Motor automatic monitoring device and motor automatic monitoring system

Abstract

The invention discloses a motor automatic monitoring device and a motor automatic monitoring system, and the device comprises an upper computer which is used for transmitting a control instruction; the lower computer is connected with the upper computer, the detection end of the lower computer is used for being connected with a three-phase coil of the motor, and the lower computer is used for measuring working current parameters and working resistance parameters of the three-phase coil of the motor according to the control instruction and outputting working parameter signals; and the upper computer is also used for receiving the working parameter signal, calculating the direct-current resistance and the insulation resistance of the three-phase coil of the motor according to the working parameter signal, generating a direct-current resistance and insulation resistance measurement report, and generating a three-phase voltage oscillogram according to the working parameter signal. The motor automatic monitoring device can integrate motor direct current resistance and insulation resistance testing functions, and is convenient to carry; and a direct current resistance and insulation resistance report of the motor is automatically generated.

Description

Technical Field

[0001] This invention relates to the field of electric motor monitoring technology, and in particular to an automatic electric motor monitoring device and an automatic electric motor monitoring system. Background Technology

[0002] During routine maintenance and repair of electric motors, it is essential to check and measure the DC resistance and insulation resistance of the three-phase stator coils to determine whether the three phases are balanced and whether there are short circuits between turns, as well as to check the phase-to-phase and phase-to-ground insulation conditions. The traditional method is to directly measure the DC resistance and insulation resistance (phase-to-phase and phase-to-ground) of the three-phase stator coils using a DC ohmmeter and an insulation resistance meter.

[0003] However, traditional methods have the following problems when inspecting and measuring motors during routine maintenance and repair: the three-phase stator coils of a three-phase motor need to be measured separately using a DC resistance meter or resistance box and an insulation meter. This requires carrying two instruments and meters on-site, and involves a lot of equipment and accessories, which is not conducive to on-site work. Furthermore, the measurement data needs to be recorded manually, which is prone to recording errors and human error, causing inconvenience to electrical testing work. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an automatic motor monitoring device and an automatic motor monitoring system, so that the automatic motor monitoring device can integrate the functions of testing the DC resistance and insulation resistance of the motor, making it easy to carry; and automatically generate reports on the DC resistance and insulation resistance of the motor.

[0005] The technical solution of the present invention is as follows: An automatic monitoring device for electric motors includes: The host computer is used to issue control commands; The lower-level machine is connected to the upper-level machine. The detection terminal of the lower-level machine is used to connect to the three-phase coil of the motor. The lower-level machine is used to measure the working current parameters and working resistance parameters of the three-phase coil of the motor according to the control command, and output the working parameter signal. The host computer is also used to receive the operating parameter signal, calculate the DC resistance and insulation resistance of the three-phase coil of the motor according to the operating parameter signal, generate a DC resistance and insulation resistance measurement report, and generate a three-phase voltage waveform diagram according to the operating parameter signal.

[0006] Optionally, the host computer includes: A processing unit, connected to the lower-level machine, is used to calculate the DC resistance and insulation resistance of the three-phase coils of the motor based on the operating parameter signals. The display unit is connected to the processing unit; the processing unit is used to control the display unit to display the operating parameter information of the three-phase coil of the motor and the three-phase voltage waveform diagram.

[0007] Optionally, the lower-level machine includes: Measurement channel; A switching module is located between the measurement channel and the three-phase coil of the motor; The control unit is connected to the host computer and also to the switching module. When the control unit receives the control command output by the host computer, it controls the switching module to conduct the electrical connection between the measurement channel and the three-phase coil of the motor. The measurement channel is used to measure and collect the operating current parameters and operating resistance parameters of the three-phase coils of the motor when the electrical connection between the two coils is made active, and outputs the operating parameter signals to the control unit.

[0008] Optionally, the measurement channels include a DC current measurement channel, a DC voltage measurement channel, an insulation voltage measurement channel, an insulation current measurement channel, a U-phase voltage measurement channel, a V-phase voltage measurement channel, and a W-phase voltage measurement channel; The DC current measurement channel and the DC voltage measurement channel are used to measure and acquire the DC current and the voltage across the three-phase coils of the motor, respectively; the insulation voltage measurement channel and the insulation current measurement channel are used to measure and acquire the insulation voltage and leakage current of the three-phase coils of the motor, respectively; the U-phase voltage measurement channel, the V-phase voltage measurement channel and the W-phase voltage measurement channel are used to measure and acquire the AC voltage across the coils of the U-phase, V-phase and W-phase coils of the motor, respectively.

[0009] Optionally, the control commands output by the host computer include DC resistance measurement commands and insulation resistance measurement commands, and the switching module includes a DC resistance measurement switching module and an insulation resistance measurement switching module; The control unit is used to control the electrical connection between the DC current measurement channel and the DC voltage measurement channel and the three-phase coil of the motor to be turned on when the DC resistance measurement command is received; The control unit is used to control the electrical connection between the insulation voltage measurement channel and the insulation current measurement channel and the three-phase coil of the motor when it receives the insulation resistance measurement command.

[0010] Optionally, the lower-level machine further includes: A constant current source is connected to the DC resistance measurement switching module. After receiving the DC resistance measurement command output by the control unit, the constant current source adjusts the magnitude of the output current and outputs it to the three-phase coil of the motor through the DC resistance measurement switching module. An insulation voltage regulating module is connected to the insulation resistance measurement switching module. After receiving the insulation resistance measurement command output by the control unit, the insulation voltage regulating module adjusts the output voltage to a preset voltage and outputs it to the three-phase coil of the motor through the insulation resistance measurement switching module.

[0011] Optionally, the lower-level machine further includes: An analog-to-digital converter module is provided, with its input terminal connected to the measurement channel and its output terminal connected to the control unit. The analog-to-digital converter module is used to convert the working parameter signal output from the measurement channel into an analog-to-digital signal and then output it to the control unit.

[0012] Optionally, the lower-level machine further includes: An isolation drive module, wherein the input terminal of the isolation drive module is connected to the control unit, and the output terminal of the isolation drive module is connected to the switching module; The control unit is used to control the switching module to work through the isolation drive module when it receives the control command output by the host computer.

[0013] Optionally, the lower-level machine further includes: A power supply unit, the output terminal of which is connected to the power supply terminal of the control unit, is used to provide operating power to the control unit.

[0014] The present invention also proposes an automatic motor monitoring system, including a motor and an automatic motor monitoring device as described above, wherein the motor is electrically connected to the automatic motor monitoring device.

[0015] This invention provides an automatic motor monitoring device comprised of a host computer and a slave device. The host computer issues control commands, while the slave device connects to it. The slave device's detection terminal connects to the motor's three-phase coils. The slave device measures the operating current and resistance parameters of the motor's three-phase coils according to the control commands from the host computer and outputs these parameters to the host computer. The host computer receives the output parameters from the slave device, calculates the DC resistance and insulation resistance of the motor's three-phase coils based on these parameters, and generates DC resistance and insulation resistance measurement reports, as well as a three-phase voltage waveform diagram. This integrated hardware design simplifies the automatic motor monitoring device, enabling both DC resistance and insulation resistance measurements without requiring instrument replacement, making it portable. Furthermore, it generates DC resistance and insulation resistance reports, as well as a three-phase voltage waveform diagram, solving the problem of inconvenient result retrieval. This allows for the tracking and management of measurement data during motor maintenance and repair, providing a more comprehensive assessment and analysis of motor performance, improving motor maintenance procedures, increasing work efficiency, and reducing recording errors associated with manual measurements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the functional modules of an embodiment of the automatic motor monitoring device of the present invention.

[0018] Figure 2 This is a schematic diagram of the functional modules of the host computer in an embodiment of the automatic motor monitoring device of the present invention.

[0019] Figure 3 This is a functional module schematic diagram of another embodiment of the automatic motor monitoring device of the present invention.

[0020] Figure 4 This is a functional module diagram of an embodiment of the switching module in the automatic motor monitoring device of the present invention.

[0021] Explanation of reference numerals in the attached diagram: 10, Control unit; 20, Measurement channel; 30, Switching module; 31, DC resistance measurement switching module; 32, Insulation resistance measurement switching module; 40, Constant current source; 50, Insulation voltage regulation module; 60, Isolation drive module; 70, Analog-to-digital conversion module; 80, Power supply unit; 100, Lower-level machine; 200, Upper-level machine; 210, Processing unit; 220, Display unit. Detailed Implementation

[0022] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0024] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0025] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0026] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0027] During routine maintenance and repair of electric motors, it is essential to check and measure the DC resistance and insulation resistance of the three-phase stator coils to determine whether the three phases are balanced and whether there are short circuits between turns, as well as to check the phase-to-phase and phase-to-ground insulation conditions. The traditional method is to directly measure the DC resistance and insulation resistance (phase-to-phase and phase-to-ground) of the three-phase stator coils using a DC ohmmeter and an insulation resistance meter.

[0028] However, traditional methods have the following problems when inspecting and measuring motors during routine maintenance and repair: the three-phase stator coils of a three-phase motor need to be measured separately using a DC resistance meter or resistance box and an insulation meter. This requires carrying two instruments and meters on-site, and involves a lot of equipment and accessories, which is not conducive to on-site work. Furthermore, the measurement data needs to be recorded manually, which is prone to recording errors and human error, causing inconvenience to electrical testing work.

[0029] To address the above problems, this invention proposes an automatic motor monitoring device.

[0030] Reference Figure 1 In one embodiment, the automatic motor monitoring device includes: The host computer 200 is used to issue control commands; The lower-level machine 100 is connected to the upper-level machine 200. The detection terminal of the lower-level machine 100 is used to connect to the three-phase coil of the motor. The lower-level machine 100 is used to measure the working current parameters and working resistance parameters of the three-phase coil of the motor according to the control command, and output the working parameter signal. The host computer 200 is also used to receive the operating parameter signal, calculate the DC resistance and insulation resistance of the three-phase coil of the motor according to the operating parameter signal, generate a DC resistance and insulation resistance measurement report, and generate a three-phase voltage waveform diagram according to the operating parameter signal.

[0031] In this embodiment, the host computer 200 can be a device such as a tablet computer, PAD, or laptop computer. The host computer 200 serves as a human-machine interface, manually or automatically issuing control commands to the slave computer 100 as needed during the measurement of the motor's DC resistance and insulation resistance. Manually issuing control commands can be achieved by setting control buttons on the host computer 200 and triggering these buttons to output control commands. Automatically issuing control commands can be achieved by setting an automatic control program in the host computer 200, which automatically executes after the host computer 200 starts, allowing it to issue control commands to the slave computer 100. The slave computer 100 can integrate multiple working modules. Its detection terminal is connected to the three-phase coils of the motor. The slave computer 100 can collect and measure the current and resistance parameters during the motor's operation and output the corresponding operating parameter signals to the host computer 200. After receiving the motor operating parameter signal output by the lower computer 100, the host computer 200 can automatically calculate the DC resistance and insulation resistance of the three-phase coils of the motor according to the motor operating parameter signal and the preset resistance calculation formula in the calculation module of the host computer 200, and generate measurement reports of the motor's DC resistance and insulation resistance. It can also generate a three-phase voltage trend chart or a three-phase voltage waveform chart based on the collected three-phase voltage of the motor for analyzing the three-phase sequence.

[0032] This invention provides an automatic motor monitoring device comprised of a host computer 200 and a slave computer 100. The host computer 200 issues control commands, while the slave computer 100 is connected to it. The slave computer 100's detection terminal connects to the motor's three-phase coils. The slave computer 100 measures the operating current and resistance parameters of the motor's three-phase coils according to the control commands from the host computer 200 and outputs these operating parameter signals to the host computer 200. The host computer 200 receives these operating parameter signals from the slave computer 100, calculates the DC resistance and insulation resistance of the motor's three-phase coils based on these signals, generates DC resistance and insulation resistance measurement reports, and generates a three-phase voltage waveform based on the operating parameter signals. This integrated hardware design simplifies the automatic motor monitoring device, enabling both DC resistance and insulation resistance measurements of the motor's three-phase coils without requiring replacement of measuring instruments, and is easily portable. Furthermore, it can generate reports on the DC resistance and insulation resistance of the motor, as well as three-phase voltage waveform diagrams, solving the problem of inconvenient result retrieval and enabling the tracking and management of measurement data during motor maintenance and repair. It can more comprehensively judge and analyze motor performance, improve motor repair projects, increase work efficiency, and reduce recording errors from manual measurements.

[0033] Reference Figure 2 In one embodiment, the host computer 200 includes: The processing unit 210 is connected to the lower-level machine 100. The processing unit 210 is used to calculate the DC resistance and insulation resistance of the three-phase coil of the motor according to the working parameter signal. The display unit 220 is connected to the processing unit 210; the processing unit 210 is used to control the display unit 220 to display the operating parameter information of the three-phase coil of the motor and the three-phase voltage waveform diagram.

[0034] In this embodiment, the processing unit 210 in the host computer 200 can receive, display, process, and store the working parameter signals uploaded by the slave computer 100. The processing unit 210 can also have a built-in resistance calculation module. Based on the stored working parameter signals and the preset resistance calculation formula within the module, it automatically calculates the DC resistance and insulation resistance of the motor's three-phase coils, and simultaneously generates a measurement report of the motor's DC resistance and insulation resistance. The display unit 220 can be a display screen. After the processing unit 210 calculates the DC resistance and insulation resistance of the motor's three-phase coils, it can control the display unit 220 to display the information, which can be displayed through text or images. Furthermore, the processing unit 210 can also control the display unit 220 to display the three-phase voltage waveforms of the motor's three-phase coils for user observation.

[0035] Reference Figure 3 In one embodiment, the lower-level machine 100 includes: Measurement channel 20; The switching module 30 is located between the measurement channel 20 and the three-phase coil of the motor; The control unit 10 is connected to the host computer 200 and the switching module 30. When the control unit 10 receives the control command output by the host computer 200, it controls the switching module 30 to conduct the electrical connection between the measurement channel 20 and the three-phase coil of the motor. The measurement channel 20 is used to measure and collect the operating current parameters and operating resistance parameters of the three-phase coils of the motor when the electrical connection between the two coils is made, and output the operating parameter signals to the control unit 10.

[0036] In this embodiment, the measurement channel 20 can be composed of multiple acquisition devices, such as resistors. The measurement channel 20 can measure and acquire the operating current and resistance parameters of the three-phase coils of the motor, and output the operating parameter signals to the control unit 10. The control unit 10 can be composed of a digital signal processor (DSP), a programmable logic device (PLD), a field-programmable gate array (FPGA), a microprocessor, an MCU, or other electronic components. Furthermore, this embodiment includes a switching module 30 between the measurement channel 20 and the three-phase coils of the motor, which can control the electrical connection between the measurement channel 20 and the three-phase coils of the motor to be turned on or off. This allows control over whether the measurement channel 20 acquires and measures the operating current and resistance parameters of the three-phase coils of the motor.

[0037] Reference Figure 3 In one embodiment, the lower-level machine 100 further includes: A constant current source 40 is connected to the DC resistance measurement switching module 31. After receiving the DC resistance measurement command output by the control unit 10, the constant current source 40 adjusts the magnitude of the output current and outputs it to the three-phase coil of the motor through the DC resistance measurement switching module 31. The insulation voltage regulating module 50 is connected to the insulation resistance measurement switching module 32. After receiving the insulation resistance measurement command output by the control unit 10, the insulation voltage regulating module 50 adjusts the output voltage to the preset voltage and outputs it to the three-phase coil of the motor through the insulation resistance measurement switching module 32.

[0038] In this embodiment, the output port of the constant current source 40 is connected to the input port of the constant current source 40 of the DC resistance measurement switching module 31. In actual operation, after receiving the DC resistance measurement command from the control unit 10, the constant current source 40 automatically adjusts its output current and applies it to the three-phase coils of the motor through the DC resistance measurement switching module 31, providing a current source for DC resistance measurement. The output port of the insulation voltage regulating module 50 is connected to the insulation voltage input port of the insulation resistance measurement switching module 32. After receiving the insulation resistance measurement command from the control unit 10, the insulation voltage regulating module 50 adjusts its output voltage to the corresponding voltage and applies it to the three-phase coils of the motor through the insulation resistance measurement switching module 32, providing a voltage source for insulation resistance measurement.

[0039] In one embodiment, the measurement channel 20 includes a DC current measurement channel, a DC voltage measurement channel, an insulation voltage measurement channel, an insulation current measurement channel, a U-phase voltage measurement channel, a V-phase voltage measurement channel, and a W-phase voltage measurement channel; The DC current measurement channel and the DC voltage measurement channel are used to measure and acquire the DC current and the voltage across the three-phase coils of the motor, respectively; the insulation voltage measurement channel and the insulation current measurement channel are used to measure and acquire the insulation voltage and leakage current of the three-phase coils of the motor, respectively; the U-phase voltage measurement channel, the V-phase voltage measurement channel and the W-phase voltage measurement channel are used to measure and acquire the AC voltage across the coils of the U-phase, V-phase and W-phase coils of the motor, respectively.

[0040] For the specific structure of the switching module, please refer to Figure 4 The settings include K1, K2, K3, K4, and K5, which are controllable switches. The DC resistance measurement channel includes a DC current measurement channel and a DC voltage measurement channel; the insulation resistance measurement channel includes an insulation voltage measurement channel and an insulation current measurement channel. By controlling the on / off state of the controllable switches, the connection between the three-phase coil and the DC resistance measurement channel and the insulation resistance measurement channel can be controlled.

[0041] Furthermore, referring to Figure 3 In one embodiment, the control commands output by the host computer 200 include DC resistance measurement commands and insulation resistance measurement commands, and the switching module 30 includes a DC resistance measurement switching module 31 and an insulation resistance measurement switching module 32. The control unit 10 is used to control the electrical connection between the DC current measurement channel and the DC voltage measurement channel and the three-phase coil of the motor to be turned on when the DC resistance measurement command is received; The control unit 10 is used to control the electrical connection between the insulation voltage measurement channel and the insulation current measurement channel and the three-phase coil of the motor when it receives the insulation resistance measurement command.

[0042] The lower-level machine 100 also includes: An isolation drive module 60 is provided, the input of which is connected to the control unit 10, and the output of which is connected to the switching module 30. The control unit 10 is used to control the switching module 30 to work through the isolation drive module 60 when it receives the control command output by the host computer 200.

[0043] In this embodiment, the output terminal of the isolation drive module 60 is connected to the control command port of the switching module 30; the input terminal of the switching module 30 is connected to the three-phase coils of the motor. In actual operation, the host computer 200 issues corresponding control commands, which, through the control unit 10 and the isolation drive module 60, control the switching module 30 to connect the three-phase coils of the motor to the corresponding measurement channel 20, the output port of the constant current source 40, and the output port of the insulation voltage regulating module 50. The insulation voltage regulating module 50 outputs the corresponding insulation measurement voltage, and the constant current source 40 outputs the corresponding DC constant current to complete the measurement and acquisition of motor data. Furthermore, the DC resistance of the motor coils is measured using DC current and DC voltage, and the insulation resistance of the motor coils is measured using insulation voltage and insulation current. Measurement data trend graphs or waveform graphs are generated using U-phase voltage, V-phase voltage, and W-phase voltage to analyze the three-phase sequence. With the switching module 30, the automatic motor monitoring device in this solution only needs to connect the three-phase coils of the motor once, without needing to change the motor coil wiring, simplifying the workflow.

[0044] In addition, this solution can also include a phase sequence monitoring module. During monitoring, an induced electromotive force is generated in the three-phase coils of the motor via a disc shaft. The phase sequence of the induced electromotive force in the three-phase coils is measured, and the phase sequence of the three-phase coils is monitored. In this way, by measuring the phase sequence of the motor in an offline state, the purpose of motor phase verification can be achieved, avoiding the phenomenon of motor reversal after on-site installation.

[0045] Reference Figure 3 In one embodiment, the lower-level machine 100 further includes: An analog-to-digital converter module 70 is provided, with its input terminal connected to the measurement channel 20 and its output terminal connected to the control unit 10. The analog-to-digital converter module 70 is used to convert the working parameter signal output from the measurement channel 20 into an analog-to-digital signal and then output it to the control unit 10.

[0046] In this embodiment, the analog input port of the analog-to-digital conversion module 70 (AD conversion module) is connected to the output port of the measurement channel 20. The analog-to-digital conversion module 70 can convert the electrical signal output by the measurement channel 20 into a corresponding digital signal and output it to the control unit 10, thereby facilitating the control unit 10 to upload it to the host computer 200.

[0047] Reference Figure 3 In one embodiment, the lower-level machine 100 further includes: A power supply unit 80 is provided, the output terminal of which is connected to the power supply terminal of the control unit 10. The power supply unit 80 is used to provide operating power to the control unit 10.

[0048] In this embodiment, the power supply unit 80 can be implemented using a DC-DC circuit. The power supply unit 80 can connect a 220V, 50Hz AC power supply to the lower-level machine 100 via a power adapter, and then convert it to a suitable operating voltage for the control unit 10. This prevents the control unit 10 from receiving a high operating voltage that could damage the device, or from receiving a low operating voltage that could prevent the control unit 10 from operating normally. In this embodiment, a power switch can also be provided. The power supply unit 80 is connected to the control unit 10, the analog-to-digital converter module 70, the isolation voltage regulator module 50, the isolation drive module 60, and the constant current source 40 via the power switch, providing operating power to the above modules and circuits.

[0049] The present invention also proposes an automatic motor monitoring system, including a motor and the automatic motor monitoring device described above, wherein the motor is electrically connected to the automatic motor monitoring device. It is understood that, since the automatic motor monitoring device described above is used in the automatic motor monitoring system of the present invention, the embodiments of the automatic motor monitoring system of the present invention include all the technical solutions of all embodiments of the automatic motor monitoring device described above, and the achieved technical effects are exactly the same, and will not be repeated here.

[0050] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An automatic monitoring device for electric motors, characterized in that, include: The host computer is used to issue control commands; The lower-level machine is connected to the upper-level machine. The detection terminal of the lower-level machine is used to connect to the three-phase coil of the motor. The lower-level machine is used to measure the working current parameters and working resistance parameters of the three-phase coil of the motor according to the control command, and output the working parameter signal. The host computer is also used to receive the operating parameter signal, calculate the DC resistance and insulation resistance of the three-phase coil of the motor according to the operating parameter signal, generate a DC resistance and insulation resistance measurement report, and generate a three-phase voltage waveform diagram according to the operating parameter signal.

2. The automatic motor monitoring device as described in claim 1, characterized in that, The host computer includes: A processing unit, connected to the lower-level machine, is used to calculate the DC resistance and insulation resistance of the three-phase coils of the motor based on the operating parameter signals. The display unit is connected to the processing unit; the processing unit is used to control the display unit to display the operating parameter information of the three-phase coil of the motor and the three-phase voltage waveform diagram.

3. The automatic motor monitoring device as described in claim 2, characterized in that, The lower-level machine includes: Measurement channel; A switching module is located between the measurement channel and the three-phase coil of the motor; The control unit is connected to the host computer and also to the switching module. When the control unit receives the control command output by the host computer, it controls the switching module to conduct the electrical connection between the measurement channel and the three-phase coil of the motor. The measurement channel is used to measure and collect the operating current parameters and operating resistance parameters of the three-phase coils of the motor when the electrical connection between the two coils is made active, and outputs the operating parameter signals to the control unit.

4. The automatic motor monitoring device as described in claim 3, characterized in that, The measurement channels include a DC current measurement channel, a DC voltage measurement channel, an insulation voltage measurement channel, an insulation current measurement channel, a U-phase voltage measurement channel, a V-phase voltage measurement channel, and a W-phase voltage measurement channel; The DC current measurement channel and the DC voltage measurement channel are used to measure and acquire the DC current and the voltage across the three-phase coils of the motor, respectively; the insulation voltage measurement channel and the insulation current measurement channel are used to measure and acquire the insulation voltage and leakage current of the three-phase coils of the motor, respectively; the U-phase voltage measurement channel, the V-phase voltage measurement channel and the W-phase voltage measurement channel are used to measure and acquire the AC voltage across the coils of the U-phase, V-phase and W-phase coils of the motor, respectively.

5. The automatic motor monitoring device as described in claim 4, characterized in that, The control commands output by the host computer include DC resistance measurement commands and insulation resistance measurement commands, and the switching module includes a DC resistance measurement switching module and an insulation resistance measurement switching module. The control unit is used to control the electrical connection between the DC current measurement channel and the DC voltage measurement channel and the three-phase coil of the motor to be turned on when the DC resistance measurement command is received; The control unit is used to control the electrical connection between the insulation voltage measurement channel and the insulation current measurement channel and the three-phase coil of the motor when it receives the insulation resistance measurement command.

6. The automatic motor monitoring device as described in claim 5, characterized in that, The lower-level machine also includes: A constant current source is connected to the DC resistance measurement switching module. After receiving the DC resistance measurement command output by the control unit, the constant current source adjusts the magnitude of the output current and outputs it to the three-phase coil of the motor through the DC resistance measurement switching module. An insulation voltage regulating module is connected to the insulation resistance measurement switching module. After receiving the insulation resistance measurement command output by the control unit, the insulation voltage regulating module adjusts the output voltage to a preset voltage and outputs it to the three-phase coil of the motor through the insulation resistance measurement switching module.

7. The automatic motor monitoring device as described in claim 3, characterized in that, The lower-level machine also includes: An analog-to-digital converter module is provided, with its input terminal connected to the measurement channel and its output terminal connected to the control unit. The analog-to-digital converter module is used to convert the working parameter signal output from the measurement channel into an analog-to-digital signal and then output it to the control unit.

8. The automatic motor monitoring device as described in claim 3, characterized in that, The lower-level machine also includes: An isolation drive module, wherein the input terminal of the isolation drive module is connected to the control unit, and the output terminal of the isolation drive module is connected to the switching module; The control unit is used to control the switching module to work through the isolation drive module when it receives the control command output by the host computer.

9. The automatic motor monitoring device as described in claim 3, characterized in that, The lower-level machine also includes: A power supply unit, the output terminal of which is connected to the power supply terminal of the control unit, is used to provide operating power to the control unit.

10. An automatic monitoring system for electric motors, characterized in that, It includes an electric motor and an automatic electric motor monitoring device as described in any one of claims 1-9, wherein the electric motor is electrically connected to the automatic electric motor monitoring device.

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