Power switching circuit and control method thereof

Abstract

The invention provides a power supply switching circuit and a control method thereof, relates to the technical field of power supply switching circuits, can avoid voltage fluctuation caused in a power supply mode switching process, and can maintain the stability of an input voltage of an external load. Furthermore, under the condition that the output voltage of the external power supply fluctuates or breaks down, power can be supplied to the external load through the capacitor, and the power supply requirement of the external load can be continuously met. The power supply switching circuit comprises a first conduction unit, a second conduction unit and a capacitor, under the condition that the first conduction unit is conducted, a first external power supply is used for charging the capacitor, the first external power supply is used for supplying power to an external load, under the condition that the second conduction unit is conducted, a second external power supply is used for charging the capacitor, and the second external power supply is used for supplying power to the external load. The second external power supply is used for supplying power to an external load; and under the condition that both the first conduction unit and the second conduction unit are turned off, the capacitor is used for supplying power to the external load.

Description

Technical Field

[0001] The present application relates to the technical field of power switching circuits, and particularly relates to a power switching circuit and a control method thereof. Background Art

[0002] In power supply places such as distribution network substations, loads with dual power supplies are usually switched between the power supply and the standby power supply through relays. For loads with a single power supply, a generator needs to be connected to supply power to the load when a failure occurs in the power supply.

[0003] However, during the switching process between the power supply and the generator, it takes a long time for the generator to reach the normal operating state from the issuance of the start command. For load devices sensitive to voltage fluctuations, the short power outage and voltage fluctuations during the power supply switching process will cause excessive impacts and faults. Summary of the Invention

[0004] Based on this, it is necessary to provide a power switching circuit and a control method thereof for the above technical problems.

[0005] In a first aspect, the present application provides a power switching circuit, including:

[0006] A first conduction unit, one end of the first conduction unit is electrically connected to a first external power supply, and the other end of the first conduction unit is electrically connected to the input end of an external load;

[0007] A second conduction unit, one end of the second conduction unit is electrically connected to a second external power supply, and the other end of the second conduction unit is electrically connected to the other end of the first conduction unit, and the input end of the external load is connected between the other end of the first conduction unit and the other end of the second conduction unit;

[0008] A capacitor, one end of the capacitor is connected between the first conduction unit and the external load, and one end of the capacitor is connected between the second conduction unit and the external load, and the other end of the capacitor is grounded;

[0009] Wherein, the first conduction unit and the second conduction unit conduct alternately. When the first conduction unit conducts, the first external power supply is used to charge the capacitor, and the first external power supply is used to supply power to the external load. When the second conduction unit conducts, the second external power supply is used to charge the capacitor, and the second external power supply is used to supply power to the external load;

[0010] When both the first conduction unit and the second conduction unit are turned off, the capacitor is used to supply power to the external load.

[0011] In one embodiment, it further includes: a first control unit, one end of the first control unit is connected between the other end of the first conduction unit and the other end of the second conduction unit, and the other end of the first control unit is electrically connected to one end of the capacitor and the input end of the external load;

[0012] Wherein, when the first conduction unit is conducting, the first control unit is conducting, the first external power supply is used to charge the capacitor, and the first external power supply is used to supply power to the external load. When the second conduction unit is conducting, the first control unit is conducting, the second external power supply is used to charge the capacitor, and the first external power supply is used to supply power to the external load.

[0013] In one embodiment, the first control unit reaches a fully conducting state after a preset time when a conduction signal is received at the control end.

[0014] In one embodiment, it further includes:

[0015] A third conduction unit, the third conduction unit is connected in parallel with the first control unit, the third conduction unit reaches a fully conducting state when the conduction signal is received at the control end, when the first conduction unit or the second conduction unit is conducting, the third conduction unit is conducting, and when the first control unit reaches a fully conducting state, the third conduction unit is turned off.

[0016] In one embodiment, the conduction duration of the third conduction unit is equal to the conduction time of the first control unit.

[0017] In one embodiment, the first external power supply includes a mains power system, and the second external power supply includes a generator.

[0018] In one embodiment, it further includes:

[0019] An inverter, one end of the inverter is electrically connected to one end of the capacitor, the other end of the inverter is electrically connected to the other end of the first conduction unit, the other end of the second conduction unit, and the external load. The inverter is used to convert the alternating current output by the mains power system and the alternating current output by the generator into direct current and output it to the capacitor, and the inverter is used to convert the direct current output by the capacitor into alternating current and output it to the external load, and / or,

[0020] A transformer, one end of the transformer is connected to the other end of the inverter, and the other end of the transformer is connected between the first control unit and the external load.

[0021] Second aspect, the present application provides a control method for a power switching circuit, which is applied to the power switching circuit of any one of the first aspects. The method includes:

[0022] Control the first conduction unit to conduct and the second conduction unit to turn off;

[0023] Control the first conduction unit to turn off and the second conduction unit to turn off;

[0024] Control the second conduction unit to conduct and the first conduction unit to turn off.

[0025] In one embodiment, when the power switching circuit includes a first control unit and a third conduction unit,

[0026] After the step of controlling the first conduction unit to conduct and the second conduction unit to turn off, it further includes:

[0027] Send a first conduction signal to the first control unit and a second conduction signal to the third conduction unit. Wherein, the third conduction unit reaches a fully conductive state when receiving the second conduction signal, and the first control unit reaches a fully conductive state after a preset time of receiving the first conduction signal;

[0028] Send a turn-off signal to the third conduction unit. The sending time of the turn-off signal is later than the sending time of the second conduction signal, and the interval between the sending time of the turn-off signal and the sending time of the second conduction signal is equal to the preset time.

[0029] In one embodiment, the first conduction signal and the second conduction signal are sent synchronously.

[0030] The power supply switching circuit and its control method provided by the embodiments of the present application. The power supply switching circuit includes: a first conduction unit, a second conduction unit, and a capacitor. By alternately conducting the first conduction unit and the second conduction unit, when the first conduction unit is conducting, the first external power supply supplies power to the capacitor and the external load. When the second conduction unit is conducting, the second external power supply supplies power to the capacitor and the external load. When both the second conduction unit and the first conduction unit are turned off, the capacitor can supply power to the external load. Therefore, when switching the power supply from the first external power supply to the second external power supply for the external load, the electrical energy stored in the capacitor is used to supply power to the external load, thereby avoiding voltage fluctuations caused during the switching of the power supply mode, maintaining the stability of the input voltage of the external load, and improving the reliability of power supply to the external load. Further, when the output voltage of the first external power supply fluctuates or the first external power supply fails, the second external power supply can supply power to the external load, and when the second external power supply also fails or its output voltage fluctuates, the electrical energy stored in the capacitor can be used to supply power to the external load, thereby continuously maintaining the power supply demand of the external load and continuously outputting a stable output voltage to supply power to the external load, avoiding problems such as operational failures of the external load due to voltage frequency changes or too low input voltage, and improving the reliability and stability of the external load during operation. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a schematic circuit diagram of a power supply switching circuit provided by an embodiment of the present application;

[0033] Figure 2 It is a flowchart of a control method for a power supply switching circuit provided by an embodiment of the present application;

[0034] Figure 3 It is a flowchart of another control method for a power supply switching circuit provided by an embodiment of the present application.

[0035] Description of the Reference Numerals:

[0036] 10. First external power supply; 20. Second external power supply; 30. External load. Detailed Embodiments

[0037] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present application are shown in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0039] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that when the terms "comprise" and / or "include" are used in this specification, the presence of the stated features, integers, elements and / or components can be ascertained, but one or more other features, integers, elements, components and / or groups thereof are not precluded from being present or added. Also, as used herein, the term "and / or" includes any and all combinations of the related listed items.

[0040] In power supply places such as distribution network substations, loads with dual power supply are usually switched between the power supply and the standby power supply through relays. For loads with a single power supply, a generator needs to be connected to supply power to the load when a fault occurs in the power supply.

[0041] However, during the switching process between the power supply and the generator, it takes a long time for the generator to reach the normal operating state from the issuance of the start command. For load devices sensitive to voltage fluctuations, the short power outage and voltage fluctuations during the power supply switching process will cause excessive impacts and faults.

[0042] Embodiments of the present application provide a power supply switching circuit. Please refer to Figure 1, the power supply switching circuit includes: a first conduction unit QF2, a second conduction unit QF1, and a capacitor LIC. One end of the first conduction unit QF2 is electrically connected to the first external power supply 10, and the other end of the first conduction unit QF2 is electrically connected to the input end of the external load 30. One end of the second conduction unit QF1 is electrically connected to the second external power supply 20, and the other end of the second conduction unit QF1 is electrically connected to the other end of the first conduction unit QF2. The input end of the external load 30 is connected between the other end of the first conduction unit QF2 and the other end of the second conduction unit QF1. One end of the capacitor LIC is connected between the first conduction unit QF2 and the external load 30, and one end of the capacitor LIC is connected between the second conduction unit QF1 and the external load 30. The other end of the capacitor LIC is grounded. Wherein, the first conduction unit QF2 and the second conduction unit QF1 conduct alternately. When the first conduction unit QF2 conducts, the first external power supply 10 is used to charge the capacitor LIC, and the first external power supply 10 is used to supply power to the external load 30. When the second conduction unit QF1 conducts, the second external power supply 20 is used to charge the capacitor LIC, and the second external power supply 20 is used to supply power to the external load 30. When both the first conduction unit QF2 and the second conduction unit QF1 are turned off, the capacitor LIC is used to supply power to the external load 30.

[0043] Exemplarily, the first conduction unit QF2 may include but is not limited to an electronic control switch. The capacitor LIC may include but is not limited to a lithium-ion supercapacitor LIC. Under the same volume, the lithium-ion supercapacitor LIC can store more energy, and can be quickly charged in a shorter time. When outputting electric energy, the lithium-ion supercapacitor LIC can provide a larger current output, and can achieve high-power electric energy output in a shorter time interval.

[0044] Exemplarily, the alternate conduction of the first conduction unit QF2 and the second conduction unit QF1 includes two cases. In one case, the first conduction unit QF2 conducts and the second conduction unit QF1 is turned off. In another case, the first conduction unit QF2 is turned off and the second conduction unit QF1 conducts. Therefore, by alternately conducting the first conduction unit QF2 and the second conduction unit QF1, the first external power supply 10 and the second external power supply 20 can alternately supply power to the external load 30, and thus the switching of the power supply demand between the first external power supply 10 and the second external power supply 20 can be realized.

[0045] The power supply switching circuit provided by the embodiment of the present application includes a first conduction unit QF2, a second conduction unit QF1, and a capacitor LIC. By alternately conducting the first conduction unit QF2 and the second conduction unit QF1, when the first conduction unit QF2 is conducting, the first external power supply 10 supplies power to the capacitor LIC and the external load 30. When the second conduction unit QF1 is conducting, the second external power supply 20 supplies power to the capacitor LIC and the external load 30. When both the second conduction unit QF1 and the first conduction unit QF2 are turned off, the capacitor LIC can supply power to the external load 30. Therefore, when switching the power supply of the external load 30 from the first external power supply 10 to the second external power supply 20, the electrical energy stored in the capacitor LIC is used to supply power to the external load 30, thereby avoiding voltage fluctuations caused during the switching of the power supply mode, maintaining the stability of the input voltage of the external load 30, and improving the reliability of power supply to the external load 30. Further, when the output voltage of the first external power supply 10 fluctuates or the first external power supply 10 fails, the second external power supply 20 supplies power to the external load 30. And when the second external power supply 20 also fails or its output voltage fluctuates, the electrical energy stored in the capacitor LIC is used to supply power to the external load 30, thereby continuously maintaining the power supply demand of the external load 30 and continuously outputting a stable output voltage to supply power to the external load 30, avoiding problems such as operating failures of the external load 30 due to voltage frequency changes or too low input voltage, and improving the reliability and stability of the external load 30 during operation.

[0046] In some embodiments, please continue to refer to Figure 1 , the power supply switching circuit further includes a first control unit SCR. One end of the first control unit SCR is connected between the other ends of the first conduction unit QF2 and the second conduction unit QF1, and the other end of the first control unit is electrically connected to one end of the capacitor LIC and the input end of the external load 30. Among them, when the first conduction unit QF2 is conducting, the first control unit SCR conducts, the first external power supply 10 is used to charge the capacitor LIC, and the first external power supply 10 is used to supply power to the external load 30. When the second conduction unit QF1 is conducting, the first control unit SCR conducts, the second external power supply 20 is used to charge the capacitor LIC, and the first external power supply 10 is used to supply power to the external load 30.

[0047] Exemplarily, the first control unit SCR may include, but is not limited to, a thyristor. When a trigger signal is applied to the control terminal of the thyristor, the thyristor can switch from the blocking state to the conducting state, allowing current to pass through. When the current drops below the holding current of the thyristor, the thyristor will automatically turn off. And by controlling the conduction time of the thyristor, the effective value control of the AC voltage can be achieved, thereby adjusting the input voltage of the external load 30.

[0048] In the power supply switching circuit provided in the embodiment of the present application, by setting the first control unit SCR, when the first conduction unit QF2 is conducting, the first control unit SCR conducts. The first external power supply 10 is used to charge the capacitor LIC and supply power to the external load 30. When the second conduction unit QF1 is conducting, the first control unit SCR conducts. The second external power supply 20 is used to charge the capacitor LIC and the first external power supply 10 is used to supply power to the external load 30. When the power supply switching between the first external power supply 10 and the second external power supply 20 is achieved, the voltage output to the external load 30 can be controlled by the first control unit SCR, so that the input voltage to the external load 30 is maintained within a stable voltage range, improving the stability of the input voltage of the external load 30.

[0049] In some embodiments, please continue to refer to Figure 1 , the first control unit SCR reaches the fully conducting state after a preset time when a conduction signal is received at the control terminal.

[0050] Exemplarily, the preset time is the time from when the thyristor is triggered to conduct until the current rises to a level that enables the thyristor to reach the fully conducting state.

[0051] In the power supply switching circuit provided in the embodiment of the present application, by setting the first control unit SCR, the first control unit SCR reaches the fully conducting state after a preset time when a conduction signal is received at the control terminal. After the first control unit SCR achieves the conducting state, a stable input voltage can be provided to the external load 30, so that the input voltage of the external load 30 maintains a continuous stable output state, improving the operating reliability of the external load 30.

[0052] In some embodiments, please continue to refer to Figure 1 , the power supply switching circuit further includes: a third conduction unit QF5, which is connected in parallel with the first control unit SCR. The third conduction unit QF5 reaches the fully conducting state when a conduction signal is received at the control terminal. When the first conduction unit QF2 or the second conduction unit QF1 is conducting, the third conduction unit QF5 conducts. When the first control unit SCR reaches the fully conducting state, the third conduction unit QF5 turns off.

[0053] Exemplarily, the third conduction unit QF5 may include an electrically controlled switch, which can precisely control power usage and has effects such as timing switching and remote control.

[0054] In the power supply switching circuit provided in the embodiment of the present application, by setting the third conduction unit QF5, which is connected in parallel with the first control unit SCR, it is possible to supply power to the external load 30 through the third conduction unit QF5 when the first control unit SCR has not reached the fully conducting state, so as to ensure the continuity of the input voltage of the external load 30 and improve the operating reliability of the external load 30.

[0055] In some embodiments, please continue to refer to Figure 1 , the conduction duration of the third conduction unit QF5 is equal to the conduction time of the first control unit SCR.

[0056] Exemplarily, the conduction duration of the third conduction unit QF5 being equal to the conduction time of the first control unit SCR can ensure that when the first control unit SCR has not reached the fully conducting state, power is supplied to the external load 30 through the conduction of the first control unit. And at the moment when the first control unit SCR reaches the fully conducting state, the third conduction unit QF5 is turned off, and the output current of the first external power supply 10 or the output current of the second external power supply 20 all enters the external load 30 through the first control unit SCR.

[0057] In the power supply switching circuit provided in the embodiment of the present application, by setting the conduction duration of the third conduction unit QF5 to be equal to the conduction time of the first control unit SCR, it can ensure that when the first control unit SCR has not reached the fully conducting state, power is supplied to the external load 30 through the conduction of the first control unit. And at the etching moment when the first control unit SCR reaches the fully conducting state, the third conduction unit QF5 is turned off, and the output current of the first external power supply 10 or the output current of the second external power supply 20 all enters the external load 30 through the first control unit SCR. Furthermore, it is possible to avoid the problem of voltage fluctuations caused by the current flowing through the third conduction unit QF5 when the first control unit SCR reaches the fully conducting state. At the same time, it can also ensure that when the first control unit SCR has not reached the fully conducting state, the output current of the first external power supply 10 or the output current of the second external power supply 20 all flows through the third conduction unit QF5 to the external load 30, avoiding the current flowing through the first control unit SCR that has not reached the conducting state and causing fluctuations in the input voltage of the external load 30. Furthermore, the continuity and stability of the input voltage of the external load 30 can be improved.

[0058] In some embodiments, please continue to refer to Figure 1 , the first external power supply 10 includes a mains power system, and the second external power supply 20 includes a generator.

[0059] It should be noted that in other examples, both the first external power supply 10 and the second external power supply 20 may include other types of power supply devices.

[0060] In the power supply switching circuit provided in the embodiments of the present application, by setting the first external power supply 10 as a mains power system, the mains power system has high stability and reliability. It can ensure that power is continuously and stably supplied to the external load 30. By setting the second external power supply 20 as a generator, it can be realized that when the first external power supply 10 fails or the output voltage of the first external power supply 10 fluctuates, the generator supplies power to the external load 30, so as to realize the stable input of the input voltage of the external load 30 device and improve the reliability and stability of the operation of the external load 30.

[0061] In some embodiments, please continue to refer to Figure 1 , the power supply switching circuit further includes: an inverter INV, one end of the inverter INV is electrically connected to one end of the capacitor LIC, the other end of the inverter INV is electrically connected to the other end of the first control unit SCR and the external load 30. The inverter INV is used to convert the alternating current output from the mains power system and the alternating current output from the generator into direct current and output it to the capacitor LIC, and the inverter INV is used to convert the direct current output from the capacitor LIC into alternating current and output it to the external load 30.

[0062] Exemplarily, the inverter INV may include, but is not limited to, a bidirectional inverter INV.

[0063] In the power supply switching circuit provided in the embodiments of the present application, by setting the inverter INV, it can be realized that the alternating current output from the mains power system and the alternating current output from the generator are converted into direct current and output to the capacitor LIC, and the inverter INV is used to convert the direct current output from the capacitor LIC into alternating current and output to the external load 30. Furthermore, the first external power supply 10 can charge the capacitor LIC, avoiding the problem that the alternating current output from the first power supply and the second external power supply 20 cannot charge the capacitor LIC, and converting the direct current output from the capacitor LIC into alternating current to supply power to the external load 30, so as to ensure a stable current input or output of the capacitor LIC.

[0064] It should be noted that, please continue to refer to Figure 1 , the power supply switching circuit further includes: a transformer TF, one end of the transformer TF is connected to the other end of the inverter INV, and the other end of the transformer TF is connected between the first control unit SCR and the external load 30.

[0065] Exemplarily, the transformer TF may include, but is not limited to, a power transformer TF.

[0066] In the embodiment of the present application, the provided power switching circuit can, by setting the transformer TF, achieve the input of a voltage with a specific power from the first external power supply 10 or the second external power supply 20 to the capacitor LIC, and can also achieve the input of a voltage with a specific power from the capacitor LIC to the external load 30. Furthermore, it can protect the capacitor LIC and the external load 30, avoiding the problem of damage to the capacitor LIC and the external load 30 due to unstable or excessive voltage power, and improving the reliability of the power switching circuit.

[0067] It should be noted that the power switching circuit provided in the embodiment of the present application may further include a fourth conduction unit QF02, a fifth conduction unit QF01, a sixth conduction unit QF03, a seventh conduction unit QF3, an eighth conduction unit QF4, and a ninth conduction unit QF6. Among them, one end of the fourth conduction unit QF02 is electrically connected to the first external power supply 10, one end of the fifth conduction unit QF01 is electrically connected to the second external power supply 20, one end of the sixth conduction unit QF03 is electrically connected to the other end of the fourth conduction unit QF02 and the other end of the fifth conduction unit QF01, and the other end of the sixth conduction unit QF03 is electrically connected to the external load 30. One end of the seventh conduction unit QF3 is electrically connected to the other end of the first external power supply 10 and the other end of the second external power supply 20, and the other end of the seventh conduction unit QF3 is electrically connected to one end of the first control unit SCR and one end of the third conduction unit QF5. One end of the eighth conduction unit QF4 is electrically connected to the other end of the seventh conduction unit QF3, and the other end of the eighth conduction unit QF4 is electrically connected to one end of the first control unit SCR. One end of the ninth conduction unit QF6 is electrically connected to the other end of the first control unit SCR and the other end of the transformer TF, and the other end of the ninth conduction unit QF6 is electrically connected to the external load 30.

[0068] The embodiment of the present application provides a control method for a power switching circuit. Please refer to Figure 2 This method is applied to the power switching circuit in any one of the above embodiments. The control method of the power switching circuit includes:

[0069] S11: Control the first conduction unit to conduct and the second conduction unit to turn off.

[0070] Exemplarily, please refer to Figure 1 By controlling the first conduction unit QF2 to conduct and the second conduction unit QF1 to turn off, the first external power supply 10 can supply power to the external load 30 and the capacitor LIC.

[0071] S12: Control the first conduction unit to turn off and the second conduction unit to turn off.

[0072] Exemplarily, please refer to Figure 1 , when the first conduction unit QF2 is controlled to turn off and the second conduction unit QF1 is turned off, neither the first external power supply 10 nor the second external power supply 20 supplies power to the external load 30. The capacitor LIC supplies power to the external load 30.

[0073] S13: Control the second conduction unit to conduct and the first conduction unit to turn off.

[0074] Exemplarily, please refer to Figure 1 , controlling the second conduction unit QF1 to conduct and the first conduction unit QF2 to turn off can enable the second external power supply 20 to supply power to the external load 30 and the capacitor LIC.

[0075] In the control method of the power supply switching circuit provided in the embodiment of the present application, for the power supply switching circuit, by controlling the first conduction unit QF2 to conduct and the second conduction unit QF1 to turn off, the first external power supply 10 can supply power to the external load 30 and the capacitor LIC. Controlling the first conduction unit QF2 to turn off and the second conduction unit QF1 to turn off, the capacitor LIC supplies power to the external load 30. Controlling the second conduction unit QF1 to conduct and the first conduction unit QF2 to turn off can enable the second external power supply 20 to supply power to the external load 30 and the capacitor LIC. Therefore, when the power supply of the external load 30 is switched from the first external power supply 10 to the second external power supply 20, the electric energy stored in the capacitor LIC is used to supply power to the external load 30, thereby avoiding voltage fluctuations caused during the switching of the power supply mode, maintaining the stability of the input voltage of the external load 30, and improving the reliability of power supply to the external load 30. Further, when the output voltage of the first external power supply 10 fluctuates or the first external power supply 10 fails, the second external power supply 20 can supply power to the external load 30, and when the second external power supply 20 also fails or its output voltage fluctuates, the electric energy stored in the capacitor LIC can be used to supply power to the external load 30, thereby continuously maintaining the power supply demand of the external load 30 and continuously outputting a stable output voltage to supply power to the external load 30, avoiding problems such as operation failures of the external load 30 due to voltage frequency changes or too low input voltage, and improving the reliability and stability of the external load 30 during operation.

[0076] In some embodiments, please refer to Figure 2 , when the power supply switching circuit includes the first control unit SCR and the third conduction unit QF5, after the step of controlling the first conduction unit QF2 to conduct and the second conduction unit QF1 to turn off, it further includes:

[0077] S21: Send a first conduction signal to the first control unit and a second conduction signal to the third conduction unit. The third conduction unit reaches a fully conductive state when receiving the second conduction signal, and the first control unit reaches a fully conductive state after a preset time from receiving the first conduction signal.

[0078] Exemplarily, refer to Figure 1 , while sending the first conduction signal to the first control unit SCR, send the second conduction signal to the third conduction unit QF5. The sending time of the first conduction signal is equal to the sending time of the second conduction signal.

[0079] S22: Send a turn-off signal to the third conduction unit. The sending time of the turn-off signal is later than the sending time of the second conduction signal, and the interval between the sending time of the turn-off signal and the sending time of the second conduction signal is equal to the preset time.

[0080] Exemplarily, refer to Figure 1 , the sending time of the turn-off signal is later than the sending time of the second conduction signal, and the interval between the sending time of the turn-off signal and the sending time of the second conduction signal is equal to the preset time, which can ensure that when the first control unit SCR has not reached the fully conductive state, the first control unit conducts to realize the power supply to the external load 30 by the first external power supply 10 or the second external power supply 20. And at the moment when the first control unit SCR reaches the fully conductive state, the third conduction unit QF5 turns off, and the output current of the first external power supply 10 or the output current of the second external power supply 20 all enters the external load 30 through the first control unit SCR.

[0081] In the embodiment of the present application, the control method of the power supply switching circuit can control the conduction time of the first control unit SCR and the third conduction unit QF5 by sending a first conduction signal to the first control unit SCR and a second conduction signal to the third conduction unit QF5. Further, a turn-off signal is sent to the third conduction unit QF5, and the sending time of the turn-off signal is later than the sending time of the second conduction signal, and the interval between the sending time of the turn-off signal and the sending time of the second conduction signal is equal to a preset time, which can ensure that when the first control unit SCR does not reach the fully-conducted state, the first external power supply 10 or the second external power supply 20 supplies power to the external load 30 through the conduction of the first control unit. And when the first control unit SCR reaches the fully-conducted state, the third conduction unit QF5 is turned off, and the output current of the first external power supply 10 or the output current of the second external power supply 20 all enters the external load 30 through the first control unit SCR. Furthermore, it can avoid the problem that the current flows through the third conduction unit QF5 when the first control unit SCR reaches the fully-conducted state, resulting in voltage fluctuations. At the same time, it can also ensure that when the first control unit SCR does not reach the fully-conducted state, the output current of the first external power supply 10 or the output current of the second external power supply 20 all flows through the third conduction unit QF5 to the external load 30, avoiding the current flowing through the first control unit SCR that has not reached the conducting state and causing fluctuations in the input voltage of the external load 30. Furthermore, the continuity and stability of the input voltage of the external load 30 can be improved.

[0082] In some embodiments, please refer to Figure 1 , the first conduction signal and the second conduction signal are sent synchronously.

[0083] Exemplarily, the first conduction signal and the second conduction signal are sent simultaneously, which can enable the first control unit SCR and the third conduction unit QF5 to receive the conduction signal at the same moment.

[0084] In the embodiment of the present application, the control method of the power supply switching circuit can enable the first control unit SCR and the third conduction unit QF5 to receive the conduction signal at the same moment by sending the first conduction signal and the second conduction signal synchronously. Furthermore, when the first external power supply 10 or the second external power supply 20 supplies power to the external load 30, the first control unit SCR can immediately receive the conduction signal, thereby shortening the time from when the first external power supply 10 or the second external power supply 20 starts to supply power to the external load 30 to when the first control unit SCR reaches the fully-conducted state.

[0085] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0086] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A power switching circuit, characterized in that: include: a first conducting unit, wherein one end of the first conducting unit is electrically connected to a first external power source, and the other end of the first conducting unit is electrically connected to an input end of an external load; a second conduction unit, wherein one end of the second conduction unit is electrically connected to a second external power source, the other end of the second conduction unit is electrically connected to the other end of the first conduction unit, and the input end of the external load is connected between the other end of the first conduction unit and the other end of the second conduction unit; A capacitor, one end of which is connected between the first conduction unit and the external load, and one end of which is connected between the second conduction unit and the external load, and the other end of which is grounded; The first conducting unit and the second conducting unit are alternately turned on. When the first conducting unit is turned on, the first external power supply is used to charge the capacitor, and the first external power supply is used to supply power to the external load. When the second conducting unit is turned on, the second external power supply is used to charge the capacitor, and the second external power supply is used to supply power to the external load. When the first conducting unit and the second conducting unit are both turned off, the capacitor is used to supply power to the external load.

2. The power switching circuit according to claim 1, characterized in that: Also includes: A first control unit, wherein one end of the first control unit is connected between the other end of the first conduction unit and the other end of the second conduction unit, and the other end of the first control unit is electrically connected to one end of the capacitor and the input end of the external load; Among them, when the first conduction unit is turned on, the first control unit is turned on, the first external power supply is used to charge the capacitor, and the first external power supply is used to power the external load, and when the second conduction unit is turned on, the first control unit is turned on, the second external power supply is used to charge the capacitor, and the first external power supply is used to power the external load.

3. The power switching circuit according to claim 2, characterized in that: The first control unit reaches a fully conductive state after a preset time when the control end receives a conductive signal.

4. The power switching circuit according to claim 2, characterized in that: Also includes: A third conduction unit, the third conduction unit is connected in parallel with the first control unit, the third conduction unit reaches a fully-conducting state when the control end receives the conduction signal, the third conduction unit is turned on when the first conduction unit or the second conduction unit is turned on, and the third conduction unit is turned off when the first control unit reaches a fully-conducting state.

5. The power switching circuit according to claim 4, characterized in that: The conduction duration of the third conduction unit is equal to the conduction time of the first control unit.

6. The power switching circuit according to claim 1, characterized in that: The first external power source includes a mains power system, and the second external power source includes a generator.

7. The power switching circuit according to claim 6, characterized in that: Also includes: an inverter, one end of the inverter being electrically connected to one end of the capacitor, the other end of the inverter being electrically connected to the other end of the first conduction unit, the other end of the second conduction unit, and the external load, the inverter being used to convert the alternating current output by the mains system and the alternating current output by the generator into direct current output to the capacitor, and the inverter being used to convert the direct current output by the capacitor into alternating current output to the external load, and / or, A transformer, one end of the transformer is connected to the other end of the inverter, and the other end of the transformer is connected between the first control unit and the external load.

8. A control method for a power switching circuit, characterized in that: The power switching circuit according to any one of claims 1 to 7, wherein the method comprises: Controlling the first conduction unit to be turned on and the second conduction unit to be turned off; Controlling the first conducting unit to be turned off and the second conducting unit to be turned off; The second conducting unit is controlled to be turned on, and the first conducting unit is controlled to be turned off.

9. The control method of the power switching circuit according to claim 8, characterized in that: In the case where the power switching circuit includes a first control unit and a third conduction unit, After the step of controlling the first conducting unit to be turned on and the second conducting unit to be turned off, the method further includes: Sending a first conduction signal to the first control unit, and sending a second conduction signal to the third conduction unit, wherein the third conduction unit reaches a fully-conducting state when receiving the second conduction signal, and the first control unit reaches a fully-conducting state after a preset time of receiving the first conduction signal; A shutoff signal is sent to the third conduction unit, wherein the sending time of the shutoff signal is later than the sending time of the second conduction signal, and the interval between the sending time of the shutoff signal and the sending time of the second conduction signal is equal to a preset time.

10. The control method of the power switching circuit according to claim 9, characterized in that: The first conduction signal and the second conduction signal are sent synchronously.

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