A frequency converter testing device and system

Abstract

The utility model discloses a kind of frequency converter testing device and system, device includes: power module, with the frequency converter to be tested connection, for power supply to frequency converter;Adjusting module is connected with the control loop of frequency converter, for triggering frequency converter test operation;Display module is connected with the outgoing line side of frequency converter, for the waveform of the output electric signal of outgoing line side;Judgment module, judgment module is connected with display module and / or judgment module is connected with outgoing line side, for in the case where output electric signal meets preset standard state, output normal signal.Visible, replace traditional high-voltage power supply by power module, avoid the damage risk possibly caused by directly accessing high-voltage loop.By adjusting module triggers frequency converter normal operation in low-voltage environment, output normal operating condition corresponding output electric signal, and according to display module and judgment module to output electric signal is shown analysis, significantly reduce the security risk in frequency converter testing process.

Description

TECHNICAL FIELD

[0001] The utility model relates to frequency converter test technical field especially relates to a frequency converter testing device and system. BACKGROUND

[0002] As the key link of motor stable operation, the stability and reliability of frequency converter performance is very important.

[0003] When the frequency converter is damaged due to failure, the repaired frequency converter is directly connected to the main loop power supply for operation, which not only has the risk of blowing the machine, but also may cause harm to personnel. Similarly, before the frequency converter is connected to the main loop power supply, the repaired frequency converter needs to be tested, and there is also the risk of blowing the machine and safety problems in the testing process. Therefore, how to safely test the frequency converter is a technical problem that needs to be solved at present. SUMMARY

[0004] The embodiment of the application provides a frequency converter testing device and system, which solves the technical problem of dangerous frequency converter testing in the prior art and achieves the technical effect of safely testing the frequency converter.

[0005] In a first aspect, the application provides a frequency converter testing device, which comprises:

[0006] A power module is connected to the frequency converter to be tested, and the power module is used to supply power to the frequency converter.

[0007] An adjustment module is connected to the control loop of the frequency converter, and the adjustment module is used to trigger the frequency converter testing operation.

[0008] A display module is connected to the output side of the frequency converter, and the display module is used to display the waveform of the output electrical signal of the output side.

[0009] A judgment module is connected to the display module and / or the output side, and the judgment module is used to output a normal signal when the output electrical signal meets the preset standard state.

[0010] In some embodiments of the application, based on the foregoing scheme, the power module comprises:

[0011] A first power module is connected to the control loop.

[0012] A second power module is connected to the DC loop of the frequency converter.

[0013] In some embodiments of the application, based on the foregoing scheme, the adjustment module comprises:

[0014] A chip assembly is provided with a pull-up resistor at the output end of the chip assembly.

[0015] a buffer, an input end of the buffer being connected with an output end of the chip assembly;

[0016] an optical fiber transmitter, an output end of the optical fiber transmitter being connected with an input end of the photoelectric converter in the control loop;

[0017] a current-limiting resistor, one end of the current-limiting resistor being connected with an output end of the buffer, and the other end of the current-limiting resistor being connected with an input end of the optical fiber transmitter.

[0018] In some embodiments of the present application, based on the foregoing scheme, the output end of the chip assembly comprises at least one chip output port, each chip output port being connected in parallel with a corresponding pull-up resistor, and each chip output port being connected to the input end of the buffer.

[0019] In some embodiments of the present application, based on the foregoing scheme, the output end of the buffer comprises at least one buffer output port, the buffer output port corresponding to the chip output port one by one, and each buffer output port being connected to the input end of the optical fiber transmitter through a corresponding current-limiting resistor.

[0020] In some embodiments of the present application, based on the foregoing scheme, the adjusting module comprises at least one optical fiber transmitter, the optical fiber transmitter corresponding to the buffer output port one by one, and the output end of each optical fiber transmitter being connected with the input end of the photoelectric converter.

[0021] In some embodiments of the present application, based on the foregoing scheme, the output end of the chip assembly outputs a three-phase PWM pulse signal, and the output end of the buffer outputs a three-phase PWM pulse signal.

[0022] In some embodiments of the present application, based on the foregoing scheme, the adjusting module further comprises:

[0023] a voltage adjusting assembly, configured to convert the received alternating voltage into direct voltage, and an output end of the voltage adjusting assembly being connected with an input end of the chip assembly.

[0024] In some embodiments of the present application, based on the foregoing scheme, the output electrical signal comprises:

[0025] a first output electrical signal between the outgoing side U phase and the V phase;

[0026] a second output electrical signal between the outgoing side V phase and the W phase;

[0027] a third output electrical signal between the outgoing side W phase and the U phase.

[0028] In a second aspect, the present application provides a frequency converter testing system, comprising the frequency converter testing device provided in the first aspect.

[0029] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0030] The embodiment of the present application provides a frequency converter testing device, comprising: a power module connected with a frequency converter to be tested, the power module being used for supplying power to the frequency converter; an adjusting module connected with a control loop of the frequency converter, the adjusting module being used for triggering the frequency converter to test run; a display module connected with an outgoing line side of the frequency converter, the display module being used for displaying a waveform of an output electrical signal of the outgoing line side; and a judging module connected with the display module and / or connected with the outgoing line side, the judging module being used for outputting a normal signal in a case where the output electrical signal meets a preset standard state.

[0031] It can be seen that, by replacing the traditional high-voltage power supply with the power module, the damage risk caused by directly connecting to the high-voltage loop is avoided, and at the same time, low-voltage direct current is provided for safe operation of the frequency converter. The adjusting module triggers the frequency converter to run normally in a low-voltage environment, outputs the output electrical signal corresponding to the normal working condition, and displays and analyzes the output electrical signal according to the display module and the judging module, so that the frequency converter fault or unstable performance can be found in time, the objectivity and accuracy of fault diagnosis are significantly improved, the safety risk in the frequency converter testing process is reduced, and the reliability and operation safety of equipment detection are improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 A structural principle schematic diagram of a frequency converter testing device provided in the embodiments of the present application is shown in the figure.

[0034] Figure 2 A structural principle schematic diagram of an adjusting module provided in the embodiments of the present application is shown in the figure.

[0035] In the above figure: 101, first power module; 102, second power module; 2, adjusting module; 201, voltage adjusting assembly; 202, chip assembly; 203, buffer; 3, display module; 4, judging module; 5, frequency converter; 501, photoelectric converter. DETAILED DESCRIPTION

[0036] The embodiments of the present application provide a frequency converter testing device, which solves the technical problem that the frequency converter testing in the prior art is dangerous.

[0037] The technical solutions of the embodiments of the present application are to solve the above technical problems, and the general idea is as follows:

[0038] The embodiment of the present application provides a frequency converter testing device, comprising: a power supply module connected with a frequency converter to be tested, the power supply module being used for supplying power to the frequency converter; an adjustment module connected with a control loop of the frequency converter, the adjustment module being used for triggering the frequency converter to test run; a display module connected with an outgoing line side of the frequency converter, the display module being used for displaying the waveform of an output electrical signal of the outgoing line side; and a judgment module connected with the display module and / or connected with the outgoing line side, the judgment module being used for outputting a normal signal in the case that the output electrical signal meets a preset standard state.

[0039] It can be seen that, by replacing the traditional high-voltage power supply with the power supply module, the risk of damage caused by direct access to the high-voltage loop is avoided, and at the same time, low-voltage direct current is provided for the safe operation of the frequency converter. By triggering the frequency converter to run normally in a low-voltage environment through the adjustment module, the output electrical signal corresponding to the normal working condition is output, and the output electrical signal is displayed and analyzed according to the display module and the judgment module, so that the frequency converter fault or unstable performance can be found in time, the objectivity and accuracy of fault diagnosis are significantly improved, the safety risk in the frequency converter testing process is reduced, and the reliability and operation safety of equipment detection are improved.

[0040] In order to better understand the above technical solutions, the above technical solutions will be described in detail in combination with the drawings of the specification and specific embodiments.

[0041] First of all, the term "and / or" appearing in this paper is only to describe the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects.

[0042] As the core equipment of modern industrial motor control system, the stability and reliability of the frequency converter are directly related to the efficient operation of the production equipment and the energy utilization efficiency. In industrial production, the frequency converter adjusts the power frequency and voltage of the motor to realize precise control of the motor speed and torque, and is widely used in key fields such as fans, pumps, compressors and conveying equipment, and plays an irreplaceable role in energy saving and process optimization.

[0043] However, with the increase of the complexity of industrial equipment and the harshness of the operating environment, the frequency converter is under multiple pressures such as high load, high frequency start-stop and electromagnetic interference for a long time, and the internal power devices (such as IGBT modules), capacitors, drive circuits and other key components are prone to aging, breakdown or logic failure, resulting in equipment downtime and even causing chain production accidents.

[0044] When the frequency converter is repaired due to failure, how to safely and effectively verify the repair effect becomes an industry problem. The traditional method usually directly connects the repaired frequency converter to the main circuit power supply for full load test, but this method has significant risks: the instantaneous impact of high-voltage power grid (such as 380V AC or higher) may cause secondary damage to the internal components of the frequency converter that is not completely repaired, which may cause IGBT module burst, capacitor burst, and other "machine explosion" accidents, or even cause fire or arc discharge due to short circuit, which poses a serious threat to the safety of operating personnel.

[0045] To solve the above problems, the embodiment of the present application provides a frequency converter testing device, as shown in Figure 1 The structure principle schematic diagram of the frequency converter testing device provided by the embodiment of the present application, including: power supply module, adjustment module 2, display module 3 and judgment module 4. It should be noted that, Figure 1 The right side of the frequency converter 5 is the outgoing line side, and the judgment module 4 and the display module 3 are connected with the outgoing line side of the frequency converter 5.

[0046] The power supply module is connected with the incoming line side of the frequency converter 5 to be tested, and is used to supply power to the frequency converter 5. The power supply module includes a first power supply module 101 and a second power supply module 102.

[0047] Among them, the first power supply module 101 is connected with the control circuit of the frequency converter 5 to supply power for the control circuit. The control circuit includes the control circuit components in the control board card, the pulse board card and the trigger board inside the frequency converter 5. The first power supply module 101 usually provides low-voltage direct current (such as 5V, 12V, 24V) to provide working power for the digital logic circuit and signal processing components in the control circuit.

[0048] The second power supply module 102 is connected with the direct current circuit of the frequency converter 5 to supply power for the direct current circuit. The direct current circuit refers to the circuit connected with the direct current bus of the frequency converter 5, and the second power supply module 102 is used to simulate the direct current bus voltage under normal operating state, but the provided voltage is reduced to a safe range (such as 24V, 48V). During use, the input voltage output from the second power supply module 102 to the frequency converter 5 is adjusted to simulate the running condition of the frequency converter 5 under different scenes, so as to realize the safe test of the frequency converter.

[0049] The adjustment module 2 is connected with the control circuit of the frequency converter 5, and the adjustment module 2 is used to trigger the test running of the frequency converter 5. Specifically, the adjustment module 2 generates and transmits three-phase PWM signals to accurately control the frequency converter 5 to drive output three-phase alternating current voltage under normal operating state.

[0050] As shown in Figure 2As shown, it is a structural principle schematic diagram of the adjustment module 2 provided by the embodiment of the application, the adjustment module 2 comprises a voltage adjustment assembly 201, a chip assembly 202, a buffer 203 and a fiber transmitter D1 connected in sequence.

[0051] The input end of the voltage adjustment assembly 201 is connected to 220V mains for converting the received AC 220V mains (alternating voltage) into direct current voltage (such as 12V or 24V), and the output end of the voltage adjustment assembly 201 is connected to the input end of the chip assembly 202.

[0052] After receiving the direct current voltage output by the voltage adjustment assembly 201, the chip assembly 202 generates a three-phase PWM pulse signal, which is used to control the switching timing of the inverter in the control loop of the frequency converter 5, so that the frequency converter 5 is in a test running state, which matches the normal running state of the frequency converter.

[0053] The input end of the buffer 203 is connected to the output end of the chip assembly 202, and the buffer 203 is used to enhance the driving capability of the three-phase PWM pulse signal and provide high-low voltage circuit isolation. For example, the weak signal (such as 5mA) output by the chip assembly 202 is amplified to a current signal (such as 20mA) that can drive the fiber transmitter D1.

[0054] A pull-up resistor R1 is also connected in parallel between the output end of the chip assembly 202 and the input end of the buffer 203, and the other end of the pull-up resistor R1 is connected to a power supply VCC1, so that when the chip assembly 202 outputs a high impedance state, the signal is pulled to a high level, preventing suspended interference, stabilizing the logic level and enhancing the signal noise immunity.

[0055] The output end of the fiber transmitter D1 is connected to the input end of the photoelectric converter 501 in the control loop. The PWM pulse signal after buffering and isolation is converted into an optical signal by the fiber transmitter D1 and output to the photoelectric converter 501 in the frequency converter 5. The photoelectric converter 501 restores the optical signal to an electrical signal and outputs it to the inverter in the frequency converter 5, so that the three-phase bridge arms in the inverter are alternately turned on to output the three-phase alternating voltage in the normal running state of the frequency converter 5.

[0056] Further, the adjustment module 2 also comprises a current limiting resistor R2. One end of the current limiting resistor R2 is connected to the output end of the buffer 203, and the other end of the current limiting resistor R2 is connected to the input end of the fiber transmitter D1. The current limiting resistor R2 limits the current (such as 20mA) flowing into the fiber transmitter D1, reduces the risk of overcurrent damage of the fiber transmitter D1, and makes the fiber transmitter D1 work in a safe current range.

[0057] Preferably, the output of the chip assembly 202 includes at least one chip output port, each chip output port is connected in parallel with a corresponding pull-up resistor R1, and each chip output port is connected to the input of the buffer 203.

[0058] Preferably, the output of the buffer 203 includes at least one buffer output port, which corresponds one-to-one with the chip output port. Each buffer output port is connected to the input of the fiber optic transmitter D1 through a corresponding current-limiting resistor R2.

[0059] Preferably, the adjustment module 2 includes at least one fiber optic transmitter D1, with each fiber optic transmitter D1 corresponding to a buffer output port, and the output of each fiber optic transmitter D1 is connected to the input of the photoelectric converter 501.

[0060] For example, such as Figure 2 As shown, the chip assembly 202 has six chip output ports for outputting six PWM pulse voltage signals (including U+, U-, V+, V-, W+, and W-). Each PWM pulse voltage signal is stabilized at its logic level by its respective pull-up resistor R1 before being output to the buffer 203. The buffer 203 also has six buffer output ports for outputting six PWM pulse voltage signals (including U+, U-, V+, V-, W+, and W-). After being current-limited by their respective current-limiting resistors R2, the six PWM pulse voltage signals output by the buffer 203 are converted into corresponding optical signals by their respective fiber optic transmitters D1 and output to the photoelectric converter 501 of the frequency converter 5.

[0061] The frequency converter testing device also includes a display module 3 and a judgment module 4.

[0062] Display module 3 is used to display the waveform of the output electrical signal on the line side. The output electrical signal includes: a first output electrical signal between phase U and phase V on the line side, a second output electrical signal between phase V and phase W on the line side, and a third output electrical signal between phase W and phase U on the line side. The first, second, and third output electrical signals are isolated from each other.

[0063] Display module 3 includes an oscilloscope with multiple input channels. Each output electrical signal is connected to a corresponding input channel and displayed in real time on the oscilloscope. The oscilloscope displays the three-phase AC voltage signal output by the frequency converter 5 as intuitive waveform data to provide a preliminary basis for judging the operating status of the frequency converter 5.

[0064] The judging module 4 automatically outputs a normal signal or an abnormal signal by comparing the real-time waveform with the preset standard state. In the case that the output electric signal conforms to the preset standard state, a normal signal is output; in the case that the output electric signal does not conform to the preset standard state, an abnormal signal is output.

[0065] The preset standard state includes standard voltage waveform data of the normal working state of the frequency converter 5, and the voltage waveform data of the output electric signal is compared with the standard voltage waveform data, so as to judge whether the working state of the frequency converter 5 is normal. If the difference between the two is large, it may mean that the frequency converter 5 has a fault or unstable performance.

[0066] The preset standard state also includes that the amplitude of the output electric signal is the same, the period is the same, and the phase difference is 120°. Specifically, the first output electric signal, the second output electric signal and the third output electric signal have the same amplitude; the first output electric signal, the second output electric signal and the third output electric signal have the same period; the first output electric signal, the second output electric signal and the third output electric signal have a phase difference of 120° (the first output electric signal leads the second output electric signal by 120°, and the second output electric signal leads the third output electric signal by 120°).

[0067] It should be noted that the amplitude of the first output electric signal, the second output electric signal and the third output electric signal also needs to conform to the amplitude of the direct current voltage output by the second power module 102. The period of the first output electric signal, the second output electric signal and the third output electric signal also needs to conform to the running frequency period of the frequency converter 5.

[0068] In the embodiment of the present application, the power module provides two-stage power supply: the first power module 101 supplies power for the control circuit to ensure stable generation of logic signals; the second power module 102 replaces the high-voltage DC bus to inject a safe direct current voltage (such as 24V) to the frequency converter 5 to drive the frequency converter 5 to generate a low-voltage equivalent three-phase waveform. The adjusting module 2 modifies the parameters of the frequency converter 5 (such as the under-voltage protection threshold, the output voltage limit, etc.), generates six-way complementary PWM signals through the chip assembly 202, transmits the signals to the frequency converter 5 through optical fiber after buffering and isolation, controls the frequency converter 5 to run under a safe low voltage (such as 24V DC), simulates normal working conditions and generates three-phase alternating current voltage signals (U-V, V-W, W-U). The multi-channel oscilloscope in the display module 3 collects and displays the three-phase voltage waveform at the line side in real time, so as to intuitively observe the waveform amplitude, period and phase difference. The judging module 4 automatically compares the measured waveform with the preset standard state, and if it conforms to the preset standard state, it is determined that the frequency converter 5 is normal, otherwise an abnormal signal is output to guide subsequent targeted maintenance.

[0069] In summary, the embodiment of the present application provides a frequency converter testing device, comprising: a power module connected with a frequency converter to be tested, the power module being used for supplying power to the frequency converter; an adjusting module connected with a control loop of the frequency converter, the adjusting module being used for triggering the frequency converter testing operation; a display module connected with an outgoing line side of the frequency converter, the display module being used for displaying a waveform of an output electrical signal of the outgoing line side; and a judging module connected with the display module and / or connected with the outgoing line side, the judging module being used for outputting a normal signal in a case that the output electrical signal meets a preset standard state.

[0070] It can be seen that, by replacing the traditional high-voltage power supply with the power module, the damage risk caused by directly connecting to the high-voltage loop is avoided, and at the same time, low-voltage direct current is provided for safe operation of the frequency converter 5. By triggering the frequency converter 5 to operate normally under low-voltage environment through the adjusting module 2, the output electrical signal corresponding to the normal working condition is output, and the output electrical signal is displayed and analyzed according to the display module 3 and the judging module 4, so that the fault or unstable performance of the frequency converter 5 can be found in time, the objectivity and accuracy of fault diagnosis are significantly improved, the safety risk in the testing process of the frequency converter 5 is reduced, and the reliability and operation safety of equipment detection are improved.

[0071] Based on the same inventive concept, the embodiment of the present application also provides a frequency converter testing system, comprising a frequency converter testing device provided as described above.

[0072] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0073] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A frequency converter testing apparatus, characterized by include: A power supply module is connected to the inverter to be tested, and the power supply module is used to supply power to the inverter; An adjustment module is connected to the control loop of the frequency converter, and the adjustment module is used to trigger the test operation of the frequency converter. The display module is connected to the output side of the frequency converter, and the display module is used to display the waveform of the output electrical signal on the output side; A judgment module is connected to the display module and / or to the output side. The judgment module is used to output a normal signal when the output electrical signal meets the preset standard state.

2. The frequency converter testing apparatus of claim 1, wherein, The power module includes: The first power supply module is connected to the control circuit; The second power supply module is connected to the DC circuit of the frequency converter.

3. The frequency converter testing apparatus of claim 1, wherein, The adjustment module includes: A chip assembly, wherein a pull-up resistor is provided at the output terminal of the chip assembly; A buffer, wherein the input of the buffer is connected to the output of the chip assembly; An optical fiber transmitter, the output of which is connected to the input of a photoelectric converter in the control loop; A current-limiting resistor, one end of which is connected to the output terminal of the buffer, and the other end of which is connected to the input terminal of the optical fiber transmitter.

4. The frequency converter testing apparatus of claim 3, wherein, The output of the chip assembly includes at least one chip output port, each chip output port is connected in parallel with a corresponding pull-up resistor, and each chip output port is connected to the input of the buffer.

5. The frequency converter testing apparatus of claim 4, wherein, The output of the buffer includes at least one buffer output port, which corresponds one-to-one with the output port of the chip. Each buffer output port is connected to the input of the optical fiber transmitter through a corresponding current-limiting resistor.

6. The frequency converter testing apparatus of claim 5, wherein, The adjustment module includes at least one optical fiber transmitter, each of which corresponds to a buffer output port. The output of each optical fiber transmitter is connected to the input of the photoelectric converter.

7. The frequency converter testing apparatus of claim 3, wherein, The chip component outputs a three-phase PWM pulse signal, and the buffer outputs a three-phase PWM pulse signal.

8. The frequency converter testing apparatus of claim 3, wherein, The adjustment module further includes: A voltage regulation component is used to convert the received AC voltage into DC voltage, and the output terminal of the voltage regulation component is connected to the input terminal of the chip component.

9. The frequency converter testing apparatus of claim 1, wherein, The output electrical signal includes: The first output electrical signal between phase U and phase V on the outgoing side; The second output electrical signal between phase V and phase W on the outgoing side; The third output electrical signal between phase W and phase U on the outgoing side.

10. A frequency converter testing system characterized by, The inverter testing device includes any one of claims 1-9.

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