A frequency converter detection device and method thereof

Abstract

The application discloses a frequency converter detection device, which comprises a shell, wherein a plurality of components are arranged on the shell, and specifically comprises incoming line terminals (R, S and T), external terminals (A, B and C), an indicator lamp HD, a switch Q, output terminals (U, V and W), an AC voltage meter AC-V, DC terminals (DC+ and DC-), and a DC voltage meter DC-V; the incoming line terminals (R, S and T) are connected with the indicator lamp HD and the switch Q on one side and are communicated with the external terminals (A, B and C) through the switch Q; the output terminals (U, V and W) are connected with the AC voltage meter AC-V; and the DC terminals (DC+ and DC-) are connected with the DC voltage meter DC-V; the frequency converter detection device has the advantages of simple structure and convenient operation, and maintenance personnel only need to connect different function electric wires and cables to the wire terminals with obvious marks on the frequency converter to quickly judge problems existing in the frequency converter itself.

Description

Technical Field

[0001] This invention relates to the field of frequency converter testing devices, specifically a frequency converter testing device and method. Background Technology

[0002] Frequency converters are composed of power electronic devices and have a very wide range of applications. Maintaining and diagnosing faults in frequency converters requires the professional skills of relevant personnel, which is quite difficult for most practitioners. There are frequent cases where misdiagnosis leads to secondary damage to problematic frequency converters and long diagnosis times affect production. Currently, there is a lack of a device for quickly diagnosing the condition of frequency converters. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems by providing a frequency converter testing device and method.

[0004] The specific solution of the present invention is as follows: A frequency converter testing device, comprising: a housing, wherein the housing is provided with a plurality of components, specifically including: input terminals (R, S, T), external terminals (A, B, C), indicator light HD, switch Q, output terminals (U, V, W), AC voltmeter AC-V, DC terminals (DC+, DC-), and DC voltmeter DC-V; The incoming terminals (R, S, T) are connected to an indicator light HD and a switch Q, and are connected to external terminals (A, B, C) through the switch Q. The output terminals (U, V, W) are connected to an AC voltmeter AC-V. The DC terminals (DC+, DC-) are connected to a DC voltmeter DC-V.

[0005] Furthermore, the indicator light HD consists of three incandescent lamps, which are connected in series with the incoming terminals (R, S, T).

[0006] A method for testing a frequency converter, using the above-mentioned device, the method comprising: S1: External terminals (A, B, C) are connected to a certain length of flexible cable with alligator clips on the other end. During testing, the three alligator clips are clamped to the external power supply. S2: A certain length of flexible cable with alligator clips on the other end is connected to the incoming terminals (R, S, T). During testing, the three alligator clips are clamped on the power input terminals of the frequency converter. S3: A certain length of flexible cable with alligator clips on the other end is connected to the output terminals (U, V, W). During testing, the three alligator clips are clamped on the inverter output power terminals. S4: A flexible cable of a certain length with alligator clips on the other end is connected to the DC terminals (DC+, DC-). During testing, the two alligator clips are clamped on the DC bus terminals of the frequency converter. Among them, it can determine whether the inverter rectifier circuit is short-circuited: After wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the casing, if any two of the three incandescent lamps have the same brightness and remain so, and the DC-V voltmeter shows a voltage of around 100V, it indicates that there is a short circuit in the rectifier circuit. This can avoid the misjudgment that occurs when using a multimeter to test some brands of frequency converters with transformers installed at the R, S, and T input terminals. It can determine whether the frequency converter's rectifier circuit is short-circuited. Among them, it can determine whether the inverter's pre-charge circuit is normal: If, after wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the device, all three incandescent lamps do not light up and the DC-V voltmeter shows zero voltage, the inverter pre-charge circuit is not working properly. Among them, it can determine whether the DC circuit of the frequency converter is grounded or short-circuited: If the three incandescent lamps are bright and continuously lit, and the DC-V voltmeter shows an abnormal voltage, it indicates that there is a short circuit or grounding fault on the DC side of the rectifier circuit. Among them, it can detect whether the three phases on the output side of the frequency converter are balanced: If the inverter's upper panel displays no faults but the motor driven by the inverter is not working properly, connect the wiring according to method S3 and start the inverter. If the three-phase voltage displayed on the AC-V voltmeter is unbalanced, it indicates that there is a fault in the inverter IGBT or its drive circuit board inside the inverter. Among them, it can charge the built-in capacitors of frequency converters that have been stored for more than one year: After wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the device, the brightness of the three incandescent lamps changes from bright to dim red. The DC-V voltmeter shows that the voltage is normal and can be maintained for two hours to complete the charging of the built-in capacitor of the frequency converter that has been stored for more than one year.

[0007] The present invention has the following beneficial effects: Using this device and method, maintenance personnel only need to connect wires and cables with different functions to the clearly marked terminals on the frequency converter to quickly determine the problems existing in the frequency converter itself. Specifically, it can solve the following problems: 1. Able to determine if the inverter's rectifier circuit is short-circuited; 2. Able to determine whether the inverter's pre-charge circuit is normal; 3. Able to determine whether the DC circuit of the frequency converter is grounded or short-circuited; 4. It can detect whether the three phases on the output side of the frequency converter are balanced; 5. It can charge the built-in capacitors of frequency converters that have been stored for more than one year. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating the working principle of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; In the diagram: 1. Input terminals (R, S, T); 2. Output terminals (U, V, W); 3. Indicator light HD; 4. Switch Q; 5. External terminals (A, B, C); 6. DC voltmeter DC-V; 7. AC voltmeter AC-V; 8. DC terminals (DC+, DC-); 9. Housing; 10. Inverter. Detailed Implementation

[0009] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0010] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0011] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0012] Please refer to Figure 1-2A frequency converter testing device includes: a housing 9, on which a plurality of components are provided, specifically including: input terminals (R, S, T) 1, external terminals (A, B, C) 5, indicator light HD3, switch Q4, output terminals (U, V, W) 2, AC voltmeter AC-V7, DC terminals (DC+, DC-) 8, and DC voltmeter DC-V6; Among them, one side of the incoming terminal (R, S, T) 1 is connected to an indicator light HD3 and a switch Q4, and is connected to the external terminal (A, B, C) 5 through the switch Q4; The output terminals (U, V, W) 2 are connected to an AC voltmeter AC-V7. The DC terminals (DC+, DC-)8 are connected to a DC voltmeter DC-V6.

[0013] In this embodiment, the indicator light HD3 consists of three incandescent lamps, which are connected in series with the input terminals (R, S, T)1 respectively.

[0014] A method for testing a frequency converter, using the above-mentioned device, the method comprising: S1: External terminals (A, B, C) 5 Connect a certain length of flexible cable with alligator clips on the other end. During testing, the three alligator clips are clamped to the external power supply. S2: The incoming terminal (R, S, T) 1 is connected to a certain length of flexible cable with alligator clips on the other end. During the test, the three alligator clips are clamped on the power input terminal of the inverter 10. S3: Output terminals (U, V, W) 2 are connected to a certain length of flexible cable with alligator clips on the other end. During testing, the three alligator clips are clamped on the output power terminals of inverter 10. S4: A certain length of flexible cable with alligator clips on the other end is connected to the DC terminal (DC+, DC-) 8. During testing, the two alligator clips are clamped on the DC bus terminal of the inverter 10. Among them, it can determine whether the rectifier circuit of inverter 10 is short-circuited: After wiring according to the methods of S1, S2, S3, and S4, and closing switch Q4 on housing 9, if any two of the three incandescent lamps have the same brightness and remain so, and the DC-V voltmeter shows a voltage of around 100V, it indicates that there is a short circuit in the rectifier circuit. This can avoid the misjudgment that occurs when using a multimeter to test some brands of frequency converter 10 when a transformer is installed at the R, S, and T input terminals. It can determine whether the rectifier circuit of frequency converter 10 is short-circuited. Among them, it can determine whether the pre-charge circuit of inverter 10 is normal: If the wiring is done according to the method of S1, S2, S3, S4, and the switch Q4 on the device is closed, and if all three incandescent lamps do not light up and the DC-V voltmeter shows zero voltage, then the pre-charge circuit of the inverter 10 is not working properly. Among them, it can determine whether the DC circuit of inverter 10 is grounded or short-circuited: If the three incandescent lamps are bright and continuously lit, and the DC-V voltmeter shows an abnormal voltage, it indicates that there is a short circuit or grounding fault on the DC side of the rectifier circuit. Among them, it can detect whether the three phases on the output side of inverter 10 are balanced: If the inverter 10 shows no fault on the upper panel and the motor driven by the inverter 10 is not working properly, connect the wiring according to the method of S3 and start the inverter 10. If the three-phase voltage displayed on the AC-V voltmeter is unbalanced, it indicates that there is a fault in the inverter IGBT or its drive circuit board inside the inverter 10. Among them, the built-in capacitor of the inverter 10, which has been stored for more than one year, can be charged: After wiring according to the methods of S1, S2, S3, and S4 and closing switch Q4 on the device, the brightness of the three incandescent lamps changes from bright to dim red. The DC-V voltmeter shows that the voltage is normal and can be maintained for two hours to complete the charging of the built-in capacitor of the inverter 10 that has been stored for more than one year.

[0015] The present invention has the following beneficial effects: Using this device and method, maintenance personnel only need to connect wires and cables with different functions to the clearly marked terminals on the inverter 10 to quickly determine the problems existing in the inverter 10 itself. Specifically, it can solve the following problems: 1. Able to determine whether the rectifier circuit of the frequency converter is short-circuited; 2. Able to determine whether the pre-charge circuit of inverter 10 is normal; 3. Able to determine whether the DC circuit of inverter 10 is grounded or short-circuited; 4. It can detect whether the three phases on the output side of the frequency converter are balanced; 5. It can charge the built-in capacitors of the frequency converter 10 that have been stored for more than one year.

[0016] The present invention is specifically embodied in a device that integrates a three-phase circuit breaker, three 40W incandescent lamps (or six incandescent lamps in pairs for a 690V system), a DC voltmeter, a digital voltmeter capable of measuring true RMS values, and a certain length of wires and cables with different functions.

[0017] In a specific application, a three-phase circuit breaker and three incandescent lamps are connected in series between the external three-phase AC power and the power input terminal or output terminal of the frequency converter 10. After the three-phase circuit breaker is closed, the three incandescent lamps quickly change from a bright state to a dim red filament. This state can solve the function involved in item 5 of the "technical problem to be solved". When inverter 10 malfunctions, connecting this device to inverter 10 will result in the following: if the brightness of the incandescent lamp does not decrease and the DC voltmeter displays abnormally, it indicates that there is a component breakdown in the rectifier circuit or the in-phase bridge arm of the inverter circuit in inverter 10; if the incandescent lamp does not light up, it indicates that there is an open circuit in the pre-charge circuit.

[0018] A DC voltmeter is connected in parallel to the DC circuit of inverter 10. Any abnormalities in the rectifier circuit or inverter circuit will be reflected in the display of this voltmeter. A digital voltmeter capable of measuring true RMS values ​​is connected to the output side of inverter 10, which can simultaneously display whether the three-phase voltages on the output side of inverter 10 are balanced.

Claims

1. A frequency converter testing device, comprising: The housing is characterized in that: the housing is provided with a number of components, specifically including: input terminals (R, S, T), external terminals (A, B, C), indicator light HD, switch Q, output terminals (U, V, W), AC voltmeter AC-V, DC terminals (DC+, DC-), and DC voltmeter DC-V; The incoming terminals (R, S, T) are connected to an indicator light HD and a switch Q, and are connected to external terminals (A, B, C) through the switch Q. The indicator light HD consists of three incandescent lamps, which are connected in series with the incoming terminals (R, S, T); The output terminals (U, V, W) are connected to an AC voltmeter AC-V. The DC terminals (DC+, DC-) are connected to a DC voltmeter DC-V; The detection method using the above-mentioned detection device includes: S1: External terminals (A, B, C) are connected to a certain length of flexible cable with alligator clips on the other end. During testing, the three alligator clips are clamped to the external power supply. S2: A certain length of flexible cable with alligator clips on the other end is connected to the incoming terminals (R, S, T). During testing, the three alligator clips are clamped on the power input terminals of the frequency converter. S3: A certain length of flexible cable with alligator clips on the other end is connected to the output terminals (U, V, W). During testing, the three alligator clips are clamped on the inverter output power terminals. S4: A flexible cable of a certain length with alligator clips on the other end is connected to the DC terminals (DC+, DC-). During testing, the two alligator clips are clamped on the DC bus terminals of the frequency converter. Among them, it can determine whether the inverter rectifier circuit is short-circuited: After wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the casing, if any two of the three incandescent lamps have the same brightness and remain so, and the DC-V voltmeter shows a voltage of around 100V, it indicates that there is a short circuit in the rectifier circuit. This can avoid the misjudgment that occurs when using a multimeter to test when a transformer is installed at the R, S, and T input terminals of the frequency converter. It can determine whether the frequency converter rectifier circuit is short-circuited. Among them, it can determine whether the inverter's pre-charge circuit is normal: If, after wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the device, all three incandescent lamps do not light up and the DC-V voltmeter shows zero voltage, the inverter pre-charge circuit is not working properly. Among them, it can determine whether the DC circuit of the frequency converter is grounded or short-circuited: If the three incandescent lamps are bright and continuously lit, and the DC-V voltmeter shows an abnormal voltage, it indicates that there is a short circuit or grounding fault on the DC side of the rectifier circuit. Among them, it can detect whether the three phases on the output side of the frequency converter are balanced: If the inverter's upper panel displays no faults but the motor driven by the inverter is not working properly, connect the wiring according to method S3 and start the inverter. If the three-phase voltage displayed on the AC-V voltmeter is unbalanced, it indicates that there is a fault in the inverter IGBT or its drive circuit board inside the inverter. Among them, it can charge the built-in capacitors of frequency converters that have been stored for more than one year: After wiring according to the methods of S1, S2, S3, and S4 and closing the switch Q on the device, the brightness of the three incandescent lamps changes from bright to dim red. The DC-V voltmeter shows that the voltage is normal and can be maintained for two hours to complete the charging of the built-in capacitor of the frequency converter that has been stored for more than one year.

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