A voltage backfeed protection device
By sampling the DC bus voltage through the ARM chip on the power supply motherboard and combining it with software algorithms to control the output contactor to trip and block PWM, the problem of equipment damage caused by voltage backflow is solved, and a cost-effective protection device is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- POWER SUZHOU
- Filing Date
- 2025-06-05
- Publication Date
- 2026-06-19
Smart Images
Figure CN224385078U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of frequency conversion and voltage transformation technology, specifically a voltage backflow protection device. Background Technology
[0002] During the use of power supply systems, voltage backflow often damages the equipment, especially during motor load testing. The phenomenon of energy backflow is frequently encountered because the reverse electromotive force generated by the braking of the motor can flow back to the DC busbar of the frequency converter through the cable, causing the busbar voltage to rise. This can damage the DC filter capacitors or IGBTs and IGBT drive circuits on the DC busbar, resulting in damage to the frequency converter equipment and affecting the service life of the power supply.
[0003] One common approach in the market is to install a load on the DC bus inside the machine. However, the load power installed in this way is generally small and usually cannot meet the usage requirements well. Another approach is to connect an external load box to the DC bus. However, connecting an external load box requires additional investment in load box and power costs, and placing the load box also occupies space, resulting in poor economic efficiency. Yet another approach is to use a voltage detection and protection board to cut off the output. This approach has better cost advantages and economic efficiency compared to other methods, but it still requires the addition of a voltage detection and protection board device, and adjusting the protection threshold is not simple. Utility Model Content
[0004] (a) Technical problems to be solved
[0005] In view of the shortcomings of the prior art, this utility model provides a voltage anti-reverse current protection device to solve the problems mentioned in the background art.
[0006] (II) Technical Solution
[0007] To achieve the above objectives, this utility model provides the following technical solution: a voltage anti-reverse current protection device, comprising a power cabinet, a touch screen installed on the front of the power cabinet, a control switch and a device interface installed on the front of the power cabinet, the control switch and the device interface being located directly below the touch screen, the device interface being located to the right of the control switch, a heat dissipation opening on the front of the power cabinet, and a main power supply device installed inside the power cabinet;
[0008] The main power supply unit internally includes: an input unit, a rectifier unit, a DC filter unit, an inverter unit, an isolation transformer unit, an output contactor, and an output unit; the output unit is connected to the load via a cable.
[0009] The DC filter unit includes a DC busbar unit, the inverter unit contains an IGBT module, and the output contactor contains a voltage sampling module, AD pins, an ARM chip, an output contactor coil, an alarm device, a PWM blocking module, and an I / O interface.
[0010] Preferably, the voltage sampling module is connected to the DC bus unit.
[0011] Preferably, the AD pin is connected to the ARM chip.
[0012] Preferably, the ARM chip is electrically connected to the output contactor coil via an I / O interface.
[0013] Preferably, the output contactor is electrically connected to the inverter unit via a PWM blocking module, and the PWM blocking module is electrically connected to the ARM chip.
[0014] Preferably, the alarm device consists of a buzzer.
[0015] (III) Beneficial Effects
[0016] Compared with the prior art, this utility model provides a voltage backflow protection device, which has the following beneficial effects:
[0017] This voltage backflow protection device samples the DC bus voltage, converts the analog signal into a digital signal, and then uses the ARM chip on the power supply motherboard, combined with software programming to set the protection threshold. When energy backflow occurs at the power supply output and the DC bus voltage rises to the protection threshold, the software algorithm triggers the protection circuit, controls the output contactor to trip through the ARM's I / O port, and simultaneously blocks the PWM, shutting down the frequency converter equipment, thereby protecting the frequency converter equipment from damage and extending the power supply's service life.
[0018] It has the following advantages:
[0019] 1) When reverse voltage occurs, ensure that the power supply equipment is not damaged and extend the service life of the power supply;
[0020] 2) No additional energy absorption load box is required, reducing costs;
[0021] 3) No additional voltage detection and protection board is required. It can be implemented using the existing ARM I / O ports on the power supply's motherboard, combined with a software algorithm, resulting in almost no increase in hardware cost. The software algorithm triggers the protection threshold, and this threshold can be set. Attached Figure Description
[0022] Figure 1 This utility model is a voltage anti-reverse current protection device;
[0023] Figure 2 This is a diagram of the voltage feedback protection system of this utility model.
[0024] In the diagram: 1. Power supply cabinet; 2. Touch screen; 3. Heat dissipation opening; 4. Control switch; 5. Equipment interface; 6. Voltage sampling module; 7. AD pin; 8. ARM chip; 9. DC busbar unit; 10. Output contactor coil; 11. Output contactor; 12. Alarm device; 13. PWM blocking module; 14. I / O interface. Detailed Implementation
[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0026] This utility model provides a technical solution.
[0027] Please see Figure 1 A voltage reverse current protection device includes a power cabinet 1, a touch screen 2 installed on the front of the power cabinet 1, a control switch 4 and an equipment interface 5 installed on the front of the power cabinet 1, the control switch 4 and the equipment interface 5 are both located directly below the touch screen 2, the equipment interface 5 is located to the right of the control switch 4, a heat dissipation opening 3 is provided on the front of the power cabinet 1, and the main power supply equipment is installed inside the power cabinet 1.
[0028] Please see Figure 2 The main power supply unit includes: an input unit, a rectifier unit, a DC filter unit, an inverter unit, an isolation transformer unit, an output contactor 11, and an output unit; the output unit is connected to the load via a cable.
[0029] The DC filter unit includes a DC busbar unit 9, the inverter unit contains an IGBT module, and the output contactor 11 contains a voltage sampling module 6, an AD pin 7, an ARM chip 8, an output contactor coil 10, an alarm device 12, a PWM blocking module 13, and an I / O interface 14.
[0030] The voltage sampling module 6 is connected to the DC bus unit 9; the AD pin 7 is connected to the ARM chip 8; the ARM chip 8 is electrically connected to the output contactor coil 10 through the I / O interface 14; the output contactor 11 is electrically connected to the inverter unit through the PWM blocking module 13, and the PWM blocking module 13 is electrically connected to the ARM chip 8; the alarm device 12 is composed of a buzzer.
[0031] The design of this voltage backflow prevention protection device represents a voltage backflow prevention protection technical solution.
[0032] An output contactor 11 is added between the isolation transformer unit and the output unit. When reverse voltage occurs, the reverse voltage is rectified into DC voltage by the IGBT of the inverter INV unit and transmitted to the DC bus unit 9. The voltage sampling module 6 samples and filters the DC voltage from the DC bus unit 9, and then sends it to the analog signal input terminal AD pin 7 of the ARM chip 8. The ARM chip 8 converts the analog signal into a digital signal and performs calibration, filtering, comparison and other algorithm processing on the data. When the sampled voltage is greater than the set protection threshold, the protection mechanism is triggered. The relay is driven through the I / O interface 14 to control the on / off state of the output contactor coil 10, thereby controlling the on / off state of the output contactor 11, cutting off the electrical connection between the isolation transformer and the output unit, thus preventing the reverse voltage from entering the DC bus unit 9, protecting the DC filter capacitor or IGBT or IGBT drive circuit on the DC bus unit 9, and thus protecting the frequency converter from damage. At the same time, the PWM drive signal of the IGBT is blocked, and the buzzer is driven to provide an alarm. The protection threshold can be adjusted on the touch screen 2.
[0033] The anti-backflow protection effect is as follows:
[0034] When the output unit supplies power to motor-type loads via cables, the frequency converter can output normally. When the motor-type load decelerates or brakes, the generated reverse electromotive force will flow back to the inverter INV terminal through the cables, output unit, output contactor 11, and isolation transformer. Then, it will be rectified into DC voltage by the IGBT of the inverter INV and transmitted to the DC bus unit 9. When the DC bus voltage rises to the limit value of the DC bus, it will damage the DC filter capacitor and may also damage the IGBT or IGBT drive circuit. Using voltage reverse current protection can ensure that the power supply system is not damaged.
[0035] By sampling the DC bus voltage, the analog signal is converted into a digital signal. Then, using the ARM chip on the power supply motherboard and combined with software programming to set the protection threshold, when energy backflow occurs at the power supply output and the DC bus voltage rises to the protection threshold, the protection circuit is triggered by the software algorithm. The output contactor is tripped through the ARM's I / O port, the IGBT drive signal is blocked by PWM, and the frequency converter is shut down.
[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0037] Although embodiments of the present invention have been shown and described, 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 present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A voltage reverse-current protection device, characterized in that; The power supply cabinet (1) includes a touch screen (2) installed on the front of the power supply cabinet (1), a control switch (4) and a device interface (5) installed on the front of the power supply cabinet (1), the control switch (4) and the device interface (5) are both located directly below the touch screen (2), the device interface (5) is located to the right of the control switch (4), the front of the power supply cabinet (1) has a heat dissipation opening (3), and the main power supply equipment is installed inside the power supply cabinet (1). The main power supply unit includes: an input unit, a rectifier unit, a DC filter unit, an inverter unit, an isolation transformer unit, an output contactor (11), and an output unit; and the output unit is connected to the load via a cable. The DC filter unit includes a DC bus unit (9), the inverter unit includes an IGBT module, and the output contactor (11) includes a voltage sampling module (6), an AD pin (7), an ARM chip (8), an output contactor coil (10), an alarm device (12), a PWM blocking module (13), and an I / O interface (14).
2. The voltage reverse current protection device according to claim 1, characterized in that: The voltage sampling module (6) is connected to the DC bus unit (9).
3. The voltage reverse current protection device according to claim 1, characterized in that: The AD pin (7) is connected to the ARM chip (8).
4. The voltage reverse current protection device according to claim 1, characterized in that: The ARM chip (8) is electrically connected to the output contactor coil (10) through the I / O interface (14).
5. A voltage reverse-current protection device according to claim 1, characterized in that: The output contactor (11) is electrically connected to the inverter unit through the PWM blocking module (13), and the PWM blocking module (13) is electrically connected to the ARM chip (8).
6. A voltage reverse-current protection device according to claim 1, characterized in that: The alarm device (12) consists of a buzzer.