Anti-impact control method for quick power-on after power failure

Abstract

The invention relates to the technical field of circuit protection, in particular to an anti-impact control method for quick power-on after power failure, which comprises the following steps of: firstly, monitoring a mains supply period state of a mains supply input end of a power supply circuit and a voltage value of an electrolytic capacitor E1 connected with a fast recovery diode D630 in an output side of a rectifier bridge BR1 of the power supply circuit in real time; secondly, if the sudden change of the commercial power period state is detected and the voltage value of the electrolytic capacitor E1 is detected to be lower than a large voltage difference threshold value within a preset time, determining that a current-limiting event is necessary, otherwise, determining that a current-limiting event is not performed; finally, when it is judged that the current limiting event is necessary, a current limiting piece is connected to the power circuit; when it is judged that the current limiting event is not the current limiting event, the current limiting part is disconnected from the power supply circuit; the problem that an existing control method cannot correctly select the intervention moment of the current limiting piece under the condition of rapid power-on after power failure is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit protection, in particular to an anti-shock control method for rapid power-on after power failure. Background Art

[0002] Frequent plugging and unplugging of household appliances (such as air conditioners) can cause them to experience power outages followed by rapid power-up. During this period, components in the power circuit, such as capacitors, rectifier bridges, and fast-recovery diodes, experience sudden voltage fluctuations, generating transient high currents (inrush currents). This long-term effect can damage components and even cause circuit burnout.

[0003] Traditional solutions for short-duration surge currents caused by plugging and unplugging devices typically only protect against the critical surge current level that could damage the power circuit, such as by installing a fuse. Alternatively, PTC thermistors are directly connected in series with the power circuit for adaptive current limiting. Traditional solutions primarily rely on circuit structure optimization to suppress or eliminate surge currents. This results in some energy-intensive current-limiting components being left connected to the power circuit for extended periods, reducing power circuit efficiency.

[0004] To this end, existing control methods directly detect whether the power circuit has lost power. If so, a current limiter is engaged to limit current upon powering back on; otherwise, the current limiter is not engaged. However, this approach ignores the fact that when power is quickly restored after a power outage, the voltage drop in the power circuit may not be large enough to create a sufficient voltage difference with the mains voltage, generating a surge current sufficient to damage the power circuit. Therefore, immediately engaging the current limiter upon a power outage is a useless measure. Summary of the Invention

[0005] In view of the above defects, the purpose of the present invention is to propose an anti-shock control method for rapid power-on after power failure, which solves the problem that the existing control method cannot correctly select the time for the current limiting component to intervene when facing the situation of rapid power-on after power failure.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A method for preventing shock from being controlled by quickly powering on after power failure comprises the following steps:

[0008] S1: Real-time monitoring of the mains cycle state of the mains input terminal of the power circuit and the voltage value of the electrolytic capacitor E1 connected to the fast recovery diode D630 on the output side of the rectifier bridge BR1 of the power circuit;

[0009] S2: If a sudden change in the mains cycle state is detected, and the voltage value of the electrolytic capacitor E1 is lower than the large voltage difference threshold within a preset time, it is determined that a current limiting event is required, otherwise it is determined as a non-current limiting event;

[0010] S3: When it is determined that the current limiting event is necessary, the current limiting device is connected to the power circuit; when it is determined that the current limiting event is not necessary, the current limiting device is disconnected from the power circuit.

[0011] Furthermore, in step S2, the large voltage difference threshold is: the voltage value measured at the electrolytic capacitor E1 when the fast recovery diode D630 is subjected to the maximum impact current it can withstand.

[0012] Furthermore, in step S2, a sudden change in the mains cycle state refers to a continuous low level within a mains cycle.

[0013] Furthermore, in step S2, a sudden change in the mains cycle state refers to a low-level duration greater than 16 ms.

[0014] Furthermore, the step S2 further includes: if it is determined to be an unrestricted flow event, further executing the following sub-steps:

[0015] S21: Continuously monitor the voltage value of the electrolytic capacitor E1. If the voltage value of the electrolytic capacitor E1 increases at a rate exceeding a preset rate, it is re-determined that a current limiting event is required.

[0016] Furthermore, step S2 further includes the following sub-steps:

[0017] S22: Count the number of times the current limiting event is triggered within a unit time; if the number of triggers exceeds a preset threshold, the current limiting event is forcibly locked and a system self-check instruction or an alarm instruction is generated.

[0018] Furthermore, the step S3 further includes: after the current limiting component is connected to the power circuit, the following sub-steps are also included:

[0019] S31: Monitor the temperature rise of the current limiting component in real time. If the temperature exceeds a safety threshold, disconnect the current limiting component from the power circuit, and trigger the fuse protection of the fuse FUSE1 in the power circuit.

[0020] Furthermore, in the sub-step S31, the current limiting component adopts a PTC thermistor.

[0021] The technical solution provided by the present invention may include the following beneficial effects: This method comprehensively determines whether current limiting is required by simultaneously monitoring the mains cycle state and the voltage value of the electrolytic capacitor E1. Compared with the traditional extensive control that only relies on the mains power-off signal, this solution introduces the dual judgment conditions of "mains sudden change + large voltage difference threshold" to accurately identify the real impact risk scenario caused by rapid power-on after power-off, that is, when the mains sudden change causes the voltage of the electrolytic capacitor E1 to drop sharply and forms a high enough voltage difference with the mains to trigger a large impact current, it will react and only connect the current limiting component at this time, optimizing the current limiting intervention time point, avoiding the ineffective action of power-off and current limiting in the traditional solution (such as when the mains power is off but the voltage value of the electrolytic capacitor E1 does not drop significantly), and actively avoiding the energy efficiency loss caused by long-term access to the current limiting component, and achieving a balance between protection effectiveness and circuit energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart of an anti-shock control method for rapid power-on after power failure according to one embodiment of the present invention.

[0023] Figure 2 FIG. 1 is a circuit diagram of a power supply circuit according to one embodiment of the present invention.

[0024] Among them: rectifier bridge BR1, fast recovery diode D630, electrolytic capacitor E1, current limiting component 1. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0026] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically specified.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two components or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0028] The following combination Figures 1 to 2 , describes an anti-shock control method for fast power-on after power failure according to an embodiment of the present invention.

[0029] A method for preventing shock from being controlled by quickly powering on after power failure comprises the following steps:

[0030] S1: Real-time monitoring of the mains cycle state of the mains input terminal of the power circuit and the voltage value of the electrolytic capacitor E1 connected to the fast recovery diode D630 on the output side of the rectifier bridge BR1 of the power circuit;

[0031] S2: If a sudden change in the mains cycle state is detected, and the voltage value of the electrolytic capacitor E1 is lower than the large voltage difference threshold within a preset time, it is determined that a current limiting event is required, otherwise it is determined as a non-current limiting event;

[0032] S3: When it is determined that the current limiting event is necessary, the current limiting component 1 is connected to the power circuit; when it is determined that the current limiting event is not necessary, the current limiting component 1 is disconnected from the power circuit.

[0033] The present invention proposes a method for preventing shock from being quickly powered on after power failure. Figure 1 As shown, this method comprehensively determines whether current limiting is required by simultaneously monitoring the mains cycle state and the voltage value of the electrolytic capacitor E1. Compared with the traditional extensive control that relies solely on the mains power-off signal, this solution introduces the dual judgment conditions of "mains power mutation + large voltage difference threshold" to accurately identify the real impact risk scenario caused by rapid power-on after power failure. That is, when the mains power mutation causes the electrolytic capacitor E1 voltage to drop sharply, forming a high enough voltage difference with the mains to trigger a large impact current, it will react and only connect the current limiting device 1 at this time, optimizing the current limiting intervention time point. This avoids the ineffective action of current limiting when power is off in the traditional solution (such as when the mains power is off but the voltage value of the electrolytic capacitor E1 does not drop significantly), and can actively avoid the energy efficiency loss caused by the long-term connection of the current limiting device 1, achieving a balance between protection effectiveness and circuit energy efficiency.

[0034] It should be noted that the reason for adopting the "mains power mutation + large voltage difference threshold" judgment combination is based on: the mains power cycle state suddenly changes, which means that the power supply circuit has changed. At this time, the power supply circuit is in a power-off or power-on state. At this time, if the voltage value of the electrolytic capacitor E1 is detected to be lower than the large voltage difference threshold within the preset time (after testing to determine how large the voltage difference will produce an unbearable impact current, based on the fact that the peak value of the mains voltage is usually constant, the peak value of the mains voltage minus the voltage difference can be set as the large voltage difference threshold), it proves that at this time, whether it is a real power-off event or a fast power-on event after power-off, an impact current will inevitably be generated.

[0035] It should also be noted that if Figure 2 As shown, the reason for detecting the voltage value of the electrolytic capacitor E1 connected to the fast recovery diode D630 in the output side of the rectifier bridge BR1 of the power circuit is because the output side voltage of the rectifier bridge BR1 is the total internal voltage (i.e. Figure 2 P+ is the voltage value of electrolytic capacitor E1). The voltage required by the subsequent circuit is obtained by stepping down the voltage. Detecting the P+ voltage can truly reflect the internal voltage situation of the power supply circuit. The fast recovery diode D630 is the first to be damaged by the impact of the impact current. Therefore, it is best to choose to detect the voltage value of the electrolytic capacitor E1 here.

[0036] Furthermore, in step S2, the large voltage difference threshold is: the voltage value measured at the electrolytic capacitor E1 when the fast recovery diode D630 is subjected to the maximum impact current that it can withstand.

[0037] In this embodiment, since the fast recovery diode D630 is the first to be damaged by the inrush current, the inrush current required to connect the current limiting device 1 is determined by the maximum inrush current that the fast recovery diode D630 can withstand. Therefore, it can be experimentally tested that when the fast recovery diode D630 is subjected to the maximum inrush current, the voltage value measured at the electrolytic capacitor E1 is set to the large voltage difference threshold, which represents the voltage difference between the peak value of the mains voltage and the large voltage difference threshold (subtracted from each other). This can generate the maximum inrush current that the fast recovery diode D630 can withstand, and is the critical value for connecting the current limiting device 1. At the same time, setting the large voltage difference threshold in this way can also simplify the testing process.

[0038] Furthermore, in step S2, a sudden change in the mains cycle state refers to a continuous low level within a mains cycle.

[0039] In this embodiment, based on normal power supply, the cycle state of the mains power is constant, and each cycle contains alternating positive and negative half-cycles; when the mains power is off or on, it is reflected in the cycle state that the duration of the low level or high level has suddenly changed. For example, if the level is low for a complete cycle (such as 20ms), it means that the mains power has been cut off. Therefore, by limiting the "mains power cycle state mutation" to "continuous low level within a mains power cycle", the abstract mains power mutation can be converted into a quantifiable electrical feature. This judgment method effectively avoids the misjudgment caused by short-term high and low level fluctuations within a cycle caused by transient interference (such as voltage fluctuations or noise), ensuring that subsequent judgment logic is triggered only in the actual power-off event, thereby enhancing the robustness of the system. At the same time, single-cycle detection takes into account both response speed and accuracy (such as response within 20ms, close to the reaction time of the current limiting component 1 fixed in series with the power circuit), avoiding the delay problem of traditional multi-cycle detection.

[0040] Furthermore, in step S2, a sudden change in the mains cycle state refers to a low level duration greater than 16 ms.

[0041] In this embodiment, when the mains power is 50HZ AC (such as China and most European countries), one cycle is approximately 20ms (high level 10ms, low level 10ms); when the mains power is 60HZ AC (such as the United States, Japan and other countries), one cycle is approximately 16ms (high level 8ms, low level 8ms); therefore, by directly setting the judgment condition for a sudden change in the mains cycle state to a low level duration greater than 16ms, it is possible to determine whether a cycle mutation occurs in most AC powers. The judgment condition is simpler and easier to program.

[0042] Furthermore, step S2 further includes: if it is determined to be an unrestricted flow event, further executing the following sub-steps:

[0043] S21: Continuously monitor the voltage value of the electrolytic capacitor E1. If the voltage value of the electrolytic capacitor E1 increases at a rate exceeding a preset rate, it is re-determined that a current limiting event is required.

[0044] In this embodiment, the voltage rise rate detection is added as a dynamic supplementary criterion to identify the risk of hidden current shock caused by the rapid charging of the electrolytic capacitor E1 (such as the fluctuation of the mains power causing the high-level voltage peak to increase, suddenly accelerating the charging of the electrolytic capacitor, and the large charging current will also cause shock damage to the fast recovery diode), further enhancing the current shock protection range.

[0045] Furthermore, step S2 further includes the following sub-steps:

[0046] S22: Count the number of times the current limiting event is triggered within a unit time; if the number of triggers exceeds a preset threshold, the current limiting event is forcibly locked and a system self-check instruction or an alarm instruction is generated.

[0047] In this embodiment, frequency statistics and protection locking mechanisms are used to address the potential risk of circuit damage caused by frequent abnormal power-on; triggering system self-check (system self-check instruction) or manual troubleshooting (alarm instruction) of the root cause of the fault (such as capacitor aging, unstable mains power).

[0048] Furthermore, step S3 further includes: after the current limiting element 1 is connected to the power circuit, the following sub-steps are also included:

[0049] S31: Real-time monitoring of the temperature rise of the current limiting component 1. If the temperature exceeds a safety threshold, the current limiting component 1 is disconnected from the power circuit, and the fuse FUSE1 in the power circuit is triggered to perform a fuse protection.

[0050] In this embodiment, when the temperature rise of the current limiting component 1 is too high, it can be known that the current inrush current has exceeded the current limiting limit of the current limiting component 1, and it needs to be disconnected in time to prevent the current limiting component 1 from overheating and damage. Subsequently, the fuse FUSE1 can trigger the fuse protection (when the temperature rise of the current limiting component 1 is too high, it means that the fuse FUSE1 is not far from being triggered).

[0051] Furthermore, in sub-step S31 , the current limiting component 1 adopts a PTC thermistor.

[0052] In this embodiment, since sub-step S31 also requires real-time monitoring of temperature rise, the current limiting component 1 preferably uses a PTC thermistor, which can not only adaptively adjust the resistance value according to the size of the inrush current to limit the current, but also serve as a temperature rise detection device. When its controller detects that the PTC thermistor is continuously at the maximum resistance value (which can be detected by voltage division, etc.) for more than the preset overheating time, it can be known that the temperature rise is serious.

[0053] Other structures and operations of the anti-shock control method for rapid power-on after power failure according to the embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0054] Throughout this specification, reference to terms such as "embodiment" or "example" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for preventing shock from being quickly powered on after power failure, characterized in that: The following steps are involved: S1: Real-time monitoring of the mains cycle state of the mains input terminal of the power circuit and the voltage value of the electrolytic capacitor E1 connected to the fast recovery diode D630 on the output side of the rectifier bridge BR1 of the power circuit; S2: If a sudden change in the mains cycle state is detected, and the voltage value of the electrolytic capacitor E1 is lower than the large voltage difference threshold within a preset time, it is determined that a current limiting event is required, otherwise it is determined as a non-current limiting event; S3: When it is determined that the current limiting event is necessary, the current limiting device is connected to the power circuit; when it is determined that the current limiting event is not necessary, the current limiting device is disconnected from the power circuit.

2. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: In step S2, the large voltage difference threshold is: the voltage value measured on the electrolytic capacitor E1 when the fast recovery diode D630 is subjected to the maximum impact current it can withstand.

3. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: In step S2, the sudden change of the mains cycle state refers to: the mains cycle is continuously at a low level.

4. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: In step S2, a sudden change in the mains cycle state means that the low level lasts longer than 16 ms.

5. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: The step S2 further includes: if it is determined to be an unrestricted flow event, further executing the following sub-steps: S21: Continuously monitor the voltage value of the electrolytic capacitor E1. If the voltage value of the electrolytic capacitor E1 increases at a rate exceeding a preset rate, it is re-determined that a current limiting event is required.

6. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: The step S2 further includes the following sub-steps: S22: Count the number of times the current limiting event is triggered within a unit time; if the number of triggers exceeds a preset threshold, the current limiting event is forcibly locked and a system self-check instruction or an alarm instruction is generated.

7. The anti-shock control method for rapid power-on after power failure according to claim 1, characterized in that: The step S3 further includes: after the current limiting component is connected to the power circuit, the following sub-steps are also included: S31: Monitor the temperature rise of the current limiting component in real time. If the temperature exceeds a safety threshold, disconnect the current limiting component from the power circuit, and trigger the fuse protection of the fuse FUSE1 in the power circuit.

8. The anti-shock control method for rapid power-on after power failure according to claim 7, characterized in that: In the sub-step S31 , the current limiting component is a PTC thermistor.

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