A method and system for quick identification of ac voltage loss of a pfc power supply and applications thereof

Abstract

The application discloses an AC voltage loss quick identification protection method and system of a PFC power supply, which comprises the following steps: on the hardware, the original circuit is still used, and AC voltage is directly sampled, and after resistance voltage division, the voltage is directly given to an MCU through RC filtering, and the MCU is sampled through an ADC module; on the software, the carrier of motor operation is set to 15 kHz, AC voltage detection is performed every time the carrier interrupt is entered, and an algorithm is used on the software, the number of times that the voltage value is continuously lower than 20Vac is recorded, and when the number of times that the voltage value is continuously lower than 20Vac is greater than 25 times, it is represented that the AC voltage is disconnected, and then the PFC power supply is turned off to perform protection. The application can detect the size and frequency of specific AC voltage; through the software algorithm, whether the AC voltage is disconnected can be judged only by using 1.667 ms, the PFC power supply is quickly disconnected, the PFC circuit is effectively protected, and the reliability of the product is enhanced.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a method and system for rapid identification and protection of AC voltage loss in a PFC power supply. Background Technology

[0002] Power factor correction (PFC) is becoming increasingly important for driving motors such as permanent magnet synchronous motors. When the input voltage is too low, the PFC circuit needs to draw more current to maintain output power, leading to overheating or even burnout of power devices (such as MOSFETs and diodes). Undervoltage protection in the PFC circuit is a critical safety mechanism used to prevent system damage or malfunction when the input or output voltage drops abnormally. Existing AC detection circuits determine whether AC power is interrupted by detecting the RMS (Root Mean Square) value of the AC voltage. If AC power is interrupted, the MCU (Microcontroller Unit) will output a low level to shut down the PFC power supply, thus protecting the PFC circuit. Since the AC detection circuit uses RMS calculated values, it requires at least one cycle of RMS value to detect an AC power interruption. When an AC voltage drop occurs, there is a probability that the PFC circuit will not be shut down in time due to an excessively long AC voltage detection time (>20ms), leading to damage to the PFC circuit. Therefore, it is necessary to design a method that can detect whether the AC voltage is disconnected more quickly and shut down the PFC power supply in time when the AC voltage is disconnected. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for rapid identification and protection of AC voltage loss in PFC power supplies, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for rapid identification and protection of AC voltage loss in a PFC power supply, the method comprising the following steps: S1. Based on the hardware circuit, the AC voltage is directly sampled, and after voltage division by resistors, it is directly fed to the MCU after RC filtering. The MCU uses the ADC module to sample and obtain the AC voltage value.

[0005] S2. The carrier wave for motor operation is set to 15kHz. With this as the period, AC voltage is detected each time the carrier wave is interrupted to determine whether the AC voltage is lower than the normal operating value.

[0006] S3. For AC voltage sampling, record the number of times the voltage value is continuously below 20Vac. When the number of times it is continuously below 20Vac is greater than 25 (Note: the interrupt time of 25 PWM cycles is 1 / 15k*25=1.667ms), it means that the AC voltage is disconnected, and then the PFC power supply is turned off for protection.

[0007] According to the above technical solution, the present invention provides a rapid AC voltage loss identification system for PFC power supplies, the system comprising: The voltage sampling module is used to sample the AC voltage, divide the voltage using resistors, filter it using RC filters, and then send it to the next stage. The judgment module is used to collect AC voltage data. Using a certain carrier frequency, it monitors the AC voltage every time the carrier is interrupted and determines whether the AC voltage is lower than the normal operating value. The control module, when recording that the AC voltage value is lower than the normal operating value for too many consecutive times, indicates that the AC voltage is disconnected, outputs a control signal, and then shuts down the PFC power supply for protection.

[0008] Based on the application of the aforementioned protection methods and systems, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it causes the electronic device to implement the method described in the first aspect of this application.

[0009] This application also provides a computer-readable storage medium for storing a computer program that, when run on a computer, causes the computer to perform the method described in the first aspect of this application.

[0010] Compared with existing technologies, the beneficial effects achieved by this invention are: This invention can detect the magnitude and frequency of specific AC voltages; through software algorithms, it can determine whether the AC voltage is disconnected in just 1.667ms, quickly disconnecting the PFC power supply, effectively protecting the PFC circuit, and enhancing product reliability. It has already been applied to agricultural single-phase fan projects, with an estimated capacity of 30,000 units per year. This solution can also be used in other single-phase power applications. Attached Figure Description

[0011] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a PFC circuit diagram of a method for rapid identification and protection of AC voltage loss in a PFC power supply according to an embodiment of this application. Figure 2This is a circuit diagram of the Drive MUC part of a method for rapid identification and protection of AC voltage loss in a PFC power supply according to an embodiment of this application; Figure 3 This is a circuit diagram of the AC Input section of a method for rapid identification and protection of AC voltage loss in a PFC power supply according to an embodiment of this application. Figure 4 This is a circuit diagram of the Power Supply portion of a method for rapid identification and protection of AC voltage loss in a PFC power supply according to an embodiment of this application. Figure 5 This is a flowchart of the steps of a method for rapid identification and protection of AC voltage loss in a PFC power supply according to an embodiment of this application; Figure 6 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0012] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0013] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0014] 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.

[0015] Please see Figure 1-6 This invention provides a technical solution: a method for rapid identification and protection of AC voltage loss in a PFC power supply, comprising: Instead of relying on the original circuit to detect the RMS value of the AC voltage to determine whether the AC power is off, the original circuit now directly samples the AC voltage, uses resistors to divide the voltage, and then sends the signal directly to the MCU after RC filtering. The MCU then uses the ADC (Analog-to-Digital Converter) module to sample the signal.

[0016] Based on software algorithms for AC voltage sampling, AC voltage detection is performed every time the input carrier is interrupted, and the number of times the voltage value is continuously lower than the reference voltage is recorded. When the number of times the voltage value is continuously lower than the reference voltage exceeds a specified number, it means that the AC voltage is disconnected, and the PFC power supply is turned off for protection.

[0017] Specifically, the flowchart of the algorithm is as follows: Figure 5 As shown, the PWM (Pulse-Width Modulation) carrier frequency is set to 15kHz. It samples the AC voltage data to determine if the voltage value is below 20V. If the voltage value is below 20V, sampling continues. When the number of consecutive times the sampled voltage value is below 20V exceeds 25 (note: the interruption time for 25 PWM cycles is 1 / 15kHz * 25 = 1.667ms), it indicates that the AC voltage is disconnected. The MCU outputs a low level through Disable PFC to shut down the 15V power supply to the PFC circuit, thus protecting it. If the sampled voltage value is not lower than 20V, it indicates that the voltage value is normal. The MCU outputs a high level through Disable PFC, and the PFC circuit operates normally.

[0018] L (live wire) and N (neutral wire) pass through Figure 3 The AC input circuit outputs L1 and N1, which are then processed by... Figure 1 After being divided by resistors, the signal is directly sent after passing through RC filtering. Figure 2 The MCU chip U9 in this embodiment is a GD323230C8T6. The MCU samples the AC voltage data. When the AC voltage is normal, the MCU outputs a high level through Disable PFC. When the AC voltage is too low, it outputs a low level.

[0019] like Figure 1 As shown in the schematic diagram, when PFC ENABLE outputs a high level, the PFC circuit operates normally; when PFC ENABLE outputs a low level, the 15V power supply to PFC is disconnected to protect the corresponding circuit.

[0020] Figure 6 For the POWER SUPPLY circuit, this embodiment uses the VIPER22ASTR-E switching power supply chip U3 to provide +15V power to the PFC circuit; the SGM2205-3.3 chip U2 to provide +3.3V power; and the SGM2205-5.0 chip U1 to provide +5V power.

[0021] Because previous AC detection circuits used RMS calculations to determine whether AC power was interrupted, detecting AC power failures required at least one RMS cycle. When AC voltage dropped, the PFC circuit might be damaged due to the excessively long AC voltage recognition time (>20ms) and the PFC circuit not shutting down in time.

[0022] Through this software algorithm, the present invention can determine the specific amplitude and frequency of the AC voltage, and only 1.667ms is needed to determine whether the AC is disconnected. It can quickly determine whether the AC voltage is disconnected and quickly disconnect the PFC power supply, effectively protecting the PFC circuit and enhancing the reliability of the product.

[0023] Similar to the embodiments described above, this application also provides a fast AC voltage loss identification system for PFC power supplies, comprising: The voltage sampling module is used to sample the AC voltage, divide the voltage using resistors, filter it using RC filters, and then send it to the next stage. The judgment module is used to collect AC voltage data, use an appropriate carrier frequency, monitor the AC voltage each time the carrier is interrupted, and determine whether the AC voltage is lower than the normal operating value. The control module, when recording that the AC voltage value is lower than the normal operating value for too many consecutive times, indicates that the AC voltage is disconnected, outputs a control signal, and then shuts down the PFC power supply for protection.

[0024] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0025] Based on the same inventive concept as the above method embodiments, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it enables the electronic device to implement the control method described in the above embodiments.

[0026] In one embodiment, the electronic device may be a server, and in this embodiment, the structure of the electronic device may be as follows: Figure 3 As shown, it includes a memory 2001, a communication module 2003, and one or more processors 2002.

[0027] The memory 2001 is used to store computer programs executed by the processor 2002. The memory 2001 may mainly include a program storage area and a data storage area. The program storage area may store the operating system and programs required to run instant messaging functions, etc.; the data storage area may store various instant messaging information and operation instruction sets, etc.

[0028] Memory 2001 may be volatile memory, such as random access memory (RAM); memory 2001 may also be nonvolatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or memory 2001 may be any other medium capable of carrying or storing a desired computer program having the form of instructions or data structures and accessible by a computer, but is not limited thereto. Memory 2001 may be a combination of the above-mentioned memories.

[0029] Processor 2002 may include one or more central processing units (CPUs) or digital processing units, etc. Processor 2002 is used to implement the above-mentioned audio data processing method when calling computer programs stored in memory 2001.

[0030] The communication module 2003 is used to communicate with terminal devices and other servers.

[0031] This application embodiment does not limit the specific connection medium between the memory 2001, communication module 2003, and processor 2002. This application embodiment... Figure 3 The memory 2001 and the processor 2002 are connected via a bus 2004, which is in... Figure 3 The connections between other components are illustrated with arrows and are for illustrative purposes only, not as limiting information. The Bus 2004 can be divided into address bus, data bus, control bus, etc. For ease of description, Figure 3 The text uses only one arrow to describe it, but does not indicate that there is only one bus or one type of bus.

[0032] Based on the same inventive concept as the above-described method embodiments, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program. When the computer program is run on a computer, it enables the electronic device to implement the control method described in the above embodiments. The computer-readable storage medium can be a readable signal medium or a readable storage medium. A 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 readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CDROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0033] Based on the same inventive concept as the above-described method embodiments, embodiments of the present invention also provide a computer program product, which includes a computer program that, when run on an electronic device, causes the electronic device to perform the steps of the control methods described above according to various exemplary embodiments of this application. The program product may take the form of any combination of one or more readable media. These computer program commands can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the commands executed by the processor of the computer or other programmable data processing device generate a process for implementing... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0034] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application. It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, 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 a process, method, article, or apparatus.

[0035] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for rapid identification and protection of AC voltage loss in a PFC power supply, characterized in that: The method includes the following steps: S1. Based on the hardware circuit, the AC voltage is directly sampled, and after voltage division by resistors, the signal is directly sent to the MCU after RC filtering. The MCU uses the ADC module to sample and obtain the AC voltage value. S2. Set the carrier wave for motor operation to a certain frequency, and use this as the period. Each time the carrier wave is interrupted, the AC voltage is detected to determine whether the AC voltage is lower than the normal operating value. S3. For AC voltage sampling, AC voltage detection is performed every time the input carrier is interrupted, and the number of times the voltage value is continuously lower than the reference voltage is recorded. When the number of times the voltage value is continuously lower than the reference voltage exceeds the specified number, it means that the AC voltage is disconnected, and then the PFC power supply is turned off for protection.

2. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 1, characterized in that: The carrier frequency in S2 is set to 15kHz.

3. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 2, characterized in that: The MCU samples the AC voltage data and determines whether the voltage value is lower than 20V. If the voltage value is lower than 20V, it continues to sample and determine.

4. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 3, characterized in that: When the sampled voltage value is below 20V more than 25 times consecutively, it indicates that the AC voltage is disconnected. The MCU outputs a low level through Disable PFC to shut down the 15V power supply of PFC. If the sampled voltage value is not lower than 20V, it indicates that the voltage value is normal. The MCU outputs a high level through Disable PFC, and the PFC circuit works normally.

5. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 1, characterized in that: The resistor voltage divider outputs L1 and N1 after the L and N lines pass through the AC Input circuit. After L1 and N1 are divided by resistors, the signals are directly sent to the MCU chip U9 after RC filtering. The MCU samples the AC voltage data. When the AC voltage is normal, the MCU outputs a high level through Disable PFC. When the AC voltage is too low, it outputs a low level.

6. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 5, characterized in that: When PFC ENABLE outputs a high level, the PFC circuit operates normally; when PFC ENABLE outputs a low level, the 15V power supply to PFC is disconnected.

7. The method for rapid identification and protection of AC voltage loss in a PFC power supply according to claim 1, characterized in that: The PFC circuit is powered by a VIPER22ASTR-E switching power supply chip U3, which provides +15V power; a SGM2205-3.3 chip U2 provides +3.3V power; and a SGM2205-5.0 chip U1 provides +5V power.

8. A fast AC voltage loss identification and protection system for a PFC power supply, applied to the fast AC voltage loss identification and protection method for a PFC power supply according to any one of claims 1-7, characterized in that: The system includes: The voltage sampling module is used to sample the AC voltage, divide it using resistors, filter it using RC filters, and then send it to the next stage. The judgment module is used to collect AC voltage data, use an appropriate carrier frequency, monitor the AC voltage each time the carrier is interrupted, and determine whether the AC voltage is lower than the normal operating value. The control module, when recording that the AC voltage value is lower than the normal operating value for too many consecutive times, indicates that the AC voltage is disconnected, outputs a control signal, and then shuts down the PFC power supply for protection.

9. An electronic device for a fast AC voltage loss identification and protection method based on PFC power supply, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it causes the electronic device to implement the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 7.

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