A voltage conversion module for traction motor defect diagnosis

Abstract

The utility model relates to motor defect diagnosis technical field, concretely, relate to a voltage conversion module for traction motor defect diagnosis, including voltage conversion module, voltage conversion module includes two voltage detection circuits, two voltage detection circuits are used for detecting two line voltages respectively, voltage detection circuit includes voltage sampling unit, former stage amplification unit, multistage comparison unit and multistage amplification unit, two input ends of voltage sampling unit are connected respectively two phase lines in traction motor, two output ends of voltage sampling unit are connected respectively two input ends of former stage amplification unit, and former stage amplification unit output end simultaneously connects the input end of multistage comparison unit and multistage amplification unit. In the utility model, multistage comparison unit can be according to the voltage signal amplitude after former stage amplification, and the optimal amplification multiple of multistage amplification unit is judged and selected automatically, and the voltage detection precision under all working conditions is promoted.

Description

Technical Field

[0001] This utility model relates to the field of motor defect diagnosis technology, and more specifically, to a voltage conversion module for traction motor defect diagnosis. Background Technology

[0002] As the core power source in rail transit, heavy industrial drive and other fields, the operating status of the traction motor directly determines the safety, stability and efficiency of the entire system. Once the traction motor has defects such as winding short circuit, insulation aging, phase imbalance, etc., it will cause equipment shutdown at best and safety accidents at worst. Therefore, real-time and accurate defect diagnosis of the traction motor has extremely high engineering value.

[0003] A utility model patent with authorization announcement number CN219496499U discloses a bus voltage acquisition and monitoring circuit, including a main control chip, a step-down amplifier circuit for generating a small voltage signal, and a comparator circuit. The bus voltage input terminal is connected to the input terminal of the step-down amplifier circuit, the output terminal of the step-down amplifier circuit is connected to the main control chip, the comparator circuit is connected in parallel with the step-down amplifier circuit, and the output terminal of the comparator circuit is connected to the main control chip. The comparator circuit includes a first comparator, a second comparator, and a threshold resistor. One end of the threshold resistor is connected to the output terminal of the step-down amplifier circuit, the input terminals of the first comparator and the second comparator are respectively connected to the threshold resistor, and the output terminals of the first comparator and the second comparator are both connected to the main control chip.

[0004] Although this invention effectively prevents IGBTs from being damaged by excessive voltage during overvoltage, and the main control chip can perform corresponding compensation actions based on the fault notification software when the bus voltage is low and the motor stalls, and the voltage acquisition can also be used in the traction motor, the amplification factor is fixed. The operating conditions of the traction motor are complex, and the voltage fluctuation range between phases can reach tens to hundreds of volts. When the voltage is too high, it is easy to cause overload distortion of the downstream circuit. When the voltage is too low, the signal-to-noise ratio is insufficient, and the voltage detection accuracy cannot be guaranteed under all operating conditions. Utility Model Content

[0005] The purpose of this invention is to provide a voltage conversion module for traction motor defect diagnosis, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A voltage conversion module for traction motor defect diagnosis includes a voltage conversion module, characterized in that: the voltage conversion module includes two voltage detection circuits, which are used to detect the voltage of two lines respectively. The voltage detection circuit includes a voltage sampling unit, a pre-amplification unit, a multi-stage comparison unit, and a multi-stage amplification unit. The two input terminals of the voltage sampling unit are respectively connected to two phase lines of the traction motor, and the two output terminals of the voltage sampling unit are respectively connected to the two input terminals of the pre-amplification unit. The output terminal of the pre-amplification unit is simultaneously connected to the input terminals of the multi-stage comparison unit and the multi-stage amplification unit. The multi-stage comparison unit selects the amplification factor of the multi-stage amplification unit by judging the voltage magnitude.

[0007] Preferably, the system comprises a current detection module, a data acquisition module, a defect diagnosis module, a 4G wireless router, a cloud platform, and a ground server. The outputs of the multi-stage comparison unit and the multi-stage amplification unit are both connected to the data acquisition module. The current detection module, the data acquisition module, the defect diagnosis module, and the 4G wireless router are electrically connected in sequence. The 4G wireless router and the ground server are both communicatively connected to the cloud platform. The defect diagnosis module performs defect diagnosis based on its internal program.

[0008] Preferably, the data acquisition module includes a data processing chip, two voltage analog-to-digital converter chips and three current analog-to-digital converter chips. The two voltage analog-to-digital converter chips and the three current analog-to-digital converter chips are all connected to the data processing chip via signals. The data processing chip performs signal processing based on an internal program.

[0009] These two settings allow the device to simultaneously collect voltage and current data from the traction motor. Compared to detecting only a single voltage, this provides a more comprehensive reflection of the motor's operating status and reduces misjudgments or omissions due to insufficient data. Simultaneously, the data can be transmitted wirelessly to a cloud platform, allowing remote access to the data via relevant servers, enhancing diagnostic convenience. The chip configuration in the data acquisition section is tailored to the requirements of voltage and current detection, preventing interference between different signals and providing reliable digital signal support for subsequent data processing and defect assessment.

[0010] Preferably, the voltage sampling unit includes a resistor R1, a voltage transformer U1, a diode D1, a diode D2, and a resistor R2; The first terminal of resistor R1 and the second input terminal of voltage transformer U1 serve as the two input terminals of the voltage sampling unit. The second terminal of resistor R1 is connected to the first input terminal of voltage transformer U1. The positive terminal of diode D1 is connected to the second output terminal of voltage transformer U1, and the negative terminal of diode D1 is connected to the first output terminal of voltage transformer U1. The positive terminal of diode D2 is connected to the first output terminal of voltage transformer U1, and the negative terminal of diode D2 is connected to the second output terminal of voltage transformer U1. The first terminal of resistor R2 is connected to the first output terminal of voltage transformer U1, and the second terminal of resistor R2 is connected to the second output terminal of voltage transformer U1.

[0011] Preferably, the preamplifier unit includes capacitor C1, resistor R3, power supply VCC, resistor R4, resistor R5, resistor R6, capacitor C2, resistor R7, capacitor C3 and operational amplifier U2. The first terminal of capacitor C1 is connected to the first terminal of resistor R2. The second terminal of capacitor C1 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the inverting input terminal of operational amplifier U2. The first terminal of resistor R7 is connected to the inverting input terminal of operational amplifier U2. The second terminal of resistor R7 is connected to the output terminal of operational amplifier U2. The first terminal of capacitor C3 is connected to the first terminal of resistor R7. The second terminal of capacitor C3 is connected to the second terminal of resistor R7. The first terminal of resistor R4 is connected to power supply VCC. The second terminal of resistor R4 is connected to the first terminal of resistor R5. The second terminal of resistor R5 is grounded. The first terminal of resistor R6 is connected to the non-inverting input terminal of operational amplifier U2. The second terminal of resistor R6 is connected to the first terminal of capacitor C2. The second terminal of capacitor C2 is grounded. The non-inverting input terminal of operational amplifier U2 is also connected to the second terminal of resistor R2.

[0012] Preferably, the multi-stage comparison unit includes diode D3, capacitor C4, resistor R8, operational amplifier U3, and operational amplifier U4; The positive terminal of diode D3 is connected to the output terminal of operational amplifier U2, the negative terminal of diode D3 is connected to the first terminal of capacitor C4, the second terminal of capacitor C4 is grounded, the first terminal of resistor R8 is connected to the negative terminal of diode D3, the second terminal of resistor R8 is grounded, the non-inverting input terminal of operational amplifier U3 is connected to the negative terminal of diode D3, the inverting input terminal of operational amplifier U3 is connected to the threshold voltage V2, the non-inverting input terminal of operational amplifier U4 is connected to the negative terminal of diode D3, the inverting input terminal of operational amplifier U4 is connected to the threshold voltage V3, and the threshold voltages V2 and V3 have different values; The output terminals of operational amplifier U3 and operational amplifier U4 are respectively connected to different input ports of the data processing chip.

[0013] Preferably, the multi-stage amplification unit includes resistor R9, operational amplifier U5, resistor R10, switch S1, switch S2, resistor R11, resistor R12, resistor R13, resistor R14, relay KA1, transistor Q1, resistor R15, resistor R16, relay KA2, and transistor Q2, wherein transistors Q1 and Q2 are both NPN transistors; The first end of resistor R9 is connected to the output terminal of operational amplifier U2, the second end of resistor R9 is connected to the non-inverting input terminal of operational amplifier U5, the first end of resistor R10 is connected to the inverting input terminal of operational amplifier U5, the second end of resistor R10 is connected to the output terminal of operational amplifier U5, the first end of switch S1 is connected to the inverting input terminal of operational amplifier U5, the second end of switch S1 is connected to the first end of resistor R11, the second end of resistor R11 is grounded, the first end of switch S2 is connected to the inverting input terminal of operational amplifier U5, the second end of switch S2 is connected to the first end of resistor R12, the second end of resistor R12 is grounded, and the output terminal of operational amplifier U5 is connected to the input port of the voltage analog-to-digital converter chip. The first end of resistor R13 is connected to the output terminal of operational amplifier U3, the second end of resistor R13 is connected to the base of transistor Q1, the first end of resistor R14 is connected to the second end of resistor R13, the second end of resistor R14 is grounded, the first end of relay KA1 is connected to power supply VCC, the second end of relay KA1 is connected to the collector of transistor Q1, the emitter of transistor Q1 is grounded, and relay KA1 is used to control the closing of switch S1. The first terminal of resistor R15 is connected to the base of transistor Q2, and the second terminal of resistor R15 is connected to the output terminal of operational amplifier U4. The first terminal of resistor R16 is connected to the first terminal of resistor R15, and the second terminal of resistor R16 is grounded. The first terminal of relay KA2 is connected to the power supply VCC, and the second terminal of relay KA2 is connected to the collector of transistor Q2. The emitter of transistor Q2 is grounded. Relay KA2 is used to control the closing of switch S2.

[0014] Of these four settings, the voltage sampling section can safely convert the high voltage of the motor phase line to low voltage, and can also resist instantaneous large current and reverse voltage, protecting internal components and extending service life; the pre-amplification section can filter out useless interference signals and initially amplify the useful signals, providing a clear signal source for subsequent processing; the comparison section can accurately capture the maximum value of the signal, providing an accurate basis for selecting the amplification factor; the amplification section can automatically select an appropriate amplification factor according to the signal size, ensuring that high signals are not distorted by overload and low signals are clear, ensuring voltage detection accuracy under all operating conditions.

[0015] Preferably, the current detection module includes three current detection circuits, each including an electrically connected current transformer and a signal amplifier. The three current transformers are respectively mounted outside the three phase lines, and the signal amplifier is connected to the current analog-to-digital converter chip.

[0016] This setting allows the current detection section to simultaneously collect current data from the three-phase circuits of the motor. The three-phase current data can help determine whether the motor has problems such as phase imbalance or winding short circuit, avoiding missed defects due to incomplete current data, and providing comprehensive current parameter basis for motor defect diagnosis.

[0017] Compared with the prior art, the beneficial effects of this utility model are: In this invention, the multi-stage comparison unit can automatically determine and select the optimal amplification factor of the multi-stage amplification unit based on the amplitude of the voltage signal after amplification by the previous stage. When the voltage signal is small, a high-magnification resistor circuit is used to enhance the signal strength and improve the signal-to-noise ratio. When the voltage signal is large, it switches to a low-magnification circuit to avoid circuit overload distortion, so that the module can adapt to the wide voltage fluctuation range of the traction motor and improve the voltage detection accuracy under all working conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the utility model; Figure 2 This is a schematic diagram showing the connection between the voltage conversion module and the data acquisition module in the utility model. Figure 3 This is a circuit schematic diagram of the voltage sampling unit and the preamplifier unit in the utility model. Figure 4 This is a circuit schematic diagram of a multi-stage comparison unit in a utility model. Figure 5 This is a circuit diagram of a multi-stage amplification unit in a utility model. Figure 6 This is a schematic diagram showing the connection between the current detection module and the data acquisition module in the utility model. In the picture: 100. Voltage conversion module; 101. Voltage sampling unit; 102. Preamplifier unit; 103. Multi-stage comparator unit; 104. Multi-stage amplification unit; 200. Current detection module; 201. Current transformer; 202. Signal amplifier; 300. Data acquisition module; 301. Data processing chip; 302. Voltage analog-to-digital converter chip; 303. Current analog-to-digital converter chip; 400. Defect Diagnosis Module; 500, 4G wireless router; Cloud platform; 700. Ground server. Detailed Implementation

[0019] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Please see Figures 1-6 The present invention provides the following technical solution: A voltage conversion module for traction motor defect diagnosis includes a voltage conversion module 100, characterized in that: the voltage conversion module 100 includes two voltage detection circuits, which are used to detect the voltage of two lines respectively. The voltage detection circuit includes a voltage sampling unit 101, a pre-amplification unit 102, a multi-stage comparison unit 103, and a multi-stage amplification unit 104. The two input terminals of the voltage sampling unit 101 are respectively connected to two phase lines of the traction motor, and the two output terminals of the voltage sampling unit 101 are respectively connected to the two input terminals of the pre-amplification unit 102. The output terminal of the pre-amplification unit 102 is simultaneously connected to the input terminals of the multi-stage comparison unit 103 and the multi-stage amplification unit 104. The multi-stage comparison unit 103 selects the amplification factor of the multi-stage amplification unit 104 by judging the voltage magnitude. By using two independent voltage detection circuits, the voltage of two lines of the traction motor can be collected simultaneously, providing more comprehensive voltage data support for subsequent defect diagnosis and avoiding the limitations of single-channel voltage detection.

[0020] In this embodiment, please refer to Figure 1 , Figure 2 and Figure 6 It also includes a current detection module 200, a data acquisition module 300, a defect diagnosis module 400, a 4G wireless router 500, a cloud platform 600, and a ground server 700. The outputs of the multi-level comparison unit 103 and the multi-level amplification unit 104 are both connected to the data acquisition module 300. The current detection module 200, data acquisition module 300, defect diagnosis module 400, and 4G wireless router 500 are electrically connected in sequence. The 4G wireless router 500 and the ground server 700 are both communicatively connected to the cloud platform 600. The defect diagnosis module 400 performs defect diagnosis based on its internal program. The newly added current detection module 200 realizes the coordinated detection of voltage and current dual parameters. Compared with single voltage detection, it can more comprehensively reflect the motor's operating status and reduce the probability of false or missed defect detection. Through the combination of the 4G wireless router 500 and the cloud platform 600, remote real-time transmission of detection data is realized, avoiding the limitations of traditional local storage, and making it convenient for staff to remotely access the cloud platform 600 to view data through the ground server 700.

[0021] Specifically, the data acquisition module 300 includes a data processing chip 301, two voltage analog-to-digital converter chips 302 and three current analog-to-digital converter chips 303. The two voltage analog-to-digital converter chips 302 and the three current analog-to-digital converter chips 303 are all connected to the data processing chip 301 and are fully matched with the two voltage detection and three current detection, avoiding signal interference caused by single-chip multi-channel conversion and improving the accuracy of analog-to-digital conversion. The data processing chip 301 performs signal processing based on its internal program.

[0022] In this embodiment, please refer to Figures 1-5The voltage sampling unit 101 includes a resistor R1, a voltage transformer U1, a diode D1, a diode D2, and a resistor R2; The first terminal of resistor R1 and the second input terminal of voltage transformer U1 serve as the two input terminals of voltage sampling unit 101. The second terminal of resistor R1 is connected to the first input terminal of voltage transformer U1. The anode of diode D1 is connected to the second output terminal of voltage transformer U1, and the cathode of diode D1 is connected to the first output terminal of voltage transformer U1. The anode of diode D2 is connected to the first output terminal of voltage transformer U1, and the cathode of diode D2 is connected to the second output terminal of voltage transformer U1. The first terminal of resistor R2 is connected to the first output terminal of voltage transformer U1, and the second terminal of resistor R2 is connected to the second input terminal of voltage transformer U1. At the output end, the two voltage sampling units 101 can detect the voltage difference between phase U and phase V, and the voltage difference between phase V and phase W, respectively. Diodes D1 and D2 are used to protect the subsequent circuits. Resistor R1 plays a current limiting protection role, which can prevent the instantaneous large current in the traction motor phase line from damaging the voltage transformer U1 and extend the service life of the voltage sampling unit 101. The voltage transformer U1 can reduce the high voltage in the traction motor phase line to a low voltage that the subsequent circuit can withstand, avoiding the high voltage from directly entering the pre-amplification unit 102 and causing the components to burn out.

[0023] Specifically, the preamplifier unit 102 includes capacitor C1, resistor R3, power supply VCC, resistor R4, resistor R5, resistor R6, capacitor C2, resistor R7, capacitor C3 and operational amplifier U2. The first terminal of capacitor C1 is connected to the first terminal of resistor R2, the second terminal of capacitor C1 is connected to the first terminal of resistor R3, the second terminal of resistor R3 is connected to the inverting input terminal of operational amplifier U2, the first terminal of resistor R7 is connected to the inverting input terminal of operational amplifier U2, the second terminal of resistor R7 is connected to the output terminal of operational amplifier U2, the first terminal of capacitor C3 is connected to the first terminal of resistor R7, the second terminal of capacitor C3 is connected to the second terminal of resistor R7, the first terminal of resistor R4 is connected to power supply VCC, the second terminal of resistor R4 is connected to the first terminal of resistor R5, the second terminal of resistor R5 is grounded, the first terminal of resistor R6 is connected to the non-inverting input terminal of operational amplifier U2, the second terminal of resistor R6 is connected to the first terminal of capacitor C2, the second terminal of capacitor C2 is grounded, the non-inverting input terminal of operational amplifier U2 is also connected to the second terminal of resistor R2, capacitor C1 is used to block DC and pass AC, which can filter out the DC component in the output signal of voltage sampling unit 101 and avoid DC interference affecting the subsequent amplification effect. Operational amplifier U2 and its surrounding circuits constitute an inverting amplifier for preliminary amplification.

[0024] Furthermore, the multi-stage comparator unit 103 includes a diode D3, a capacitor C4, a resistor R8, an operational amplifier U3, and an operational amplifier U4; The positive terminal of diode D3 is connected to the output terminal of operational amplifier U2, and the negative terminal of diode D3 is connected to the first terminal of capacitor C4. The second terminal of capacitor C4 is grounded. The first terminal of resistor R8 is connected to the negative terminal of diode D3, and the second terminal of resistor R8 is grounded. The non-inverting input terminal of operational amplifier U3 is connected to the negative terminal of diode D3, and the inverting input terminal of operational amplifier U3 is connected to the threshold voltage V2. The non-inverting input terminal of operational amplifier U4 is connected to the negative terminal of diode D3, and the inverting input terminal of operational amplifier U4 is connected to the threshold voltage V3. The threshold voltages V2 and V3 have different values. The peak detection circuit composed of diode D3, capacitor C4, and resistor R8 can accurately extract the peak value of the output voltage signal of the preamplifier unit 102, ensuring that the multi-stage comparison unit 103 makes judgments based on the maximum amplitude of the signal, avoiding misjudgments caused by signal fluctuations. The output terminals of operational amplifier U3 and operational amplifier U4 are respectively connected to different input ports of data processing chip 301.

[0025] In addition, the multi-stage amplification unit 104 includes resistor R9, operational amplifier U5, resistor R10, switch S1, switch S2, resistor R11, resistor R12, resistor R13, resistor R14, relay KA1, transistor Q1, resistor R15, resistor R16, relay KA2, and transistor Q2. Transistors Q1 and Q2 are both NPN transistors. NPN transistors are turned on when their base is high and turned off when their base is low. The first terminal of resistor R9 is connected to the output terminal of operational amplifier U2, the second terminal of resistor R9 is connected to the non-inverting input terminal of operational amplifier U5, the first terminal of resistor R10 is connected to the inverting input terminal of operational amplifier U5, the second terminal of resistor R10 is connected to the output terminal of operational amplifier U5, the first terminal of switch S1 is connected to the inverting input terminal of operational amplifier U5, the second terminal of switch S1 is connected to the first terminal of resistor R11, the second terminal of resistor R11 is grounded, the first terminal of switch S2 is connected to the inverting input terminal of operational amplifier U5, the second terminal of switch S2 is connected to the first terminal of resistor R12, the second terminal of resistor R12 is grounded, and the output terminal of operational amplifier U5 is connected to the input port of voltage analog-to-digital converter chip 302. The first end of resistor R13 is connected to the output terminal of operational amplifier U3, the second end of resistor R13 is connected to the base of transistor Q1, the first end of resistor R14 is connected to the second end of resistor R13, the second end of resistor R14 is grounded, the first end of relay KA1 is connected to power supply VCC, the second end of relay KA1 is connected to the collector of transistor Q1, the emitter of transistor Q1 is grounded, and relay KA1 is used to control the closing of switch S1. Resistor R15 is connected to the base of transistor Q2 at its first end and to the output of operational amplifier U4 at its second end. Resistor R16 is connected to the first end of resistor R15 at its first end and to ground at its second end. Relay KA2 is connected to power supply VCC at its first end and to the collector of transistor Q2 at its second end. Transistor Q2's emitter is grounded. Relay KA2 is used to control the closing of switch S2, and its automatic switching of amplification factor ensures the accuracy of voltage signal amplification under all operating conditions.

[0026] In this embodiment, please refer to Figure 1 and Figure 6 The current detection module 200 includes three current detection circuits. Each current detection circuit includes an electrically connected current transformer 201 and a signal amplifier 202. The three current transformers 201 are respectively mounted outside the three phase lines. The signal amplifier 202 is connected to the current analog-to-digital converter chip 303 to provide complete current data for judging whether the motor has defects such as phase imbalance.

[0027] When the voltage conversion module for traction motor defect diagnosis of this utility model is in use, the two voltage sampling units 101 acquire two line voltages, and the other line voltage can be obtained by the internal program of the data processing chip 301. Then the pre-amplification unit 102 performs primary amplification. In the multi-stage comparator unit 103, diode D3, capacitor C4, and resistor R8 are used to obtain the peak value of the output signal V1 of the pre-amplifier unit 102. Operational amplifiers U3 and U4 both constitute voltage comparators, and the threshold voltages V2 and V3 are different; here, it is assumed that V2 is greater than V3. If V1 is greater than V2, then the output signal V4 of operational amplifier U3 is high, transistor Q1 is turned on, relay KA1 operates, and switch S1 is closed. The output signal V5 of operational amplifier U4 is high, transistor Q2 is turned on, relay KA2 operates, and switch S2 is closed. Operational amplifier U5 and its peripheral components constitute a proportional amplifier circuit. At this time, the output signal V6 of operational amplifier U5 is calculated by formula... If V1 is greater than V3 and less than V2, then the operational amplifier U3 output signal V4 is low, transistor Q1 is cut off, the operational amplifier U4 output signal V5 is high, transistor Q2 is turned on, relay KA2 operates, driving switch S2 to close. At this time, the operational amplifier U5 output signal V6 is determined by the formula... The amplification factor can be selected by different values ​​of V1. A voltage comparator and a feedback resistor can also be added to make the amplification factor more diverse. Alternatively, the output signal V1 can be directly obtained by the voltage analog-to-digital converter chip 302. The data processing chip 301 can simultaneously receive the output signal V5 of operational amplifier U4 and the output signal V4 of operational amplifier U3 to determine the amplification factor, which is convenient for data processing. Two voltage analog-to-digital converter chips 302 respectively receive the voltage signals output by two multi-stage amplification units 104 and convert the analog voltage signals into digital voltage signals. Three current analog-to-digital converter chips 303 respectively receive the current signals output by three signal amplifiers 202 and convert the analog current signals into digital current signals. The data processing chip 301 receives digital signals output by the voltage analog-to-digital converter chip 302 and the current analog-to-digital converter chip 303, and simultaneously acquires control signals transmitted by the multi-level comparison unit 103 to determine the voltage amplification factor; it performs filtering, amplification factor calibration and other processing on the digital signals through an internal preset program to obtain standardized voltage and current data, and then transmits the standardized data to the defect diagnosis module 400. The defect diagnosis module 400 receives standardized data transmitted by the data processing chip 301 and automatically determines whether the traction motor has defects and the type of defects based on internal preset programs (such as identifying abnormal currents corresponding to winding short circuits and voltage fluctuations corresponding to insulation aging). The 4G wireless router 500 receives the defect diagnosis results and raw test data and wirelessly transmits the data to the cloud platform 600 via the 4G network. The cloud platform 600 stores all the data transmitted by the 4G wireless router 500 and establishes a communication connection with the ground server 700. By accessing the ground server 700, staff can remotely view the traction motor operating data and defect diagnosis results stored in the cloud platform 600, realizing real-time monitoring and subsequent analysis of the motor's operating status.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A voltage conversion module for traction motor defect diagnosis, comprising a voltage conversion module (100), characterized in that: The voltage conversion module (100) includes two voltage detection circuits, which are used to detect the voltage of two lines respectively. The voltage detection circuit includes a voltage sampling unit (101), a preamplifier unit (102), a multi-stage comparison unit (103), and a multi-stage amplification unit (104). The two input terminals of the voltage sampling unit (101) are respectively connected to two phase lines of the traction motor. The two output terminals of the voltage sampling unit (101) are respectively connected to the two input terminals of the preamplifier unit (102). The output terminal of the preamplifier unit (102) is simultaneously connected to the input terminals of the multi-stage comparison unit (103) and the multi-stage amplification unit (104). The multi-stage comparison unit (103) selects the amplification factor of the multi-stage amplification unit (104) by judging the voltage magnitude.

2. The voltage conversion module for traction motor defect diagnosis according to claim 1, characterized in that: It also includes a current detection module (200), a data acquisition module (300), a defect diagnosis module (400), a 4G wireless router (500), a cloud platform (600), and a ground server (700). The output terminals of the multi-level comparison unit (103) and the multi-level amplification unit (104) are both connected to the data acquisition module (300). The current detection module (200), the data acquisition module (300), the defect diagnosis module (400), and the 4G wireless router (500) are electrically connected in sequence. The 4G wireless router (500) and the ground server (700) are both communicatively connected to the cloud platform (600).

3. The voltage conversion module for traction motor defect diagnosis according to claim 2, characterized in that: The data acquisition module (300) includes a data processing chip (301), two voltage analog-to-digital converter chips (302) and three current analog-to-digital converter chips (303), and the two voltage analog-to-digital converter chips (302) and the three current analog-to-digital converter chips (303) are all connected to the data processing chip (301) via signals.

4. The voltage conversion module for traction motor defect diagnosis according to claim 3, characterized in that: The voltage sampling unit (101) includes a resistor R1, a voltage transformer U1, a diode D1, a diode D2, and a resistor R2; The first terminal of resistor R1 and the second input terminal of voltage transformer U1 serve as the two input terminals of the voltage sampling unit (101). The second terminal of resistor R1 is connected to the first input terminal of voltage transformer U1. The positive terminal of diode D1 is connected to the second output terminal of voltage transformer U1, and the negative terminal of diode D1 is connected to the first output terminal of voltage transformer U1. The positive terminal of diode D2 is connected to the first output terminal of voltage transformer U1, and the negative terminal of diode D2 is connected to the second output terminal of voltage transformer U1. The first terminal of resistor R2 is connected to the first output terminal of voltage transformer U1, and the second terminal of resistor R2 is connected to the second output terminal of voltage transformer U1.

5. The voltage conversion module for traction motor defect diagnosis according to claim 4, characterized in that: The preamplifier unit (102) includes capacitor C1, resistor R3, power supply VCC, resistor R4, resistor R5, resistor R6, capacitor C2, resistor R7, capacitor C3 and operational amplifier U2. The first terminal of capacitor C1 is connected to the first terminal of resistor R2. The second terminal of capacitor C1 is connected to the first terminal of resistor R3. The second terminal of resistor R3 is connected to the inverting input terminal of operational amplifier U2. The first terminal of resistor R7 is connected to the inverting input terminal of operational amplifier U2. The second terminal of resistor R7 is connected to the output terminal of operational amplifier U2. The first terminal of capacitor C3 is connected to the first terminal of resistor R7. The second terminal of capacitor C3 is connected to the second terminal of resistor R7. The first terminal of resistor R4 is connected to power supply VCC. The second terminal of resistor R4 is connected to the first terminal of resistor R5. The second terminal of resistor R5 is grounded. The first terminal of resistor R6 is connected to the non-inverting input terminal of operational amplifier U2. The second terminal of resistor R6 is connected to the first terminal of capacitor C2. The second terminal of capacitor C2 is grounded. The non-inverting input terminal of operational amplifier U2 is also connected to the second terminal of resistor R2.

6. The voltage conversion module for traction motor defect diagnosis according to claim 5, characterized in that: The multi-stage comparison unit (103) includes diode D3, capacitor C4, resistor R8, operational amplifier U3 and operational amplifier U4; The positive terminal of diode D3 is connected to the output terminal of operational amplifier U2, the negative terminal of diode D3 is connected to the first terminal of capacitor C4, the second terminal of capacitor C4 is grounded, the first terminal of resistor R8 is connected to the negative terminal of diode D3, the second terminal of resistor R8 is grounded, the non-inverting input terminal of operational amplifier U3 is connected to the negative terminal of diode D3, the inverting input terminal of operational amplifier U3 is connected to the threshold voltage V2, the non-inverting input terminal of operational amplifier U4 is connected to the negative terminal of diode D3, the inverting input terminal of operational amplifier U4 is connected to the threshold voltage V3, and the threshold voltages V2 and V3 have different values; The output terminals of operational amplifier U3 and operational amplifier U4 are respectively connected to different input ports of the data processing chip (301).

7. The voltage conversion module for traction motor defect diagnosis according to claim 5, characterized in that: The multi-stage amplification unit (104) includes resistor R9, operational amplifier U5, resistor R10, switch S1, switch S2, resistor R11, resistor R12, resistor R13, resistor R14, relay KA1, transistor Q1, resistor R15, resistor R16, relay KA2 and transistor Q2, where transistors Q1 and Q2 are both NPN transistors; The first end of resistor R9 is connected to the output terminal of operational amplifier U2, the second end of resistor R9 is connected to the non-inverting input terminal of operational amplifier U5, the first end of resistor R10 is connected to the inverting input terminal of operational amplifier U5, the second end of resistor R10 is connected to the output terminal of operational amplifier U5, the first end of switch S1 is connected to the inverting input terminal of operational amplifier U5, the second end of switch S1 is connected to the first end of resistor R11, the second end of resistor R11 is grounded, the first end of switch S2 is connected to the inverting input terminal of operational amplifier U5, the second end of switch S2 is connected to the first end of resistor R12, the second end of resistor R12 is grounded, and the output terminal of operational amplifier U5 is connected to the input port of the voltage analog-to-digital converter chip (302). The first end of resistor R13 is connected to the output terminal of operational amplifier U3, the second end of resistor R13 is connected to the base of transistor Q1, the first end of resistor R14 is connected to the second end of resistor R13, the second end of resistor R14 is grounded, the first end of relay KA1 is connected to power supply VCC, the second end of relay KA1 is connected to the collector of transistor Q1, the emitter of transistor Q1 is grounded, and relay KA1 is used to control the closing of switch S1. The first terminal of resistor R15 is connected to the base of transistor Q2, and the second terminal of resistor R15 is connected to the output terminal of operational amplifier U4. The first terminal of resistor R16 is connected to the first terminal of resistor R15, and the second terminal of resistor R16 is grounded. The first terminal of relay KA2 is connected to the power supply VCC, and the second terminal of relay KA2 is connected to the collector of transistor Q2. The emitter of transistor Q2 is grounded. Relay KA2 is used to control the closing of switch S2.

8. The voltage conversion module for traction motor defect diagnosis according to claim 3, characterized in that: The current detection module (200) includes three current detection circuits. The current detection circuit includes an electrically connected current transformer (201) and a signal amplifier (202). The three current transformers (201) are respectively mounted outside the three phase lines. The signal amplifier (202) is connected to the current analog-to-digital converter chip (303).

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