Power supply switching circuit and method, and power supply system

Abstract

The present application relates to a power supply switching circuit and method, and a power supply system. The power supply switching circuit comprises a first path, a second path, a first switch, and a voltage comparison circuit; a first end of the first path is a first power supply connecting end of the power supply switching circuit, one end of the second path is connected to a second power supply connecting end of the power supply switching circuit by means of the first switch, and a second end of the first path and the other end of the second path are both connected to a load connecting end of the power supply switching circuit; a third end of the first path and the second power supply connecting end are both connected to an input end of the voltage comparison circuit, and an output end of the voltage comparison circuit is connected to a control end of the first switch. Embodiments of the present application achieve a more flexible power supply switching mode, so that a first power supply can preferentially supply power to a load by means of the first path on the basis of a reliable load power supply voltage.

Description

Power supply switching circuit, method and power supply system

[0001] Cross-references

[0002] This application refers to Chinese patent application No. 202311524932.1 filed on November 15, 2023, entitled “Power supply switching circuit, method and power supply system”, which is incorporated into this application in its entirety by reference. Technical Field

[0003] The present application relates to the field of power supply technology, and in particular to a power supply switching circuit, method and power supply system. Background Art

[0004] Typically, a DC power supply is required in an energy storage system to power the equipment (or simply, the load) within the system. Energy storage systems require high reliability in powering these devices, and typically use two power sources.

[0005] However, in the related art, when one power source fails, the backup power source is switched, and the switching mode of the two power sources is not flexible enough.

[0006] Summary of the Invention

[0007] In view of the above problems, the present application provides a power supply switching circuit, method and power supply system, which can solve the problem of insufficient flexibility of the switching method in the related art.

[0008] In a first aspect, the present application provides a power supply switching circuit, which includes: a first path, a second path, a first switch, and a voltage comparison circuit; the first end of the first path is the first power connection end of the power supply switching circuit, one end of the second path is connected to the second power connection end of the power supply switching circuit through the first switch, and the second end of the first path and the other end of the second path are both connected to the load connection end of the power supply switching circuit; the third end of the first path and the second power connection end are both connected to the input end of the voltage comparison circuit, and the output end of the voltage comparison circuit is connected to the control end of the first switch.

[0009] In the technical solution of the embodiment of the present application, a voltage comparison circuit is provided, connected to the first path and the second path respectively, so that the voltage comparison circuit can output a corresponding drive signal to the first switch based on the comparison result of the voltage of the first path and the voltage of the second path, thereby controlling the on-off state of the first switch, thereby controlling whether the first path or the second path supplies power to the load. It can be seen that the embodiment of the present application realizes a more flexible power supply switching method, which is conducive to preferentially supplying power to the load through the first path by the first power supply on the basis of reliable load supply voltage.

[0010] In some embodiments, the first path includes a first unidirectional conduction switch, wherein one end of the first unidirectional conduction switch is connected to the first power connection terminal and the input terminal of the voltage comparison circuit, and the other end of the first unidirectional conduction switch is connected to the load connection terminal; or

[0011] One end of the first unidirectional conducting switch is connected to the first power supply connection end, and the other end of the first unidirectional conducting switch is connected to the input end of the voltage comparison circuit and the load connection end.

[0012] In the technical solution of the embodiment of the present application, the first path includes a first unidirectional conduction switch, which can not only achieve flexible power supply switching but also prevent current backflow, thereby effectively alleviating the circulation problem.

[0013] In some embodiments, the first path further includes a second switch connected in series with the first unidirectional conduction switch, wherein when the power supply switching circuit is not in operation, the second switch can be in an open state, which is conducive to saving power of the first power supply.

[0014] In some embodiments, the second path includes a second unidirectional conducting switch connected in series with the first switch.

[0015] In the technical solution of the embodiment of the present application, the second path includes a second unidirectional conduction switch connected in series with the first switch, which can not only achieve flexible power supply switching but also prevent current backflow, thereby effectively alleviating the circulation problem.

[0016] In some embodiments, the power supply switching circuit also includes a voltage-regulated power supply path, wherein a first end of the voltage-regulated power supply path is connected to the second power supply connection end, a second end of the voltage-regulated power supply path is connected to the load connection end, and a third end of the voltage-regulated power supply path is connected to the input end of the voltage comparison circuit.

[0017] In the technical solution of the embodiment of the present application, by setting up a regulated power supply path between the second path and the voltage comparison circuit, it is possible to achieve flexible power supply switching and also to switch power to the load without power failure, thereby further improving the reliability of the load power supply voltage.

[0018] In some embodiments, the voltage-regulated power supply path includes: a voltage-regulating circuit and a third unidirectional conducting switch connected in series, wherein one end of the voltage-regulating circuit is connected to the second power supply connection end, the other end of the voltage-regulating circuit and one end of the third unidirectional conducting switch are both connected to the input end of the voltage comparison circuit, and the other end of the third unidirectional conducting switch is connected to the load connection end.

[0019] In the technical solution of the embodiments of the present application, the voltage-regulated power supply path includes a voltage-regulating circuit and a third unidirectional conduction switch connected in series. This allows for flexible power supply switching and also enables load switching without power loss, thereby further improving the reliability of the load supply voltage. Furthermore, the provision of the third unidirectional conduction switch prevents current backflow, effectively alleviating circulating current issues.

[0020] In some embodiments, the first switch is a fully-controlled switching device, and / or the second switch is a fully-controlled switching device.

[0021] In some embodiments, the first unidirectional conducting switch is a fully controlled switch device or a diode device.

[0022] In some embodiments, the second unidirectional conducting switch is a fully controlled switch device or a diode device.

[0023] In some embodiments, the third unidirectional conducting switch is a fully controlled switch device or a diode device.

[0024] In a second aspect, the present application provides a power supply switching method, the method comprising:

[0025] Obtaining a first voltage of the first path and a second voltage of the second path;

[0026] According to the comparison result of the first voltage and the second voltage, the first path or the second path is turned on to supply power to the load.

[0027] In some embodiments, according to a comparison result between the first voltage and the second voltage, turning on the first path or the second path to supply power to the load includes:

[0028] When the comparison result meets the preset normal working conditions, the first path is turned on to supply power to the load;

[0029] When the comparison result does not meet the preset normal working condition, the second path is turned on to supply power to the load.

[0030] In some embodiments, the method further comprises:

[0031] During the process of switching power supply for the load between the first path and the second path, a support voltage is provided to power the load.

[0032] In a third aspect, the present application provides a power supply system, the power supply system comprising: a first power supply, a second power supply, a load, and a power supply switching circuit as described in any one of the first aspects above;

[0033] The first power connection terminal of the power supply switching circuit is connected to the first power supply, the second power connection terminal of the power supply switching circuit is connected to the second power supply, and the load connection terminal of the power supply switching circuit is connected to the load.

[0034] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0036] FIG1 is a schematic structural diagram of a power supply switching circuit provided in some embodiments of the present application;

[0037] FIG2 is a schematic diagram of the structure of a comparison circuit module provided in some embodiments of the present application;

[0038] FIG3 is a schematic structural diagram of a power supply switching circuit provided in some other embodiments of the present application;

[0039] FIG4 is a schematic structural diagram of a power supply switching circuit provided in some other embodiments of the present application;

[0040] FIG5 is a schematic structural diagram of a power supply switching circuit provided in some other embodiments of the present application;

[0041] FIG6 is a schematic structural diagram of a power supply switching circuit provided in some other embodiments of the present application;

[0042] FIG7 is a schematic structural diagram of a power supply switching circuit provided in other embodiments of the present application;

[0043] FIG8 is a schematic structural diagram of a voltage stabilizing circuit module provided in some embodiments of the present application;

[0044] FIG9 is a schematic structural diagram of a power supply switching circuit provided in some other embodiments of the present application;

[0045] FIG10 is a schematic flow chart of a power supply switching method provided in some embodiments of the present application;

[0046] FIG11 is a schematic structural diagram of a power supply system provided in some embodiments of the present application. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the term "include" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0049] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not 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 this application, the meaning of "plurality" is two or more (including two), unless otherwise clearly and specifically defined.

[0050] The power supply switching circuit, method, and power supply system involved in the embodiments of the present application can be applied to power supply switching application scenarios of power energy storage systems, and of course can also be applied to other application scenarios.

[0051] It should be noted that, for ease of description, the following embodiments illustrate the power supply switching application scenario of the power supply switching circuit, method, and power supply system of the present application as an example. It should be understood that when the power supply switching circuit, method, and power supply system of the present application are applied to other scenarios, their implementation principles and technical effects are similar.

[0052] In power storage systems, a DC power supply is required to power the devices (or simply, the load) within the energy storage system. Energy storage systems have high demands on the reliability of the power supply to these devices, and typically use two power sources to power these devices.

[0053] In the related art, when one power source fails, the other power source is usually switched to supply power. However, the switching method of the two power sources in the related art is not flexible enough.

[0054] In order to solve the problem of insufficient flexibility in the switching mode in the related art, the embodiment of the present application proposes a method of providing a voltage comparison circuit connected to the first path and the second path respectively, so that according to the comparison result of the voltage of the first path and the voltage of the second path, the first path or the second path can be controlled to supply power to the load, thereby achieving a more flexible power supply switching mode, which is conducive to preferentially supplying power to the load through the first path by the first power supply on the basis of a reliable load supply voltage.

[0055] In some embodiments, Figure 1 is a structural schematic diagram of a power supply switching circuit provided in some embodiments of the present application. As shown in Figure 1, the power supply switching circuit of the embodiment of the present application may include: a first path 101, a second path 102, a first switch B and a voltage comparison circuit 103.

[0056] For example, the first end of the first path 101 in the embodiment of the present application can be the first power connection terminal P1 of the power switching circuit, where the first power connection terminal P1 can be used to connect to the first power source. One end of the second path 102 can be connected to the second power connection terminal P2 of the power switching circuit via the first switch B, where the second power connection terminal P2 can be used to connect to the second power source. The second end of the first path 101 and the other end of the second path 102 in the embodiment of the present application can both be connected to the load connection terminal P3 of the power switching circuit, where the load connection terminal P3 can be used to connect to a load.

[0057] It should be noted that the first power supply in the embodiment of the present application can be the main power supply, and the second power supply can be the backup power supply, or the first power supply in the embodiment of the present application can be the backup power supply, and the second power supply can be the main power supply.

[0058] For example, the third terminal of the first path 101 and the second power connection terminal P2 may both be connected to the input terminal of the voltage comparison circuit 103 , and the output terminal of the voltage comparison circuit 103 may be connected to the control terminal of the first switch B.

[0059] In the embodiment of the present application, the voltage comparison circuit 103 can be configured to output a drive signal for controlling the first switch based on a comparison result between the voltage Vn1 (or the first voltage) at the third terminal of the first path 101 and the voltage Vn2 (or the second voltage) at the second path 102, thereby controlling whether the first path 101 or the second path 102 supplies power to the load. The voltage Vn2 of the second path 102 can include, but is not limited to, the voltage Vin2 of the second power connection terminal P2.

[0060] It should be noted that in the embodiment of the present application, when the second path 102 is in the disconnected state, the first path 101 is in the conductive state; and when the second path 102 is in the conductive state, the first path 101 is in the disconnected state. In the embodiment of the present application, the voltage comparison circuit 103 controls the on / off states of the first path 101 and the second path 102 by controlling the on / off state of the first switch via a drive signal.

[0061] Illustratively, the voltage comparison circuit 103 in the embodiment of the present application may include but is not limited to a comparator or a comparison circuit module.

[0062] FIG2 is a schematic diagram of the structure of a comparison circuit module provided in some embodiments of the present application. As shown in FIG2 , the comparison circuit module of the embodiment of the present application may include but is not limited to an operational amplifier U1, a voltage divider resistor R1-voltage divider resistor R4; wherein V out Used to power the operational amplifier U1, V o As the comparison result output by the comparison circuit module.

[0063] Of course, the voltage comparison circuit 103 in the embodiment of the present application may also adopt other forms of comparison circuit modules.

[0064] In one possible implementation, when the comparison result satisfies a preset normal operating condition, that is, when the first power supply is in a normal operating state, the voltage comparison circuit 103 can output a first drive signal according to the comparison result to cause the first switch B to be in an off state and the second path 102 to be in an off state, thereby causing the first path 101 to be in an on state, so that the first power supply can supply power to the load through the first path 101.

[0065] The preset normal operating conditions in the embodiments of the present application can be used to indicate conditions under which the first power supply is in a normal operating state. For example, the preset normal operating conditions may include, but are not limited to: the difference between voltage Vn1 and voltage Vn2 is greater than a first preset difference, or voltage Vn1 is greater than or equal to the product of voltage Vn2 and a first preset coefficient. The first preset coefficient is a modulated voltage ratio coefficient, and the value range of the first preset coefficient may include, but is not limited to, 0.8 to 1.

[0066] For example, as shown in FIG2 , since voltage Vn1 is connected to the inverting input terminal of operational amplifier U1 and voltage Vn2 is connected to the non-inverting input terminal of operational amplifier U1, if the comparison result indicates that voltage Vn1 is greater than or equal to the product of voltage Vn2 and a first predetermined coefficient (i.e., the comparison result is a negative voltage), voltage comparison circuit 103 may use the comparison result as a driving signal to control first switch B to be disconnected, thereby switching second path 102 to an off state.

[0067] Of course, the voltage comparison circuit 103 can also control the first path 101 to be in the conducting state in other ways.

[0068] In the prior art, because two power supplies cannot be directly connected in parallel, two diodes are typically connected in parallel, with their cathodes connected to the primary and backup power supplies, respectively. Typically, power is switched to the other power supply only if one power supply fails. Furthermore, prioritizing the primary power supply is impossible without regulating the voltage difference between the primary and backup power supplies to at least 2V.

[0069] It can be seen that, compared with the related art, in the embodiment of the present application, by providing a voltage comparison circuit respectively connected to the first path and the second path, when the comparison result of the voltage of the first path and the voltage of the second path meets the preset normal working conditions, by controlling the conduction of the first path, there is no need to modulate the voltage of the first power supply and the second power supply so that the voltage difference meets certain requirements. It can still be achieved that when the first power supply is in a normal working state, the first path that can be connected to the first power supply is preferentially controlled to be conducted, so that the first power supply can preferentially supply power to the load through the first path.

[0070] In another possible implementation, the voltage comparison circuit 103 of the embodiment of the present application can output a second drive signal according to the comparison result to turn on the first switch B when the comparison result does not meet the preset normal working conditions, that is, when the first power supply is in an abnormal working state, thereby turning on the second path 102 and turning off the first path 101, so that the second power supply can supply power to the load through the second path 102.

[0071] For example, as shown in FIG2 , if the comparison result indicates that the voltage V n1 is less than the product of the voltage V n2 and the first preset coefficient (i.e., the comparison result is a positive voltage), the voltage comparison circuit 103 can use the comparison result as a driving signal to control the first switch B to be turned on, thereby switching the second path 102 to a conductive state.

[0072] Of course, the voltage comparison circuit 103 can also control the second path 102 to be in the conducting state in other ways.

[0073] It can be seen that in the embodiment of the present application, by providing a voltage comparison circuit respectively connected to the first path and the second path, when the comparison result of the voltage of the first path and the voltage of the second path does not meet the preset normal working conditions, by controlling the conduction of the second path, it is possible to achieve that when the first power supply is in an abnormal working state, the second path connected to the second power supply is controlled to be conducted, so that the second power supply can supply power to the load through the second path, thereby facilitating the reliability of the power supply voltage of the load.

[0074] In summary, the power supply switching circuit in the embodiment of the present application includes: a first path, a second path, a first switch, and a voltage comparison circuit. Among them, the first end of the first path is the first power connection terminal of the power supply switching circuit, one end of the second path is connected to the second power connection terminal of the power supply switching circuit through the first switch, and the second end of the first path and the other end of the second path are both connected to the load connection terminal of the power supply switching circuit; the third end of the first path and the second power connection terminal are both connected to the input terminal of the voltage comparison circuit, and the output terminal of the voltage comparison circuit is connected to the control terminal of the first switch. Compared with the switching method in the related art, in the embodiment of the present application, by providing a voltage comparison circuit connected to the first path and the second path respectively, the voltage comparison circuit can output a corresponding drive signal to the first switch according to the comparison result of the voltage of the first path and the voltage of the second path to control the on-off state of the first switch, thereby controlling whether the first path or the second path is used to supply power to the load. It can be seen that the embodiment of the present application realizes a more flexible power supply switching method, which is conducive to preferentially supplying power to the load through the first path by the first power supply on the basis of a reliable load supply voltage.

[0075] In some embodiments, based on the above embodiments, FIG3 is a structural diagram of a power supply switching circuit provided in other embodiments of the present application. As shown in FIG3 , the first path 101 of the embodiment of the present application may include a first unidirectional conduction switch D1.

[0076] In the embodiment of the present application, if the voltage difference between the positive terminal and the negative terminal of the first unidirectional conduction switch D1 satisfies a first preset conduction condition, the first unidirectional conduction switch D1 switches to an on state; otherwise, the first unidirectional conduction switch D1 switches to an off state. Due to the unidirectional conduction characteristic of the first unidirectional conduction switch D1, current backflow can be prevented, thereby effectively alleviating the problem of circulating current.

[0077] For example, the first unidirectional conduction switch D1 in the embodiment of the present application may include but is not limited to a diode device.

[0078] As another example, the first unidirectional conduction switch D1 in the embodiment of the present application may include but is not limited to a fully controlled switch device. For example, the first unidirectional conduction switch D1 may be an equivalent diode including a MOS transistor.

[0079] Since the heating power of the MOS tube is lower than the heating power of the diode, the first unidirectional conduction switch D1 including the MOS tube in the embodiment of the present application can not only prevent current backflow, thereby effectively alleviating the circulation problem, but also reduce the heating power, thereby saving power.

[0080] In one possible implementation, as shown in FIG3 , one end (or the positive end) of the first unidirectional conducting switch D1 can be connected to the first power connection terminal P1 and the input terminal of the voltage comparison circuit 103, and the other end (or the negative end) of the first unidirectional conducting switch D1 can be connected to the load connection terminal P3. It should be understood that one end of the first unidirectional conducting switch D1 corresponds to the first and third ends of the first path 101, and the other end of the first unidirectional conducting switch D1 corresponds to the second end of the first path 101. Correspondingly, the voltage at one end of the first unidirectional conducting switch D1 in this embodiment of the present application (i.e., the voltage Vin1 at the first power connection terminal P1) can be the voltage Vn1 of the first path 101.

[0081] In another possible implementation, one end (also known as the positive end) of the first unidirectional conducting switch D1 can be connected to the first power connection terminal P1 (not shown in FIG3 ), and the other end (also known as the negative end) of the first unidirectional conducting switch D1 can be connected to the input terminal of the voltage comparison circuit 103 and the load connection terminal P3 (not shown in FIG3 ). It should be understood that one end of the first unidirectional conducting switch D1 corresponds to the first end of the first path 101, and the other end of the first unidirectional conducting switch D1 corresponds to the second and third ends of the first path 101. Accordingly, the voltage at the other end of the first unidirectional conducting switch D1 in the embodiment of the present application can be the voltage Vn1 of the first path 101.

[0082] For ease of understanding, the following embodiments of the present application provide an exemplary introduction and description of the relevant contents of the voltage comparison circuit 103 .

[0083] In one possible implementation, the voltage comparison circuit 103 in the embodiment of the present application can, when the comparison result satisfies the preset normal operating conditions, control the second path 102 to switch to the disconnected state, so that the voltage difference across the first unidirectional conduction switch D1 satisfies the first preset conduction condition, and the first unidirectional conduction switch D1 switches to the conductive state, that is, the first path 101 switches to the conductive state, so that the first power supply can supply power to the load through the first path 101.

[0084] In another possible implementation, the voltage comparison circuit 103 in the embodiment of the present application can control the second path 102 to switch to the on state when the comparison result does not meet the preset normal operating conditions, so that the voltage difference between the two sides of the first unidirectional conduction switch D1 does not meet the first preset conduction condition, and the first unidirectional conduction switch D1 is switched to the off state, that is, the first path 101 is switched to the off state, so that the second power supply can supply power to the load through the second path 102.

[0085] It can be seen that the first path 101 in the embodiment of the present application can prevent current backflow on the basis of realizing flexible power supply switching by including the first unidirectional conduction switch D1, thereby effectively alleviating the circulating current problem.

[0086] In some embodiments, based on the above embodiments, Figure 4 is a structural diagram of the power supply switching circuit provided in other embodiments of the present application. As shown in Figure 4, the first path 101 of the embodiment of the present application may further include a second switch A connected in series with the first unidirectional conduction switch D1.

[0087] For example, as shown in FIG4 , one end of the second switch A can be connected to the first power connection terminal P1, and the other end of the second switch A can be connected to the input terminal of the voltage comparison circuit 103 and the first unidirectional conduction switch D1. It should be understood that one end of the second switch A can correspond to the first end of the first path 101, and the other end of the second switch A can correspond to the third end of the first path 101. Correspondingly, the voltage Vn1 of the first path 101 in the embodiment of the present application can include, but is not limited to, the voltage at the other end of the second switch A or the voltage at one end of the first unidirectional conduction switch D1.

[0088] It should be noted that the positions of the first unidirectional conduction switch D1 and the second switch A can be interchanged; this is not limited in the embodiment of the present application.

[0089] For example, in the embodiment of the present application, the second switch A can always be in the on state when the power supply switching circuit is in the working state. It should be understood that the second switch A can be in the off state when the power supply switching circuit is not in the working state, which is conducive to saving power of the first power supply.

[0090] The first unidirectional conduction switch D1 in the embodiment of the present application can not only be used to control the on / off state of the first path 101 , but also be used to prevent current backflow, thereby effectively alleviating the circulating current problem.

[0091] For example, the second switch A in the embodiment of the present application may be a fully controlled switch device. For example, the second switch A may be an equivalent switch including a MOS tube. Of course, the second switch A may also include other devices, such as a first voltage divider resistor.

[0092] Since the heating power of the MOS tube is lower than the heating power of the diode, the embodiment of the present application can reduce the heating power by replacing the diode in the related art with the second switch A including the MOS tube, thereby saving power.

[0093] In some embodiments, based on the above embodiments, one end of the second switch A in the present application can be connected to the first power connection terminal P1 and the input terminal of the voltage comparison circuit 103 (this connection is not shown in FIG4 ), and the other end of the second switch A can be connected to the first unidirectional conduction switch D1. It should be understood that one end of the second switch A can correspond to the first and third ends of the first path 101. Correspondingly, the voltage Vn1 of the first path 101 in the present application can include, but is not limited to, the voltage at one end of the second switch A (i.e., the voltage Vin1 at the first power connection terminal P1).

[0094] It can be seen that the first path 101 in the embodiment of the present application can achieve flexible power supply switching by including the second switch A and the first unidirectional conduction switch D1 in series, which can not only prevent current backflow, thereby effectively alleviating the circulation problem, but also help save the power of the first power supply.

[0095] In some embodiments, based on the above embodiments, Figure 5 is a structural schematic diagram of the power supply switching circuit provided in other embodiments of the present application. As shown in Figure 5, the second path 102 of the embodiment of the present application may include a second unidirectional conduction switch D2 connected in series with the first switch B.

[0096] For example, as shown in FIG5 , one end of the first switch B can be connected to the second power connection terminal P2 and the input terminal of the voltage comparison circuit 103, the other end of the first switch B is connected to one end of the second unidirectional conduction switch D2, and the other end of the second unidirectional conduction switch D2 is connected to the load connection terminal P3.

[0097] It should be noted that the positions of the second unidirectional conduction switch D2 and the first switch B can be interchanged; this is not limited in the embodiment of the present application.

[0098] In the embodiment of the present application, when the voltage difference between the positive terminal and the negative terminal of the second unidirectional conduction switch D2 meets the second preset conduction condition, the second unidirectional conduction switch D2 will switch to the on state; otherwise, the second unidirectional conduction switch D2 will switch to the off state.

[0099] For example, the second unidirectional conduction switch D2 in the embodiment of the present application may include but is not limited to a diode device.

[0100] As another example, the second unidirectional conduction switch D2 in the embodiment of the present application may include but is not limited to a fully controlled switch device. For example, the second unidirectional conduction switch D2 may be an equivalent diode including a MOS transistor.

[0101] Since the heating power of the MOS tube is lower than the heating power of the diode, the second unidirectional conduction switch D2 including the MOS tube in the embodiment of the present application can not only prevent current backflow, thereby effectively alleviating the circulation problem, but also reduce the heating power, thereby saving power.

[0102] For example, the first switch B in the embodiment of the present application may be a fully controlled switch device. For example, the first switch B may be an equivalent switch including a MOS tube. Of course, the first switch B may also include other devices, such as a second voltage-dividing resistor.

[0103] Since the heating power of the MOS tube is lower than the heating power of the diode, the embodiment of the present application uses the first switch B including the MOS tube to replace the diode in the related art, thereby reducing the heating power and saving power.

[0104] It should be understood that in one possible implementation, the voltage comparison circuit 103 in the embodiment of the present application can, when the comparison result satisfies the preset normal operating conditions, control the first switch B to switch to the off state, so that the voltage difference between the two sides of the second unidirectional conduction switch D2 does not satisfy the second preset conduction condition, and the second unidirectional conduction switch D2 is switched to the off state, that is, the second path 102 is switched to the off state, thereby putting the first path 101 in the on state, so that the first power supply can supply power to the load through the first path 101.

[0105] In another possible implementation, the voltage comparison circuit 103 in the embodiment of the present application can control the first switch B to switch to the on state when the comparison result does not meet the preset normal operating conditions, so that the voltage difference between the two sides of the second unidirectional conduction switch D2 meets the second preset conduction condition. The second unidirectional conduction switch D2 is switched to the on state, that is, the second path 102 is switched to the on state, and the first path 101 is switched to the off state, so that the second power supply can supply power to the load through the second path 102.

[0106] It can be seen that the second path 102 in the embodiment of the present application can prevent current backflow on the basis of achieving flexible power supply switching by including a second unidirectional conduction switch connected in series with the first switch B, thereby effectively alleviating the circulating current problem.

[0107] In some embodiments, based on the above embodiments, Figure 6 is a structural diagram of the power supply switching circuit provided in other embodiments of the present application. As shown in Figure 6, the power supply switching circuit of the embodiment of the present application may further include a voltage-stabilized power supply path 104.

[0108] The voltage-regulated power supply path 104 in the embodiment of the present application can be used to power the load during the process of switching power supply for the load between the first path 101 and the second path 102, so that the load can be switched without power failure, thereby further improving the reliability of the load power supply voltage.

[0109] For example, the first end of the voltage-regulated power supply path 104 in the embodiment of the present application can be connected to the second power connection terminal P2, the second end of the voltage-regulated power supply circuit 104 can be connected to the load connection terminal P3, and the third end of the voltage-regulated power supply path 104 can be connected to the input terminal of the voltage comparison circuit 103.

[0110] It should be understood that, since a voltage-stabilized power supply path 104 is provided between the second path 102 and the voltage comparison circuit 103 in the embodiment of the present application, the voltage Vn2 of the second path 102 (i.e., the voltage Vin2 of the second power connection terminal P2) is obtained after passing through the voltage-stabilized power supply path 104 to obtain the output voltage V LDO Correspondingly, the voltage comparison circuit 103 in the embodiment of the present application can compare the voltage Vn1 of the first path 101 with the output voltage V of the regulated power supply path 104. LDO A comparison is performed, and if the comparison result meets the preset normal working conditions, a first drive signal can be output according to the comparison result to make the first switch B in an off state and the second path 102 in an off state, thereby making the first path 101 in an on state, so that the first power supply can supply power to the load through the first path 101; if the comparison result does not meet the preset normal working conditions, a second drive signal can be output according to the comparison result to make the first switch B in an on state, the second path 102 in an on state, and the first path 101 in an off state, so that the second power supply can supply power to the load through the second path 102.

[0111] Correspondingly, the preset normal working conditions in the embodiment of the present application may include but are not limited to: the voltage V n1 and the output voltage V of the regulated power supply path 104 LDO The difference between them is greater than the second predetermined difference, or the voltage V n1 is greater than or equal to the output voltage V of the regulated power supply path 104. LDO The product of the second preset coefficient, wherein the second preset coefficient is a modulated voltage ratio coefficient, and the value range of the second preset coefficient may include but is not limited to 0.8 to 1.

[0112] It can be seen that in the embodiment of the present application, by providing a voltage-regulated power supply path 104 between the second path 102 and the voltage comparison circuit 103, it is possible to achieve flexible power supply switching and also to switch power to the load without power failure, thereby further improving the reliability of the load power supply voltage.

[0113] In some embodiments, based on the above embodiments, FIG7 is a schematic diagram of the structure of the power supply switching circuit provided in other embodiments of the present application. As shown in FIG7, the voltage stabilizing power supply path 104 of the embodiment of the present application may include a voltage stabilizing circuit R and a third unidirectional conducting switch D3 connected in series. The voltage stabilizing circuit R can be used to provide a stable output voltage V LDO The third unidirectional conduction switch D3 can be used to prevent current backflow, thereby effectively alleviating the circulating current problem.

[0114] Illustratively, the voltage stabilizing circuit R in the embodiment of the present application may include but is not limited to a voltage stabilizer or a voltage stabilizing circuit module.

[0115] FIG8 is a schematic diagram of the structure of a voltage-stabilizing circuit module provided in some embodiments of the present application. As shown in FIG8 , the voltage-stabilizing circuit module in the embodiments of the present application may include, but is not limited to, an operational amplifier U2, a voltage-stabilizing diode Z, a transistor V1, a transistor V2, a current-limiting resistor R5, a voltage-divider resistor R6, and a voltage-divider resistor R7. Transistors V1 and V2 may be combined into a Darlington transistor to increase the amplification factor of operational amplifier U2; the inverting input terminal - of operational amplifier U2 is connected to the output terminal of operational amplifier U2 to form negative feedback, which can maintain the voltage at the inverting input terminal - and the positive input terminal + of operational amplifier U2 equal.

[0116] Of course, the voltage stabilizing circuit R in the embodiment of the present application may also adopt other forms of voltage stabilizing circuit modules.

[0117] In the embodiment of the present application, when the voltage difference between the positive terminal and the negative terminal of the third unidirectional conduction switch D3 meets the third preset conduction condition, the third unidirectional conduction switch D3 will switch to the on state; otherwise, the third unidirectional conduction switch D3 will switch to the off state.

[0118] For example, the third unidirectional conducting switch D3 in the embodiment of the present application may include but is not limited to an uncontrollable switching device. For example, the third unidirectional conducting switch D3 may be a diode.

[0119] As another example, the third unidirectional conduction switch D3 in the embodiment of the present application may include but is not limited to a fully controlled switch device. For example, the third unidirectional conduction switch D3 may be an equivalent diode including a MOS transistor.

[0120] Since the heating power of the MOS tube is lower than the heating power of the diode, the third unidirectional conduction switch D3 including the MOS tube in the embodiment of the present application can not only prevent current backflow, thereby effectively alleviating the circulation problem, but also reduce the heating power, thereby saving power.

[0121] For example, as shown in FIG7 , one end of the voltage stabilizing circuit R in the embodiment of the present application can be connected to the second power connection terminal P2, the other end of the voltage stabilizing circuit R and one end of the third unidirectional conduction switch D3 can both be connected to the input end of the voltage comparison circuit 103, and the other end of the third unidirectional conduction switch D3 can be connected to the load connection terminal P3. LDO The difference between the voltage Vin2 at the second power connection terminal P2 and the voltage Vin2 at the second power connection terminal P2 may be a third preset difference, and the value range of the third preset difference may include but is not limited to 2V to 6V.

[0122] Correspondingly, the voltage comparison circuit 103 in the embodiment of the present application can be configured to be greater than or equal to the output voltage V of the voltage stabilizing circuit R when the voltage Vn1 of the first path 101 is greater than or equal to the output voltage V LDO When the voltage Vn1 of the first path 101 is less than the output voltage V of the voltage stabilizing circuit R, the first path 101 can be controlled to be in a conducting state so that the first power supply can supply power to the load through the first path 101. LDO When the product of the second preset coefficient is obtained, the second path 102 can be controlled to be in a conducting state, so that the second power supply can supply power to the load through the second path 102.

[0123] It should be noted that the voltage comparison circuit 103 can also compare the voltage Vn1 of the first path 101 with the output voltage V of the voltage stabilizing circuit R. LDO When the difference between the voltage Vn1 and the output voltage V of the voltage stabilizing circuit R is greater than the second preset difference, the first path 101 can be controlled to be in a conducting state so that the first power supply can supply power to the load through the first path 101; LDO When the difference between the first and second second predetermined differences is not greater than the second predetermined difference, the second path 102 can be controlled to be in an on state, so that the second power supply can supply power to the load through the second path 102.

[0124] As can be seen, the voltage-regulated power supply path 104 in the embodiment of the present application, by including the voltage-regulating circuit R and the third unidirectional conduction switch D3 in series, can achieve flexible power supply switching and can also switch power to the load without power loss, thereby further improving the reliability of the load supply voltage. Furthermore, the provision of the third unidirectional conduction switch D3 can prevent current backflow, thereby effectively alleviating the problem of circulating current.

[0125] In some embodiments, based on the above embodiments, FIG9 is a schematic structural diagram of a power supply switching circuit provided in other embodiments of the present application. As shown in FIG9 , the power supply switching circuit in the embodiment of the present application may include: a first path 101, a second path 102, a first switch B, a voltage comparison circuit 103, and a regulated power supply path 104. One end of the second path 102 may be connected to the second power connection terminal P2 via the first switch B.

[0126] In the embodiment of the present application, the first path 101 may include a second switch A and a first unidirectional conduction switch D1 connected in series. One end of the second switch A may be connected to the first power supply connection terminal P1, and the other end of the second switch A may be connected to the input terminal of the voltage comparison circuit 103 and one end of the first unidirectional conduction switch D1. The other end of the first unidirectional conduction switch D1 is connected to the load connection terminal P3. It should be understood that in the embodiment of the present application, the voltage at the other end of the second switch A or the voltage at one end of the first unidirectional conduction switch D1 may be the voltage Vn1 of the first path 101.

[0127] It should be noted that, in the embodiment of the present application, the voltage at the control terminal of the second switch A can be a voltage obtained by dividing the voltage Vin1 of the first power connection terminal P1 through the first voltage-dividing resistor, that is, the second switch A always meets its preset conduction condition. However, due to the presence of the first unidirectional conduction switch D1, it is possible to achieve that when the second path 102 is in the on state, the first path 101 is in the off state.

[0128] In the embodiment of the present application, the second path 102 may include a second unidirectional conducting switch D2 connected to the first switch B. One end of the first switch B may be connected to the second power connection terminal P2 and the input terminal of the voltage comparison circuit 103, while the other end of the first switch B may be connected to one end of the second unidirectional conducting switch D2. The other end of the second unidirectional conducting switch D2 may be connected to the load connection terminal P3. It should be understood that the voltage Vn2 of the second path 102 in the embodiment of the present application may be the voltage Vin2 of the second power connection terminal P2.

[0129] For example, in an embodiment of the present application, the output end of the voltage comparison circuit 103 can be connected to the control end of the first switch B, so that the voltage comparison circuit 103 can output a driving signal to the control end of the first switch B to control the on-off state of the first switch B; wherein the control end of the first switch B may include but is not limited to the gate of the MOS tube in the first switch B.

[0130] In the embodiment of the present application, the voltage-stabilized power supply path 104 may include a voltage-stabilizing circuit R and a third unidirectional conduction switch D3 connected in series. One end of the voltage-stabilizing circuit R may be connected to the second power supply connection terminal P2, the other end of the voltage-stabilizing circuit R and one end of the third unidirectional conduction switch D3 may both be connected to the input terminal of the voltage comparison circuit 103, and the other end of the third unidirectional conduction switch D3 may be connected to the load connection terminal P3. The output voltage V LDO The difference between the voltage Vin2 at the second power connection terminal P2 and the voltage Vin2 at the second power connection terminal P2 may be a third preset difference k1.

[0131] For example, when batteries (such as 6 lithium batteries) are used as the first power source and a DC-DC power source is used as the second power source, the value of the third preset difference k1 may be 5V.

[0132] For another example, when a DC-DC power supply (such as 24V) is used as the first power supply and a battery is used as the second power supply, the value of the third preset difference k1 may be 2V.

[0133] For another example, when both the first power supply and the second power supply are DC-DC power supplies, the value of the third preset difference k1 may be 2V.

[0134] As shown in FIG9 , in a possible implementation, the voltage comparison circuit 103 can be configured to generate a voltage Vn1 when the voltage Vn1 of the first path 101 is greater than or equal to the output voltage V of the voltage stabilizing circuit R. LDO The product of Vn1≥V LDO In the case of *k2), a first drive signal can be output to the control terminal of the first switch B to control the first switch B to switch to the off state, so that the voltage difference across the first unidirectional conduction switch D1 satisfies the first preset conduction condition. The first unidirectional conduction switch D1 is switched to the on state, i.e., the first path 101 is switched to the on state. This allows the voltage Vin1 at the first power connection terminal P1 to pass through the second switch A to obtain the voltage Vn1, which is then output to the load after passing through the first unidirectional conduction switch D1. The voltage Vn1 can be lower than the output voltage Vin1. Thus, the embodiment of the present application enables the first power supply to preferentially supply power to the load when the first power supply is in normal operation.

[0135] For example, when batteries (such as 6 lithium batteries) are used as the first power source and a DC-DC power source is used as the second power source, the value of the second preset coefficient k2 may be 1.

[0136] For another example, when a DC-DC power supply (such as 24V) is used as the first power supply and a battery is used as the second power supply, the value of the second preset coefficient k2 may be 0.82.

[0137] For another example, when both the first power supply and the second power supply are DC-DC power supplies, the value of the third preset difference k1 may be 1.

[0138] In another possible implementation, the voltage comparison circuit 103 may be configured to compare the voltage Vn1 of the first path 101 with the output voltage Vn1 of the voltage stabilizing circuit R when the voltage Vn1 is less than the output voltage Vn1 of the voltage stabilizing circuit R. LDO The product of Vn1 and the second preset coefficient k2 <V LDO *k2), a second drive signal can be output to the control terminal of the first switch B to control the first switch B to switch to the on state, so that the voltage difference across the first unidirectional conduction switch D1 does not meet the first preset conduction condition. The first unidirectional conduction switch D1 is switched to the off state, that is, the first path 101 is switched to the off state, so that the voltage Vin2 at the second power connection terminal P2 is output to the load after passing through the first switch B and the second unidirectional conduction switch D2 in sequence. Thus, the embodiment of the present application enables the second power supply to supply power to the load when the first power supply is in an abnormal working state, thereby improving the reliability of the load supply voltage.

[0139] In addition, considering that switching from the first path 101 to the second path 102 may require a certain switching time, the voltage difference between the two sides of the third unidirectional conduction switch D3 in the voltage-stabilized power supply path 104 in the embodiment of the present application satisfies the corresponding conduction condition during the switching process, and the third unidirectional conduction switch D3 is in the conducting state, so that the output voltage V LDO The output voltage V LDO As a support voltage for the load, it can be seen that the embodiment of the present application realizes that when the first power supply is in an abnormal working state, the first power supply is switched to the second power supply to supply power to the load without power failure, thereby further improving the reliability of the load supply voltage.

[0140] In summary, the power supply switching circuit of the embodiment of the present application achieves high reliability and has an active current sharing function, which is conducive to the long-term and reliable operation of the power storage system.

[0141] In some embodiments, based on the above embodiments, FIG10 is a flowchart of a power supply switching method provided in some embodiments of the present application. As shown in FIG10 , the method of the embodiment of the present application may include the following steps:

[0142] Step S1001: Acquire a first voltage of a first path and a second voltage of a second path.

[0143] For example, the first voltage of the first path in the embodiment of the present application can be used to indicate the voltage of the first power supply connected to the first path, and the second voltage of the second path can be used to indicate the voltage of the second power supply connected to the second path.

[0144] Step S1002: Based on the comparison result of the first voltage and the second voltage, the first path or the second path is turned on to supply power to the load.

[0145] In a possible implementation, when the comparison result meets a preset normal working condition, the first path is turned on to supply power to the load.

[0146] In another possible implementation, when the comparison result does not meet the preset normal working condition, the second path is turned on to supply power to the load.

[0147] In some embodiments, based on the above embodiments, the method of the embodiments of the present application may further include:

[0148] During the process of switching power supply for the load between the first path and the second path, a support voltage is provided to power the load.

[0149] The implementation principle and technical effects of the power supply switching method in the embodiment of the present application are similar to the relevant contents in the above-mentioned power supply switching circuit embodiment, and will not be repeated here.

[0150] In some embodiments, based on the above embodiments, FIG11 is a schematic structural diagram of a power supply system provided in some embodiments of the present application. As shown in FIG11 , the power supply system in the embodiment of the present application may include: a first power supply 1101, a second power supply 1102, a load 1103, and a power supply switching circuit 1104. The first power connection terminal P1 of the power supply switching circuit 1104 is connected to the first power supply 1101, the second power connection terminal P2 of the power supply switching circuit 1104 is connected to the second power supply 1102, and the load connection terminal P3 of the power supply switching circuit 1104 is connected to the load 1103.

[0151] The implementation principle and technical effects of the power supply system in the embodiment of the present application are similar to the relevant contents in the above-mentioned power supply switching circuit embodiment, and will not be repeated here.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A power supply switching circuit, wherein: The power supply switching circuit includes: a first path, a second path, a first switch and a voltage comparison circuit; the first end of the first path is the first power connection end of the power supply switching circuit, one end of the second path is connected to the second power connection end of the power supply switching circuit through the first switch, the second end of the first path and the other end of the second path are both connected to the load connection end of the power supply switching circuit; the third end of the first path and the second power connection end are both connected to the input end of the voltage comparison circuit, and the output end of the voltage comparison circuit is connected to the control end of the first switch.

2. The power supply switching circuit according to claim 1, wherein: The first path includes a first unidirectional conduction switch, wherein one end of the first unidirectional conduction switch is connected to the first power connection end and the input end of the voltage comparison circuit, and the other end of the first unidirectional conduction switch is connected to the load connection end; or, One end of the first unidirectional conducting switch is connected to the first power supply connection end, and the other end of the first unidirectional conducting switch is connected to the input end of the voltage comparison circuit and the load connection end.

3. The power supply switching circuit according to claim 2, wherein: The first path also includes a second switch connected in series with the first unidirectional conducting switch.

4. The power supply switching circuit according to any one of claims 1 to 3, wherein: The second path includes a second unidirectional conducting switch connected in series with the first switch.

5. The power supply switching circuit according to any one of claims 1 to 4, wherein: The power supply switching circuit also includes a voltage-regulated power supply path, wherein a first end of the voltage-regulated power supply path is connected to the second power supply connection end, a second end of the voltage-regulated power supply path is connected to the load connection end, and a third end of the voltage-regulated power supply path is connected to the input end of the voltage comparison circuit.

6. The power supply switching circuit according to claim 5, wherein: The voltage-stabilized power supply path includes: a voltage-stabilizing circuit and a third unidirectional conducting switch connected in series, wherein one end of the voltage-stabilizing circuit is connected to the second power supply connection end, the other end of the voltage-stabilizing circuit and one end of the third unidirectional conducting switch are both connected to the input end of the voltage comparison circuit, and the other end of the third unidirectional conducting switch is connected to the load connection end.

7. The power supply switching circuit according to claim 3, wherein: The first switch is a fully-controlled switch device, and / or the second switch is a fully-controlled switch device.

8. The power supply switching circuit according to claim 2 or 3, wherein: The first unidirectional conducting switch is a fully controlled switch device or a diode device.

9. The power supply switching circuit according to claim 4, wherein: The second unidirectional conducting switch is a fully controlled switch device or a diode device.

10. The power supply switching circuit according to claim 6, wherein: The third unidirectional conducting switch is a fully controlled switch device or a diode device.

11. A power supply switching method, wherein: The method comprises: Acquire a first voltage of the first path and a second voltage of the second path; According to a comparison result between the first voltage and the second voltage, the first path is turned on or the second path is turned on to supply power to a load.

12. The method according to claim 11, wherein: The step of conducting the first path or the second path to supply power to a load according to a comparison result of the first voltage and the second voltage includes: When the comparison result satisfies a preset normal working condition, conducting the first path to supply power to the load; When the comparison result does not satisfy the preset normal working condition, the second path is turned on to supply power to the load.

13. The method according to claim 11 or 12, wherein: The method further comprises: In the process of switching power supply for the load through the first path and the second path, a support voltage is provided to power the load.

14. A power supply system, wherein: The power supply system comprises: a first power supply, a second power supply, a load and a power supply switching circuit as described in any one of claims 1 to 10; The first power connection terminal of the power supply switching circuit is connected to the first power supply, the second power connection terminal of the power supply switching circuit is connected to the second power supply, and the load connection terminal of the power supply switching circuit is connected to the load.

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