Switching power supply short circuit protection method and system

Abstract

The invention discloses a switching power supply short-circuit protection method and system, and relates to the technical field of switching power supplies. The method is executed by a main control module in the switching power supply, the switching power supply further comprises a power supply output end voltage detection module and a PWM signal generation module, the output end of the PWM signal generation module is used for being electrically connected with a plurality of load branches respectively, and the same fuses are connected to the load branches in series. If the voltage detection value is greater than the normal working current value of the load branch, the main control module judges whether at least one load branch with short circuit risk exists in real time according to the voltage detection value; if yes, the PWM signal generation module is controlled to continuously output direct current used for triggering fuse protectors on the load branch circuits to be disconnected, so that independent short-circuit protection can be carried out on different load branch circuits based on the fuse protectors, and the purpose that when a load short-circuit fault occurs in a certain load branch circuit, other non-fault loads can still work normally is achieved at low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of switching power supplies, and particularly relates to a short - circuit protection method and system for a switching power supply. Background Art

[0002] With the rapid development of electronic technology, switching power supplies play an increasingly important role in electronic system devices. The design of the switching power supply is crucial for the stable and reliable operation of load devices. In a power supply system based on a switching power supply for realizing single - output and multi - load parallel connection, if a load short - circuit fault occurs in a certain load branch, the current in the corresponding branch will increase instantaneously and the output voltage of the power supply will decrease instantaneously, which will cause the switching power supply to disconnect the output, making other non - fault loads unable to work properly.

[0003] In view of the above situation, in order to ensure that other non - fault loads can still work properly when a load short - circuit fault occurs in a certain load branch, the existing short - circuit protection scheme is to install an electronic fuse on each load branch and set a current - limiting value to independently protect the corresponding load branch against short - circuits. However, the hardware cost of the electronic fuse is much higher than that of fuses and self - recovering fuses (Polymeric Positive Temperature Coefficient Thermistor, PPTC), and it is only applicable to scenarios involving precision instruments and high - reliability systems. Therefore, how to provide a new switching - power - supply short - circuit protection scheme based on fuses and self - recovering fuses that can also ensure that other non - fault loads can still work properly when a load short - circuit fault occurs in a certain load branch, so as to significantly reduce the hardware cost of short - circuit protection, is an urgent research topic for those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a short - circuit protection method and system for a switching power supply to solve the problem that the existing short - circuit protection scheme has a relatively high hardware cost of short - circuit protection due to the use of electronic fuses when ensuring that other non - fault loads can still work properly.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] In a first aspect, a short - circuit protection method for a switching power supply is provided, which is executed by a main control module in the switching power supply. Wherein, the switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each of the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the corresponding load branch;

[0007] The short - circuit protection method for the switching power supply includes:

[0008] Receiving in real - time the voltage detection value from the power output terminal voltage detection module;

[0009] According to the voltage detection value, determining in real - time whether there is at least one load branch with a short - circuit risk among the multiple load branches;

[0010] If it is determined that there is at least one load branch with a short - circuit risk among the multiple load branches, then controlling the PWM signal generation module to continuously output a first direct - current, so as to trigger the disconnection of the fuse on the at least one load branch through the first direct - current. Wherein, the current value of the first direct - current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first direct - current is greater than the disconnection trigger response duration of the fuse.

[0011] Based on the above - mentioned invention content, a new short - circuit protection solution for a switching power supply that can also ensure that other non - faulty loads can still work normally when a load short - circuit fault occurs in a certain load branch based on a fuse is provided. That is, the method is executed by a main control module in the switching power supply. Wherein, the switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the PWM signal generation module is used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the corresponding load branch. The main control module will determine in real - time whether there is at least one load branch with a short - circuit risk according to the voltage detection value. If so, it will control the PWM signal generation module to continuously output a direct - current for triggering the disconnection of the fuse on these load branches. In this way, independent short - circuit protection can be carried out for different load branches based on the fuse, and the purpose of enabling other non - faulty loads to still work normally when a load short - circuit fault occurs in a certain load branch can be achieved at low cost, which is convenient for practical application and popularization.

[0012] In a possible design, the multiple load branches have the same operating resistance, and a self - reset fuse is also connected in series on the load branch. Among them, the disconnection trigger current threshold I of the self - reset fuse th2 is greater than the normal operating current value of the load branch and less than the disconnection trigger current threshold I of the fuse th1 , the disconnection trigger response duration of the self - reset fuse is greater than the duration of the first DC current, and any two of the self - reset fuses on different load branches have the same disconnection trigger response duration and different self - recovery durations;

[0013] After controlling the PWM signal generation module to continuously output the first DC current, the method further includes:

[0014] Controlling the PWM signal generation module to continuously output a second DC current so as to trigger the disconnection of the self - reset fuse on the currently unbroken branch through the second DC current. Among them, the current value of the second DC current is greater than K×I th2 and less than (K - 1)×I th1 , K represents the number of branches in the multiple load branches, the currently unbroken branch refers to the load branch in the multiple load branches and in series with the fuse that is still not disconnected at present, and the duration of the second DC current is greater than the disconnection trigger response duration of the self - reset fuse;

[0015] Controlling the PWM signal generation module to continuously output a third DC current, where the current value of the third DC current is less than I th2 , the duration of the third DC current is t sr,max +τ, t sr,max represents the maximum self - recovery duration among the multiple self - recovery durations corresponding to the multiple load branches one by one, and τ represents a preset duration;

[0016] During the process of waiting for the self - reset fuses to recover one by one, continue to receive the voltage detection value from the power output terminal voltage detection module in real - time, and obtain a voltage detection timing data with a recording duration of t sr,max +τ;

[0017] Determine the currently broken branch according to the voltage detection timing data and the multiple self - recovery durations, where the currently broken branch refers to the load branch in the multiple load branches and in series with the fuse that is currently disconnected;

[0018] For the currently broken branch, trigger and execute the corresponding alarm action.

[0019] In a possible design, determining the currently broken branch according to the voltage detection timing data and the multiple self - recovery durations includes:

[0020] Determine the number of voltage jumps k according to the voltage detection timing data;

[0021] If it is found that the number of voltage jumps k is less than K, determine k voltage jump delay durations according to the voltage detection timing data, where the voltage jump delay duration refers to the delay duration from the recording start time to the voltage jump time;

[0022] According to the matching result between the k voltage jump delay durations and the multiple self-recovery durations, determine K-k matching failure durations among the multiple self-recovery durations, where the matching failure duration refers to a self-recovery duration that does not match any of the voltage jump delay durations among the k voltage jump delay durations;

[0023] Determine the load branches corresponding one-to-one to the matching failure durations as the currently disconnected branches, where the currently disconnected branches refer to the load branches among the multiple load branches and in series with the currently disconnected fuse.

[0024] In a possible design, the time interval between any two of the multiple self-recovery durations is greater than or equal to 5 milliseconds.

[0025] In a possible design, if it is found that the number of voltage jumps k is equal to K, determine that there is no currently disconnected branch among the multiple load branches, where the currently disconnected branch refers to the load branch among the multiple load branches and in series with the currently disconnected fuse.

[0026] In a possible design, after determining that there is no currently disconnected branch among the multiple load branches, the method further includes:

[0027] Control the PWM signal generation module to resume normal output and continue to receive voltage detection new values from the power output terminal voltage detection module in real time;

[0028] If it is still determined according to the voltage detection new value that there is at least one load branch with a short circuit risk among the multiple load branches, control the PWM signal generation module to continuously output a fourth DC current so as to trigger the disconnection of the fuse on the at least one load branch through the fourth DC current, where the current value of the fourth DC current is greater than 2×I th1 and less than (K-2)×I th1 , and the duration of the fourth DC current is greater than the disconnection trigger response duration of the fuse.

[0029] In a possible design, after controlling the PWM signal generation module to continuously output the fourth DC current, the method further includes:

[0030] Control the PWM signal generation module to continuously output a fifth DC current, so as to trigger the self - restoring fuse on the currently unbroken branch to disconnect through the fifth DC current, where the current value of the fifth DC current is greater than K×I th2 and less than (K - 2)×I th1 and the duration of the fifth DC current is greater than the disconnection trigger response duration of the self - restoring fuse;

[0031] Control the PWM signal generation module to continuously output the third DC current;

[0032] During the process of waiting for the self - restoring fuses to recover one by one, continue to receive the voltage detection values from the power output terminal voltage detection module in real - time, and obtain a new voltage detection timing data with a recording duration of t sr,max +τ;

[0033] Determine the currently broken branch according to the new voltage detection timing data and the multiple self - restoring durations;

[0034] For the currently broken branch, trigger and execute corresponding alarm actions.

[0035] In a possible design, when the switching power supply further includes a voice module communicatively connected to the main control module, for the currently broken branch, triggering and executing corresponding alarm actions includes:

[0036] For the currently broken branch, generate a voice signal for broadcasting that a short - circuit fault has occurred in the corresponding branch;

[0037] Transmit the voice signal to the voice module for voice alarm.

[0038] In a second aspect, a switching power supply short - circuit protection system is provided, which is applicable to be arranged in the main control module of a switching power supply. The switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is further communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch among the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal working current value of the corresponding load branch;

[0039] The switching power supply short - circuit protection system includes a detection data receiving unit, a short - circuit risk judgment unit, and an output current control unit that are communicatively connected in sequence;

[0040] The detection data receiving unit is configured to receive in real time the voltage detection value from the voltage detection module of the power supply output terminal;

[0041] The short - circuit risk judgment unit is configured to judge in real time whether there is at least one load branch with short - circuit risk among the multiple load branches according to the voltage detection value;

[0042] The output current control unit is configured to, when it is determined that there is at least one load branch with short - circuit risk among the multiple load branches, control the PWM signal generation module to continuously output a first direct - current, so as to trigger the fuse on the at least one load branch to disconnect through the first direct - current. Wherein, the current value of the first direct - current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first direct - current is greater than the disconnection trigger response duration of the fuse.

[0043] In a third aspect, the present invention provides a switching power supply short - circuit protection system, including a switching power supply and multiple load branches respectively electrically connected to the output terminal of the switching power supply. Wherein, the switching power supply includes a main control module, a power supply output - terminal voltage detection module, and a PWM signal generation module. The output terminal of the power supply output - terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply. The same fuse is connected in series on each load branch among the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the corresponding load branch;

[0044] The power supply output - terminal voltage detection module is configured to monitor in real time the voltage of the output terminal of the switching power supply and transmit the monitoring result to the main control module in real time;

[0045] The PWM signal generation module is configured to output a PWM signal with a specified duty cycle under the control of the main control module to supply the load branch;

[0046] The main control module is configured to execute the switching power supply short - circuit protection method as described in the first aspect or any possible design in the first aspect.

[0047] The beneficial effects of the above - mentioned solution:

[0048] (1) The present invention creatively provides a new short - circuit protection scheme for a switching power supply that can ensure that other non - faulty loads can still work normally when a load short - circuit fault occurs in a certain load branch based on fuses. That is, the method is executed by the main control module in the switching power supply. Among them, the switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the PWM signal generation module is used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch. The disconnection trigger current threshold of the fuse is greater than the normal working current value of the corresponding load branch. The main control module will continuously judge whether there is at least one load branch with a short - circuit risk according to the voltage detection value in real - time. If so, it will control the PWM signal generation module to continuously output a DC current for triggering the disconnection of the fuses on these load branches. In this way, independent short - circuit protection can be carried out for different load branches based on fuses, and the purpose of enabling other non - faulty loads to still work normally when a load short - circuit fault occurs in a certain load branch can be achieved at low cost;

[0049] (2) It is also possible to achieve the purpose of accurately identifying the currently disconnected branch and alarming after the fuse is triggered to disconnect by utilizing the characteristics of the self - restoring fuse and specific design. Furthermore, it is convenient for maintenance personnel to quickly sense the load branch where the short - circuit occurs and perform maintenance in a timely manner;

[0050] (3) It is also possible to perform short - circuit protection again when it is found that the previous short - circuit protection fails, improving the reliability of the short - circuit protection scheme and facilitating practical application and promotion. Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0052] Figure 1 It is a schematic flow chart of the switching power supply short - circuit protection method provided by the embodiment of the present application.

[0053] Figure 2 It is a schematic structural diagram of the switching power supply short - circuit protection virtual system provided by the embodiment of the present application.

[0054] Figure 3 It is a schematic structural diagram of the switching power supply short - circuit protection physical system provided by the embodiment of the present application. Detailed Embodiments

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the accompanying drawings and the description of the embodiments or the prior art. Obviously, the following description of the structures of the accompanying drawings is only some embodiments of the present invention. For those of ordinary skill in the art, other embodiments can be obtained based on these embodiments without creative efforts. It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention.

[0056] It should be understood that although terms such as first and second etc. may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another. For example, the first object can be called the second object, and similarly, the second object can be called the first object, without departing from the scope of the exemplary embodiments of the present invention.

[0057] It should be understood that for the term "and / or" that may appear in this article, it is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, or A and B exist simultaneously, etc.; another example, A, B, and / or C can mean any one of A, B, and C or any combination of them; for the term " / and" that may appear in this article, it is a description of another association object relationship, indicating that two relationships can exist. For example, A / and B can mean: A exists alone or A and B exist simultaneously, etc.; in addition, for the character " / " that may appear in this article, generally it means that the front and rear associated objects are an "or" relationship.

[0058] Embodiment

[0059] Such as Figure 1 And Figure 3As shown, the switch power supply short - circuit protection method provided in the first aspect of this embodiment can be, but is not limited to, executed by a main control module with certain computing resources in the switch power supply. Among them, the switch power supply further includes, but is not limited to, a power output terminal voltage detection module, a PWM signal generation module, etc. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switch power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch among the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal working current value of the corresponding load branch. The power output terminal voltage detection module is used to monitor the output terminal voltage of the switch power supply in real - time and transmit the monitoring result to the main control module in real - time. Its specific circuit, specific connection relationship with the power output terminal, and specific working principle can be, but are not limited to, derived conventionally with reference to existing electronic fuse solutions. The PWM signal generation module is one of the core modules of the switch power supply, and is used to output a PWM (Pulse Width Modulation) signal with a specified duty cycle to supply the load under the control of the main control module. Its specific circuit and specific working principle can be, but are not limited to, derived conventionally with reference to existing switch power supply solutions. The multiple load branches can be the same (for example, all are, but are not limited to, lighting branches), or different (for example, one load branch is a lighting branch, and the other load branch is a fan branch, etc.). The fuse is used to disconnect when the working current value of the corresponding load branch reaches the corresponding disconnection trigger current threshold and this situation lasts for the corresponding disconnection trigger response duration, so as to cut off the corresponding load branch at one time. Specifically, it can be, but is not limited to, implemented by using an existing fuse (whose disconnection trigger response duration is in the order of microseconds).

[0060] The switch power supply short - circuit protection method includes, but is not limited to, the following steps S1 - S3.

[0061] S1. Receive the voltage detection value from the power output terminal voltage detection module in real - time.

[0062] S2. According to the voltage detection value, determine in real - time whether there is at least one load branch with a short - circuit risk among the multiple load branches.

[0063] In step S2, the specific judgment process can be, but is not limited to, including: judging whether the power output terminal voltage shows an instantaneous decrease according to the voltage detection value. If so, it is determined that there is at least one load branch with a short - circuit risk among the multiple load branches; otherwise, it is determined that there is no load branch with a short - circuit risk among the multiple load branches.

[0064] S3. If it is determined that there is at least one load branch with a short - circuit risk among the multiple load branches, control the PWM signal generation module to continuously output a first DC current, so as to trigger the fuse on the at least one load branch to disconnect through the first DC current, where the current value of the first DC current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first DC current is greater than the disconnection trigger response duration of the fuse.

[0065] In step S3, considering that when a short - circuit fault occurs in the at least one load branch, the resistance of the at least one load branch will mutate to a very small value, so that the output current of the switching power supply will mainly flow through the at least one load branch. Then, when the current value of the first DC current is greater than the disconnection trigger current threshold of the fuse, the purpose of triggering the fuse on the at least one load branch to disconnect through the first DC current to cut off the at least one load branch can be achieved. To avoid the situation that after the at least one load branch is disconnected, the first DC current also triggers the fuses on other load branches to disconnect, the current value of the first DC current also needs to be less than the sum of the disconnection trigger current thresholds of the fuses on all the other load branches. Since it is difficult to determine the specific number of the at least one load branch in the previous step S2, it is also difficult to determine the total number of all the other load branches and the sum of the disconnection trigger current thresholds. Furthermore, considering that the actual situation of two load branches with short - circuit risk existing simultaneously is less, when the multiple load branches have the same working resistance, first make the current value of the first DC current greater than the disconnection trigger current threshold Ith1 of the fuse and less than (K - 1)×I th1 (K represents the number of branches among the multiple load branches), so as to first cut off a certain load branch with the highest short - circuit risk (because its resistance is the smallest when short - circuited), and ensure that the remaining K - 1 load branches will not be cut off. The specific way to control the PWM signal generation module to continuously output the first DC current may include, but is not limited to: based on existing conventional technical means, adjusting the duty cycle of the PWM signal to 100% or close to 100%, and adjusting the pulse height of the PWM signal to the current value of the first DC current. In addition, the duration of the first DC current needs to be greater than the disconnection trigger response duration of the fuse, so as to be able to trigger the fuse on the at least one load branch to disconnect.

[0066] Based on the switching power supply short - circuit protection method described in the foregoing steps S1 - S3, a new switching power supply short - circuit protection solution is provided, which can also ensure that other non - faulty loads can still work normally when a load short - circuit fault occurs in a certain load branch based on a fuse. That is, the method is executed by the main control module in the switching power supply. Among them, the switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output end of the PWM signal generation module is used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch. The disconnection trigger current threshold of the fuse is greater than the normal working current value of the load branch to which it belongs. The main control module will continuously judge whether there is at least one load branch with a short - circuit risk according to the voltage detection value in real time. If so, it will control the PWM signal generation module to continuously output a DC current for triggering the disconnection of the fuses on these load branches. In this way, independent short - circuit protection can be carried out on different load branches based on the fuse, and the purpose of enabling other non - faulty loads to still work normally when a load short - circuit fault occurs in a certain load branch can be achieved at low cost, which is convenient for practical application and popularization.

[0067] Based on the technical solution of the foregoing first aspect, this embodiment also provides a possible design for identifying the currently disconnected branch and alarming after the fuse is triggered to disconnect. That is, the multiple load branches have the same working resistance, and a self - resetting fuse is also connected in series on the load branch. Among them, the disconnection trigger current threshold I of the self - resetting fuse th2 is greater than the normal working current value of the load branch and less than the disconnection trigger current threshold I of the fuse th1 , and the disconnection trigger response duration of the self - resetting fuse is greater than the duration of the first DC current. Any two self - resetting fuses on different load branches have the same disconnection trigger response duration and different self - reset durations. The self - resetting fuse is also used to disconnect when the working current value of the load branch to which it belongs reaches the corresponding disconnection trigger current threshold and this situation lasts for the corresponding disconnection trigger response duration, so as to temporarily cut off the load branch to which it belongs (that is, it will automatically resume conduction after the corresponding self - reset duration). Specifically, it can generally achieve the following purpose through different designs in terms of material, type, and / or assembly form, etc.: Any two self - resetting fuses on different load branches have the same disconnection trigger response duration and different self - reset durations. Generally, since the self - resetting fuse relies on the thermal accumulation effect to achieve temporary disconnection, its disconnection trigger response duration is in the millisecond level, which is much greater than the disconnection trigger response duration of the fuse. In this way, when controlling the PWM signal generation module to continuously output the first DC current, although the current value of the first DC current is also greater than the disconnection trigger current threshold I of the self - resetting fuse th2, but since the disconnection trigger response duration of the self - restoring fuse is greater than the duration of the first DC current, the fuse on at least one of the load branches will still disconnect before the self - restoring fuse.

[0068] In the first possible design and after controlling the PWM signal generation module to continuously output the first DC current, the method further includes but is not limited to the following steps S41 - S45.

[0069] S41. Control the PWM signal generation module to continuously output a second DC current so as to trigger the disconnection of the self - restoring fuse on the currently unbroken branch through the second DC current, where the current value of the second DC current is greater than K×I th2 and less than (K - 1)×I th1 , K represents the number of branches among the multiple load branches, the currently unbroken branch refers to the load branch among the multiple load branches in which the currently un - disconnected fuse is connected in series, and the duration of the second DC current is greater than the disconnection trigger response duration of the self - restoring fuse.

[0070] In step S41, considering the situation in step S3 where at least one of the load branches fails to disconnect successfully (for example, when there are two load branches with short - circuit risks simultaneously and the current value of the first DC current is less than 2×I th1 , since the resistances of these two load branches are extremely small and similar, the currents flowing through them are similar and less than I th1 , so the fuses on these two load branches will not disconnect), therefore, the current value of the second DC current needs to be greater than K×I th2 to ensure that the self - restoring fuses on all load branches will be temporarily disconnected. Also considering the situation in step S3 where one of the load branches has been successfully disconnected (at this time, the actual situation of two load branches with short - circuit risks existing simultaneously is not considered), therefore, the current value of the second DC current needs to be less than (K - 1)×I th1 to ensure that the fuses on all currently unbroken branches will not disconnect. In addition, the specific control output method of the second DC current can be conventionally derived with reference to the first DC current in the previous step S3, and will not be elaborated here.

[0071] S42. Control the PWM signal generation module to continuously output a third DC current, where the current value of the third DC current is less than I th2 , and the duration of the third DC current is t sr,max +τ, t sr,max represents the maximum self - recovery duration among the multiple self - recovery durations corresponding to the multiple load branches one by one, and τ represents a preset duration.

[0072] In the step S42, since the current value of the third DC current is less than I th2 , it can ensure that the self - reset fuse on any of the currently unbroken branches will not break again after automatically recovering to conduction; and since the duration of the third DC current is t sr,max +τ, it can also ensure that the self - reset fuses on all the currently unbroken branches have recovered to conduction; for example, the preset duration τ can be designed as 10 milliseconds. In addition, the specific control output method of the third DC current can also be conventionally derived from the first DC current in the foregoing step S3, which will not be elaborated here.

[0073] S43. During the process of waiting for the self - reset fuses to recover one by one, continue to receive the voltage detection value from the voltage detection module at the power supply output end in real time, and obtain a voltage detection timing data with a recording duration of t sr,max +τ.

[0074] In the step S43, the voltage detection timing data contains the voltage detection values arranged in the order from early to late according to the receiving time. In addition, the foregoing step S43 and the foregoing step S42 are synchronous execution steps without a sequence.

[0075] S44. Determine the currently broken branch according to the voltage detection timing data and the multiple self - recovery durations, where the currently broken branch refers to the load branch among the multiple load branches and in series with the currently disconnected fuse.

[0076] In the step S44, since different currently unbroken branches correspond to different self - recovery durations, and when the currently unbroken branches recover to conduction, there will be a phenomenon of voltage jump at the power supply output end due to the continuous output of the third DC current (when the multiple load branches have the same working resistance, the jump amplitude will be theoretically the same). Therefore, the voltage jump time information reflected by the voltage detection timing data can be combined with the multiple self - recovery durations to identify the specific currently unbroken branches, and then determine the currently broken branch. Specifically, determining the currently broken branch according to the voltage detection timing data and the multiple self - recovery durations includes, but is not limited to, the following steps S441 - S444.

[0077] S441. Determine the number of voltage jumps k according to the voltage detection timing data.

[0078] In the step S441, since the voltage detection timing data includes voltage detection values arranged in the order from the earliest to the latest reception time, the voltage jump phenomena at each power output terminal can be conventionally detected according to the voltage detection timing data, and then the number of voltage jumps k and the corresponding k voltage jump delay durations can be determined.

[0079] S442. If it is found that the number of voltage jumps k is less than K, k voltage jump delay durations are determined according to the voltage detection timing data, where the voltage jump delay duration refers to the delay duration from the recording start time to the voltage jump time.

[0080] In the step S442, specifically, if it is also found that the number of voltage jumps k is equal to K, it is determined that there is no currently broken branch in the multiple load branches, where the currently broken branch refers to the load branch in the multiple load branches and in series with the currently disconnected fuse; at this time, it can be confirmed that there is a situation where at least one load branch has not been successfully disconnected in the step S3.

[0081] S443. According to the matching result between the k voltage jump delay durations and the multiple self - recovery durations, K - k mismatched durations are determined among the multiple self - recovery durations, where the mismatched duration refers to the self - recovery duration that does not match any of the voltage jump delay durations among the k voltage jump delay durations.

[0082] In the step S443, the matching process between the voltage jump delay duration and the self - recovery duration does not require them to be equal. Instead, for each self - recovery duration among the multiple self - recovery durations, it is determined whether there is a voltage jump delay duration falling within the surrounding interval of the corresponding duration. If so, they match; otherwise, they do not match. For example, if a certain self - recovery duration is 50 milliseconds, and it is assumed that the duration of the second DC current is greater than the disconnection trigger response duration of the self - recovery fuse by 1 millisecond, the surrounding interval of the certain self - recovery duration can be [47, 51] milliseconds. At the same time, if a certain voltage jump delay duration is 48 milliseconds, it is determined that the certain self - recovery duration matches the certain voltage jump delay duration, while if another voltage jump delay duration is 53 milliseconds, it is determined that the certain self - recovery duration does not match the other voltage jump delay duration. To ensure that there will be no one - to - many or many - to - one matching situations between the voltage jump delay duration and the self - recovery duration, the duration interval between any two of the multiple self - recovery durations is preferably greater than or equal to 5 milliseconds.

[0083] S444. Determine the load branch corresponding to each of the matching failure durations one by one as the currently broken branch, where the currently broken branch refers to the load branch among the multiple load branches in which the currently disconnected fuse is connected in series.

[0084] In step S444, since the fuse on the currently broken branch has been disconnected once through the aforementioned step S3, the self - reset fuse on the currently broken branch will not be disconnected in the aforementioned step S41, and will not cause a voltage jump phenomenon at the power output terminal due to automatic recovery and conduction in the aforementioned step S42. Therefore, each matching failure duration will correspond to a unique currently broken branch, and thus the purpose of accurately identifying the currently broken branch can be achieved.

[0085] S45. Trigger and execute corresponding alarm actions for the currently broken branch.

[0086] In step S45, the purpose of triggering the alarm action is to facilitate the maintenance personnel to quickly sense the currently broken branch where the load short - circuit occurs, so as to perform maintenance in a timely manner. Specifically, it can but is not limited to forms such as sound and light alarm or sending short messages to the maintenance personnel. Preferably, when the switching power supply further includes a voice module communicatively connected to the main control module, for the currently broken branch, triggering and executing corresponding alarm actions include but are not limited to: first, generating a voice signal for announcing that a short - circuit fault has occurred in the corresponding branch for the currently broken branch; then transmitting the voice signal to the voice module for voice alarm.

[0087] Thus, based on the foregoing possible design one, it is also possible to achieve the purpose of accurately identifying the currently broken branch and alarming after the fuse is triggered to disconnect by utilizing the characteristics of the self - reset fuse and specific designs, and further facilitate the maintenance personnel to quickly sense the load branch where the short - circuit occurs and perform maintenance in a timely manner.

[0088] Based on the technical solution of the foregoing possible design one, this embodiment also provides a possible design two for short - circuit protection again when it is found that the previous short - circuit protection fails, that is, after determining that there is no currently broken branch among the multiple load branches, the method further includes but is not limited to the following steps S51 - S52.

[0089] S51. Control the PWM signal generation module to resume normal output, and continue to receive new voltage detection values from the power output terminal voltage detection module in real - time.

[0090] S52. If it is still determined according to the new voltage detection value that there is at least one load branch with a short - circuit risk among the multiple load branches, then control the PWM signal generation module to continuously output a fourth DC current, so as to trigger the fuse on the at least one load branch to disconnect through the fourth DC current, where the current value of the fourth DC current is greater than 2×I th1 and less than (K - 2)×I th1 , and the duration of the fourth DC current is greater than the disconnection trigger response duration of the fuse.

[0091] In step S52, the current value of the fourth DC current is greater than 2×I th1 and less than (K - 2)×I th1 Specifically, it is designed considering the relatively rare actual situation where three load branches with short - circuit risks exist simultaneously, so as to cut off the two load branches with the highest short - circuit risks first and ensure that the remaining K - 2 load branches will not be cut off. Additionally, in order to continue to accurately identify the currently disconnected branch and give an alarm, preferably, after controlling the PWM signal generation module to continuously output the fourth DC current, the method further includes but is not limited to the following steps S531 - S535.

[0092] S531. Control the PWM signal generation module to continuously output a fifth DC current, so as to trigger the self - resetting fuse on the currently un - disconnected branch to disconnect through the fifth DC current, where the current value of the fifth DC current is greater than K×I th2 and less than (K - 2)×I th1 , and the duration of the fifth DC current is greater than the disconnection trigger response duration of the self - resetting fuse.

[0093] S532. Control the PWM signal generation module to continuously output the third DC current.

[0094] S533. During the process of waiting for the self - resetting fuses to recover one by one, continue to receive the voltage detection values from the power output terminal voltage detection module in real - time, and obtain a new voltage detection timing data with a recording duration of t sr,max +τ.

[0095] S534. Determine the currently disconnected branch according to the new voltage detection timing data and the multiple self - recovery durations.

[0096] S535. For the currently disconnected branch, trigger the execution of corresponding alarm actions.

[0097] The specific details of the foregoing steps S531 to S535 can be obtained by conventional derivation with reference to the foregoing steps S41 to S45, and will not be elaborated here. In addition, if the previous short-circuit protection still fails, return to execute steps S51 to S52 and steps S531 to S535, and design the fourth DC current (i.e., the current value of the fourth DC current is greater than 3×I th1 and less than (K - 3)×I th1 ) and the fifth DC current (i.e., the current value of the fifth DC current is greater than K×Ith2 and less than (K - 3)×I th1 ) considering the relatively rare actual situation of four load branches with short-circuit risk existing simultaneously; and so on in sequence until it is found that the previous short-circuit protection is not failed.

[0098] Based on the foregoing possible design two, the reliability of the short-circuit protection scheme can also be improved by performing short-circuit protection again when it is found that the previous short-circuit protection fails.

[0099] As Figure 2 shown, in the second aspect of this embodiment, a virtual system for implementing the switching power supply short-circuit protection method described in the first aspect or any possible design in the first aspect is provided, which is applicable to being arranged in the main control module of the switching power supply. Among them, the switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch among the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the load branch to which it belongs;

[0100] The virtual system includes a detection data receiving unit, a short-circuit risk judgment unit, and an output current control unit that are communicatively connected in sequence;

[0101] The detection data receiving unit is used to receive the voltage detection value from the power output terminal voltage detection module in real time;

[0102] The short-circuit risk judgment unit is used to judge in real time whether there is at least one load branch with short-circuit risk among the multiple load branches according to the voltage detection value;

[0103] The output current control unit is configured to control the PWM signal generation module to continuously output a first DC current when it is determined that there is at least one load branch with a short - circuit risk among the multiple load branches, so as to trigger the fuse on the at least one load branch to disconnect through the first DC current. Wherein, the current value of the first DC current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first DC current is greater than the disconnection trigger response duration of the fuse.

[0104] For the working process, working details and technical effects of the foregoing device provided in the second aspect of this embodiment, reference can be made to the switching power supply short - circuit protection method described in the first aspect or any possible design in the first aspect, which will not be elaborated herein.

[0105] As Figure 3 shown, in the third aspect of this embodiment, an entity system for implementing the switching power supply short - circuit protection method described in the first aspect or any possible design in the first aspect is provided, including a switching power supply and multiple load branches respectively electrically connected to the output terminal of the switching power supply. Wherein, the switching power supply includes a main control module, a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply. The same fuse is connected in series on each of the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the corresponding load branch;

[0106] The power output terminal voltage detection module is configured to monitor the output terminal voltage of the switching power supply in real time and transmit the monitoring result to the main control module in real time;

[0107] The PWM signal generation module is configured to output a PWM signal with a specified duty cycle under the control of the main control module to supply the load branch;

[0108] The main control module is configured to execute the switching power supply short - circuit protection method described in the first aspect or any possible design in the first aspect.

[0109] For the working process, working details and technical effects of the foregoing system provided in the third aspect of this embodiment, reference can be made to the switching power supply short - circuit protection method described in the first aspect or any possible design in the first aspect, which will not be elaborated herein.

[0110] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A switching power supply short - circuit protection method, characterized in that, It is executed by the main control module in the switching power supply. The switching power supply further includes a power output terminal voltage detection module and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module. The main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each of the multiple load branches. The disconnection trigger current threshold of the fuse is greater than the normal operating current value of the corresponding load branch; The switching power supply short-circuit protection method includes: Receiving in real time the voltage detection value from the power output terminal voltage detection module; According to the voltage detection value, judging in real time whether there is at least one load branch with a short-circuit risk among the multiple load branches; If it is determined that there is at least one load branch with a short-circuit risk among the multiple load branches, then control the PWM signal generation module to continuously output a first direct current, so as to trigger the disconnection of the fuse on the at least one load branch through the first direct current. The current value of the first direct current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first direct current is greater than the disconnection trigger response duration of the fuse.

2. The switching power supply short-circuit protection method according to claim 1, wherein The multiple load branches have the same working resistance, and a self - reset fuse is also connected in series on the load branch. Among them, the disconnection trigger current threshold I of the self - reset fuse th2 is greater than the normal working current value of the load branch and less than the disconnection trigger current threshold I of the fuse th1 , the disconnection trigger response duration of the self - reset fuse is greater than the duration of the first DC current, and any two of the self - reset fuses located on different load branches have the same disconnection trigger response duration and different self - recovery durations; After controlling the PWM signal generation module to continuously output the first direct current, the method further includes: Control the PWM signal generation module to continuously output a second DC current, so as to trigger the disconnection of the self - restoring fuse on the currently unbroken branch through the second DC current, where the current value of the second DC current is greater than K×I th2 and less than (K - 1)×I th1 , K represents the number of branches in the multiple load branches, and the currently unbroken branch refers to the load branch in the multiple load branches that is serially connected with the fuse that is still not disconnected at present. The duration of the second DC current is greater than the disconnection trigger response duration of the self - restoring fuse; Control the PWM signal generation module to continuously output a third DC current, where the current value of the third DC current is less than I th2 , and the duration of the third DC current is t sr,max +τ, t sr,max represents the maximum self-recovery duration among multiple self-recovery durations corresponding to the multiple load branches one by one, and τ represents a preset duration; During the process of waiting for the self - restoring fuses to recover one by one, continue to receive the voltage detection values from the voltage detection module at the power output end in real - time, and obtain a voltage detection timing data with a recording duration of t sr,max +τ; Determining the currently disconnected branch according to the voltage detection timing data and the multiple self-recovery durations, where the currently disconnected branch refers to the load branch in the multiple load branches and in which the currently disconnected fuse is connected in series; Triggering and executing a corresponding alarm action for the currently disconnected branch.

3. The switching power supply short-circuit protection method according to claim 2, wherein, Determining the currently disconnected branch according to the voltage detection timing data and the multiple self-recovery durations includes: Determining the number k of voltage jumps according to the voltage detection timing data; If it is found that the number k of voltage jumps is less than K, then determining k voltage jump delay durations according to the voltage detection timing data, where the voltage jump delay duration refers to the delay duration from the start time of recording to the voltage jump time; Determining K-k mismatch durations among the multiple self-recovery durations according to the matching result between the k voltage jump delay durations and the multiple self-recovery durations, where the mismatch duration refers to the self-recovery duration that does not match any of the voltage jump delay durations among the k voltage jump delay durations; Determining the load branches corresponding to the mismatch durations one by one as the currently disconnected branches, where the currently disconnected branch refers to the load branch in the multiple load branches and in which the currently disconnected fuse is connected in series.

4. The switching power supply short-circuit protection method according to claim 3, characterized in that, The time interval between any two of the multiple self-recovery durations is greater than or equal to 5 milliseconds.

5. The switch power supply short-circuit protection method according to claim 3, wherein, If it is found that the number of voltage jumps k is equal to K, it is determined that there is no currently broken branch among the multiple load branches, where the currently broken branch refers to a load branch among the multiple load branches in which the currently disconnected fuse is connected in series.

6. The switch power supply short-circuit protection method according to claim 5, wherein After determining that there is no currently broken branch among the multiple load branches, the method further includes: Controlling the PWM signal generation module to resume normal output and continue to receive new voltage detection values from the power supply output voltage detection module in real time; If it is still determined according to the new voltage detection value that there is at least one load branch with a short - circuit risk among the multiple load branches, then control the PWM signal generation module to continuously output a fourth DC current, so as to trigger the fuse on the at least one load branch to disconnect through the fourth DC current, where the current value of the fourth DC current is greater than 2×I th1 and less than (K - 2)×I th1 , and the duration of the fourth DC current is greater than the disconnection trigger response duration of the fuse.

7. The switching power supply short-circuit protection method according to claim 6, wherein After controlling the PWM signal generation module to continuously output the fourth DC current, the method further includes: Control the PWM signal generation module to continuously output a fifth DC current, so as to trigger the disconnection of the self - reset fuse on the currently unbroken branch through the fifth DC current, where the current value of the fifth DC current is greater than K×I th2 and less than (K - 2)×I th1 , and the duration of the fifth DC current is greater than the disconnection trigger response duration of the self - reset fuse; Controlling the PWM signal generation module to continuously output the third DC current; While waiting for the self - restoring fuses to recover one by one, continue to receive the voltage detection values from the voltage detection module at the power output terminal in real time, and obtain a new voltage detection timing data with a recording duration of t sr,max +τ; Determining the currently broken branch according to the new voltage detection timing data and the multiple self-recovery durations; Triggering and executing a corresponding alarm action for the currently broken branch.

8. The switching power supply short-circuit protection method according to claim 2, wherein When the switching power supply further includes a voice module communicatively connected to the main control module, triggering and executing a corresponding alarm action for the currently broken branch includes: Generating a voice signal for announcing a short-circuit fault in the corresponding branch for the currently broken branch; Transmitting the voice signal to the voice module for voice alarm.

9. A switching power supply short-circuit protection system, characterized in that, Applicable to be arranged in the main control module of a switching power supply, where the switching power supply further includes a power supply output voltage detection module and a PWM signal generation module. The output end of the power supply output voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled end of the PWM signal generation module. The output end of the PWM signal generation module is used as the output end of the switching power supply and is also used to be electrically connected to multiple load branches respectively. The same fuse is connected in series on each load branch among the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the load branch to which it belongs; The switching power supply short-circuit protection system includes a detection data receiving unit, a short-circuit risk judgment unit, and an output current control unit that are communicatively connected in sequence; The detection data receiving unit is used to receive the voltage detection value from the power supply output voltage detection module in real time; The short-circuit risk judgment unit is used to determine in real time whether there is at least one load branch with a short-circuit risk among the multiple load branches according to the voltage detection value; The output current control unit is used to control the PWM signal generation module to continuously output a first DC current when it is determined that there is at least one load branch with a short-circuit risk among the multiple load branches, so as to trigger the disconnection of the fuse on the at least one load branch through the first DC current, where the current value of the first DC current is greater than the disconnection trigger current threshold of the fuse, and the duration of the first DC current is greater than the disconnection trigger response duration of the fuse.

10. A switching power supply short-circuit protection system, characterized in that, It includes a switching power supply and multiple load branches respectively electrically connected to the output terminal of the switching power supply. Among them, the switching power supply includes a main control module, a power output terminal voltage detection module, and a PWM signal generation module. The output terminal of the power output terminal voltage detection module is communicatively connected to the main control module, and the main control module is also communicatively connected to the controlled terminal of the PWM signal generation module. The output terminal of the PWM signal generation module is used as the output terminal of the switching power supply. The same fuse is connected in series on each of the multiple load branches, and the disconnection trigger current threshold of the fuse is greater than the normal operating current value of the load branch to which it belongs; The power output terminal voltage detection module is used to monitor the output terminal voltage of the switching power supply in real time and transmit the monitoring result to the main control module in real time; The PWM signal generation module is used to output a PWM signal with a specified duty cycle under the control of the main control module to supply the load branch; The main control module is used to execute the switching power supply short-circuit protection method described in any one of claims 1 to 8.

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