Inverter busbar inductance value detection device
By designing an inverter busbar inductance detection device including power supply power, load inductor, pulse signal transmitting device, high-voltage signal acquisition device and current acquisition device, the problems of low acquisition accuracy and easy to trigger incorrectly are solved, and high-precision detection of the inverter busbar inductance is realized.
Patent Information
- Application Number
- CN202422203695.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-09-09
AI Technical Summary
The existing busbar inductance detection device has low acquisition accuracy and few judgment contents, which is prone to error triggering.
An inverter busbar inductance detection device is designed, including a power supply power supply, a load inductor, a pulse signal transmitting device, a high-voltage signal acquisition device and a current acquisition device. Through the upper or lower bridge testing, the load inductor is used to connect it in parallel with the IGBT to measure the voltage between the IGBT emitter and the collector and the current flowing through the IGBT, and accurately measure the busbar inductance.
It improves the acquisition accuracy of the busbar inductance, can more accurately detect the inductance of the inverter busbar, avoids false triggering, and meets the detection requirements for the normal operation of the IGBT module.
Smart Images
Figure CN223006231U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an inductance detection device, and more specifically, to an inductance detection device for an inverter busbar. Background Art
[0002] IGBT modules are widely used in fields such as new energy, rail transit, and smart grid. IGBT modules can not only invert the direct current on the busbar into alternating current, but also rectify the alternating current and input it to the busbar. The IGBT module in the inverter inverts the alternating current on the busbar. The inductance value of the inverter unit busbar affects whether the core IGBT module of the entire system can operate normally and reliably. Therefore, in order to ensure the normal operation of the IGBT module, it is necessary to detect the inductance value of the busbar.
[0003] Currently, for the detection device of the busbar inductance value, most use traditional analog or digital ammeters to judge the busbar inductance, which has disadvantages such as low acquisition accuracy, few judgment contents, and false triggering. For this reason, a new type of inductance detection device for an inverter busbar is proposed in this article to conveniently and quickly detect the inductance value of the unit busbar. Summary of the Invention
[0004] The utility model provides an inductance detection device for an inverter busbar in order to overcome the above technical problems.
[0005] The inductance detection device for an inverter busbar of the utility model includes a power supply, a load inductor, a pulse signal transmitting device, a high-voltage signal acquisition device, and a current acquisition device. A support capacitor, an upper-bridge IGBT, and a lower-bridge IGBT are connected between the positive busbar and the negative busbar of the inverter, and the upper-bridge IGBT and the lower-bridge IGBT are connected in series to form an inverter bridge; the power supply is connected to the positive busbar and the negative busbar to provide a DC voltage for the inverter busbar; its characteristics are as follows:
[0006] When using the lower-bridge test: one end of the load inductor is connected to the output end of the inverter bridge and the other end is connected to the positive busbar, the pulse signal transmitting device is connected to the gate of the lower-bridge IGBT, one end of the high-voltage signal acquisition device is connected to the output end of the inverter bridge and the other end is connected to the negative busbar, and the current acquisition device is connected to the negative busbar;
[0007] When using the upper-bridge test: one end of the load inductor is connected to the output end of the inverter bridge and the other end is connected to the negative busbar, the pulse signal transmitting device is connected to the gate of the upper-bridge IGBT, one end of the high-voltage signal acquisition device is connected to the output end of the inverter bridge and the other end is connected to the positive busbar, and the current acquisition device is connected to the positive busbar.
[0008] The inverter busbar inductance detection device of the present utility model includes a low-voltage signal acquisition device. When using the lower-bridge test: one end of the low-voltage signal acquisition device is connected to the gate of the lower-bridge IGBT, and the other end is connected to the emitter of the lower-bridge IGBT. When using the upper-bridge test: one end of the low-voltage signal acquisition device is connected to the gate of the upper-bridge IGBT (1), and the other end is connected to the emitter of the upper-bridge IGBT.
[0009] The inverter busbar inductance detection device of the present utility model includes a pulse signal capture device. The three input channels of the pulse signal capture device are respectively connected to the output ends of a high-voltage signal acquisition device, a current acquisition device, and a low-voltage signal acquisition device.
[0010] The inverter busbar inductance detection device of the present utility model, the pulse signal transmitting device includes an upper-bridge signal transmitting device and a lower-bridge signal transmitting device. The output ends of the upper-bridge signal transmitting device and the lower-bridge signal transmitting device are respectively connected to the gates of the upper-bridge IGBT and the lower-bridge IGBT.
[0011] The beneficial effects of the present utility model are as follows: The inverter busbar inductance detection device of the present utility model is provided with a power supply, a load inductor, a pulse signal transmitting device, a high-voltage signal acquisition device, and a current acquisition device. According to different upper-bridge or lower-bridge tests, the load inductor is connected in parallel with the upper-bridge or lower-bridge IGBT. The power supply provides a DC voltage for the inverter busbar. The pulse signal transmitting device provides a pulse signal to the upper-bridge or lower-bridge that is not connected in parallel with the IGBT to control the corresponding IGBT device to turn on and off. The high-voltage signal acquisition device is used to measure the voltage between the emitter and the collector of the upper-bridge or lower-bridge IGBT that is not connected in parallel with the load inductor. The current acquisition device is used to measure the current flowing through the load inductor (i.e., the IGBT that is not connected in parallel with the load inductor). In this way, through the measured voltage between the emitter and the collector of the IGBT and the current signal of the IGBT that is not connected in parallel with the load inductor, the value of the inverter busbar inductance can be accurately measured. Compared with the existing analog or digital meters for judging the busbar inductance, the acquisition accuracy of the busbar inductance is higher.
[0012] Furthermore, a low-voltage signal acquisition device connected to the gate and the emitter of the upper-bridge or lower-bridge IGBT is provided. By using the waveforms collected by the low-voltage signal acquisition device and the high-voltage acquisition device, it can be judged whether the pulse signal transmitting device has successfully transmitted a pulse signal.
[0013] Furthermore, a pulse signal capture device is provided. The three input channels of the pulse signal capture device are respectively connected to the output ends of the high-voltage signal acquisition device, the current acquisition device, and the low-voltage signal acquisition device. It can achieve a perfect reproduction of the collected signals, and perform waveform display, capture, and burning when necessary, and then perform a detailed calculation of the inverter busbar inductance through the voltage and current signals. Description of the Drawings
[0014] Figure 1 It is a schematic diagram of the device for detecting the inductance of the inverter busbar of the present utility model;
[0015] Figure 2 It is a schematic diagram of the electrical connection of the device for detecting the inductance of the inverter busbar of the present utility model.
[0016] In the figure: 1 upper-bridge IGBT, 2 lower-bridge IGBT, 3 support capacitor, 4 power supply, 5 load inductor, 6 pulse signal transmitting device, 7 high-voltage signal acquisition device, 8 current acquisition device, 9 low-voltage signal acquisition device. Detailed Implementation Manner
[0017] The present utility model will be further described below in conjunction with the drawings and embodiments.
[0018] As Figure 1 and Figure 2 shown, a schematic diagram of the principle and a schematic diagram of the electrical connection of the device for detecting the inductance of the inverter busbar of the present utility model are given. It is composed of a support capacitor 3, a power supply 4, a load inductor 5, a pulse signal transmitting device 6, a high-voltage signal acquisition device 7 and a current acquisition device 8. The inverter busbar shown is composed of a positive busbar and a negative busbar. Both ends of the support capacitor 3 are connected to the positive busbar and the negative busbar. The emitter of the upper-bridge IGBT is connected to the collector of the lower-bridge IGBT. The collector of the upper-bridge IGBT is connected to the positive busbar, and the collector of the lower-bridge IGBT is connected to the negative busbar. The upper-bridge IGBT and the lower-bridge IGBT form an inverter bridge, and the connection between the upper-bridge IGBT and the lower-bridge IGBT forms the output end of the inverter bridge.
[0019] Figure 1 and Figure 2 The schematic diagram of the device for detecting the inductance of the inverter busbar of the present utility model given is the schematic diagram of the principle when the lower-bridge is tested. Both ends of the shown load inductor 5 are connected to the collector and emitter of the upper-bridge IGBT (i.e., the output end of the inverter bridge), that is, the load inductor 5 is connected in parallel with the upper-bridge IGBT. The output end of the power supply 4 is connected to the positive busbar and the negative busbar, and the power supply 4 provides a DC voltage for the inverter busbar. The pulse signal output end of the pulse signal transmitting device 6 is connected to the gate (i.e., the grid) of the lower-bridge IGBT to provide a pulse signal for the conduction and cut-off of the lower-bridge IGBT. One input end of the high-voltage signal acquisition device 7 is connected to the output end of the inverter bridge (i.e., the collector of the lower-bridge IGBT), and the other input end is connected to the negative busbar (i.e., the emitter of the lower-bridge IGBT) to measure the voltage change across the lower-bridge IGBT. The current acquisition device 8 is connected to the negative busbar, and it measures the current flowing through the negative busbar by means of current mutual induction, that is, it measures the current flowing through the lower-bridge IGBT and the load inductor 5.
[0020] For an inverter bridge with a rated current of 300 A, it is necessary to ensure that the measured current reaches 300 A. The magnitude of the current can be changed by altering the pulse duty cycle of the pulse signal transmitting device 6 or by changing the inductance value of the load inductor 5 to meet the detection requirements.
[0021] There is the following relationship between the voltage change across the IGBT device (lower-bridge IGBT) and the busbar inductance:
[0022] △V = Ls × [di(t) / dt] (1)
[0023] Where △V is the voltage change between the collector and emitter of the lower-bridge IGBT, Ls is the busbar inductance of the inverter, and di(t) is the change in current flowing between the collector and emitter of the lower-bridge IGBT over time.
[0024] From formula (1), we can obtain:
[0025] Ls = △V × [dt / di(t)] (2)
[0026] Among them, △V is obtained from the measurement data of the high-voltage signal acquisition device 7, and di(t) is obtained from the measurement data of the current acquisition device 8.
[0027] Figure 1 、 Figure 2 The schematic diagram and electrical connection diagram of the parallel connection of the load inductor 5 with the upper-bridge IGBT are given. The load inductor 5 can also be connected in parallel to the lower-bridge IGBT for detecting the busbar inductance. When the load inductor 5 is connected in parallel with the lower-bridge IGBT, the pulse signal output terminal of the pulse signal transmitting device 6 is connected to the gate of the upper-bridge IGBT, one end of the high-voltage signal acquisition device 7 is connected to the output terminal of the inverter bridge (i.e., the emitter of the upper-bridge IGBT), and the other end is connected to the positive busbar (i.e., the collector of the upper-bridge IGBT), and the test position of the current acquisition device 8 remains unchanged.
[0028] In order to enable the pulse signal transmitting device 6 to send pulse signals for controlling the upper-bridge IGBT and the lower-bridge IGBT, the pulse signal transmitting device can be composed of an upper-bridge signal transmitting device and a lower-bridge signal transmitting device. The output terminals of the upper-bridge signal transmitting device and the lower-bridge signal transmitting device are respectively connected to the gates of the upper-bridge IGBT and the lower-bridge IGBT.
[0029] In order to accurately reflect whether the pulse signal sent by the pulse signal transmitting device 6 is successfully transmitted, a low-voltage signal acquisition device 9 is also provided. Figure 2One end of the low-voltage signal acquisition device is connected to the gate of the lower-bridge IGBT, and the other end is connected to the emitter of the lower-bridge IGBT. When the load inductor 5 is connected in parallel with the lower-bridge IGBT, one end of the low-voltage signal acquisition device is connected to the gate of the upper-bridge IGBT, and the other end is connected to the emitter of the upper-bridge IGBT.
[0030] To achieve perfect reproduction of the acquired signal, and perform waveform display, capture, and recording when necessary. Furthermore, to calculate the busbar inductance in detail through voltage and current signals, a pulse signal capture device 6 can also be set up. The three input channels of the pulse signal capture device 6 are respectively connected to the output terminals of the high-voltage signal acquisition device 7, the current acquisition device 8, and the low-voltage signal acquisition device 9.
Claims
1. An inverter busbar inductance detection device, comprising a power supply (4), a load inductor (5), a pulse signal transmitting device (6), a high-voltage signal acquisition device (7) and a current acquisition device (8), wherein a support capacitor (3) and an upper bridge IGBT (1) and a lower bridge IGBT (2) are connected between the positive busbar and the negative busbar of the inverter, and the upper bridge IGBT and the lower bridge IGBT are connected in series to form an inverter bridge; the power supply is connected to the positive busbar and the negative busbar to provide a DC voltage to the inverter busbar; the characteristics are as follows: When the lower bridge test is adopted: one end of the load inductor is connected to the output end of the inverter bridge and the other end is connected to the positive busbar, the pulse signal transmitting device (6) is connected to the gate of the lower bridge IGBT, one end of the high voltage signal collecting device is connected to the output end of the inverter bridge and the other end is connected to the negative busbar, and the current collecting device is connected to the negative busbar; When the upper bridge test is adopted: one end of the load inductor is connected to the output end of the inverter bridge and the other end is connected to the negative busbar, the pulse signal transmitting device (6) is connected to the gate of the upper bridge IGBT, one end of the high-voltage signal acquisition device is connected to the output end of the inverter bridge and the other end is connected to the positive busbar, and the current acquisition device is connected to the positive busbar.
2. The inverter busbar inductance detection device according to claim 1, characterized in that: It comprises a low-voltage signal acquisition device (9). When the lower bridge test is adopted: one end of the low-voltage signal acquisition device is connected to the gate of the lower bridge IGBT (2), and the other end is connected to the emitter of the lower bridge IGBT; when the upper bridge test is adopted: one end of the low-voltage signal acquisition device is connected to the gate of the upper bridge IGBT (1), and the other end is connected to the emitter of the upper bridge IGBT.
3. The inverter busbar inductance detection device according to claim 2, characterized in that: It comprises a pulse signal capture device, wherein three input channels of the pulse signal capture device are respectively connected to the output ends of a high-voltage signal acquisition device (7), a current acquisition device (8) and a low-voltage signal acquisition device (9).
4. The inverter busbar inductance detection device according to claim 1 or 2, characterized in that: The pulse signal transmitting device (6) comprises an upper bridge signal transmitting device and a lower bridge signal transmitting device, wherein the output ends of the upper bridge signal transmitting device and the lower bridge signal transmitting device are respectively connected to the gates of the upper bridge IGBT (1) and the lower bridge IGBT (2).