltage, DC current and DC resistance.

[0023] Optionally, the digital multimeter has an accuracy level of 0.01.

[0024] The automatic detection device provided by the application adopts a star-triangle transformation method of increasing an existing three-phase isolation transformer, so that the three-phase current does not exceed the rated current of the existing AC three-phase autotransformer and is less than 25A three-phase power supply current. Therefore, the automatic detection device provided by the application does not need to change the power supply condition of the laboratory modified from an office, thereby saving a large amount of cost and time. The automatic detection device provided by the application is a high-precision DC large-current detection / calibration device, which can be used for detecting / calibrating high-power instruments and equipment such as a battery load instrument, and is also a detection / standard device of a DC inspection instrument, and can accurately detect and calibrate a DC bus system test instrument. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, not the limitation of the present application. For those skilled in the art, other drawings can also be obtained without creative labor.

[0026] Fig. 1 is a structure diagram of the automatic detection device of the battery load instrument (not including the battery load instrument) of the present application;

[0027] Fig. 2 is a connection mode schematic diagram of the star-to-triangle transformation of the three-phase isolation transformer in the present application;

[0028] Fig. 3 is a structure diagram of the automatic detection device of the battery load instrument with an auxiliary module (not including the battery load instrument) of the present application;

[0029] The drawings show that: 100 is a battery load instrument; 200 is a voltage regulation and transformation module; 210 is a three-phase autotransformer; 220 is a three-phase isolation transformer; 300 is a rectification and filtering module; 310 is a three-phase rectification filter; 400 is a main control module; 500 is an auxiliary module. DETAILED DESCRIPTION

[0030] Some embodiments of the present application will be described in detail with reference to the drawings. In the case of no conflict, the features in the following examples can be combined with each other. The present application will be described in detail with reference to the drawings.

[0031] Please refer to Figs. 1 to 3 The embodiment provides an automatic detection device for a battery load instrument, which comprises a voltage regulating and converting module 200, a rectification and filtering module 300 and a main control module 400. The voltage regulating and converting module 200 comprises a three-phase self-coupling voltage regulator 210 and a three-phase isolation transformer 220. The rectification and filtering module 300 comprises a three-phase rectification and filtering device 310.

[0032] The A1, B1 and C1 of the input end of the three-phase self-coupling voltage regulator 210 are electrically connected with the three-phase alternating current of the power supply. The a1, b1 and c1 of the output end of the three-phase self-coupling voltage regulator 210 are electrically connected with the A2, B2 and C2 of the input end of the three-phase isolation transformer 220. The neutral point N1 of the input end of the three-phase self-coupling voltage regulator 210 is electrically connected with the neutral point n1 of the output end. The neutral point N2 of the input end of the three-phase isolation transformer 220 and the neutral point n2 of the output end are both suspended. The input end (A2, B2, C2) of the three-phase isolation transformer 220 and the output end (a2, b2, c2) are transformed from star to triangle by changing the connection mode. The a2, b2 and c2 of the output end of the three-phase isolation transformer 220 are electrically connected with the A3, B3 and C3 of the input end of the three-phase rectification and filtering device 310. The OUT1 and OUT2 of the three-phase rectification and filtering device 310 are electrically connected with the IN1 and IN2 of the battery load instrument 100. The main control module 400 is electrically connected with the control end D1 of the three-phase self-coupling voltage regulator 210, the positive pole and the negative pole of the output end of the three-phase rectification and filtering device 310. The output voltage, the output current and the discharge capacity of the rectification and filtering module are the output voltage, the output current and the discharge capacity of the automatic detection device for the battery load instrument. The output voltage, the output current and the discharge capacity of the automatic detection device for the battery load instrument are used as the input voltage, the input current and the discharge capacity of the battery load instrument.

[0033] The three-phase self-coupling voltage regulator 210 adjusts the input alternating voltage to the alternating voltage near the target voltage value to adapt to different loads and voltage requirements. The power supply alternating current is connected to the input end of the three-phase self-coupling voltage regulator 210. The three-phase self-coupling voltage regulator 210 is controlled by a synchronous motor through manual or electronic controller to gradually increase the output voltage to the target value. The output voltage can be controlled within 10% of the target voltage value. The target voltage value is set by the main control unit. The target voltage value is generally 220V or 110V direct current voltage, which is also the specific value of the direct current bus of the power substation.

[0034] The three-phase isolation transformer 220 is used to further adjust the input voltage of the rectification filter circuit, to adjust the input AC voltage to the target AC voltage value, to play an electrical isolation role, and to enhance the safety and anti-harmonic interference of the circuit.

[0035] In order to reduce the input current of the three-phase autotransformer 210, a star-triangle transformation needs to be performed inside the three-phase isolation transformer 220, as shown in FIG. 2B. Fig. 2 Fig. 2 The red line in FIG. 2B is the connection mode of the three-phase isolation transformer for star-to-triangle transformation, and the star-to-triangle transformation is performed between the input end and the output end of the three-phase isolation transformer to reduce the output voltage of the three-phase isolation transformer and reduce the input current of the three-phase autotransformer. The star-triangle transformation is achieved by changing the connection of the input end A2, B2, C2 and the output end a2, b2, c2 of the three-phase isolation transformer, specifically including: connecting the end of each phase coil of the input end (A2, B2, C2) of the three-phase isolation transformer together, and leaving the neutral point N2 of the input end floating; connecting the end of each phase coil of the output end (a2, b2, c2) of the three-phase isolation transformer to the start of the adjacent phase coil, and forming a closed-loop triangular connection, and leaving the neutral point n2 of the output end floating. By converting the star connection of the three-phase isolation transformer 220 to a triangle connection, the voltage of each phase can be reduced (the delta circuit line voltage is equal to the phase voltage, both being 380V / √3=220V), that is, the current is reduced.

[0036] The output current and output voltage of the automatic measuring device are the output current and output voltage of the three-phase rectification filter, so the output voltage of the three-phase rectification filter is DC 220V, and the rated output current is 60A. The DC power at the output end of the three-phase rectification filter is 13.2kW (220Vx60A). If the three-phase rectification filter is powered by three-phase AC 380V, the output DC voltage of the three-phase rectification filter is about DC 537V (AC 380Vx√2), and if it needs to be reduced to DC 220V, the voltage reduction ratio is 0.41 (220V / 537V). At this time, the input three-phase voltage of the three-phase rectification filter is AC 156V (AC 380Vx0.41), or the result is the same by using the equal power method. If the three-phase rectification filter and the three-phase autotransformer are directly electrically connected, the current through each phase of the secondary side of the three-phase autotransformer is 28A (13.2kW / 156 / √3 / √3, assuming that the pure resistance load power factor is equal to 1 and that the device capacity margin is equal to 1), and the three-phase autotransformer is overloaded (the rated current of the three-phase autotransformer is 16A). Therefore, the three-phase isolation transformer is added between the three-phase autotransformer and the three-phase rectification filter, and the three-phase isolation transformer bears this current to reduce the current of the secondary side of the three-phase autotransformer.

[0037] ​If the three-phase isolation transformer is Y / Y transformed, it only plays an isolation role and does not play a current reduction role, and cannot solve the problem. The three-phase isolation transformer is Y / △ (star-triangle) transformed to 380 / 220 in the application, that is, the primary and secondary side voltages of the three-phase isolation transformer are 380V / 220V. At this time, the three-phase isolation transformer secondary side 156V is also the three-phase rectifier filter input voltage. The three-phase isolation transformer output line current is equal to 28A (13.2kW / 156V / 3), and the three-phase isolation transformer primary side line current is 156 / 270*28A=16A. Since the input of the three-phase isolation transformer is equal to the output of the three-phase autotransformer, that is, the secondary side voltage of the three-phase autotransformer is 270V, and the input of the three-phase autotransformer is 270 / 380*16A=11.4A, which meets the working requirements of the three-phase autotransformer and the three-phase air switch. Only the 220V case is calculated in the application file, and the 110V case also meets the working requirements of the three-phase autotransformer and the three-phase air switch. The proof process is not described in detail here.

[0038] The rectifier filter module 300 outputs a direct current voltage after rectifying and filtering the input alternating current voltage. The output direct current voltage is filtered of alternating current components, reducing the ripple of the output direct current voltage and current. The rectifier filter module 300 can directly use a three-phase rectifier filter 310, or can be designed by itself through a capacitor and an inductor to form a π-type filter circuit.

[0039] The main control module is used to collect the output voltage, current and discharge capacity of the rectifier filter module in real time, and adjust the three-phase autotransformer to realize that the output voltage of the automatic detection device is stable at the target voltage value. The main control module includes a measurement unit and a control unit, which are independent of each other and not electrically connected. The measurement unit is used to collect the output voltage, output current and discharge capacity of the rectifier filter module in real time. The control unit controls the synchronous motor through an operational amplifier comparator circuit to compare the output voltage value of the automatic detection device with the target voltage value, obtain the difference, and then obtain the control signal. According to the control signal, the synchronous motor is automatically adjusted to realize the adjustment of the three-phase autotransformer brush position and the fluctuation range of the output voltage, and then the output voltage of the three-phase autotransformer is adjusted, so that the output voltage of the automatic detection device is stable at the target voltage value. The output voltage of the three-phase autotransformer is 90%-110% of the target voltage value.

[0040] The target voltage value is set by the control unit, which is generally a direct current voltage of 220V or 110V (a specific value of the direct current bus of the power substation). After receiving the output voltage of the real-time automatic detection device collected by the sampling voltage dividing resistor, the control unit compares it with the set target voltage value, calculates the difference through the control circuit composed of the built-in operational amplifier and comparator, and generates the corresponding control signal. The control signal includes increasing the output voltage of the automatic detection device if the output voltage of the automatic detection device is lower than the target voltage value, and reducing the output voltage of the automatic detection device if the output voltage of the automatic detection device is higher than the target voltage value.

[0041] The measuring unit further comprises a digital multimeter and a PC for controlling the digital multimeter and processing measurement data, the PC comprising a control program for controlling the digital multimeter, the digital multimeter being used to measure at least one of alternating current voltage, alternating current, direct current voltage and direct current resistance, the control program being capable of automatically adjusting the measurement settings of the digital multimeter according to preset measurement parameters, the control program further comprising a user interface for displaying measurement results and operation guidance. The digital multimeter and the PC realize transmission of the control program and measurement data through a USB interface, and the communication protocol between the PC and the digital multimeter conforms to the USB standard. The digital multimeter can detect the voltage, current and discharge capacity of the battery load instrument in real time during the working process, and is used as a standard device. The digital multimeter can be used to collect output voltage, current and other data of the rectification and filtering module 300 in real time, and compare the data with the data recorded by the battery load instrument, so as to obtain the measurement uncertainty of the battery load instrument. The digital multimeter measures the rectification and filtering module according to the control program, and obtains the measurement data of the rectification and filtering module, including the output voltage, output current and discharge capacity of the rectification and filtering module, and the accuracy level of the digital multimeter is 0.01. The measurement accuracy of the existing single-chip A / D usually cannot reach the accuracy of the digital multimeter, so for detecting / calibrating the battery load instrument, the technical indicators of 0.1% voltage and 0.2% or 0.5% current cannot meet the detection / calibration uncertainty requirements. The automatic detection device provided in the present application converts current measurement into voltage measurement by using a large-current standard resistor, and uses a 0.01-level digital multimeter and a 0.01-level large-current standard resistor as high-accuracy standard devices. Each unit cooperates as a whole to achieve high detection accuracy and meet the accuracy technical requirements of the JJF2039-2023 calibration specification for battery load instrument calibration / detection work.

[0042] The automatic detection device of the battery load instrument of the present application also needs to use a large-current standard resistor, a sampling resistor voltage divider, and a shunt. The large-current standard resistor serves as a current detection standard device. During the process of simulating the battery discharge by the automatic detection device, the discharge current is accurately measured and the discharge capacity is calculated by the PC program, so as to evaluate the measurement uncertainty of the current and the discharge capacity of the calibrated / detected battery load instrument. The large-current standard resistor is at least 0.01 level. The sampling resistor voltage divider is used for monitoring the output DC voltage. The uncertainty of the sampling resistor voltage divider is 0.1%. The shunt is mainly used for monitoring the output DC current. The shunt is at least 0.1 level.

[0043] In the present embodiment, as shown in Fig. 3 The auxiliary module 500 includes a temperature monitoring unit, a radiator fan control unit, a voltage monitoring unit, and a current monitoring unit,

[0044] The temperature monitoring unit is used for monitoring the temperature of the other modules. It is realized by temperature sensors such as thermistors, thermocouples, etc. These sensors can convert temperature information into electrical signals in real time for subsequent processing or alarm use.

[0045] The radiator fan control unit is used for controlling the speed or on-off state of the radiator fan according to the data provided by the temperature monitoring unit, so as to adjust the temperature inside the automatic detection device, ensure that the automatic detection device works within a safe temperature range, and prevent overheating damage.

[0046] The voltage monitoring unit is used for monitoring the input and output three-phase voltages of the voltage regulation and conversion module 200 (three-phase self-coupled voltage regulator 210) and the input and output three-phase voltages of the rectification and filtering module 300 in real time through AC / DC voltmeters. This helps to ensure the correctness of the power supply voltage, discover voltage abnormalities in time and handle them, and protect the subsequent circuit from damage.

[0047] The current monitoring unit is used for monitoring the input and output currents of the voltage regulation and conversion module 200 (three-phase self-coupled voltage regulator 210) and the input and output currents of the rectification and filtering module 300 in real time through AC / DC ammeters, so as to take measures in time to prevent equipment damage.

[0048] The auxiliary module 500 realizes the functions of temperature control, voltage and current monitoring of the rectification and filtering unit and its related components, and ensures the safe and stable operation of the entire system.

[0049] The automatic detection device provided by the application can be used as a standard of direct current large current, can be used for calibrating or detecting some special large current instruments and meters, and can also be used as a standard of a direct current inspection instrument.

[0050] The above merely illustrates the specific implementation of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery load gauge automatic detection device, characterized in that: The voltage regulating conversion module, the rectification filter module and the main control module are included. The voltage regulating conversion module includes at least one three-phase self-coupled voltage regulator and one three-phase isolation transformer. The three-phase self-coupled voltage regulator is configured to regulate the input AC voltage to an AC voltage within a preset fluctuation range based on a target voltage value. The three-phase isolation transformer is configured to regulate the input AC voltage to an AC target voltage value. The rectification filter module includes at least one three-phase rectification filter.

2. The battery load meter automatic detection device according to claim 1, wherein The main control module is configured to collect the output voltage, output current and discharge capacity of the rectification filter module in real time, and adjust the three-phase self-coupled voltage regulator to realize the output voltage of the automatic detection device stabilizing at the target voltage value. The output voltage, output current and discharge capacity of the rectification filter module are the output voltage, output current and discharge capacity of the automatic detection device of the battery load instrument. The output voltage, output current and discharge capacity of the automatic detection device of the battery load instrument are used as the input voltage, input current and discharge capacity of the battery load instrument.

3. The battery load meter automatic detection device according to claim 1, wherein The output end of the three-phase self-coupled voltage regulator and the input end of the three-phase isolation transformer are electrically connected.

4. The battery load meter automatic detection device according to claim 3, wherein The output end of the three-phase isolation transformer and the input end of the three-phase rectification filter are electrically connected.

5. The battery load meter automatic detection device according to claim 3, wherein The output end of the three-phase rectification filter and the input end of the battery load instrument are electrically connected.

6. The battery load meter automatic detection device according to claim 3, wherein The main control module is electrically connected to the control end of the three-phase self-coupled voltage regulator and the output end of the three-phase rectification filter. Star-to-delta transformation is performed between the input end and the output end of the three-phase isolation transformer to reduce the output voltage of the three-phase isolation transformer and the input current of the three-phase self-coupled voltage regulator. The star-to-delta transformation between the input end and the output end of the three-phase isolation transformer includes: The ends of each phase coil of the input end of the three-phase isolation transformer are connected together to realize star connection, and the neutral point of the input end is left hanging. The ends of each phase coil of the output end of the three-phase isolation transformer are connected to the ends of adjacent phase coils to form a closed-loop delta connection to realize delta connection, and the neutral point of the output end is left hanging. The main control module includes a measurement unit and a control unit. The measurement unit is configured to collect the output voltage, output current and discharge capacity of the rectification filter module in real time. The control unit is configured to obtain a control signal by comparing the output voltage value of the automatic detection device with the target voltage value, and automatically adjust the output voltage of the three-phase self-coupled voltage regulator according to the control signal to realize the output voltage of the automatic detection device stabilizing at the target voltage value. The control unit controls the synchronous motor through an operational amplifier comparator circuit to realize the comparison of the output voltage value of the automatic detection device with the target voltage value, and then obtains the control signal. The target voltage value is set by the control unit, and the target voltage value is DC 220V or DC 110V. The control unit adjusts the brush position and the fluctuation range of the output voltage of the three-phase self-coupled voltage regulator according to the control signal to realize the DC voltage output by the three-phase self-coupled voltage regulator stabilizing at 90%-110% of the target voltage value.

7. The battery load bank automatic detection apparatus of claim 1, wherein The auxiliary module comprises a temperature monitoring unit, a radiator fan control unit, a voltage monitoring unit and a current monitoring unit, The temperature monitoring unit is configured to monitor and control the temperature of each module; The radiator fan control unit is configured to control the rotation speed and / or on-off state of the radiator fan according to the data provided by the temperature monitoring unit, so as to adjust the temperature inside the automatic detection device; The voltage monitoring unit is configured to monitor the three-phase AC input voltage of the automatic detection device, the three-phase AC output voltage of the voltage conversion module and the DC voltage of the output loop of the rectification and filtering module in real time; The current monitoring unit is configured to monitor the three-phase input current of the automatic detection device, the three-phase output current of the voltage conversion module and the DC current of the output loop of the rectification and filtering module in real time.

8. The battery load bank automatic detection apparatus of claim 3, wherein The measurement unit comprises a digital multimeter and a PC used for controlling the digital multimeter and processing measurement data, the digital multimeter and the PC are connected through a USB interface to realize the transmission of measurement data, the digital multimeter measures the rectification and filtering module to obtain measurement data of the rectification and filtering module, the measurement data at least comprises the output voltage, the output current and the discharge capacity of the rectification and filtering module.

9. The automatic detection device for battery load meter according to claim 8, wherein The digital multimeter is used to measure at least one of AC / DC voltage, AC / DC current and DC resistance.

10. The battery load bank automatic detection apparatus of claim 8, wherein The accuracy level of the digital multimeter is 0.01 level.

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