A frequency converter IGBT power module drive detection system and method

Abstract

The application discloses a kind of frequency converter IGBT power module drive detection system and method, including signal acquisition synchronous frequency converter, signal acquisition detection unit, PLC signal analysis processing unit, touch screen six-way histogram display unit;The signal acquisition detection unit is connected with signal acquisition synchronous frequency converter, PLC signal analysis processing unit communication respectively;The touch screen six-way histogram display unit is connected with PLC signal analysis processing unit communication;The beneficial effects of the application are: to the frequency converter being used, can be detected without disassembly, can early find the implicit and slight failure of frequency converter, timely repair or replacement, avoid the loss and security risk that sudden stop of failure expansion brings to production;When frequency converter drive circuit failure is maintained, the fault position can be quickly determined, and the maintenance speed is improved;Frequency converter after maintenance or long time not in use can be detected, and whether its working state is normal is confirmed.

Description

Technical Field

[0001] This invention belongs to the field of frequency converter output detection technology, specifically relating to a frequency converter IGBT power module drive detection system and method. Background Technology

[0002] Low-voltage frequency conversion equipment, such as motor control frequency converters and frequency conversion air conditioners, cannot be directly inspected and judged to determine whether the six drive signals of IGBT power devices and the conduction status of the six power components are normal during routine inspections and maintenance when a fault occurs. Problems with the six drive signals cannot be compared and judged. Currently, there is no system or method to perform simple and accurate detection and judgment of the six drive signals, and to compare the synchronization of the six signals and the consistency of the conduction of the six power components. Summary of the Invention

[0003] The purpose of this invention is to provide a test system and method for driving IGBT power modules of frequency converters, which can test frequency converters in use without disassembly; it can also test frequency converters that have been repaired or have not been used for a long time.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a frequency converter IGBT power module drive detection system, comprising a signal acquisition synchronous frequency converter, a signal acquisition and detection unit, a PLC signal analysis and processing unit, and a touch screen six-channel bar chart display unit;

[0005] The signal acquisition and detection unit is communicatively connected to the signal acquisition synchronous frequency converter and the PLC signal analysis and processing unit, respectively.

[0006] The touchscreen six-channel bar chart display unit is communicatively connected to the PLC signal analysis and processing unit;

[0007] The signal acquisition synchronous frequency converter is used to acquire the U, V and W three-phase alternating output voltages of the frequency converter and convert the high voltage into an alternating low voltage signal.

[0008] The signal acquisition and detection unit is used for signal separation and conversion;

[0009] The PLC signal analysis and processing unit is used to analyze and process signals;

[0010] The touchscreen six-way bar chart display unit is used to display signal status.

[0011] As a preferred technical solution of the present invention, the six-channel bar chart display unit of the touch screen displays the signal status to determine whether the IGBT conduction voltage is the same and whether the driving frequency is consistent.

[0012] As a preferred technical solution of the present invention, the three-phase frequency adjustable alternating voltage output by the frequency converter is obtained by driving the IGBT through the CPU computer board of the frequency converter.

[0013] As a preferred technical solution of the present invention, it also includes a signal acquisition and detection circuit, which detects the alternating voltages UW, VU, and WV.

[0014] As a preferred embodiment of the present invention, the PLC signal analysis and processing unit has a built-in power supply that provides power to it.

[0015] As a preferred technical solution of the present invention, the drive detection system is connected in parallel with the load at the three-phase output terminals U, V, and W of the frequency converter, and the frequency converter is powered on and the frequency is set to 5-10 Hz.

[0016] This invention also discloses a method for driving and detecting IGBT power modules in a frequency converter, including a signal acquisition synchronous frequency converter. The signal acquisition synchronous frequency converter acquires the three-phase alternating output voltages of the frequency converter (U, V, W), converts the high voltage into an alternating low voltage signal, and then transmits this signal to a signal acquisition and detection unit. The signal acquisition and detection unit performs signal separation and conversion to obtain three upper bridge arm DC pulsating signals (T1, T3, T5) and three lower bridge arm DC pulsating signals (T2, T4, T6). These six signals are transmitted to a PLC signal analysis and processing unit. After analysis and processing, the status of the six signals is displayed by a six-channel bar chart display unit on a touch screen.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. For frequency converters in use, testing can be performed without disassembly, allowing for the early detection of hidden and minor faults in the frequency converter, timely repair or replacement, and avoiding the loss of production and safety hazards caused by sudden shutdowns due to the escalation of faults.

[0019] 2. When repairing inverter drive circuit faults, the fault location can be quickly determined, improving the repair speed;

[0020] 3. Inverters that have been repaired or have not been used for a long time can be tested to confirm whether their working status is normal. Attached Figure Description

[0021] Figure 1 This is a basic schematic diagram of the frequency converter of the present invention;

[0022] Figure 2 This is a block diagram of the detection system of the present invention;

[0023] Figure 3 This is a circuit diagram for signal acquisition and detection of the present invention;

[0024] Figure 4This is a diagram of the PLC signal analysis and processing unit of the present invention. Detailed Implementation

[0025] 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 some embodiments of the present invention, and not all embodiments. 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.

[0026] Example 1

[0027] Please see Figure 1 , Figure 2 ... Figure 3 , Figure 4 This is the first embodiment of the present invention. This embodiment provides a frequency converter IGBT power module drive detection system, including a signal acquisition synchronous frequency converter, a signal acquisition and detection unit, a PLC signal analysis and processing unit, and a touch screen six-channel bar chart display unit.

[0028] The signal acquisition and detection unit is communicatively connected to the signal acquisition synchronous frequency converter and the PLC signal analysis and processing unit, respectively.

[0029] The touchscreen six-channel bar chart display unit is communicatively connected to the PLC signal analysis and processing unit;

[0030] The signal acquisition synchronous frequency converter is used to acquire the U, V, W three-phase alternating output voltage of the frequency converter and convert the high voltage into an alternating low voltage signal.

[0031] The signal acquisition and detection unit is used for signal separation and conversion;

[0032] The PLC signal analysis and processing unit is used to analyze and process signals;

[0033] The touchscreen six-channel bar chart display unit is used to display signal status.

[0034] Figure 1 The diagram shows the basic principle of a frequency converter. Three-phase or single-phase AC power is rectified by D1-D6 to obtain DC power, filtered by capacitors C1 and C2, and then transmitted to the IGBT inverter circuit composed of T1-T6. The inverter is then driven and triggered by the CPU computer board drive circuit, so that the frequency-adjustable three-phase AC power can be obtained at the U, V, and W three-phase output terminals of the frequency converter.

[0035] Figure 3As shown, the drive detection system is connected in parallel with the load to the three-phase output terminals U, V, and W of the frequency converter. The frequency converter is powered on and the frequency is set to 5 Hz. After the frequency converter starts, the changes in the drive frequency and conduction voltage of the six IGBTs (upper and lower three bridge arms) under the control of the frequency converter CPU can be displayed on the touch screen.

[0036] By observing the display of the six-channel bar chart on the touchscreen, it is possible to determine whether the conduction voltages of the six IGBTs are the same and whether the drive frequencies are consistent. Gradually increase the frequency to the operating frequency and continue to observe whether the voltages and frequencies of the six drive signals are the same to determine whether the inverter is operating normally. If it is observed that the bar chart of a certain channel on the touchscreen is inconsistent with the other bar charts, it indicates that there is a fault in that drive or module. The faulty channel can be identified in the six drive circuits on the drive circuit board, quickly identifying the faulty circuit and reducing repair time. After the repair is completed, it can be tested again until all six signals are the same.

[0037] By connecting to the U, W, and W three-phase alternating voltage output of the frequency converter, the frequency converter in operation can be tested online without disassembling the equipment. The touch screen displays the test results intuitively and accurately, allowing for quick determination of whether the equipment is operating normally and whether there are any potential faults.

[0038] The three-phase adjustable alternating voltage output by the frequency converter is obtained by driving the IGBTs through the frequency converter's CPU. The detection equipment detects UW, VU, and WV respectively through the signal acquisition circuit. Figure 3 As shown, the frequency and voltage of the six forward and reverse conduction channels in three groups, U1U2, U3U4, V1V2, V3V4, and W1W2, W3W4, are measured and displayed on the touch screen. This allows for a direct assessment of whether the frequency converter is operating normally and whether there is a fault. If a fault is found, the fault range can be determined on the CPU computer board drive circuit based on the display on the touch screen.

[0039] For example, a frequency converter operates normally under light load, but the motor will produce noise and vibration under full load. When connected to the detection system, it was found that one drive signal was abnormal and the voltage was lower than the other five, causing the three-phase output to be unbalanced. Through measurement, it was confirmed that the fault was caused by the insufficient driving capability of the drive optocoupler of this one channel. After replacing the drive optocoupler, the fault was eliminated.

[0040] Before installing, powering on, and applying a load to a frequency converter that has undergone repair, it is impossible to determine whether it is fully repaired. Temporarily powering it on and connecting it to the rated load is difficult, and only a small load can be connected for testing. Because the load is small, hidden faults cannot be exposed, and it appears to be operating normally. At this time, by connecting to the drive detection system, it is possible to visually check on the touch screen whether the frequency converter is fully repaired and whether there are any hidden faults.

[0041] A method for driving and detecting IGBT power modules in a frequency converter includes a signal acquisition synchronous frequency converter. The signal acquisition synchronous frequency converter acquires the three-phase alternating output voltages (U, V, W) of the frequency converter, converts the high voltage into an alternating low voltage signal, and then transmits this signal to a signal acquisition and detection unit. The signal acquisition and detection unit separates and converts the signal to obtain three upper bridge arm DC pulsating signals (T1, T3, T5) and three lower bridge arm DC pulsating signals (T2, T4, T6). These six signals are transmitted to a PLC signal analysis and processing unit. After analysis and processing, the status of the six signals is displayed by a six-channel bar chart display unit on a touch screen. This allows for analysis and judgment of whether the six drive signals of the frequency converter are normal.

[0042] Example 2

[0043] Please see Figure 1 , Figure 2 ... Figure 3 , Figure 4 This is the second embodiment of the present invention, which is based on the previous embodiment, but differs in that:

[0044] Connect the drive detection system in parallel with the load to the three-phase output terminals U, V, and W of the frequency converter. Power on the frequency converter and set the frequency to 8 Hz. After the frequency converter starts, the changes in the drive frequency and conduction voltage of the six IGBTs (upper and lower three bridge arms) under the control of the frequency converter CPU can be displayed on the touch screen.

[0045] Example 3

[0046] Please see Figure 1 , Figure 2 ... Figure 3 , Figure 4 This is the third embodiment of the present invention, which is based on the previous embodiment, but differs in that:

[0047] Connect the drive detection system in parallel with the load to the three-phase output terminals U, V, and W of the frequency converter. Power on the frequency converter and set the frequency to 10 Hz. After the frequency converter starts, the changes in the drive frequency and conduction voltage of the six IGBTs (upper and lower three bridge arms) under the control of the frequency converter CPU can be displayed on the touch screen.

[0048] Although embodiments of the invention have been shown and described in detail above, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A drive detection system for IGBT power modules of a frequency converter, characterized in that: Includes a signal acquisition synchronous frequency converter, a signal acquisition and detection unit, a PLC signal analysis and processing unit, and a touch screen six-channel bar chart display unit; The signal acquisition and detection unit is communicatively connected to the signal acquisition synchronous frequency converter and the PLC signal analysis and processing unit, respectively. The touchscreen six-channel bar chart display unit is communicatively connected to the PLC signal analysis and processing unit; The signal acquisition synchronous frequency converter is used to acquire the U, V and W three-phase alternating output voltages of the frequency converter and convert the high voltage into an alternating low voltage signal. The signal acquisition and detection unit is used for signal separation and conversion; The PLC signal analysis and processing unit is used to analyze and process signals; The touchscreen six-way bar chart display unit is used to display signal status.

2. The inverter IGBT power module drive detection system according to claim 1, characterized in that: The six-channel bar chart display unit on the touch screen displays the signal status to determine whether the IGBT conduction voltage is the same and whether the driving frequency is consistent.

3. The inverter IGBT power module drive detection system according to claim 1, characterized in that: The three-phase frequency adjustable alternating voltage output by the frequency converter is obtained by driving the IGBT through the frequency converter's CPU computer board.

4. The inverter IGBT power module drive detection system according to claim 1, characterized in that: It also includes a signal acquisition and detection circuit, which detects the alternating voltages UW, VU, and WV.

5. The inverter IGBT power module drive detection system according to claim 1, characterized in that: The PLC signal analysis and processing unit has a built-in power supply that provides it with power.

6. The inverter IGBT power module drive detection system according to claim 1, characterized in that: The drive detection system is connected in parallel with the load at the three-phase output terminals U, V, and W of the frequency converter. The frequency converter is powered on and the frequency is set to 5-10 Hz.

7. A method for driving and detecting IGBT power modules in a frequency converter, characterized in that: The system includes a signal acquisition synchronous frequency converter in the drive detection system as described in any one of claims 1-6. The detection method is as follows: the signal acquisition synchronous frequency converter acquires the U, V, and W phase alternating output voltages of the frequency converter, converts the high voltage into an alternating low voltage signal, and then transmits this signal to the signal acquisition and detection unit. The signal acquisition and detection unit performs signal separation and conversion to obtain the DC pulsating signals of the three upper bridge arms (T1, T3, and T5) and the DC pulsating signals of the three lower bridge arms (T2, T4, and T6). These six signals are transmitted to the PLC signal analysis and processing unit. After analysis and processing, the status of the six signals is displayed by the six-channel bar chart display unit on the touch screen.

Images