A safe power supply circuit and control method thereof

Abstract

The present application discloses a safety power supply circuit and a control method thereof; the safety power supply circuit comprises: a relay component, a rectifier module, a UPS module and a step-down module; the first input end of the relay component receives a first alternating current, and the second input end of the relay component receives a second alternating current; the rectifier module is connected to the relay component; the alternating current output by the relay component is converted into direct current based on the rectifier module; the first alternating current or the second alternating current is input to the rectifier module based on the relay component; the voltage stabilization of direct current is realized based on the UPS module; the output end of the UPS module is connected to a primary power-consuming device; the secondary power-consuming device is connected to the input end of the UPS module; the input end of the step-down module receives high-voltage direct current, the output end of the step-down module is connected to the input end of the UPS module, and the high-voltage direct current is reduced and output to the UPS module based on the step-down module. The uninterrupted power supply of important loads is maintained by switching the first alternating current, the second alternating current and the high-voltage direct current.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a safe power supply circuit and a control method thereof. Background Art

[0002] With the popularization of energy storage systems, higher requirements are placed on the stability and reliability of key equipment such as energy storage controllers; it becomes particularly important to ensure that these devices can continue to work in the face of extreme failures.

[0003] However, traditional power supply systems usually rely on a single power input and cannot guarantee the normal operation of all equipment in the event of a failure. Especially in emergency situations, this may lead to problems such as communication interruption and control system failure. Summary of the invention

[0004] To solve the above problems, the present application discloses a safe power supply circuit and a control method thereof, which maintains uninterrupted power supply to important loads by switching between a first alternating current, a second alternating current and a high-voltage direct current; and also proposes a corresponding control method to achieve power management in different situations.

[0005] The first technical solution adopted in the present application is: providing a safe power supply circuit, acting on electrical equipment, the electrical equipment including primary electrical equipment and secondary electrical equipment, the safe power supply circuit comprising:

[0006] A relay component, wherein a first input terminal of the relay component receives a first alternating current, and a second input terminal of the relay component receives a second alternating current;

[0007] A rectifier module, the rectifier module is connected to the relay assembly; based on the rectifier module, the AC power output by the relay assembly is converted into DC power; based on the relay assembly, the first AC power or the second AC power is controlled to be input into the rectifier module;

[0008] A UPS module, wherein the UPS module is connected to the rectifier module to receive the DC power, and voltage stabilization of the DC power is achieved based on the UPS module; the output end of the UPS module is connected to the primary power-consuming device; and the secondary power-consuming device is connected to the input end of the UPS module;

[0009] A step-down module, wherein the input end of the step-down module receives high-voltage direct current, the output end of the step-down module is connected to the input end of the UPS module, and the step-down module reduces the high-voltage direct current and outputs it to the UPS module.

[0010] Among them, the relay assembly includes a first switch and a first coil; one end of the first coil receives a first alternating current, and the other end of the first coil is grounded; the normally open contact of the first switch is connected to the output end of the first alternating current, and the normally closed contact of the first switch is connected to the output end of the second alternating current; based on whether the first coil is energized, the closed contact of the first switch is controlled, thereby controlling the relay assembly to output the first alternating current or the second alternating current.

[0011] Wherein, the UPS module includes a second switch and a battery; the charge and discharge state of the battery is adjusted based on the second switch; if there is current input at the input end of the UPS module, the battery is charged; if there is no current input at the input end of the UPS module, the battery is discharged to the primary power-consuming equipment.

[0012] Wherein, the safety power supply circuit also includes a first diode and a second diode; the positive terminal of the first diode is connected to the output terminal of the rectifier module, and the negative terminal of the first diode is connected to the input terminal of the UPS module; the positive terminal of the second diode is connected to the output terminal of the step-down module, and the negative terminal of the second diode is connected to the input terminal of the UPS module.

[0013] The input end of the step-down module is connected to a current-limiting resistor, and the high-voltage direct current flowing into the step-down module is reduced based on the current-limiting resistor.

[0014] Among them, the safety power supply circuit also includes a first protection switch, a second protection switch, a third protection switch and a fourth protection switch; one end of the first protection switch is connected to the relay assembly, and the other end of the first protection switch is connected to the rectifier module; one end of the second protection switch receives high-voltage direct current, and the other end of the second protection switch is connected to the current limiting resistor; one end of the third protection switch is connected to the negative end of the first diode and the negative end of the second diode, and the other end of the third protection switch is connected to the UPS module; one end of the fourth protection switch is connected to the battery, and the other end of the fourth protection switch is connected to the primary electrical equipment.

[0015] The second technical solution adopted by the present application is to provide a control method, which is applied to the safety power supply circuit as described in any of the above items, and the steps of inputting the first AC power into the safety power supply circuit are as follows:

[0016] The first alternating current flows to the first coil, and the first switch switches from a normally closed contact to a normally open contact;

[0017] The first alternating current is input into the rectifier module through the relay module, and the rectifier module converts the alternating current into direct current;

[0018] The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

[0019] Among them, the steps of only the second AC input safety power supply circuit are as follows:

[0020] The second alternating current is directed to the relay module, and the first switch maintains a normally closed contact;

[0021] The second alternating current is input into the rectifier module through the relay module, and the rectifier module converts the alternating current into direct current;

[0022] The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

[0023] Among them, the steps of inputting only high-voltage DC into the safety power supply circuit are as follows:

[0024] The high-voltage DC current is directed to the step-down module, which reduces the high-voltage DC current;

[0025] The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

[0026] Among them, the steps of inputting a safe power supply circuit without input electricity are as follows:

[0027] The battery supplies power to the primary electrical device through the second switch, and the secondary electrical device has no current input.

[0028] Beneficial effects of the present application: Different from the prior art, the present application discloses a safe power supply circuit and a control method thereof; the safe power supply circuit comprises: a relay assembly, a rectifier module, a UPS module and a step-down module; the first input end of the relay assembly receives the first alternating current, and the second input end of the relay assembly receives the second alternating current; the rectifier module is connected to the relay assembly; the alternating current output by the relay assembly is converted into direct current based on the rectifier module; the first alternating current or the second alternating current is input to the rectifier module based on the relay assembly; the voltage stabilization of direct current is achieved based on the UPS module; the output end of the UPS module is connected to the primary power-consuming device; the secondary power-consuming device is connected to the input end of the UPS module; the input end of the step-down module receives high-voltage direct current, the output end of the step-down module is connected to the input end of the UPS module, and the high-voltage direct current is reduced and output to the UPS module based on the step-down module. The uninterrupted power supply of important loads is maintained by switching the first alternating current, the second alternating current and the high-voltage direct current. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] in:

[0031] Figure 1 A schematic diagram of a framework of an embodiment of a safety power supply circuit provided by the present application;

[0032] Figure 2 A schematic diagram of the structure of an embodiment of a safety power supply circuit provided by the present application;

[0033] Figure 3 A schematic diagram of a flow chart of an embodiment of a first AC input safety power supply circuit provided by the present application;

[0034] Figure 4 A schematic diagram of a flow chart of an embodiment of a safety power supply circuit with only a second alternating current input provided by the present application;

[0035] Figure 5 A schematic diagram of a flow chart of an embodiment of a high-voltage direct current input-only safety power supply circuit provided in the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0037] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0038] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] The present application provides a safety power supply circuit and a control method thereof; the safety power supply circuit acts on electrical equipment, and the electrical equipment includes primary electrical equipment and secondary electrical equipment, such as Figure 1 As shown, Figure 1 This is a schematic diagram of a framework of an embodiment of a safety power supply circuit provided by the present application. The safety power supply circuit 10 includes a relay assembly 11, a rectifier module 12, a UPS module 13 and a step-down module 14;

[0040] The first input end of the relay component 11 receives a first alternating current, and the second input end of the relay component 11 receives a second alternating current; for example, the alternating current is city power (AC220V), and the second alternating current is fire backup power (AC220V); the relay component 11 contains an electromagnetic coil inside, which generates a magnetic field when current passes through, driving the mechanical switch to operate; in this embodiment, when the first alternating current is input, the relay switch switches from a normally closed contact to a normally open contact; in other embodiments, when the first alternating current is input, the relay switch can switch from a normally open contact to a normally closed contact, and there is no limitation on this.

[0041] The rectifier module 12 is connected to the relay component 11; the rectifier module 12 converts the AC power output by the relay component 11 into DC power; the relay component 11 controls the first AC power or the second AC power input to the rectifier module 12; the rectifier module 12 is usually composed of a bridge rectifier, which can convert AC power into DC power; for example, full-wave rectification or half-wave rectification, etc.; in this embodiment, the rectifier module 12 outputs 25V DC power.

[0042] When the mains power (first AC power) is input normally, the coil in the relay assembly 11 is energized, the normally open contact is closed, the normally closed contact is disconnected, and the mains power enters the rectifier module 12 through the common terminal; the AC power entering the rectifier module 12 is converted into DC power; if the mains power is interrupted, the relay assembly 11 automatically switches to the fire standby power (second AC power). At this time, the normally open contact is disconnected, the normally closed contact is closed, and the fire standby power becomes the new input source and continues to be converted into DC power through the rectifier module 12.

[0043] The use of the relay assembly 11 and the rectifier module 12 realizes a dual power supply redundancy design, which significantly improves the fault tolerance and reliability of the system. Even if one power supply fails, the other power supply can take over in time, avoiding the risk of downtime caused by the failure of a single power supply.

[0044] The UPS module 13 (uninterruptible power supply module) is connected to the rectifier module 12 to receive direct current, and the voltage stabilization of direct current is achieved based on the UPS module 13; the output end of the UPS module 13 is connected to the primary power-consuming device 15; the secondary power-consuming device 16 is connected to the input end of the UPS module 13; when there is city power or fire backup power, the rectifier module 12 converts the alternating current into direct current, and outputs it to the primary power-consuming device 15 after voltage stabilization through the UPS module 13. At this time, if the secondary power-consuming device 16 also has a demand for direct current, it can directly obtain power from the input end of the UPS module 13; in this embodiment, the UPS module 13 converts 25V direct current into 24V direct current for output.

[0045] Through the voltage stabilization function, the UPS module 13 can eliminate fluctuations in the input voltage, provide a pure power environment for sensitive primary electrical equipment 15, and reduce the risk of hardware damage caused by voltage instability.

[0046] The input end of the step-down module 14 receives high-voltage direct current, and the output end of the step-down module 14 is connected to the input end of the UPS module 13. The step-down module 14 reduces the high-voltage direct current and outputs it to the UPS module 13; the high-voltage direct current (for example, 48V, 72V or higher voltage) comes from other energy storage devices or DC power supply systems, and these power sources may be solar panels, wind turbines, backup battery packs, etc.; the step-down module 14 can select a switching buck converter or a linear buck regulator, without any limitation; in this embodiment, the step-down module 14 outputs 24V direct current.

[0047] By introducing high-voltage direct current as a backup power source, the step-down module 14 provides the system with more power options and enhances the flexibility and adaptability of the power supply system. Whether it is solar energy, wind energy or other forms of renewable energy, they can be integrated into the existing power supply system through the step-down module 14 to achieve multi-energy complementarity; the existence of the step-down module 14 increases the power supply redundancy. Even if the mains power and fire backup power are unavailable, the high-voltage direct current can still provide support for the system through the step-down module 14 to ensure the continuous operation of key equipment. This multi-layer protection mechanism significantly improves the reliability and fault tolerance of the entire power supply system.

[0048] In summary, the safety power supply circuit of this embodiment includes: a relay component 11, a rectifier module 12, a UPS module 13 and a step-down module 14; the first input end of the relay component 11 receives the first alternating current, and the second input end of the relay component 11 receives the second alternating current; the rectifier module 12 is connected to the relay component 11; the alternating current output by the relay component 11 is converted into direct current based on the rectifier module 12; the first alternating current or the second alternating current is controlled to be input to the rectifier module 12 based on the relay component 11; the voltage stabilization of direct current is realized based on the UPS module 13; the output end of the UPS module 13 is connected to the primary power-consuming device 15; the secondary power-consuming device 16 is connected to the input end of the UPS module 13; the input end of the step-down module 14 receives high-voltage direct current, the output end of the step-down module 14 is connected to the input end of the UPS module 13, and the high-voltage direct current is reduced and output to the UPS module 13 based on the step-down module 14. The uninterrupted power supply of important loads is maintained by switching the first alternating current, the second alternating current and the high-voltage direct current.

[0049] In one embodiment, the relay assembly 11 includes a first switch and a first coil. Figure 2 As shown, Figure 2 A schematic diagram of the structure of an embodiment of a safety power supply circuit provided by the present application;

[0050] One end of the first coil receives the first alternating current, and the other end of the first coil is grounded; that is, one end of the first switch is connected to the first alternating current, and the other end is grounded. When current passes through the coil, a magnetic field is generated to drive the first switch of the relay to operate.

[0051] The normally open contact of the first switch is connected to the output end of the first alternating current, and the normally closed contact of the first switch is connected to the output end of the second alternating current; the common end of the first switch is connected to the rectifier module 12, and whether it is connected to the input power supply is controlled by the normally open or normally closed contact; the closed contact of the first switch is controlled based on whether the first coil is energized, and then the relay component 11 is controlled to output the first alternating current or the second alternating current. The working principle of the relay module in different input states is described in detail below:

[0052] The first AC power is input, that is, the first coil is energized, and the first switch is switched from a normally closed contact to a normally open contact. The first AC power flows to the rectifier module 12 through the normally open contact and the common end of the first switch, and the rectifier module 12 receives the first AC power.

[0053] The second AC input, that is, the first coil is not energized, the first switch keeps the normally closed contact closed, the second AC flows to the rectifier module 12 through the normally closed contact and the common end of the first switch, and the rectifier module 12 receives the second AC.

[0054] Giving priority to the more efficient mains power as the main power source and only using the backup power source when necessary can help save energy and reduce operating costs. In addition, the efficient relay switching mechanism can also reduce energy loss and improve the energy efficiency of the overall system.

[0055] In one embodiment, the UPS module 13 includes a second switch and a battery; the charge and discharge state of the battery is adjusted based on the second switch; when current is input to the input end of the UPS module 13, the battery is in a charging state and the battery is safely charged; when no current is input to the input end of the UPS module 13, the battery is switched to a discharging state and power is provided to the primary electrical equipment 15 through the second switch.

[0056] If there is current input at the input end of the UPS module 13, the battery is charged; if there is no current input at the input end of the UPS module 13, the battery is discharged to the primary power-consuming device 15. The UPS module 13 monitors whether there is current input at the input end in real time; if it detects that there is current input at the input end (for example, direct current from the rectifier module 12 or the step-down module 14), it enters the charging mode; if there is no current input at the input end (for example, both the mains and the backup power supply fail), the UPS module 13 immediately enters the discharging mode and supplies power to the primary power-consuming device 15 through the battery; when the external power supply is restored (for example, the mains is reconnected), the UPS module 13 detects that there is current input at the input end again, and the UPS module 13 continues to output the input direct current to the primary power-consuming device 15 after stabilizing the voltage, and returns to the normal working state.

[0057] Through built-in batteries and intelligent charge and discharge control, the UPS module 13 can quickly switch to battery power mode when the external power supply is interrupted, ensuring the uninterrupted operation of the primary power-consuming equipment 15 and avoiding problems such as data loss and system crash due to sudden power outages.

[0058] In one embodiment, the safety power supply circuit 10 also includes a first diode D1 and a second diode D2; the positive terminal of the first diode D1 is connected to the output terminal of the rectifier module 12, and the negative terminal of the first diode D1 is connected to the input terminal of the UPS module 13; the positive terminal of the second diode D2 is connected to the output terminal of the step-down module 14, and the negative terminal of the second diode D2 is connected to the input terminal of the UPS module 13.

[0059] When there is mains power or fire backup power, the rectifier module 12 converts AC power into DC power and transmits it to the UPS module 13 through the first diode D1. At this time, if the step-down module 14 also provides DC power, but due to its lower priority, the current will not flow into the UPS module 13 through the second diode D2, because the first diode D1 has provided sufficient power.

[0060] If both the mains and the fire backup power are interrupted, the rectifier module 12 cannot provide direct current, and the first diode D1 will prevent reverse current from flowing. At this time, the direct current provided by the step-down module 14 can be transmitted to the UPS module 13 through the second diode D2 to supply power to the electrical equipment.

[0061] When all external power sources fail, the battery inside the UPS module 13 takes over the power supply task. At this time, the diode can prevent the battery current from flowing back into the rectifier module 12 or the step-down module 14, protecting these modules from damage.

[0062] It should be made clear that the power supply priority is first AC power > second AC power > high-voltage DC power > battery power.

[0063] In one embodiment, the input end of the step-down module 14 is connected to a current limiting resistor R1, and the high-voltage direct current flowing into the step-down module 14 is reduced based on the current limiting resistor R1; the current limiting resistor R1 is used to limit the current flowing into the step-down module 14 to prevent the step-down module 14 or other circuit components from being damaged due to excessive current; the current limiting resistor R1 reduces the risk of failure caused by current fluctuations or transient high currents, and enhances the stability and reliability of the entire power supply system. Even under extreme conditions, such as power short circuit or overload, the current limiting resistor R1 can effectively protect the circuit and ensure the continuous operation of the system.

[0064] In one embodiment, the safety power supply circuit 10 further includes a first protection switch, a second protection switch, a third protection switch and a fourth protection switch.

[0065] One end of the first protection switch is connected to the relay assembly 11 , and the other end of the first protection switch is connected to the rectifier module 12 ; the first protection switch is used to protect the rectifier module 12 from abnormal current or voltage shock from the relay assembly 11 .

[0066] One end of the second protection switch receives high voltage DC power, and the other end of the second protection switch is connected to the current limiting resistor; the second protection switch is used to protect the current limiting resistor R1 and the step-down module 14 from abnormal conditions of the high voltage DC power supply (such as overvoltage, short circuit, etc.).

[0067] One end of the third protection switch is connected to the negative end of the first diode and the negative end of the second diode, and the other end of the third protection switch is connected to the UPS module 13; the third protection switch is used to protect the UPS module 13 from abnormal current or voltage shocks from the rectifier module 12 and the step-down module 14.

[0068] One end of the fourth protection switch is connected to the battery, and the other end of the fourth protection switch is connected to the primary electrical equipment 15 through the second switch; the fourth protection switch is used to protect the battery and the primary electrical equipment 15 from abnormal conditions (such as over-discharge, short circuit, etc.).

[0069] The existence of the protection switch significantly enhances the fault tolerance of the entire power supply system. Even if a part fails, the protection switch can quickly isolate the fault area to prevent the fault from spreading and ensure that other parts continue to work normally; by timely cutting off the abnormal current path, the protection switch can prevent key equipment (such as the rectifier module 12, the step-down module 14, the UPS module 13, the battery, etc.) from being damaged due to overload or overheating, thereby extending the service life of the equipment.

[0070] The present application also provides a control method, which is applied to the safe power supply circuit described in any of the above embodiments. Figure 3 As shown, Figure 3 The flowchart of an embodiment of the first AC input safety power supply circuit provided in the present application includes the following steps:

[0071] S11: The first alternating current flows to the first coil, and the first switch switches from a normally closed contact to a normally open contact.

[0072] S12: The first alternating current is input into the rectifying module 12 through the relay module, and the rectifying module 12 converts the alternating current into direct current.

[0073] S13: The DC power is input into the UPS module 13 to supply power to the primary power-consuming device 15 , and the DC power is directly input into the secondary power-consuming device 16 .

[0074] like Figure 4 As shown, Figure 4 The flowchart of an embodiment of a safety power supply circuit with only a second AC input provided by the present application includes the following steps:

[0075] S21: The second alternating current flows to the relay module, and the first switch maintains a normally closed contact.

[0076] S22: The second AC power is input into the rectifier module 12 through the relay module, and the rectifier module 12 converts the AC power into DC power.

[0077] S23: The DC power is input into the UPS module 13 to supply power to the primary power-consuming device 15 , and the DC power is directly input into the secondary power-consuming device 16 .

[0078] like Figure 5 As shown, Figure 5 A schematic diagram of a flow chart of an embodiment of a high-voltage direct current input-only safety power supply circuit provided in the present application includes the following steps:

[0079] S31: The high-voltage direct current is directed to the step-down module 14, and the step-down module 14 reduces the high-voltage direct current.

[0080] S32: The DC power is input into the UPS module 13 to supply power to the primary power-consuming device 15, and the DC power is directly input into the secondary power-consuming device 16.

[0081] In one embodiment, the steps of inputting a safety power supply circuit 10 without input power are as follows:

[0082] The battery supplies power to the primary power-consuming device 15 through the second switch, and the secondary power-consuming device 16 has no current input.

[0083] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only illustrative, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0084] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0085] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0086] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A safety power supply circuit, acting on electrical equipment, the electrical equipment includes primary electrical equipment and secondary electrical equipment, characterized in that: The safety power supply circuit comprises: A relay component, wherein a first input terminal of the relay component receives a first alternating current, and a second input terminal of the relay component receives a second alternating current; A rectifier module, the rectifier module is connected to the relay assembly; based on the rectifier module, the AC power output by the relay assembly is converted into DC power; based on the relay assembly, the first AC power or the second AC power is controlled to be input into the rectifier module; A UPS module, wherein the UPS module is connected to the rectifier module to receive the DC power, and voltage stabilization of the DC power is achieved based on the UPS module; the output end of the UPS module is connected to the primary power-consuming device; and the secondary power-consuming device is connected to the input end of the UPS module; A step-down module, wherein the input end of the step-down module receives high-voltage direct current, the output end of the step-down module is connected to the input end of the UPS module, and the step-down module reduces the high-voltage direct current and outputs it to the UPS module.

2. The safety power supply circuit according to claim 1, characterized in that: The relay assembly includes a first switch and a first coil; one end of the first coil receives a first alternating current, and the other end of the first coil is grounded; the normally open contact of the first switch is connected to the output end of the first alternating current, and the normally closed contact of the first switch is connected to the output end of the second alternating current; based on whether the first coil is energized, the closed contact of the first switch is controlled, thereby controlling the relay assembly to output the first alternating current or the second alternating current.

3. The safety power supply circuit according to claim 2, characterized in that: The UPS module includes a second switch and a battery; the charge and discharge state of the battery is adjusted based on the second switch; if there is current input to the input end of the UPS module, the battery is charged; if there is no current input to the input end of the UPS module, the battery is discharged to the primary power-consuming equipment.

4. The safety power supply circuit according to claim 3, characterized in that: The safety power supply circuit also includes a first diode and a second diode; the positive terminal of the first diode is connected to the output terminal of the rectifier module, and the negative terminal of the first diode is connected to the input terminal of the UPS module; the positive terminal of the second diode is connected to the output terminal of the step-down module, and the negative terminal of the second diode is connected to the input terminal of the UPS module.

5. The safety power supply circuit according to claim 4, characterized in that: The input end of the step-down module is connected to a current limiting resistor, and the high-voltage direct current flowing into the step-down module is reduced based on the current limiting resistor.

6. The safety power supply circuit according to claim 5, characterized in that: The safety power supply circuit also includes a first protection switch, a second protection switch, a third protection switch and a fourth protection switch; one end of the first protection switch is connected to the relay assembly, and the other end of the first protection switch is connected to the rectifier module; one end of the second protection switch receives high-voltage direct current, and the other end of the second protection switch is connected to the current limiting resistor; one end of the third protection switch is connected to the negative end of the first diode and the negative end of the second diode, and the other end of the third protection switch is connected to the UPS module; one end of the fourth protection switch is connected to the battery, and the other end of the fourth protection switch is connected to the primary electrical equipment.

7. A control method, applied to the safety power supply circuit according to any one of claims 1 to 6, characterized in that: The steps for the first AC input safety power supply circuit are as follows: The first alternating current flows to the first coil, and the first switch switches from a normally closed contact to a normally open contact; The first alternating current is input into the rectifier module through the relay module, and the rectifier module converts the alternating current into direct current; The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

8. The control method according to claim 7, characterized in that: The steps for the second AC input safety power supply circuit are as follows: The second alternating current is directed to the relay module, and the first switch maintains a normally closed contact; The second alternating current is input into the rectifier module through the relay module, and the rectifier module converts the alternating current into direct current; The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

9. The control method according to claim 8, characterized in that: The steps to input only high voltage DC into the safety power supply circuit are as follows: The high-voltage DC current is directed to the step-down module, which reduces the high-voltage DC current; The DC power is input into the UPS module to supply power to the primary power-consuming equipment, and the DC power is directly input into the secondary power-consuming equipment.

10. The control method according to claim 9, characterized in that: The steps for inputting a safe power supply circuit without input power are as follows: The battery supplies power to the primary electrical device through the second switch, and the secondary electrical device has no current input.

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