Circuits, methods, and apparatus for testing the safety of frequency converters

Abstract

This application relates to the field of industrial automatic control technology, and discloses a circuit, method, and apparatus for detecting the safety of frequency converter equipment. The circuit includes: multiple contactors, including a first AC contactor, a second AC contactor, a first DC contactor, and a second DC contactor; and multiple light bulbs, including a first light bulb, a second light bulb, a third light bulb, a fourth light bulb, and a fifth light bulb. One end of the first AC contactor is connected to the second AC contactor, and the other end is connected to a first power supply. One end of the first DC contactor is connected to the second DC contactor, and the other end is connected to a second power supply. The second AC contactor is connected to the first light bulb, the second light bulb, and the third light bulb, respectively. The second DC contactor is connected to the fourth light bulb and the fifth light bulb, respectively. The technical solution proposed in this application can quickly detect potential problems in frequency converter equipment, preventing the fault from escalating to the point of being unrecoverable.

Description

Technical Field

[0001] This application relates to the field of industrial automatic control technology, and discloses a circuit, method and apparatus for detecting the safety of frequency converter equipment. Background Technology

[0002] Steel enterprises have a high degree of automation and use a large number of frequency converters. Whether it's new frequency converters being put into production or repaired faulty frequency converters undergoing trial operation, they all require power-on testing. If the frequency converter's internal capacitors are damaged and short-circuited; the power devices in the rectifier and inverter sections experience performance degradation or damage; or there are phase-to-phase or ground short circuits in the output, the power-on test operation is highly susceptible to blasting and explosions. These explosions can further damage the faulty frequency converter, increase repair difficulty, severely impact normal production operations, and even cause personal injury to electrical operators. During long-term shutdowns for maintenance, or after prolonged periods of inactivity or restoration, frequency converters are prone to catastrophic failures due to internal or field grounding short circuits, severely affecting production. However, existing technologies for frequency converter repair are difficult and costly. Therefore, this paper proposes a circuit for detecting the safety of frequency converters. This circuit can quickly identify potential problems, prevent the fault from escalating to the point of being irrecoverable, make testing and repairing frequency converters safer and more reliable, improve work efficiency, and reduce production costs. Summary of the Invention

[0003] This application relates to the field of industrial automatic control technology, and discloses a circuit, method, and apparatus for detecting the safety of variable frequency drive (VFD) equipment. It can quickly identify potential equipment problems, prevent the escalation of faults to the point of being irreversible, make testing and maintenance of VFD equipment safer and more reliable, improve work efficiency, and reduce production costs.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to a first aspect of the embodiments of this application, a circuit for detecting the safety of a frequency converter is provided. The circuit includes: a plurality of contactors, the contactors including a first AC contactor, a second AC contactor, a first DC contactor, and a second DC contactor; a plurality of light bulbs, the light bulbs including a first light bulb, a second light bulb, a third light bulb, a fourth light bulb, and a fifth light bulb; wherein, one end of the first AC contactor is connected to the second AC contactor and the other end is connected to a first power source, one end of the first DC contactor is connected to the second DC contactor and the other end is connected to a second power source, the second AC contactor is connected to the first light bulb, the second light bulb, and the third light bulb respectively, and the second DC contactor is connected to the fourth light bulb and the fifth light bulb respectively.

[0006] In one embodiment of this application, based on the aforementioned scheme, both the first AC contactor and the second AC contactor are three-phase AC contactors, and the second AC contactor includes a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal, and a third output terminal.

[0007] In one embodiment of this application, based on the aforementioned scheme, one end of the first bulb, the second bulb, and the third bulb are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second AC contactor, and the other end of the first bulb, the second bulb, and the third bulb are respectively connected to the first output terminal, the second output terminal, and the third output terminal of the second AC contactor.

[0008] In one embodiment of this application, based on the aforementioned scheme, the second DC contactor includes a fourth input terminal, a fifth input terminal, a fourth output terminal, a fifth output terminal, and a fourth bulb. One end of the fifth bulb is connected to the fourth input terminal and the fifth input terminal of the second DC contactor, respectively, and the other end of the fourth bulb and the fifth bulb is connected to the fourth output terminal and the fifth output terminal of the second DC contactor, respectively.

[0009] In one embodiment of this application, based on the aforementioned scheme, the closing states of the first AC contactor, the second AC contactor, the first DC contactor, and the second DC contactor are controlled to detect whether the frequency converter equipment has malfunctioned.

[0010] In one embodiment of this application, based on the aforementioned scheme, the brightness changes of the first bulb, the second bulb, the third bulb, the fourth bulb, and the fifth bulb are used to determine whether the frequency converter has malfunctioned.

[0011] According to a second aspect of the present application, a method for detecting the safety of a frequency converter is provided, the method comprising: acquiring an operating signal of the circuit; controlling the circuit to detect the safety of the frequency converter based on the operating signal; and determining the safety of the frequency converter based on the brightness changes of each bulb in the circuit.

[0012] In one embodiment of this application, based on the aforementioned scheme, controlling the circuit to detect the safety of the frequency converter includes: detecting whether the frequency converter has malfunctioned by changing the closing state of each contactor in the circuit, so as to determine the safety of the frequency converter.

[0013] In one embodiment of this application, based on the aforementioned scheme, determining the safety of the frequency converter based on the brightness changes of each bulb in the circuit includes: determining the brightness changes of each bulb in the circuit based on the closing state of each contactor in the circuit; and determining whether the frequency converter has malfunctioned based on the brightness changes of each bulb in the circuit.

[0014] According to a third aspect of the present application, an apparatus for detecting the safety of a frequency converter is provided. The apparatus includes: an acquisition unit configured to acquire an operating signal of the circuit; a detection unit configured to control the circuit to detect the safety of the frequency converter based on the operating signal; and a judgment unit configured to judge the safety of the frequency converter based on the brightness changes of each bulb in the circuit.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0017] Figure 1 A circuit diagram of a circuit for detecting the safety of a frequency converter according to an embodiment of this application is shown;

[0018] Figure 2 This application shows a partial circuit diagram of a circuit for detecting the safety of a frequency converter according to an embodiment of the present application.

[0019] Figure 3 A flowchart of a method for detecting the safety of frequency converter equipment according to an embodiment of this application is shown;

[0020] Figure 4 A block diagram of a device for detecting the safety of frequency converter equipment according to an embodiment of this application is shown;

[0021] Figure 5 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown. Detailed Implementation

[0022] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0023] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0024] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0025] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0026] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0028] The implementation details of the technical solutions in the embodiments of this application are described in detail below:

[0029] Figure 1 A circuit diagram of a circuit for detecting the safety of frequency converter equipment according to an embodiment of this application is shown.

[0030] like Figure 1 As shown, the circuit for detecting the safety of the frequency converter includes: multiple contactors, including a first AC contactor 101, a second AC contactor 102, a first DC contactor 103, and a second DC contactor 104; and multiple light bulbs, including a first light bulb 105, a second light bulb 106, a third light bulb 107, a fourth light bulb 108, and a fifth light bulb 109. One end of the first AC contactor 101 is connected to the second AC contactor 102, and the other end is connected to a first power source. One end of the first DC contactor 103 is connected to the second DC contactor 104, and the other end is connected to a second power source. The second AC contactor 102 is connected to the first light bulb 105, the second light bulb 106, and the third light bulb 107, respectively. The second DC contactor 104 is connected to the fourth light bulb 108 and the fifth light bulb 109, respectively.

[0031] In this application, one end of the first AC contactor 101 is connected to the second AC contactor 102, and the other end is connected to the first power supply. The other end of the second AC contactor 102 is connected to the frequency converter. One end of the first DC contactor 103 is connected to the second DC contactor 104, and the other end is connected to the second power supply. The other end of the second DC contactor 104 is connected to two phases of the DC bus CD of the frequency converter.

[0032] In this application, the first power source is an AC power source, L1, L2, and L3 correspond to the three-phase power sources of the AC power source, the second power source is a DC power source, the three-phase input terminal of the first AC contactor 101 is connected to the three-phase AC power source, and the input terminal of the first DC contactor 103 is connected to the two-phase DC power source.

[0033] In this application, the first AC contactor 101, the second AC contactor 102, the first DC contactor 103 and the second DC contactor 104, the first light bulb 105, the second light bulb 106, the third light bulb 107, the fourth light bulb 108, and the fifth light bulb 109 can be placed in the test box 110.

[0034] In one embodiment of this application, both the first AC contactor 101 and the second AC contactor 102 are three-phase AC contactors. The second AC contactor 102 includes a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal, and a third output terminal.

[0035] In one embodiment of this application, one end of the first bulb 105, the second bulb 106, and the third bulb 107 are respectively connected to the first input terminal, the second input terminal, and the third input terminal of the second AC contactor 102, and the other end of the first bulb 105, the second bulb 106, and the third bulb 107 are respectively connected to the first output terminal, the second output terminal, and the third output terminal of the second AC contactor 102.

[0036] In this application, the three-phase contacts of the second AC contactor 102 are respectively short-circuited to the two ends of the first bulb 105, the second bulb 106, and the third bulb 107.

[0037] In one embodiment of this application, the second DC contactor 104 includes a fourth input terminal, a fifth input terminal, a fourth output terminal, a fifth output terminal, a fourth bulb 108, and a fifth bulb 109. One end of each bulb is connected to the fourth input terminal and the fifth input terminal of the second DC contactor 104, respectively, and the other end of each bulb is connected to the fourth output terminal and the fifth output terminal of the second DC contactor 104, respectively.

[0038] In this application, the two phase contacts of the second DC contactor 104 are respectively short-circuited across the fourth bulb 108 and the fifth bulb 109.

[0039] In one embodiment of this application, the closing states of the first AC contactor 101, the second AC contactor 102, the first DC contactor 103, and the second DC contactor 104 are controlled to detect whether the frequency converter equipment has malfunctioned.

[0040] In this application, the first AC contactor 101, the second AC contactor 102, the first DC contactor 103 and the second DC contactor 104 are controlled to close or open to detect whether the frequency converter equipment has a fault.

[0041] In one embodiment of this application, the frequency converter is used to determine whether it has malfunctioned based on the brightness changes of the first bulb 105, the second bulb 106, the third bulb 107, the fourth bulb 108, and the fifth bulb 109.

[0042] In this application, the brightness changes of the first bulb 105, the second bulb 106, the third bulb 107, the fourth bulb 108, and the fifth bulb 109 are used to determine whether the frequency converter has malfunctioned, and to determine the cause and location of the malfunction. For example, if only the first AC contactor 101 is closed, and the first bulb 105, the second bulb 106, and the third bulb 107 all flash briefly with uniform brightness and then go out, it indicates that the frequency converter is not malfunctioning or the malfunction has been repaired. The flashing of the first bulb 105, the second bulb 106, and the third bulb 107 is due to the charging of the frequency converter's capacitor bank.

[0043] To enable those skilled in the art to more easily understand this application, the following will be combined with Figure 1 and Figure 2 This application will be illustrated with specific embodiments.

[0044] Figure 2 A partial circuit diagram of a frequency converter for detecting the safety of frequency converters according to an embodiment of this application is shown.

[0045] First embodiment:

[0046] like Figure 1 and Figure 2 As shown, one end of the first AC contactor 101 is connected to the AC power supply, and the other end is connected to the second AC contactor 102. One end of the first DC contactor 103 is connected to the DC power supply, and the other end is connected to the second DC contactor 104. The three-phase contacts of the second AC contactor 102 are short-circuited between the two ends of the first bulb 105, the second bulb 106, and the third bulb 107, respectively. The two-phase contacts of the second DC contactor 104 are short-circuited between the two ends of the fourth bulb 108 and the fifth bulb 109, respectively. The lower contact of the second AC contactor 102 is connected to the three-phase input line RST of the frequency converter, and the lower contact of the second DC contactor 104 is connected to the two phases 2C and 2D of the DC busbar of the frequency converter. The first bulb 105, the second bulb 106, the third bulb 107, the fourth bulb 108, and the fifth bulb 109 are all 100W incandescent bulbs. The following steps are followed for testing:

[0047] Step 1: With the power devices of the measuring equipment functioning normally and good phase-to-phase and phase-to-ground insulation, power is supplied by connecting the AC power supply and closing only the first AC contactor 101. Based on the brightness changes of the first bulb 105, the second bulb 106, and the third bulb 107, the following phenomena may occur:

[0048] (1) All three bulbs flashed brightly for a moment and then went out.

[0049] This phenomenon indicates that the rectifier module 204 of the frequency converter is not faulty or has been repaired. The flashing of the three bulbs after power is due to the charging of the capacitor bank 201 of the inverter module 205 of the frequency converter.

[0050] (2) Only 2 out of the 3 light bulbs are lit.

[0051] This phenomenon indicates that the inverter's rectifier module 204 may be missing a phase for some reason, and the bulb connected to the missing phase will not light up. Alternatively, it may be that a phase is faulty, in which case the bulb connected to the faulty phase will also not light up.

[0052] (3) All three bulbs are flashing, but the flashing brightness is dim and the duration is short.

[0053] This phenomenon suggests that there may be a problem with the DC electrolytic capacitor bank 201 in the main circuit of the frequency converter. It may be caused by leakage, bulging, reduced capacity, and reduced charging current in capacitor bank 201.

[0054] Step 2: To prevent accidental failure during inverter power testing, two 100W AC 220V bulbs are connected in series at the DC input terminals of phases C and D after the inverter's energy storage capacitor. These are bulb number 108 (fourth bulb) and bulb number 109 (fifth bulb). The reason for using two 100W AC 220V bulbs is based on the inverter's DC voltage. The calculated number of bulbs is approximately 530V, requiring two bulbs in series to meet the voltage withstand requirements. Furthermore, the connection point should ideally be after the energy storage capacitor; otherwise, the stored charge in the capacitor could potentially release enough energy to destroy the inverter module in the event of a fault in the inverter circuit. During no-load testing, if a short circuit fault exists in the inverter circuit, the bulbs' voltage reduction and current limiting effect will limit the inverter's supply current to below 100mA, preventing further damage to the inverter module. Early detection and handling can prevent the fault from escalating. When the AC power is connected and the first DC contactor 103 is closed after power-on, the following phenomena may occur based on the changes in brightness of the fourth bulb 108 and the fifth bulb 109:

[0055] (1) The inverter is in the off state, and both light bulbs are lit.

[0056] This phenomenon indicates that one of the three modules in the inverter module 205 of the frequency converter has leakage in both the upper and lower IGBT arms, such as Q1 and Q2. This type of leakage is not easily detected under low voltage conditions; for example, a multimeter may not be able to detect it. However, after introducing high DC voltage, a significant leakage occurs, indicating a serious insulation defect inside the module. A process of elimination can be used for troubleshooting. For example, if the bulbs do not light up after removing the U-phase modules (Q1 and Q2), it indicates that the module is damaged.

[0057] (2) After the inverter is powered on, neither of the two bulbs lights up. However, after the inverter module 205 of the inverter receives the running signal, the light of the bulbs flashes and lights up synchronously as the frequency increases.

[0058] This phenomenon indicates that a fault has occurred in the upper or lower IGBT of a certain phase in the inverter module 205 of the frequency converter. For example, when the excitation signal of Q1 is turned on, the damaged Q2, together with the conducting Q1, forms a short circuit to the power supply. The two series-connected bulbs emit light under a 530V DC voltage. The IGBT power module can conduct but cannot be turned off. This phenomenon may also be due to a fault in the drive circuit.

[0059] (3) After the inverter is powered on, the two bulbs remain off. Even after receiving the running signal, the bulbs still do not light up.

[0060] After this phenomenon occurs, use the AC 500V range of an analog multimeter to measure the output voltage of terminals U, V, and W. The voltage increases uniformly with the frequency, and the three-phase output voltage is balanced, indicating that the inverter output module is basically good and can be tested with a load.

[0061] Step 3: Test with motor 203. Connect the AC power supply and the first DC contactor 103, and disconnect the second AC contactor 102 and the second DC contactor 104 before starting the low-speed test. Because the inverter's input lines are connected in series with the first bulb 105, the second bulb 106, and the third bulb 107, and the inverter's input circuit is connected in series with the fourth bulb 108 and the fifth bulb 109, after starting the inverter, all five bulbs will flash evenly, indicating that the device is operating normally. The second AC contactor 102 and the second DC contactor 104 can then be closed, and the bulbs can be disconnected to test the high-speed operation of motor 203. Check that the fan and panel display are operating normally, and that the operating current is normal. Use a multimeter to measure that the output voltages U, V, and W are balanced and the amplitude is normal. At this point, the inverter test is complete, and the inverter's safety is confirmed to be acceptable; it can be put into normal use.

[0062] Second embodiment:

[0063] like Figure 1 and Figure 2As shown, one end of the first AC contactor 101 is connected to the AC power supply, and the other end is connected to the second AC contactor 102. One end of the first DC contactor 103 is connected to the DC power supply, and the other end is connected to the second DC contactor 104. The three-phase contacts of the second AC contactor 102 are short-circuited between the two ends of the first bulb 105, the second bulb 106, and the third bulb 107, respectively. The two-phase contacts of the second DC contactor 104 are short-circuited between the two ends of the fourth bulb 108 and the fifth bulb 109, respectively. The lower terminal of the second AC contactor 102 is connected to the three-phase input line RST of the rectifier unit 204 of the inverter. The lower terminal of the second DC contactor 104 is connected to the two phases 2C and 2D of the DC busbar of the inverter unit 205 of the inverter. The first bulb 105, the second bulb 106, the third bulb 107, the fourth bulb 108, and the fifth bulb 109 are all 100W incandescent bulbs. The following steps are followed for testing:

[0064] Step 1: With the power devices of the measuring equipment functioning normally and good phase-to-phase and phase-to-ground insulation, power is supplied by connecting the AC power supply and closing only the first AC contactor 101. Based on the brightness changes of the first bulb 105, the second bulb 106, and the third bulb 107, the following phenomena may occur:

[0065] (1) All three bulbs flashed brightly for a moment and then went out.

[0066] This phenomenon indicates that the rectifier unit 204 is not faulty or has been repaired. The reason why the three bulbs flash after power is that the capacitor bank 201 of the inverter unit 205 of the inverter is charging.

[0067] (2) Only 2 out of the 3 light bulbs are lit.

[0068] This phenomenon suggests that the rectifier unit 204 may be missing a phase for some reason, and the bulb connected to the missing phase will not light up. Alternatively, it may be that a phase is faulty, and the bulb connected to the faulty phase will also not light up.

[0069] (3) All three bulbs are flashing, but the flashing brightness is dim and the duration is short.

[0070] This phenomenon suggests that there may be a problem with the DC electrolytic capacitor bank 201 in the main circuit of the inverter. It may be caused by leakage, bulging, reduced capacity, and reduced charging current in capacitor bank 201.

[0071] Step 2: To prevent accidental failure during inverter power testing, two 100W AC 220V light bulbs are connected in series at the DC input terminals 2C and 2D of the DC bus CD after the energy storage capacitor 201. These are designated as bulb 108 (fourth bulb) and bulb 109 (fifth bulb). The reason for connecting two 100W AC 220V light bulbs is based on the inverter's DC voltage. The calculated number of bulbs is approximately 530V, requiring two bulbs in series to meet the voltage withstand requirements. If the connection point were before the energy storage capacitor, the stored charge on the capacitor could potentially release enough energy to destroy the inverter module in the event of a circuit fault. During no-load testing, when a short-circuit fault exists in the inverter circuit, the bulbs' voltage reduction and current limiting effect will limit the inverter's supply current to below 100mA, preventing further damage to the inverter module. Early detection and handling prevent the fault from escalating. When the rectifier unit 204 is turned on and the first DC contactor 103 is closed, the following phenomena may occur based on the brightness changes of the fourth bulb 108 and the fifth bulb 109:

[0072] (1) When the inverter is off, both light bulbs are lit.

[0073] This phenomenon indicates that one of the three modules in inverter unit 205 of the inverter has leakage in both the upper and lower IGBT arms, such as Q1 and Q2. This type of leakage is not easily detected under low voltage conditions; for example, a multimeter may not be able to detect it. However, after introducing high DC voltage, a significant leakage occurs, indicating a serious insulation defect inside the module. A process of elimination can be used for troubleshooting. For example, if the bulbs do not light up after removing the U-phase module (Q1, Q2), it indicates that the module is damaged.

[0074] (2) After the inverter is powered on, neither of the two bulbs lights up. However, after the inverter unit 205 of the inverter receives the operation signal, the light of the bulbs flashes and lights up synchronously as the frequency increases.

[0075] This phenomenon indicates that a fault has occurred in the upper or lower arm IGBT of one phase in the inverter unit 205 of the inverter. For example, when the excitation signal of Q1 is turned on, the damaged Q2, together with the conducting Q1, forms a short circuit to the power supply. The two series-connected bulbs emit light under a 530V DC voltage. The IGBT power module can conduct but cannot be turned off. This phenomenon may also be due to a fault in the drive circuit.

[0076] (3) After the inverter is powered on, the two bulbs remain off. Even after receiving the operation signal, the bulbs still do not light up.

[0077] After this phenomenon occurs, use the AC 500V range of an analog multimeter to measure the output voltage of terminals U, V, and W. The voltage increases uniformly with the frequency, and the three-phase output voltage is balanced, indicating that the inverter output module is basically good and can be tested with a load.

[0078] Step 3: Test with motor 203. At the start of the low-speed test, because the input lines of rectifier unit 204 are connected in series with the first bulb 105, the second bulb 106, and the third bulb 107, and the input lines of inverter are connected in series with the fourth bulb 108 and the fifth bulb 109, after starting the inverter, all five bulbs flash evenly, indicating that rectifier unit 204 and inverter are operating normally. The second AC contactor 102 and the second DC contactor 104 can then be closed to allow the bulbs to be removed and motor 203 to be tested at high speed. Check that the fan, panel display, and operating current are normal. Use a multimeter to measure the output voltages U, V, and W; they should be balanced and have normal amplitudes. At this point, rectifier unit 204 and inverter have completed the test. The safety of rectifier unit 204 and inverter has been verified, and they are ready for normal use.

[0079] In order to better utilize the circuit for detecting the safety of frequency converter equipment in the first aspect of the above embodiments of this application, this application also proposes a method for detecting the safety of frequency converter equipment.

[0080] Figure 3 A flowchart illustrating a method for detecting the safety of frequency converter equipment according to an embodiment of this application is shown.

[0081] like Figure 3 As shown, the method for detecting the safety of frequency converter equipment includes at least steps 310 to 350.

[0082] The following will be about Figure 3 Steps 310 to 350 are described in detail below:

[0083] In step 310, the operating signal of the circuit is obtained.

[0084] In this application, the operating signal of the circuit is obtained, and the circuit is the circuit for detecting the safety of frequency converter equipment described in the above embodiments.

[0085] Continue to refer to Figure 3 In step 330, based on the working signal, the circuit is controlled to detect the safety of the frequency converter.

[0086] Continue to refer to Figure 3 In step 350, the safety of the frequency converter is determined based on the brightness changes of each bulb in the circuit.

[0087] In this application, the control circuit detects the frequency converter, and based on the brightness changes of each bulb in the circuit, determines whether the frequency converter has malfunctioned, and determines the location and cause of the malfunction.

[0088] In one embodiment of this application, controlling the circuit to detect the safety of the frequency converter includes: detecting whether the frequency converter has malfunctioned by changing the closing state of each contactor in the circuit, so as to determine the safety of the frequency converter.

[0089] In this application, the fault of the frequency converter is detected by controlling the closing or opening of each contactor in the circuit. If the frequency converter malfunctions, the cause and location of the fault are determined.

[0090] In one embodiment of this application, determining the safety of the frequency converter based on the brightness changes of each bulb in the circuit includes: determining the brightness changes of each bulb in the circuit based on the closing state of each contactor in the circuit; and determining whether the frequency converter has malfunctioned based on the brightness changes of each bulb in the circuit.

[0091] In this application, by controlling the closing or opening of each contactor in the circuit, the brightness change of each bulb in the circuit is obtained. Based on the brightness change of each bulb in the circuit, it is determined whether the frequency converter has malfunctioned, and the cause and location of the malfunction are determined.

[0092] The one or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0093] The technical solution proposed in this application can quickly identify potential equipment problems, prevent the fault from escalating to the point of being unrecoverable, make the maintenance and testing of frequency converters safer and more reliable, improve work efficiency, and reduce production costs.

[0094] The technical solution proposed in this application can detect potential equipment problems in advance and handle faults in a timely manner, avoiding secondary equipment accidents and personal injury to operators, and playing an effective role in maintaining stable production.

[0095] The technical solution proposed in this application can effectively prevent the significant production losses caused by the explosion of frequency converter equipment and the long-term handling of faults.

[0096] The following describes an apparatus embodiment of this application, which can be used to execute the method for detecting the safety of frequency converter equipment according to the second aspect of the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method for detecting the safety of frequency converter equipment according to the second aspect of this application.

[0097] Figure 4 A block diagram of an apparatus for detecting the safety of frequency converter equipment according to an embodiment of this application is shown.

[0098] like Figure 4As shown in the embodiment of this application, the device 400 for detecting the safety of frequency converter equipment includes: an acquisition unit 401, a detection unit 402, and a judgment unit 403.

[0099] The acquisition unit 401 is used to acquire the operating signal of the circuit; the detection unit 402 is used to control the circuit to detect the safety of the frequency converter based on the operating signal; and the judgment unit 403 is used to judge the safety of the frequency converter based on the brightness changes of each bulb in the circuit.

[0100] In some embodiments of this application, based on the foregoing scheme, the detection unit 402 is configured to: detect whether the frequency converter has malfunctioned by changing the closing state of each contactor in the circuit, so as to determine the safety of the frequency converter.

[0101] In some embodiments of this application, based on the foregoing scheme, the judgment unit 403 is configured to: determine the brightness change of each bulb in the circuit based on the closing state of each contactor in the circuit; and determine whether the frequency converter has malfunctioned based on the brightness change of each bulb in the circuit.

[0102] This application also provides a computer program product comprising computer instructions stored in a computer-readable storage medium and adapted to be read and executed by a processor to cause a computer device having the processor to perform the method for detecting the safety of frequency converter equipment as described in the above embodiments.

[0103] This application also provides a computer-readable medium, which may be included in an electronic device or exist independently without being assembled into an electronic device. The computer-readable storage medium stores at least one line of program code, which is loaded and executed by a processor to implement the method for detecting the safety of frequency converters described in the above embodiments.

[0104] This application also provides an electronic device, which includes one or more processors and one or more memories, wherein at least one piece of program code is stored in the one or more memories, and the at least one piece of program code is loaded and executed by the one or more processors to implement the method for detecting the safety of frequency converters as described in any of the above embodiments.

[0105] Figure 5 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown.

[0106] It should be noted that, Figure 5The computer system 500 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0107] like Figure 5 As shown, the computer system 500 includes a Central Processing Unit (CPU) 501, which can perform various appropriate actions and processes based on programs stored in Read-Only Memory (ROM) 502 or programs loaded from storage portion 508 into Random Access Memory (RAM) 503, such as performing the methods described in the above embodiments. The RAM 503 also stores various programs and data required for system operation. The CPU 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0108] The following components are connected to I / O interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to I / O interface 505 as needed. Removable media 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 510 as needed so that computer programs read from them can be installed into storage section 508 as needed.

[0109] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by central processing unit (CPU) 501, it performs various functions defined in the system of this application.

[0110] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0111] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0112] The units described in the embodiments of this application can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0113] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0114] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of this application.

[0115] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0116] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this application, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0117] It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A circuit for detecting the safety of frequency converter equipment, characterized in that, The circuit includes: Multiple contactors, including a first AC contactor, a second AC contactor, a first DC contactor, and a second DC contactor; Multiple light bulbs, including a first light bulb, a second light bulb, a third light bulb, a fourth light bulb, and a fifth light bulb; Wherein, one end of the first AC contactor is connected to the second AC contactor and the other end is connected to the first power supply; one end of the first DC contactor is connected to the second DC contactor and the other end is connected to the second power supply; the second AC contactor is connected to the first bulb, the second bulb, and the third bulb respectively; and the second DC contactor is connected to the fourth bulb and the fifth bulb respectively. Controlling the closing states of the first AC contactor, the second AC contactor, the first DC contactor, and the second DC contactor to detect whether a fault has occurred in the frequency converter equipment includes: When the AC power is connected, only the first AC contactor is closed to test the rectifier module and DC electrolytic capacitor bank. Connect the AC power supply, close the first DC contactor after power-on, and test the inverter module; Connect the AC power supply and the first DC contactor, disconnect the second AC contactor and the second DC contactor, and begin the low-speed test with the motor. Close the second AC contactor and the second DC contactor, and perform a high-speed test with the motor. At least two of the bulbs are connected in series in the circuit where the frequency converter is located.

2. The circuit according to claim 1, characterized in that, Both the first AC contactor and the second AC contactor are three-phase AC contactors. The second AC contactor includes a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal, and a third output terminal.

3. The circuit according to claim 2, characterized in that, One end of the first bulb, the second bulb, and the third bulb is connected to the first input terminal, the second input terminal, and the third input terminal of the second AC contactor, respectively. The other end of the first bulb, the second bulb, and the third bulb is connected to the first output terminal, the second output terminal, and the third output terminal of the second AC contactor, respectively.

4. The circuit according to claim 3, characterized in that, The second DC contactor includes a fourth input terminal, a fifth input terminal, a fourth output terminal, a fifth output terminal, and a fourth bulb. One end of the fifth bulb is connected to the fourth input terminal and the fifth input terminal of the second DC contactor, respectively. The other end of the fourth bulb and the fifth bulb is connected to the fourth output terminal and the fifth output terminal of the second DC contactor, respectively.

5. The circuit according to claim 4, characterized in that, Based on the brightness changes of the first bulb, the second bulb, the third bulb, the fourth bulb, and the fifth bulb, determining whether the frequency converter has malfunctioned includes: When the AC power is connected and only the first AC contactor is closed, the rectifier module and DC electrolytic capacitor bank are detected based on the first, second, and third light bulbs. When the AC power is connected and the first DC contactor is closed after power-on, the inverter module is detected based on the fourth and fifth light bulbs. With the motor connected for testing, the AC power supply and the first DC contactor are connected, and the second AC contactor and the second DC contactor are disconnected. The first light bulb, the second light bulb, and the third light bulb are connected in series with the inverter input line, and the fourth light bulb and the fifth light bulb are connected in series with the inverter input line circuit, and the low-speed test begins. When the second AC contactor and the second DC contactor are closed, the light bulb is removed and the motor is tested at high speed.

6. A method for detecting the safety of frequency converter equipment, characterized in that, The method, using the circuit as described in claim 5, comprises: Obtain the operating signals of the circuit; Based on the operating signal, the control circuit detects the safety of the frequency converter. The safety of the frequency converter is determined based on the brightness changes of each bulb in the circuit.

7. The method according to claim 6, characterized in that, The control circuit for detecting the safety of the frequency converter includes: By changing the closed state of each contactor in the circuit, the safety of the frequency converter is determined by detecting whether the frequency converter has malfunctioned.

8. The method according to claim 7, characterized in that, The method of determining the safety of the frequency converter based on the brightness changes of each bulb in the circuit includes: Based on the closed state of each contactor in the circuit, determine the brightness change of each bulb in the circuit; Based on the brightness changes of each bulb in the circuit, it is determined whether the frequency converter has malfunctioned.

9. A device for detecting the safety of variable frequency drive (VFD) equipment, comprising the method for detecting the safety of VFD equipment as described in any one of claims 6 to 8, characterized in that, The device includes: The acquisition unit is used to acquire the operating signals of the circuit; The detection unit is used to control the circuit to detect the safety of the frequency converter based on the working signal; The judgment unit is used to determine the safety of the frequency converter based on the brightness changes of each bulb in the circuit.

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