Circuit protection method and device, electrical appliance and storage medium

Abstract

The present disclosure relates to a circuit protection method, device, electrical equipment and storage medium, wherein the method comprises: determining an adjustment range of a duty cycle of a switch tube in a current carrier cycle PFC circuit; and adjusting the duty cycle of the current carrier cycle within the adjustment range to adjust the current of the PFC circuit within a preset range. In the method of the present disclosure, the adjustment of the duty cycle of the switch tube is always within the set adjustment range, and in the scenario of voltage mutation, the increased amplitude of the duty cycle will not exceed the adjustment range, so that the current of the PFC circuit is always below the overcurrent threshold. Under the premise of being able to protect the electrical equipment, the electrical equipment can be stably operated without shutdown. In turn, it effectively reduces the abnormal shutdown of the electrical equipment caused by unstable power grid, and improves the user experience.

Description

Technical Field

[0001] This disclosure relates to the field of circuit protection, and more particularly to a circuit protection method, apparatus, electrical equipment, and storage medium. Background Technology

[0002] Power grids may experience voltage fluctuations due to factors such as transmission lines and electrical loads. When a power grid experiences voltage fluctuations or is affected by harmonic interference, it can cause electrical equipment to malfunction or even be damaged. In such scenarios, power factor correction (PFC) circuits are of great significance.

[0003] PFC circuits are commonly used in electrical appliances such as air conditioners, refrigerators, or washing machines. They have advantages such as high power factor, low harmonic current, and stable output voltage. They can be used to improve the total harmonic distortion (THD) or power factor (PF) of power supply products or electrical appliances.

[0004] When the power grid experiences voltage fluctuations or harmonic interference, the PFC circuit can trigger the shutdown of the power switching transistor (hereinafter referred to as the switching transistor) in the PFC circuit through circuit protection measures such as voltage protection or overcurrent protection, so as to control the electrical equipment to stop and achieve the protection purpose.

[0005] While PFC circuit protection measures in related technologies can protect devices from damage, the shutdown of temperature control equipment such as air conditioners and refrigerators during use can lead to poor temperature control comfort and affect user experience. Summary of the Invention

[0006] To overcome the problems existing in related technologies, this disclosure provides a circuit protection method, device, electrical equipment, and storage medium.

[0007] According to a first aspect of the embodiments of this disclosure, a circuit protection method is proposed, the method comprising:

[0008] Determine the adjustment range of the duty cycle of the switching transistor in the PFC circuit during the current carrier cycle;

[0009] The duty cycle of the current carrier cycle is adjusted within the adjustment range to regulate the current of the PFC circuit within a preset range.

[0010] In some embodiments, determining the adjustment range of the duty cycle of the switching transistor in the PFC circuit during the current carrier period includes:

[0011] Obtain the duty cycle data from the previous carrier cycle of the current carrier cycle;

[0012] The adjustment range is determined based on the duty cycle data.

[0013] In some embodiments, determining the adjustment range based on the duty cycle data includes:

[0014] Set parameter variables;

[0015] The adjustment range is determined based on the parameter variables and the duty cycle data.

[0016] In some embodiments, determining the adjustment range based on the parameter variable and the duty cycle data includes:

[0017] Based on the sum of each duty cycle in the duty cycle data and the parameter variable, the corresponding duty cycle limit value in the adjustment range is determined.

[0018] In some embodiments, the method further includes:

[0019] The parameter dimensions of the adjustment range are determined based on the frequency of the input voltage and the switching frequency of the switching transistor.

[0020] In some embodiments, the adjustment range is a curve showing the change of a duty cycle limit value over time and input voltage.

[0021] In some embodiments, the adjustment range is a mapping relationship between time and duty cycle limit values.

[0022] According to a second aspect of the present disclosure, a circuit protection device is provided for performing the circuit protection method described in any of the preceding claims.

[0023] According to a third aspect of the embodiments of this disclosure, an electrical device is provided, comprising:

[0024] processor;

[0025] Memory used to store the processor's executable instructions;

[0026] The processor is configured to perform the circuit protection method as described in any of the preceding claims.

[0027] According to a fourth aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, which, when instructions in the storage medium are executed by a processor of an electrical device, enables the electrical device to perform the circuit protection method as described in any of the preceding claims.

[0028] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0029] In the method disclosed herein, the duty cycle of the switching transistor is always adjusted within a set range. Even in the event of a voltage surge, the increase in the duty cycle will not exceed the adjustment range. Consequently, the current in the PFC circuit remains below the overcurrent threshold, ensuring stable operation of the electrical equipment without shutdown, thus effectively reducing abnormal shutdowns caused by grid instability and improving user experience.

[0030] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0032] Figure 1 This is a schematic diagram illustrating the change in duty cycle during voltage surges in related technologies.

[0033] Figure 2 This is a flowchart illustrating a method according to an exemplary embodiment.

[0034] Figure 3 This is a flowchart illustrating a method according to an exemplary embodiment.

[0035] Figure 4 This is a schematic diagram illustrating the adjustment range according to an exemplary embodiment.

[0036] Figure 5 This is a block diagram of an apparatus according to an exemplary embodiment.

[0037] Figure 6 This is a block diagram of an electrical appliance according to an exemplary embodiment. Detailed Implementation

[0038] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0039] Circuit protection measures in related technologies typically include the following two approaches:

[0040] First, voltage surge protection: Real-time monitoring of the input voltage of the PFC circuit. When the input voltage meets the set voltage surge condition, the power switch in the PFC circuit is turned off, and the electrical equipment is shut down to achieve the protection purpose.

[0041] Second, overcurrent protection: Real-time monitoring of the current in the PFC circuit. When the current in the PFC circuit reaches the overcurrent threshold, the power switch in the PFC circuit is turned off, and the electrical equipment is shut down to achieve the protection purpose.

[0042] When the power grid experiences voltage fluctuations or harmonic interference, both of the above methods can protect electrical equipment and its components, such as control boards, from damage.

[0043] But combined Figure 1 The diagram illustrates the duty cycle change during voltage surges. The PFC circuit satisfies: Vout = Vin / (1-D), where Vout is the output voltage of the PFC circuit, Vin is the input AC voltage of the PFC circuit, and D is the duty cycle of the switching transistor. When a voltage surge occurs in the mains, such as at point A', the input voltage of the PFC circuit suddenly drops, and D increases significantly to maintain Vout at its target value. However, when the input voltage recovers, D may lag behind and remain at a relatively high value before falling back. A larger input voltage and a larger D will cause the circuit to generate a larger current, leading to the PFC circuit reaching its overcurrent threshold and triggering a shutdown.

[0044] To address the problems in the aforementioned related technologies, this disclosure proposes a circuit protection method. The method includes: determining the adjustment range of the duty cycle of a switching transistor in a PFC circuit during the current carrier cycle; and adjusting the duty cycle of the current carrier cycle within the adjustment range to regulate the current of the PFC circuit within a preset range. In this method, the adjustment of the switching transistor's duty cycle is always within the set adjustment range. Even in scenarios of voltage surges, the increase in the duty cycle will not exceed the adjustment range, thus ensuring that the current of the PFC circuit remains below the overcurrent threshold. Under the premise of protecting the electrical equipment, the equipment will not shut down but will operate stably. This effectively reduces abnormal shutdowns of electrical equipment caused by grid instability and improves the user experience.

[0045] In one exemplary embodiment, such as Figure 2 As shown, the method in this embodiment may include the following steps:

[0046] S210. Determine the adjustment range of the duty cycle of the switching transistor in the PFC circuit during the current carrier cycle.

[0047] S220. Adjust the duty cycle of the current carrier cycle within the adjustment range to adjust the current of the PFC circuit within the preset range.

[0048] In step S210, the input power supply of the PFC circuit is AC, and the current carrier period refers to the current period of the AC signal. The PFC circuit belongs to the BOOST topology and satisfies the following output voltage relationship: Vout = Vin / (1-D), where Vout is the output voltage of the PFC circuit, Vin is the input voltage of the AC power supply to the PFC circuit, and D is the duty cycle of the switching transistor.

[0049] The switching transistor in a PFC circuit can be a metal-oxide-semiconductor (MOS) or an insulated-gate bipolar transistor (IGBT). The duty cycle of the switching transistor reflects the proportion of the carrier cycle that the transistor is on during.

[0050] In this step, the adjustment range includes the upper limit of the adjustable duty cycle for each time point within the corresponding carrier cycle. The adjustment range for the corresponding duty cycle can be determined for each carrier cycle. The adjustment range can take various limiting forms.

[0051] In the first example, such as Figure 4 As shown, the adjustment range is a curve representing the change in the duty cycle limit value over time and input voltage. In this example, the adjustment curve represented by the adjustment range is... Figure 1 The modulation curves of the duty cycle show roughly the same trend, but as shown at point C, when the voltage at point A suddenly drops, the modulation curve is always smaller than the adjustment curve represented by the adjustment range. Figure 4 The curve representing the adjustment range has time on the horizontal axis, duty cycle on the left vertical axis, and input voltage on the right vertical axis.

[0052] In the second example, the adjustment range is the mapping relationship between time and duty cycle limits. In this example, each time point corresponds to a duty cycle limit, and the duty cycle at that time point is adjusted according to this limit. When adjusting the duty cycle at any time point, it should always be less than the corresponding duty cycle limit.

[0053] In step S220, the preset range includes: less than the overcurrent threshold, that is, the current of the PFC circuit is less than the overcurrent threshold.

[0054] In this step, the duty cycle of the current carrier cycle is adjusted according to the adjustment range corresponding to the current carrier cycle, so that the adjusted duty cycle is always less than the corresponding value in the adjustment range.

[0055] For example, combining this with the first example above: based on the adjustment curve represented by the adjustment range, the duty cycle at each time point is adjusted, and the adjusted duty cycle is always less than the adjustment curve. Even in scenarios where the voltage suddenly drops, the increase in the duty cycle is always within a limited range and will not be excessive. Therefore, the current in the PFC circuit will not reach the overcurrent threshold, improving the problem of electrical equipment shutdown.

[0056] Alternatively, combining this with the second example mentioned above: based on the mapping relationship corresponding to the adjustment range, the duty cycle limit value corresponding to each time node can be obtained, and the duty cycle at each time node can be adjusted accordingly. The adjusted duty cycle will always be less than the corresponding duty cycle limit value. In scenarios where the voltage suddenly drops, the increase in duty cycle will always remain within the limit range and will not be excessive. Therefore, the current in the PFC circuit will not reach the overcurrent threshold, improving the problem of electrical equipment shutdown.

[0057] In this embodiment, it can be applied to voltage anomalies such as sudden changes in grid voltage. When the input voltage suddenly drops or is subject to harmonic interference, this embodiment can keep electrical equipment such as air conditioners running stably without shutting down, while effectively protecting the internal control board components of electrical equipment from damage, thus improving the user experience.

[0058] In one exemplary embodiment, the method of this embodiment includes Figure 2 Steps S210 to S220 are shown. (As...) Figure 3 As shown, step S210 may include the following steps:

[0059] S301. Obtain the duty cycle data from the previous carrier cycle of the current carrier cycle.

[0060] S302. Determine the adjustment range based on the duty cycle data.

[0061] In step S301, the duty cycle data for the previous carrier cycle includes the duty cycle value at each time point. The duty cycle data can be in the form of an array or a point set, or it can be a change curve corresponding to the adjustment curve.

[0062] In step S302, after obtaining the duty cycle data of the previous carrier cycle, this embodiment of the present disclosure uses the duty cycle data of the previous carrier cycle to dynamically determine the adjustment range of the current carrier cycle.

[0063] In one exemplary embodiment, step S302 includes the following steps:

[0064] S3021, Set parameter variables.

[0065] S3022. Determine the adjustment range based on the parameter variables and duty cycle data.

[0066] In step S3021, the values ​​of the parameter variables may be the same or different under different carrier cycles. The parameter variables are used to limit the change in duty cycle. The parameter variables must satisfy the condition that the sum of the duty cycle data with any duty cycle data in the previous carrier cycle will not cause the current of the PFC circuit to reach the overcurrent threshold. For example, the parameter variable can be set to 10%.

[0067] In step S3022, the duty cycle in the duty cycle data corresponds one-to-one with the duty cycle limit value in the adjustment range. The duty cycle data includes the duty cycle corresponding one-to-one with each time node in the previous carrier cycle, and the adjustment range includes the duty cycle limit value corresponding one-to-one with each time node in the current carrier cycle.

[0068] Combination Figure 4 As shown, the parameter variable is denoted as D0, and the adjustment curve representing the adjustment range is denoted as D. limit [n], duty cycle data is represented as D last [n], i.e., D limit [n] and D last [n] represents an n-dimensional array.

[0069] In this step, based on each duty cycle D in the duty cycle data... last [i] The sum of [i] and parameter variable D0 determines the corresponding duty cycle limit value D within the adjustment range. limit [i], i.e., D limit [i] = D last [i]+D0, where: i=1, 2,...,n.

[0070] In one exemplary embodiment, the method of this embodiment further includes:

[0071] S300. Determine the parameter dimensions of the adjustment range based on the frequency of the input voltage and the switching frequency of the switching transistor.

[0072] This step can be performed before step S301 or step S302, or during the execution of step S302.

[0073] In this step, the frequency of the input voltage generally refers to the operating frequency f of the alternating current. in For example, 50Hz. The switching frequency f of the switching transistor. switch It depends on the type of switching transistor; for example, the switching frequency of a MOSFET is 50kHz.

[0074] In this embodiment, the parameter dimension n = f switch / f in For example, n = 50kHz / 50Hz = 1000, the adjustment range D limit[n] represents 1000 duty cycle limits, which can be plotted as adjustment curves based on the corresponding time points. Understandably, the duty cycle data D... last [n] includes 1000 duty cycles, such as curves that change over time.

[0075] In this embodiment of the disclosure, by setting as follows Figure 4 The curve representing the adjustment range shown effectively limits the range of duty cycle fluctuations at each time point. In voltage fluctuation scenarios, such as a voltage drop at point A, the duty cycle is effectively limited and does not suddenly increase significantly as in related technologies, for example at point B, but remains below the adjustment curve, for example at point C. Therefore, the duty cycle only increases slightly during voltage drops, preventing the PFC circuit current from reaching the overcurrent threshold. This ensures that the PFC circuit does not experience large current changes due to external input disturbances, improving the shutdown of electrical equipment caused by PFC circuit overcurrent during power grid fluctuations.

[0076] In one exemplary embodiment, this disclosure also provides a circuit protection device for performing the circuit protection method described in the above embodiments.

[0077] like Figure 5 As shown, the apparatus of this embodiment includes a determining module 110 and an adjusting module 120. During implementation, the determining module 110 is used to determine the adjustment range of the duty cycle of the switching transistor in the PFC circuit during the current carrier cycle. The adjusting module 120 is used to adjust the duty cycle of the current carrier cycle within the adjustment range to regulate the current of the PFC circuit within a preset range.

[0078] In one example, the adjustment range is the curve showing the change of the duty cycle limit value over time and input voltage.

[0079] In one example, the adjustment range is the mapping relationship between time and duty cycle limits.

[0080] In one exemplary embodiment, reference is still made to... Figure 5 As shown, the apparatus of this embodiment includes a determining module 110 and an adjusting module 120. The determining module 110 is used to: acquire duty cycle data from the previous carrier cycle of the current carrier cycle; and determine an adjusting range based on the duty cycle data.

[0081] In this embodiment, the determining module 110 is used to: set parameter variables; and determine the adjustment range based on the parameter variables and duty cycle data.

[0082] In this embodiment, the determining module 110 is used to: determine the corresponding duty cycle limit value in the adjustment range based on the sum of each duty cycle and parameter variable in the duty cycle data.

[0083] In this embodiment, the determining module is also used to: determine the parameter dimension of the adjustment range based on the frequency of the input voltage and the switching frequency of the switching transistor.

[0084] like Figure 6 The diagram shown is a block diagram of an electrical appliance. This disclosure also provides an electrical appliance, for example, appliance 500 may be a temperature control device such as an air conditioner or refrigerator.

[0085] Device 500 may include one or more of the following components: processing component 502, memory 504, power component 506, circuit structure 508, communication component 510, and input / output interface 512.

[0086] Processing component 502 typically controls the overall operation of device 500. Processing component 502 may include one or more processors 520 to execute instructions to complete all or part of the steps of the methods described above. In addition, processing component 502 may include one or more modules to facilitate interaction between processing component 502 and other components.

[0087] Memory 504 is configured to store various types of data to support the operation of device 500. Memory 504 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0088] The power supply component 506 provides power to the various components of the device 500. The power supply component 506 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to the device 500.

[0089] Circuit structure 508 may include PFC circuit.

[0090] I / O interface 512 provides an interface between processing component 502 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons. Communication component 510 is configured to facilitate wired or wireless communication between device 500 and other devices. Device 500 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 510 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 510 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0091] In an exemplary embodiment, device 500 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the methods described above.

[0092] Another exemplary embodiment of this disclosure provides a non-transitory computer-readable storage medium, such as a memory 504 including instructions that can be executed by a processor 520 of a device 500 to perform the described method. For example, the computer-readable storage medium may be a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, or optical data storage device. When the instructions in the storage medium are executed by a processor of an electrical device, the electrical device is able to perform the described method.

[0093] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0094] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method of circuit protection, characterized by, The method comprises: determining a regulation range of a duty cycle of a switch tube in a current carrier cycle PFC circuit, the regulation range comprising duty cycle limit values corresponding to each time node in the current carrier cycle; regulating the duty cycle of the current carrier cycle within the regulation range to regulate a current of the PFC circuit within a preset range. The determination of the regulation range of the duty cycle of the switch tube in the current carrier cycle PFC circuit comprises: obtaining duty cycle data in a previous carrier cycle of the current carrier cycle; determining the regulation range according to the duty cycle data.

2. The method of claim 1, wherein, The determination of the regulation range according to the duty cycle data comprises: setting a parameter variable; determining the regulation range according to the parameter variable and the duty cycle data.

3. The method of claim 2, wherein, The determination of the regulation range according to the parameter variable and the duty cycle data comprises: determining a corresponding duty cycle limit value in the regulation range according to a sum of each duty cycle in the duty cycle data and the parameter variable.

4. The method according to any one of claims 1 to 3, characterized in that, The method further comprises: determining a parameter dimension of the regulation range according to a frequency of an input voltage and a switching frequency of the switch tube.

5. The method according to any one of claims 1 to 3, characterized in that, The regulation range is a variation curve of the duty cycle limit value varying with time and input voltage.

6. The method according to any one of claims 1 to 3, characterized in that, The regulation range is a mapping relationship between time and the duty cycle limit value.

7. A circuit protection device, characterized by The circuit protection device is configured to perform the circuit protection method of any one of claims 1 to 6.

8. An electrical appliance, characterized in that comprises: a processor; a memory for storing executable instructions of the processor; wherein the processor is configured to perform the circuit protection method of any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium, comprising: When the instructions in the storage medium are executed by the processor of the electrical appliance device, the electrical appliance device is enabled to perform the circuit protection method of any one of claims 1 to 6.

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