Fault power supply automatic switching circuit and system

Abstract

The invention discloses a fault power supply automatic switching circuit and system, and the circuit is characterized in that a first power supply outputs a current signal to a first current switching device, so that the first current switching device outputs the current signal to a control device; when the current signal indicates that the current is lower than a current threshold value, the control device starts a second power supply based on the current signal, so that the second power supply outputs a second current to a second current switching device, generates a fault state signal based on the current signal and sends the fault state signal to a relay coil device; the relay coil device switches a second current switching device from a first contact working state to a second contact working state based on the fault state signal, so that the second current switching device outputs a second current to the control device based on the second contact working state, and then the control device controls a second power supply to supply power based on the second current; therefore, the reliability of automatic switching of the fault power supply is improved.

Description

Technical Field

[0001] This invention relates to the field of automatic power switching in case of failure, and more particularly to an automatic power switching circuit and system. Background Technology

[0002] In scenarios with extremely high requirements for power supply continuity, such as electrical fire protection and industrial automation control, the stable power supply of core loads, such as emergency lighting and precision control equipment, is directly related to system safety and functional reliability. Therefore, the automatic switching scheme of main and backup dual power supplies has become a standard configuration in the industry.

[0003] In existing technologies, when the main power supply malfunctions, manual monitoring and activation of the backup power supply are required, or an automatic power switching device is used. However, traditional automatic power switching solutions have significant limitations: mixed sampling of multiple power supply signals can easily lead to false or missed fault detections, and delays in contact action during main / backup power switching can easily cause load power outages. In such scenarios, the continuous power supply to the core load is directly related to system safety and functional reliability. Therefore, there is an urgent need for a switching solution that can achieve isolation between high-voltage power supply and low-voltage control, accurate fault diagnosis, fast switching response, and reliable protection to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] This invention provides an automatic power switching circuit and system for faulty power supplies, which can solve the above-mentioned problems and improve the reliability of automatic power switching for faulty power supplies.

[0005] This invention provides an automatic power supply switching circuit for faults, including a first power supply, a first current switching device, a relay coil device, a control device, a second power supply, and a second current switching device. The initial contact operating state of the first current switching device is the first contact operating state, and the initial contact operating state of the second current switching device is the second contact operating state, wherein:

[0006] The first power supply outputs a current signal to the first current switching device, so that the first current switching device outputs the current signal to the control device;

[0007] When the current signal is lower than the current threshold, the control device starts the second power supply based on the current signal, so that the second power supply outputs the second current to the second current switching device, and generates a fault status signal based on the current signal, and sends the fault status signal to the relay coil device.

[0008] The relay coil device switches the second current switching device from the first contact working state to the second contact working state based on the fault state signal, so that the second current switching device outputs the second current to the control device based on the second contact working state, and in turn the control device controls the second power supply to supply power to the load device based on the second current.

[0009] In the above scheme, the second power supply startup and the fault state signal generation are synchronously realized by the control device based on the current signal, effectively ensuring the accuracy and timeliness of the power supply switching; after receiving the fault state signal, the relay coil device synchronously drives the first current switching device to switch from the first contact working state to the second contact working state, and the second current switching device to switch from the second contact working state to the first contact working state, realizing the coordinated linkage of the main and standby power supply link switching, completely avoiding the power supply conflict or disconnection problem caused by the asynchronization of power supply startup and contact switching; at the same time, the current signal and the second current as the control basis of the control device ensure the accuracy of fault determination, and cooperate with the accurate switching of the contact working state, so that the second power supply can quickly and stably supply power to the load device, significantly improving the reliability of the switching process and effectively avoiding the risk of power failure of the load device during power supply switching.

[0010] Further, the first current switching device comprises a first current sensing and transmitting device and a first contact device, wherein:

[0011] The input end of the first current sensing and transmitting device is electrically connected with the output end of the first power supply, and the output end of the first current sensing and transmitting device is electrically connected with the input end of the first contact device;

[0012] The first output end of the first contact device is grounded, and the second output end of the first contact device is electrically connected with the input end of the control device.

[0013] In the above scheme, the first current sensing and transmitting device and the first contact device are integrated by the first current switching device, the first current sensing and transmitting device can convert the large current of the first power supply into a small current signal, which not only realizes accurate sampling of the first power supply current, but also isolates the high voltage on the first power supply side through high insulation characteristics; at the same time, the first output end of the first contact device is grounded, and the second output end is connected with the control device, which can stably transmit the small current signal to the control device when the first power supply is normal, and release the open-circuit high voltage of the first current sensing and transmitting device through the grounding circuit when the first power supply fails, effectively balancing the accuracy of signal monitoring and the safety of circuit operation.

[0014] Further, the second current switching device comprises a second current sensing and transmitting device and a second contact device, wherein:

[0015] The input terminal of the second current sensing transmitter is electrically connected to the output terminal of the second power supply, and the output terminal of the second current sensing transmitter is electrically connected to the input terminal of the second contact device.

[0016] The first output terminal of the second contact device is grounded, and the second output terminal of the second contact device is electrically connected to the input terminal of the control device.

[0017] In the above scheme, a second current sensing transmitter and a second contact device are configured symmetrically with the first current switching device through the second current switching device. This allows the current of the second power supply to be converted into a small current signal through the second current sensing transmitter and then selectively transmitted to the control device or grounded through the second contact device. This achieves consistency in the monitoring of the main and backup power supply currents and keeps the protection logic of the dual power supply links symmetrical, ensuring that signal monitoring and safety protection can respond synchronously when the main and backup power supplies are switched.

[0018] Furthermore, the control device includes a current receiving protection device and a control module, wherein:

[0019] The first input terminal of the current receiving protection device is electrically connected to the second output terminal of the first contact device, and the second input terminal of the current receiving protection device is electrically connected to the second output terminal of the second contact device.

[0020] The output terminal of the current receiving protection device is electrically connected to the input terminal of the control module;

[0021] The first output terminal of the control module is electrically connected to the first input terminal of the relay coil device, and the second output terminal of the control module is electrically connected to the second input terminal of the relay coil device.

[0022] In the above scheme, the control device includes a current receiving and protection device and a control module. The current receiving and protection device can simultaneously receive small current signals transmitted by the first and second contact devices, perform secondary processing on the signals, and avoid abnormal signals interfering with subsequent logic. The control module can generate control commands based on the processed signals and output them to the relay coil device, which improves the accuracy of fault diagnosis, ensures efficient linkage of the relay coil device, and enhances the control reliability of the circuit.

[0023] Furthermore, the first contact device includes a first grounding contact module and a first current transmission contact module, wherein:

[0024] The input terminal of the first grounding contact module is electrically connected to the output terminal of the first current sensing transmitter, and the output terminal of the first grounding contact module is grounded.

[0025] The input end of the first current transmission contact module is electrically connected with the output end of the first current sensing transducer, and the output end of the first current transmission contact module is electrically connected with the first input end of the current receiving protection device.

[0026] In the above scheme, the first contact device is refined into a first grounding contact module and a first current transmission contact module, both of which share the output end of the first current sensing transducer, so that a small current signal can be transmitted to the current receiving protection device through the first current transmission contact module when the first power supply is normal, and the first current sensing transducer is grounded through the first grounding contact module when the first power supply fails, thereby realizing on-demand switching of signal transmission and high-voltage protection.

[0027] Further, the relay coil device includes a first coil module, a second coil module, a third coil module, and a fourth coil module, wherein:

[0028] The input end of the first coil module is electrically connected with the first output end of the control module, and the output end of the first coil module is grounded.

[0029] The input end of the second coil module is electrically connected with the first output end of the control module, and the output end of the second coil module is grounded.

[0030] The input end of the third coil module is electrically connected with the second output end of the control module, and the output end of the third coil module is grounded.

[0031] The input end of the fourth coil module is electrically connected with the second output end of the control module, and the output end of the fourth coil module is grounded.

[0032] In the above scheme, the first, second, third, and fourth coil modules are provided in the relay coil device, which correspond to the contact modules of the first and second current switching devices, respectively, and each coil module is independently connected to the control module and the ground, thereby realizing precise and independent control of different contact modules.

[0033] Further, the first coil module includes a relay coil, a connecting frame, an armature, and a driving rod, the connecting frame includes a bottom connecting plate, a connecting structure, and a top connecting plate, one end of the connecting structure is connected with one end of the top layer of the bottom connecting plate, and the other end of the connecting structure is connected with one end of the bottom layer of the top connecting plate, wherein:

[0034] One end of the relay coil is connected with the first output end of the control module, and the other end of the relay coil is grounded.

[0035] The top layer of the bottom connecting plate is connected with the bottom of the relay coil.

[0036] The armature is arranged on the bottom layer of the top connecting plate;

[0037] The other end of the top connecting plate is connected with one end of the driving rod;

[0038] The other end of the driving rod is connected with the first contact device.

[0039] In the above scheme, through the mechanical linkage structure of the relay coil of the first coil module, the connecting frame, the armature and the driving rod, when the relay coil is powered on, the armature, the connecting frame and the driving rod can be driven by electromagnetic attraction, thereby driving the first contact device to switch state. The relay coil and the first contact device are only linked through mechanical structure, which not only ensures the fast response of the contact switching, but also isolates the high-voltage loop and the low-voltage control loop through high insulation design, effectively reduces the risk of damage of the control module by high voltage, and improves the safety and timeliness of the contact switching.

[0040] Further, the automatic fault power switching circuit further comprises a common device, wherein:

[0041] The first input end of the common device is connected with the common power supply, the second input end of the common device is electrically connected with the output end of the relay coil device, the first output end of the common device is grounded, and the second output end of the common device is electrically connected with the input end of the first power supply.

[0042] In the above scheme, the common device is additionally provided and connected with the common power supply and the relay coil device. The common device can supply power to the load device through its own loop during the interval of the first and second power supply switching or when both of them fail, which not only avoids the power failure of the load caused by the switching of the main and standby power supplies, but also serves as an emergency power supply in extreme failure scenarios, significantly improving the power supply continuity of the automatic fault power switching circuit.

[0043] Further, the common device comprises a common coil module and a common contact device, wherein:

[0044] The first input end of the common coil module is the first input end of the common device, the second input end of the common coil module is the second input end of the common device, and the driving rod of the common coil module is connected with the common contact device.

[0045] In the above scheme, the common device comprises a common coil module and a common contact device. The common coil module can receive the state signal of the relay coil device and drive the common contact device to switch state through the driving rod, realizing the linkage control of the common device and the main and standby power supply link, and ensuring the continuous power supply to the load device.

[0046] Another embodiment of the present application also provides a failure power automatic switching system, comprising a load device and a failure power automatic switching circuit as described above, wherein the failure power automatic switching circuit supplies power to the load device. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0048] Figure 1 is a structural schematic diagram of a failure power automatic switching circuit provided by an embodiment of the present application;

[0049] Figure 2 is a structural schematic diagram of a connection relationship of a first current sensing device, a second current sensing device and a load device provided by an embodiment of the present application;

[0050] Explanation of Reference Signs:

[0051] 1: first power supply, 2: second power supply, 3: relay coil device, 4: control device, 5: common device. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions in the present application will be described clearly and completely in the following with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort are within the scope of protection of the present application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0055] Reference within this document to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As those skilled in the art will readily appreciate, various features, structures, and characteristics described in connection with one embodiment can be applied to other embodiments.

[0056] In the description of the embodiments of the present application, the term "and / or" is merely used to describe an associated relationship between associated objects, and can represent three relationships, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in this document generally represents an "or" relationship between the front and rear associated objects.

[0057] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0058] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0059] Reference is made to Figure 1 To solve the above problems and improve the reliability of the automatic switching of the power supply, an embodiment of the present application provides a kind of automatic switching of power supply circuit of failure, including first power supply 1, first current switching device, relay coil device 3, control device 4, second power supply 2 and second current switching device, wherein:

[0060] The first power supply 1 outputs current signal to the first current switching device, so that the first current switching device outputs the current signal to the control device 4;

[0061] When the current signal is current lower than current threshold, the control device 4 starts the second power supply 2 based on the current signal, so that the second power supply 2 outputs second current to the second current switching device, and generates a failure state signal based on the current signal, and sends the failure state signal to the relay coil device 3;

[0062] The relay coil device 3 switches the second current switching device from the first contact working state to the second contact working state based on the fault state signal, so that the second current switching device outputs the second current to the control device 4 based on the second contact working state, and then the control device 4 controls the second power supply 2 to supply power based on the second current.

[0063] In the above scheme, the second power supply 2 starting and the fault state signal generation are realized synchronously by the control device 4 based on the current signal, which effectively guarantees the accuracy and timeliness of the power supply switching; after receiving the fault state signal, the relay coil device 3 synchronously drives the first current switching device to switch from the first contact working state to the second contact working state, and the second current switching device to switch from the second contact working state to the first contact working state, realizing the cooperative linkage of the main and standby power supply link switching, and completely avoiding the power supply conflict or disconnection problem caused by the asynchronization of power supply starting and contact switching; at the same time, the current signal and the second current as the control basis of the control device 4 ensure the accuracy of fault determination, and cooperate with the accurate switching of the contact working state, so that the second power supply 2 can supply power quickly and stably, significantly improving the reliability of the switching process, and effectively avoiding the risk of power failure of the load device during power supply switching.

[0064] It should be noted that, as shown in Figure 1 The switch corresponding to the first power supply 1 is QF1, and the switch corresponding to the second power supply 2 is QF2.

[0065] In another embodiment, the first current switching device includes a first current sensing transmitter device and a first contact device, wherein:

[0066] The input end of the first current sensing transmitter device is electrically connected with the output end of the first power supply 1, and the output end of the first current sensing transmitter device is electrically connected with the input end of the first contact device;

[0067] The first output end of the first contact device is grounded, and the second output end of the first contact device is electrically connected with the input end of the control device 4.

[0068] It should be noted that the first power supply 1 outputs three-phase current (L11, L21 and L31), which is input to the first current sensing transducer, which is essentially a current transformer (CT) that converts the current signal (such as 1500A) output by the first power supply 1 belonging to a large current into a small current (such as 15A) in proportion, and the conversion ratio can be adjusted according to the actual application scene (such as 100:1); the first current sensing transducer has high insulation characteristics and can isolate the high voltage on the first power supply 1 side to prevent high voltage from entering the subsequent control loop and ensure circuit safety; the first contact device includes KA14a, KA14b, KA14c, KA14com1, KA12a, KA12b, KA12c, KA12com1 corresponding to the three-phase small current (Ia1, Ib1, Ic1) output by the first current sensing transducer and the current output by the common point (com1), so that the current after being converted into a small current is output to the corresponding circuit through different contacts.

[0069] In another embodiment, the second current switching device includes a second current sensing transducer and a second contact device, wherein:

[0070] The input end of the second current sensing transducer is electrically connected to the output end of the second power supply 2, and the output end of the second current sensing transducer is electrically connected to the input end of the second contact device;

[0071] The first output end of the second contact device is grounded, and the second output end of the second contact device is electrically connected to the input end of the control device 4.

[0072] It should be noted that the structure and working principle of the second current sensing transducer are completely consistent with those of the first current sensing transducer, and it also has mutual inductance conversion function and high insulation characteristics, and the converted second current is used for state monitoring and power supply control of the control device 4; the second contact device includes KA15a, KA15b, KA15c, KA15com1, KA13a, KA13b, KA13c, KA13com2 corresponding to the three-phase small current (Ia2, Ib2, Ic2) output by the first current sensing transducer and the current output by the common point (com2). It can be understood that Ia1 and Ia2 will eventually be collected to the Ia line and then input to the current receiving protection device, Ib1 and Ib2 will eventually be collected to the Ib line and then input to the current receiving protection device, Ic1 and Ic2 will eventually be collected to the Ic line and then input to the current receiving protection device, and com1 and com2 will eventually be collected to the com line and then input to the current receiving protection device. Reference Figure 2 , the first power supply 1 supplies power to the same load device through the first current sensing transducer, and the second power supply 2 supplies power to the same load device through the second current sensing transducer.

[0073] In another embodiment, the control device 4 comprises a current receiving protection device and a control module, wherein:

[0074] The first input end of the current receiving protection device is electrically connected with the second output end of the first contact device, and the second input end of the current receiving protection device is electrically connected with the second output end of the second contact device;

[0075] The output end of the current receiving protection device is electrically connected with the input end of the control module;

[0076] The first output end of the control module is electrically connected with the first input end of the relay coil device 3, and the second output end of the control module is electrically connected with the second input end of the relay coil device 3.

[0077] It should be noted that the current receiving protection device comprises an existing mutual inductor and a preset resistance, the current signals transmitted by the first contact device and the second contact device are input to the mutual inductor, the processed current signals are converted by the mutual inductor for secondary mutual induction, and the current signals are converted into voltage signals (such as 15A x 0.1Ω = 1.5V) by the preset resistance; the control module comprises an existing operational amplifier INA196, an existing low-pass filter, an existing ADI AD7403 isolation type analog-to-digital converter (ADC) and an existing STM32 processor, wherein the specific signal processing process of the control module is as follows: the operational amplifier INA196 amplifies the voltage signal output by the sampling resistance to adapt to the input range of the ADC (such as 2.5V, 5V), the low-pass filter suppresses the signal frequency to 500Hz to eliminate high-frequency noise, the AD7403 converts the analog signal into a digital signal, and the STM32 processor obtains the current effective value through the square root operation at the software level, and then realizes fault judgment and control instruction output based on the current effective value and the preset current threshold.

[0078] In another embodiment, the first contact device comprises a first ground contact module and a first current transmission contact module, wherein:

[0079] The input end of the first ground contact module is electrically connected with the output end of the first current sensing variable device, and the output end of the first ground contact module is grounded;

[0080] The input end of the first current transmission contact module is electrically connected with the output end of the first current sensing variable device, and the output end of the first current transmission contact module is electrically connected with the first input end of the current receiving protection device.

[0081] It should be noted that the first ground contact module is a normally closed contact (including KA14a, KA14b, KA14c, KA14com1, corresponding to the first coil module KA14), and the first current transmission contact module is a normally open contact (including KA12a, KA12b, KA12c, KA12com1, corresponding to the second coil module KA12). It should be noted that the first contact working state is that the first ground contact module is normally closed, and the first current transmission contact module is normally open. When the first power supply 1 is normal, the current signal output by the first power supply 1 flows through the first current switching device and the control device 4, and then the relay coil device 3 is powered based on the fault state signal generated by the control device 4, and the first contact working state of the first current switching device is switched to the second contact working state based on the fault state signal, that is, the first ground contact module is driven to be open, and the first current transmission contact module is closed, so that the current signal output by the first current sensing sending device (at this time the current signal is a current equal to or higher than the current threshold) is transmitted to the current receiving protection device through the first current transmission contact module; when the first power supply 1 fails, the relay coil device 3 loses power, the first ground contact module is reset to be closed, and the first current transmission contact module is open, so that the first current sensing sending device realizes high voltage protection through the ground loop, avoiding open circuit high voltage damage to the equipment. At this time, the first power supply 1 does not output current to the control device 4, so the current signal is lower than the current threshold.

[0082] Further, as above, the second contact device includes a second ground contact module and a second current transmission contact module, wherein: the second ground contact module is a normally closed contact (corresponding to the KA15 relay contact, including KA15a, KA15b, KA15c, KA15com2, corresponding to the second coil module KA15), and the second current transmission contact module is a normally open contact (corresponding to the KA13 relay contact, including KA13a, KA13b, KA13c, KA13com2, corresponding to the second coil module KA13).

[0083] In another embodiment, the relay coil device 3 includes a first coil module, a second coil module, a third coil module, and a fourth coil module, wherein:

[0084] The input end of the first coil module is electrically connected to the first output end of the control module, and the output end of the first coil module is grounded;

[0085] The input end of the second coil module is electrically connected to the first output end of the control module, and the output end of the second coil module is grounded;

[0086] The input end of the third coil module is electrically connected to the second output end of the control module, and the output end of the third coil module is grounded;

[0087] An input end of the fourth coil module is electrically connected with a second output end of the control module, and an output end of the fourth coil module is grounded.

[0088] It should be noted that the first coil module KA12 is used to control the on-off of the first current transmission contact module; the second coil module KA14 is used to control the on-off of the first grounding contact module; the third coil module KA13 is used to control the on-off of the second current transmission contact module in the second current switching device; and the fourth coil module KA15 is used to control the on-off of the second grounding contact module in the second current switching device. The four coil modules are all low-voltage controlled (such as 5V or 12V) and have high insulation characteristics, so as to ensure isolation from the high-voltage loop of the contact side and improve the safety of the circuit.

[0089] In another embodiment, the first coil module comprises a relay coil, a connecting frame, an armature and a driving rod, the connecting frame comprises a bottom connecting plate, a connecting structure and a top connecting plate, one end of the connecting structure is connected with one end of the top layer of the bottom connecting plate, and the other end of the connecting structure is connected with one end of the bottom layer of the top connecting plate, wherein:

[0090] One end of the relay coil is connected with a first output end of the control module, and the other end of the relay coil is grounded;

[0091] The top layer of the bottom connecting plate is connected with the bottom of the relay coil;

[0092] The armature is arranged on the bottom layer of the top connecting plate;

[0093] The other end of the top connecting plate is connected with one end of the driving rod;

[0094] The other end of the driving rod is connected with the first contact device.

[0095] It should be noted that the working principle of the first coil module is as follows: when the relay coil is powered, an electromagnetic attraction force is generated to attract the armature to drive the top connecting plate to rotate around the connecting structure, and then the driving rod pushes the contact of the first contact device to act; when the relay coil loses power, the electromagnetic attraction force disappears, the connecting frame is reset by its own elasticity (or a matched spring is reset) to drive the contact to return to the initial state; the relay coil and the contact are linked through the mechanical structure of the connecting frame, the armature and the like, and electrical isolation is realized by relying on high insulation materials, so as to avoid high voltage from entering the coil loop, the contact switching response speed of the first coil module is fast, thereby ensuring the fast switching of the power supply link.

[0096] In another embodiment, the automatic switching circuit further comprises a common device 5, wherein:

[0097] The first input end of the common device 5 is connected with the common power supply, the second input end of the common device 5 is electrically connected with the output end of the relay coil device 3, the first output end of the common device 5 is grounded, and the second output end of the common device 5 is electrically connected with the input end of the first power supply 1.

[0098] It should be noted that the common power supply is an additional power supply independent of the first power supply 1 and the second power supply 2, which is used to provide transition power supply or emergency power supply for the load device.

[0099] In another embodiment, the common device 5 comprises a common coil module and a common contact device, wherein:

[0100] The first input end of the common coil module is the first input end of the common device 5, the second input end of the common coil module is the second input end of the common device 5, and the driving rod of the common coil module is connected with the common contact device.

[0101] It should be noted that the common coil module corresponds to the coil of the KA24 high-speed relay, which has a millisecond-level response characteristic (contact switching response time <10 ms), and can quickly adapt to the switching gap of the main and standby power supplies. The common contact device comprises a normally open contact and a normally closed contact. When the first power supply 1 or the second power supply 2 normally supplies power, the common coil module is powered, the normally open contact of the common contact device is closed, the normally closed contact is opened, and the common power supply is in standby state. The current flowing through the relay coil device 3 of the first power supply 1 or the second power supply 2 at last will be grounded through the closed normally open contact, thereby forming a loop. When the main and standby power supplies are switched or simultaneously fail, the common coil module loses power, the normally closed contact of the common contact device is closed, the normally open contact is opened, and the common power supply realizes power supply through the loop of common power supply→KA24 relay→common contact device closed normally closed contact→first power supply 1→load device.

[0102] Reference Figure 1 The following provides specific embodiments:

[0103] (1) Normal operating state (no fault):

[0104] The first power supply 1 and the second power supply 2 are simultaneously connected, and the corresponding first current sensing variable device and the second current sensing variable device supply power to the load device, the first power supply 1 is the main power supply, and the second power supply 2 is the standby power supply.

[0105] The first current sensing device converts the current signal into a small current signal in proportion, and forms a loop with the grounding device through the first grounding contact module, thereby avoiding high voltage; the control device 4 receives the real-time current signal through the first current transmission contact module, and continuously monitors the load running state. The processing flow of the current signal in the control device 4 is: the current signal is converted into voltage through a preset resistor, and then is amplified by an operational amplifier: amplified to 2.5V / 5V by INA196, then low-pass filtered to suppress 500Hz high-frequency noise, and then converted into an analog signal: isolated sampling by AD7403, and finally processed by an STM32 processor: square root operation to obtain the effective current value, and the effective current value is compared with the preset current threshold to determine whether the load is normal, and when the effective current value is greater than or equal to the current threshold, such as 10A, it indicates that the current power supply is normal. The first current sensing device sends a heartbeat packet (data frame 0x55) through the RS485 interface at a fixed time, and the control device 4 receives it every 3 seconds to confirm that the first power supply 1 is online: for example, the function code 0x01 corresponds to the reply frame: 01 01 00 00 00 01 91 88. At this time, the control device 4 sends a fault state signal (i.e. output current) to the first coil module and the second coil module, at this time, the two are powered on, correspondingly, the first current transmission contact module is closed, and the first grounding contact module is disconnected, then the fault state signal is sent to KA24, and KA24 is powered on, correspondingly, the normally open contact is closed, thereby outputting the ground from L1.

[0106] (2) Fault monitoring and automatic switching:

[0107] When the first power supply 1 load output fails, the first current sensing device has no current signal output, or the current signal output is abnormally small, then the effective current value corresponding to the current signal is 0, or lower than the current threshold (such as <10A), and the heartbeat signal is not received within 3 seconds, and the control module in the control device 4 determines that the first power supply 1 fails.

[0108] The control module immediately disconnects the first power supply 1 (disconnects QF1), and simultaneously disconnects the fault state signal supplied to KA12 and KA14, both of which are de-energized, the first current transmission contact module returns to the normally open contact state, the first grounding contact module returns to the normally closed contact state, the monitoring loop of the first power supply 1 is cut off, and the first current sensing device is grounded at the same time; instead, the control device 4 outputs a fault state signal to KA13 and KA15, both of which are energized, the second current transmission contact module is closed, the second grounding contact module is disconnected, and the second power supply 2 is started (QF2 is closed), and three-phase current (L21, L22 and L32) is output to supply power to the load device through the second current sensing device. Similarly, when the second power supply 2 fails, the control device 4 automatically switches back to the first power supply 1 for power supply, realizing bidirectional redundant switching of the main and standby power supplies. Through contact control monitoring signals, the monitoring signals drive the switching of the main power supply loop (QF1 and QF2).

[0109] (3) High-voltage protection mechanism:

[0110] When used on the load side, the current sensing device in the open circuit state will generate high voltage, at which time the first / second current transmission contact module relay normally closed contact is closed, forming an equipotential circuit with the corresponding grounding device, and eliminating the risk of high voltage.

[0111] In the monitoring state, the control device 4 outputs a fault state signal to control the relay coil device 3, and then controls the KA14 / KA15 relay contact to act, disconnects the grounding connection, and at the same time closes the first / second grounding contact module relay contact, transmits the weak current signal to the control device 4, realizes dynamic switching of continuous monitoring and high-voltage protection.

[0112] It can be understood that if the first power supply 1 and the second power supply 2 cannot supply power, at this time there is no current through KA24, the normally closed contact of KA24 will be closed, and the first power supply 1 will be replaced by the common power supply N to supply power to the load device.

[0113] As shown in Figure 2 , on the basis of the above embodiment, corresponding system item embodiments are provided;

[0114] An embodiment of the present application provides a fault power automatic switching system, which comprises a load device and a fault power automatic switching circuit as described above, and the fault power automatic switching circuit supplies power to the load device.

[0115] The system synchronously realizes the generation of the second power start and the fault state signal based on the current signal through the control device, effectively guarantees the accuracy and timeliness of the power supply switching; after the relay coil device receives the fault state signal, the first current switching device is synchronously driven to switch from the first contact working state to the second contact working state, and the second current switching device is synchronously driven to switch from the second contact working state to the first contact working state, realizing the cooperative linkage of the main and standby power supply link switching, completely avoiding the power supply conflict or disconnection problem caused by the asynchronization of the power start and the contact switching; meanwhile, the current signal and the second current serve as the control basis of the control device, ensuring the accuracy of the fault determination, cooperating with the accurate switching of the contact working state, so that the second power can quickly and stably supply power to the load device, significantly improving the reliability of the switching process, and effectively avoiding the power-off risk of the load device during the power supply switching.

[0116] The above is the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements are also considered to be within the scope of the present application.

Claims

1. An automatic power supply switching circuit for faults, characterized in that, It includes a first power supply, a first current switching device, a relay coil device, a control device, a second power supply, and a second current switching device. The initial contact operating state of the first current switching device is the first contact operating state, and the initial contact operating state of the second current switching device is the second contact operating state. The first power supply outputs a current signal to the first current switching device, so that the first current switching device outputs the current signal to the control device; When the current signal is lower than the current threshold, the control device starts the second power supply based on the current signal, so that the second power supply outputs the second current to the second current switching device, and generates a fault status signal based on the current signal, and sends the fault status signal to the relay coil device. The relay coil device switches the second current switching device from the first contact working state to the second contact working state based on the fault status signal, so that the second current switching device outputs the second current to the control device based on the second contact working state, thereby enabling the control device to control the second power supply to supply power based on the second current.

2. The automatic fault power switching circuit according to claim 1, characterized in that, The first current switching device includes a first current sensing and transmitting device and a first contact device, wherein: The input terminal of the first current sensing transmitter is electrically connected to the output terminal of the first power supply, and the output terminal of the first current sensing transmitter is electrically connected to the input terminal of the first contact device. The first output terminal of the first contact device is grounded, and the second output terminal of the first contact device is electrically connected to the input terminal of the control device.

3. The automatic fault power switching circuit according to claim 2, characterized in that, The second current switching device includes a second current sensing and transmitting device and a second contact device, wherein: The input terminal of the second current sensing transmitter is electrically connected to the output terminal of the second power supply, and the output terminal of the second current sensing transmitter is electrically connected to the input terminal of the second contact device. The first output terminal of the second contact device is grounded, and the second output terminal of the second contact device is electrically connected to the input terminal of the control device.

4. The automatic power switching circuit for faulty power supplies according to claim 3, characterized in that, The control device includes a current receiving and protection device and a control module, wherein: The first input terminal of the current receiving protection device is electrically connected to the second output terminal of the first contact device, and the second input terminal of the current receiving protection device is electrically connected to the second output terminal of the second contact device. The output terminal of the current receiving protection device is electrically connected to the input terminal of the control module; The first output terminal of the control module is electrically connected to the first input terminal of the relay coil device, and the second output terminal of the control module is electrically connected to the second input terminal of the relay coil device.

5. The automatic fault power switching circuit according to claim 4, characterized in that, The first contact device includes a first grounding contact module and a first current transmission contact module, wherein: The input terminal of the first grounding contact module is electrically connected to the output terminal of the first current sensing transmitter, and the output terminal of the first grounding contact module is grounded. The input terminal of the first current transmission contact module is electrically connected to the output terminal of the first current sensing and transmitting device, and the output terminal of the first current transmission contact module is electrically connected to the first input terminal of the current receiving and protection device.

6. The automatic fault power switching circuit according to claim 4, characterized in that, The relay coil device includes a first coil module, a second coil module, a third coil module, and a fourth coil module, wherein: The input terminal of the first coil module is electrically connected to the first output terminal of the control module, and the output terminal of the first coil module is grounded. The input terminal of the second coil module is electrically connected to the first output terminal of the control module, and the output terminal of the second coil module is grounded. The input terminal of the third coil module is electrically connected to the second output terminal of the control module, and the output terminal of the third coil module is grounded. The input terminal of the fourth coil module is electrically connected to the second output terminal of the control module, and the output terminal of the fourth coil module is grounded.

7. The automatic fault power switching circuit according to claim 6, characterized in that, The first coil module includes a relay coil, a connecting frame, an armature, and a drive rod. The connecting frame includes a bottom connecting plate, a connecting structure, and a top connecting plate. One end of the connecting structure is connected to one end of the top layer of the bottom connecting plate, and the other end of the connecting structure is connected to one end of the bottom layer of the top connecting plate. One end of the relay coil is connected to the first output terminal of the control module, and the other end of the relay coil is grounded. The top layer of the bottom connecting plate is connected to the bottom of the relay coil; The armature is disposed on the bottom layer of the top connecting plate; The other end of the top connecting plate is connected to one end of the drive rod; The other end of the drive rod is connected to the first contact device.

8. The automatic fault power switching circuit according to claim 1, characterized in that, The automatic fault power switching circuit also includes a common device, wherein: The first input terminal of the common device is connected to a common power supply, the second input terminal of the common device is electrically connected to the output terminal of the relay coil device, the first output terminal of the common device is grounded, and the second output terminal of the common device is electrically connected to the input terminal of the first power supply.

9. The automatic fault power switching circuit according to claim 8, characterized in that, The common device includes a common coil module and a common contact device, wherein: The first input terminal of the common coil module is the first input terminal of the common device, the second input terminal of the common coil module is the second input terminal of the common device, and the drive rod of the common coil module is connected to the common contact device.

10. An automatic power switching system for faulty power supplies, characterized in that, It includes a load device and an automatic power supply switching circuit as described in any one of claims 1-9, wherein the automatic power supply switching circuit supplies power to the load device.

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