Motor testing device

Abstract

The utility model discloses a motor testing device, relating to the motor testing field, the motor testing device is provided with a first high-voltage wire inlet module, a four-quadrant frequency converter and a switching module, when a motor needs to be started, the first high-voltage wire inlet module is disconnected, the four-quadrant frequency converter works, and the power grid frequency is converted; the converted electric energy is transmitted to the motor through the switching module so that the motor can be started normally, after the motor is started, the first high-voltage wire inlet module is closed, and the power grid supplies power to the motor and enables the motor to operate normally. The four-quadrant frequency converter transmits the converted electric energy to the generator through the switching module so as to enable the generator to be normally started, and due to the fact that only one four-quadrant frequency converter is arranged in the scheme, normal starting and dragging loading of the motor and the generator can be successfully achieved, and cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of motor testing, in particular to a motor testing device. Background Art

[0002] In the prior art, two motors are often used to load the towing station to complete the temperature rise, load characteristics, overload and other point tests. Figure 1 It is shown that when the tested machine is an asynchronous motor, in order to reduce the starting impact, it is necessary to first perform frequency modulation starting through the frequency converter, that is, first use the frequency converter to adjust the frequency of the electric energy transmitted by the power grid, and start the motor according to the adjusted frequency to make the motor have a certain speed, and then use the four-quadrant frequency converter to drive the generator to work and load the motor with torque. However, two frequency converters are required to drive the motors separately when conducting the towing test, and large frequency converters are generally expensive, so the cost of using two frequency converters is high. Utility Model Content

[0003] The utility model aims to provide a motor test device. The solution successfully realizes the normal starting and operation of the motor and the generator by only one four-quadrant frequency converter, thereby reducing the cost.

[0004] In order to solve the above technical problems, the utility model provides a motor test device, comprising:

[0005] A first high-voltage incoming line module, wherein the input end of the first high-voltage incoming line module is connected to the power grid, and the output end is connected to the motor, and is used to control whether the power grid energy transmitted by the power grid is transmitted to the motor;

[0006] The four-quadrant frequency converter, the input end of which is connected to the power grid, and the output end of which is connected to the input end of the switching module, is used to perform corresponding frequency conversion processing on the power energy of the power grid;

[0007] The switching module, the output end of the switching module is connected to the motor and the generator respectively, and is used to select the input end of the switching module to be connected to the motor or the generator.

[0008] Optionally, the first high-voltage incoming line module includes:

[0009] A first fuse, wherein an input end of the first fuse is connected to the power grid, an output end of the first fuse is connected to an input end of a first isolating switch, and is used for disconnecting when a current in the loop exceeds a first preset current threshold;

[0010] The first isolating switch, wherein an output end of the first isolating switch is connected to the motor, is used to control whether the grid power is transmitted to the motor.

[0011] Optionally, the first high-voltage incoming line cabinet further includes:

[0012] A first current transformer, connected to an output end of the first isolating switch, and used to measure a first current value of the grid electric energy;

[0013] A first voltage transformer is connected to an output end of the first isolating switch and is used to measure a first voltage value of the grid electric energy.

[0014] Optionally, the four-quadrant frequency converter comprises:

[0015] A rectifier module, the input end of which is connected to the power grid and is used to convert the alternating current transmitted by the power grid into corresponding direct current;

[0016] An inverter module, wherein the input end of the inverter module is connected to the output end of the rectifier module, and the output end is connected to the input end of the switching module, and is used to convert the direct current into a preset alternating current.

[0017] Optionally, the four-quadrant frequency converter further includes:

[0018] A filter module, wherein the input end of the filter module is connected to the output end of the rectifier module, and the output end is respectively connected to the input end of the inverter module, and is used to perform corresponding filtering on the direct current.

[0019] Optionally, also include:

[0020] A second high-voltage incoming line module, the input end of the second high-voltage incoming line module is connected to the power grid, and the output end is connected to the input end of the four-quadrant inverter, and is used to control whether the power of the power grid is transmitted to the four-quadrant inverter.

[0021] Optionally, also include:

[0022] a first measuring cabinet, wherein an input end of the first measuring cabinet is connected to an output end of the switching module, and an output end of the first measuring cabinet is connected to the motor, and is used to measure a second current value and a second voltage value received by the motor;

[0023] A second measuring cabinet, wherein the input end of the second measuring cabinet is connected to the output end of the switching module, and the output end is connected to the generator, and is used to measure a third current value and a third voltage value received by the generator.

[0024] Optionally, the second high-voltage incoming line module includes:

[0025] A second fuse, wherein the input end of the second fuse is connected to the power grid, and the output end is connected to the input end of the second isolating switch, and is used for disconnecting when the current in the loop exceeds a second preset current threshold;

[0026] The second isolating switch, the output end of the second isolating switch is connected to the input end of the four-quadrant frequency converter, and is used to control whether the grid power is transmitted to the four-quadrant frequency converter;

[0027] a second current transformer, the second current transformer being connected to an output end of the second isolating switch and being used to measure the first current value;

[0028] A second voltage transformer, wherein the second voltage transformer is connected to an output end of the second isolating switch and is used to measure the first voltage value.

[0029] Optionally, the switching module includes:

[0030] A first switching switch, wherein an input end of the first switching switch is connected to an output end of the four-quadrant frequency converter, and an output end of the first switching switch is connected to the motor, and is used for transmitting the grid power after the frequency conversion process to the motor when the first switching switch is closed;

[0031] A second switching switch, wherein the input end of the second switching switch is connected to the output end of the four-quadrant inverter, and the output end is connected to the generator, and is used for transmitting the grid power after the frequency conversion process to the generator when the second switching switch is closed.

[0032] Optionally, the switching module further includes:

[0033] a third switching switch, wherein the input end of the switching switch is connected to the output end of the four-quadrant frequency converter, and the output end of the switching switch is connected to the input end of the first transformer, and is used for transmitting the grid power after the frequency conversion process to the first transformer when the third switching switch is closed;

[0034] The motor testing device further comprises:

[0035] The first transformer, the output end of which is connected to the generator, is used to convert the third voltage value of the grid electric energy after the frequency conversion process into a fourth voltage value;

[0036] A second transformer, wherein the second transformer is connected to an output end of the first high-voltage incoming line module, and an output end is connected to the motor, and is used for converting the first voltage value into a fifth voltage value.

[0037] The utility model provides a motor test device, which is provided with a first high-voltage incoming line module, a four-quadrant frequency converter and a switching module. When the motor needs to be started, the first high-voltage incoming line module is disconnected, the four-quadrant frequency converter works, and converts the grid frequency. The converted electric energy is transmitted to the motor through the switching module to enable the motor to start normally. When the motor is started, the first high-voltage incoming line module is closed, the grid supplies power to the motor and enables the motor to run normally. After the motor is started, the four-quadrant frequency converter transmits the converted electric energy to the generator through the switching module to enable the generator to start normally. Because this scheme only sets up one four-quadrant frequency converter, it can successfully realize the normal starting and drag loading of the motor and the generator, thereby reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0039] Figure 1 It is a schematic diagram of a motor drag test scheme commonly used in the prior art;

[0040] Figure 2 A schematic diagram of the structure of a motor test device provided by the utility model;

[0041] Figure 3 A schematic diagram of a motor test provided by the utility model;

[0042] Figure 4 Another motor test schematic diagram provided by the utility model;

[0043] Figure 5 Another motor test schematic diagram provided by the utility model;

[0044] Figure 6 Another motor test schematic diagram provided by the utility model;

[0045] Figure 7 Another motor test schematic diagram provided by the utility model;

[0046] Figure 8 The present invention is a schematic structural diagram of another motor testing device provided by the utility model. DETAILED DESCRIPTION

[0047] The core of the utility model is to provide a motor test device. This solution successfully realizes the normal starting and operation of the motor and the generator through only one four-quadrant frequency converter, thereby reducing the cost.

[0048] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0049] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a motor test device provided by the utility model. The device includes:

[0050] A first high-voltage incoming line module 1, the input end of the first high-voltage incoming line module 1 is connected to the power grid, and the output end is connected to the motor, and is used to control whether the power grid energy transmitted by the power grid is transmitted to the motor;

[0051] A four-quadrant frequency converter 2, the input end of which is connected to the power grid, and the output end of which is connected to the input end of the switching module 3, for performing corresponding frequency conversion processing on the power grid;

[0052] The switching module 3 has an output end connected to the motor and the generator respectively, and is used to select the input end of the switching module 3 to be connected to the motor or the generator.

[0053] In the utility model, in order to accurately realize the towing test, it is necessary to first disconnect the first high-voltage incoming line module 1, make the four-quadrant frequency converter 2 work, and the output end of the switching module 3 is connected to the motor, so that the motor can receive the grid power after the four-quadrant frequency converter 2 is converted, and start. When the power frequency output by the four-quadrant frequency converter is the same as the grid power frequency, the first high-voltage incoming line module 1 is detected, and closed after meeting the grid connection conditions, and the grid supplies power to the motor, and the motor is made to operate normally to generate a speed. After the motor generates a speed, it will drive the generator to rotate and generate electricity. After that, the output end of the switching module 3 is connected to the generator, so that the generator can receive the grid power after the four-quadrant frequency converter 2 is converted, and start, and change its own torque through the adjustment of the four-quadrant frequency converter, so as to successfully complete the torque loading of the motor. This scheme successfully realizes the normal starting and operation of the motor and the generator through only one four-quadrant frequency converter 2, thereby reducing the cost.

[0054] It should be noted that the fourth quadrant is in the reverse braking state, and the inverter that can make the motor work in all four quadrants is the four-quadrant inverter 2. In addition, after starting the motor test, the four-quadrant inverter 2 needs to drive the motor to the grid frequency (power frequency). The control process is as follows Figure 3 As shown, at this time, the motor is ready for grid connection, the inverter is disconnected, and the motor is driven by the grid. The control process is as follows Figure 4 As shown, the inverter then cuts into the generator test circuit to load the motor. The four-quadrant inverter 2 adopts the torque control mode to output the frequency-modulated electric energy to control the operation of the generator. Because the motor and the generator are connected through a coupling, the torque direction of the generator is opposite to the rotation direction of the motor. At this time, the generator outputs torque to the motor to load the motor. The control process is as follows Figure 5 shown.

[0055] The present embodiment provides a motor test device, which is provided with a first high-voltage incoming line module, a four-quadrant frequency converter 2 and a switching module 3. When the motor needs to be started, the first high-voltage incoming line module 1 is disconnected, the four-quadrant frequency converter 2 works, and converts the grid frequency, and transmits the converted electric energy to the motor through the switching module 3 to enable the motor to start normally. When the motor starts to the working frequency, the first high-voltage incoming line module 1 is closed, and the grid supplies power to the motor and enables the motor to run normally. After the motor starts, the four-quadrant frequency converter 2 transmits the converted electric energy to the generator through the switching module 3 to enable the generator to start normally. Because the present solution only provides one four-quadrant frequency converter 2, the normal starting and operation of the motor and the generator are successfully achieved, thereby reducing costs.

[0056] Based on the above embodiments:

[0057] As an optional embodiment, the first high-voltage incoming line cabinet includes:

[0058] A first fuse, the input end of the first fuse is connected to the power grid, the output end is connected to the input end of the first isolating switch, and is used to disconnect when the current in the loop exceeds a first preset current threshold;

[0059] The first isolating switch has an output end connected to the motor and is used to control whether the power of the power grid is transmitted to the motor.

[0060] In the utility model, a first high-voltage incoming line cabinet is provided with a first fuse and a first isolating switch, wherein the first fuse is used to actively disconnect when an overcurrent condition occurs in the circuit to protect various electronic components in the circuit, and the first isolating switch is used to disconnect based on control so that the motor can receive the electric energy transmitted by the power grid and operate normally after variable frequency starting. In addition, the first isolating switch can also bear a part of the current when an overcurrent condition occurs in the circuit to protect other electronic components in the circuit, thereby improving the safety of the solution.

[0061] As an optional embodiment, the first high-voltage incoming line cabinet further includes:

[0062] A first current transformer, connected to an output end of the first isolating switch, and used to measure a first current value of grid electric energy;

[0063] The first voltage transformer is connected to the output end of the first isolating switch and is used to measure a first voltage value of the electric energy of the power grid.

[0064] In the utility model, a first current transformer and a first voltage transformer are also provided in the first high-voltage incoming line cabinet. The first current transformer can accurately measure the first current value of the grid electric energy, and the first voltage transformer can accurately measure the first voltage value of the grid electric energy, which is convenient for the subsequent calculation of parameters such as the motor speed and torque.

[0065] As an optional embodiment, the four-quadrant frequency converter 2 includes:

[0066] A rectifier module, the input end of which is connected to the power grid and is used to convert the alternating current transmitted by the power grid into corresponding direct current;

[0067] The inverter module has an input end connected to the output end of the rectifier module, and an output end connected to the input end of the switching module 3, and is used to convert direct current into preset alternating current.

[0068] In the utility model, a rectifier module and an inverter module are provided in the four-quadrant inverter 2, wherein the rectifier module can convert the alternating current transmitted by the power grid into corresponding direct current, and the inverter module can convert the direct current into preset alternating current. Through the control of the inverter module, the variable frequency starting and industrial frequency operation of the motor can be accurately realized. In addition, the four-quadrant inverter 2 used in this solution only includes an inverter module and a rectifier module, which reduces the cost.

[0069] As an optional embodiment, the four-quadrant frequency converter 2 further includes:

[0070] The filter module has an input end connected to the output end of the rectifier module, and an output end connected to the input end of the inverter module, for filtering the direct current accordingly.

[0071] In the utility model, a filtering module is also provided in the four-quadrant frequency converter 2. The function of the filtering module is to filter the direct current output by the rectifier module. Because the frequency converter will generate a large number of high-frequency harmonics and high-order harmonics during the rectification process, these harmonics will enter the motor along the power supply line, making the motor prone to a series of problems such as work disorder and frequent damage. Therefore, setting up a filtering module can effectively filter out this part of the harmonic interference and improve the stability of the solution.

[0072] As an optional embodiment, it also includes:

[0073] The second high-voltage incoming line module 4 has an input end connected to the grid, and an output end connected to the input end of the four-quadrant inverter 2 , and is used to control whether grid power is transmitted to the four-quadrant inverter 2 .

[0074] In the utility model, the motor testing device is also provided with a second high-voltage incoming line module 4. The function of the second high-voltage incoming line module 4 is to control whether the four-quadrant frequency converter 2 receives the alternating current transmitted by the power grid. When the motor test is required, the second high-voltage incoming line module 4 is turned on and the first high-voltage incoming line module 1 is turned off. The frequency at which the four-quadrant frequency converter 2 outputs electric energy to the motor continues to increase. When the frequency is close to the power grid frequency, the second high-voltage incoming line module 4 is turned on. While the four-quadrant frequency converter 2 and the switching module 3 supply power to the generator, the first high-voltage incoming line module 1 is turned on. At this time, the power supply of the motor becomes the power grid, which accurately realizes the variable frequency starting and industrial frequency operation process of the motor.

[0075] As an optional embodiment, it also includes:

[0076] A first measuring cabinet 5, wherein an input end of the first measuring cabinet 5 is connected to an output end of the switching module 3, and an output end of the first measuring cabinet 5 is connected to the motor, and is used to measure a second current value and a second voltage value received by the motor;

[0077] The second measuring cabinet 6 has an input end connected to the output end of the switching module 3 and an output end connected to the generator, and is used to measure the third current value and the third voltage value received by the generator.

[0078] In the utility model, the motor testing device is also provided with a first measuring cabinet 5 and a second measuring cabinet 6, wherein the first measuring cabinet 5 can measure the second current value and the second voltage value received by the motor, and the second measuring cabinet 6 can measure the third current value and the third voltage value received by the generator. Because the purpose of the motor test may be to test its own voltage, current, power and other parameters under different loads, the setting of the first measuring cabinet 5 and the second measuring cabinet 6 can complete the measurement of electrical parameters such as the voltage value, current value, power value, power factor value and the like received by the motor and the generator in real time and accurately.

[0079] As an optional embodiment, the second high-voltage incoming line module 4 includes:

[0080] A second fuse, the input end of the second fuse is connected to the power grid, the output end is connected to the input end of the second isolating switch, and is used to disconnect when the current in the loop exceeds a second preset current threshold;

[0081] A second isolating switch, wherein the output end of the second isolating switch is connected to the input end of the four-quadrant frequency converter 2, and is used to control whether the power of the grid is transmitted to the four-quadrant frequency converter 2;

[0082] A second current transformer, the second current transformer is connected to the output end of the second isolating switch and is used to measure the first current value;

[0083] A second voltage transformer is connected to the output end of the second isolating switch and is used to measure the first voltage value.

[0084] In the utility model, the second high-voltage incoming line module 4 includes a second fuse, a second isolating switch, a second current transformer and a second voltage transformer, wherein the function of the second fuse is to actively disconnect when an overcurrent condition occurs in the circuit to protect the various electronic devices in the circuit, and the function of the second isolating switch is to be disconnected based on control so that the generator can receive the electric energy transmitted by the power grid and start and operate normally. In addition, the second isolating switch can also bear part of the current when an overcurrent condition occurs in the circuit to protect other electronic devices in the circuit. The second current transformer can accurately measure the first current value of the power grid, and the second voltage transformer can accurately measure the first voltage value of the power grid, which is convenient for the subsequent calculation of parameters such as the generator speed and torque.

[0085] As an optional embodiment, the switching module 3 includes:

[0086] A first switching switch, wherein the input end of the first switching module 3 is connected to the output end of the four-quadrant frequency converter 2, and the output end is connected to the motor, and is used to transmit the frequency-converted grid power to the motor when the first switching switch is closed;

[0087] The second switching switch, the input end of the second switching module 3 is connected to the output end of the four-quadrant inverter 2, and the output end is connected to the generator, and is used to transmit the grid power after frequency conversion to the generator when the second switching switch is closed.

[0088] In the utility model, the switching module 3 includes a first switching switch and a second switching switch. The function of the first switching switch is to connect or disconnect the power supply process between the four-quadrant inverter 2 and the motor, while the function of the second switching switch is to connect or disconnect the power supply process between the four-quadrant inverter 2 and the generator, which can accurately realize the switching process from motor start-up to generator start-up.

[0089] As an optional embodiment, the switching module 3 further includes:

[0090] a third switching switch, the input end of the switching switch is connected to the output end of the four-quadrant frequency converter 2, and the output end is connected to the input end of the first transformer 7, and is used to transmit the grid power after frequency conversion to the first transformer 7 when the third switching switch is closed;

[0091] The motor test device also includes:

[0092] A first transformer 7, the output end of which is connected to the generator, for converting the third voltage value of the grid electric energy after frequency conversion processing into a fourth voltage value;

[0093] The second transformer 8 is connected to the output end of the first high-voltage incoming line module 1, and the output end is connected to the motor, and is used to convert the first voltage value into a fifth voltage value.

[0094] In the utility model, a third switching switch is also provided in the switching module 3. The function of the third switching switch is to connect or disconnect the power supply process between the four-quadrant frequency converter 2 and the first transformer 7. The motor test device is also provided with a first transformer 7 and a second transformer 8. In order to meet the different voltage levels required by different generators, when the generator in the motor test is changed, it is necessary to introduce the first transformer 7 to convert the voltage of the electric energy output by the four-quadrant frequency converter 2 so that it meets the operation needs of the generator. When it is necessary to change the voltage value received by the motor, it is necessary to add the second transformer 8 to meet the test requirements of the motor under different voltage conditions, thereby improving the flexibility of the solution.

[0095] It should be noted that for motors of different voltage levels, the test requirements can be met by adding a second transformer 8. At this time, the motor test device only uses one four-quadrant inverter 2, which can widely meet the test requirements of industrial frequency motors of different voltages and powers.

[0096] It should also be noted that when the motor is an asynchronous motor, a first transformer 7 and a second transformer 8 need to be introduced. The test circuit is as follows: Figure 6 At this time, the capacity of the tested motor (electric motor) is equal to the capacity of the inverter.

[0097] It should also be noted that when the motor is a permanent magnet motor, a direct-connected test circuit is used, and there is no need to introduce the first transformer 7. Figure 7 At this time, when the rated voltage of the tested motor is lower than the rated voltage of the inverter, it needs to be operated at a reduced capacity. The structural diagram of the motor test device after adding the first transformer 7 and the second transformer 8 is as follows: Figure 8 shown.

[0098] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0099] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A motor test device, characterized in that: include: A first high-voltage incoming line module, wherein the input end of the first high-voltage incoming line module is connected to the power grid, and the output end is connected to the motor, and is used to control whether the power grid energy transmitted by the power grid is transmitted to the motor; A four-quadrant frequency converter, wherein the input end of the four-quadrant frequency converter is connected to the power grid, and the output end is connected to the input end of the switching module, and is used for performing corresponding frequency conversion processing on the power energy of the power grid; The switching module, the output end of the switching module is connected to the motor and the generator respectively, and is used to select the input end of the switching module to be connected to the motor or the generator.

2. The motor testing device according to claim 1, characterized in that: The first high-voltage incoming line module comprises: A first fuse, wherein an input end of the first fuse is connected to the power grid, an output end of the first fuse is connected to an input end of a first isolating switch, and is used for disconnecting when a current in the loop exceeds a first preset current threshold; The first isolating switch, wherein an output end of the first isolating switch is connected to the motor, is used to control whether the grid power is transmitted to the motor.

3. The motor testing device according to claim 2, characterized in that: The first high-voltage incoming line module further includes: A first current transformer, connected to an output end of the first isolating switch, and used to measure a first current value of the grid electric energy; A first voltage transformer is connected to an output end of the first isolating switch and is used to measure a first voltage value of the grid electric energy.

4. The motor testing device according to claim 1, characterized in that: The four-quadrant frequency converter comprises: A rectifier module, the input end of which is connected to the power grid and is used to convert the alternating current transmitted by the power grid into corresponding direct current; An inverter module, wherein the input end of the inverter module is connected to the output end of the rectifier module, and the output end is connected to the input end of the switching module, and is used to convert the direct current into a preset alternating current.

5. The motor testing device according to claim 4, characterized in that: The four-quadrant frequency converter further comprises: A filter module, wherein the input end of the filter module is connected to the output end of the rectifier module, and the output end is respectively connected to the input end of the inverter module, and is used to perform corresponding filtering on the direct current.

6. The motor testing device according to claim 3, characterized in that: Also includes: A second high-voltage incoming line module, the input end of the second high-voltage incoming line module is connected to the power grid, and the output end is connected to the input end of the four-quadrant inverter, and is used to control whether the power of the power grid is transmitted to the four-quadrant inverter.

7. The motor testing device according to claim 3, characterized in that: Also includes: a first measuring cabinet, wherein an input end of the first measuring cabinet is connected to an output end of the switching module, and an output end of the first measuring cabinet is connected to the motor, and is used to measure a second current value and a second voltage value received by the motor; A second measuring cabinet, wherein the input end of the second measuring cabinet is connected to the output end of the switching module, and the output end is connected to the generator, and is used to measure a third current value and a third voltage value received by the generator.

8. The motor testing device according to claim 6, characterized in that: The second high-voltage incoming line module comprises: A second fuse, wherein the input end of the second fuse is connected to the power grid, and the output end is connected to the input end of the second isolating switch, and is used for disconnecting when the current in the loop exceeds a second preset current threshold; The second isolating switch, the output end of the second isolating switch is connected to the input end of the four-quadrant frequency converter, and is used to control whether the grid power is transmitted to the four-quadrant frequency converter; a second current transformer, the second current transformer being connected to an output end of the second isolating switch and being used to measure the first current value; A second voltage transformer, wherein the second voltage transformer is connected to an output end of the second isolating switch and is used to measure the first voltage value.

9. The motor testing device according to claim 7, characterized in that: The switching module comprises: A first switching switch, wherein an input end of the first switching switch is connected to an output end of the four-quadrant frequency converter, and an output end of the first switching switch is connected to the motor, and is used for transmitting the grid power after the frequency conversion process to the motor when the first switching switch is closed; A second switching switch, wherein the input end of the second switching switch is connected to the output end of the four-quadrant inverter, and the output end is connected to the generator, and is used for transmitting the grid power after the frequency conversion processing to the generator when the second switching switch is closed.

10. The motor testing device according to claim 9, characterized in that: The switching module further includes: a third switching switch, the input end of which is connected to the output end of the four-quadrant frequency converter, and the output end of which is connected to the input end of the first transformer, for transmitting the grid power after the frequency conversion process to the first transformer when the third switching switch is closed; The motor testing device further comprises: The first transformer, the output end of which is connected to the generator, is used to convert the third voltage value of the grid electric energy after the frequency conversion process into a fourth voltage value; A second transformer, wherein the second transformer is connected to an output end of the first high-voltage incoming line module, and an output end is connected to the motor, and is used for converting the first voltage value into a fifth voltage value.

Images