A switched mode power supply and energy storage device

Abstract

A switching power supply and energy storage device are disclosed to meet energy storage needs in various scenarios and reduce equipment costs. The switching power supply includes a first switching circuit, a second switching circuit, a bidirectional converter, and a controller. The first switching circuit is connected between a battery pack and a first terminal of the bidirectional converter. The second switching circuit is connected between an energy storage element and the first terminal of the bidirectional converter. The second terminal of the bidirectional converter is connected to a load or other power source. The controller can control the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, as well as the power consumption of the device connected to the second terminal of the bidirectional converter. In scenarios with frequent charging and discharging, closing the switching circuit connected to the energy storage element allows the energy storage element to meet the device's power needs when the device's power demand is low, reducing the number of charge / discharge cycles of the battery pack and extending its lifespan.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a switching power supply and energy storage device. Background Technology

[0002] Uninterruptible power systems (UPS) and grid-connected renewable energy equipment all require energy storage devices. Batteries and supercapacitors are commonly used energy storage devices, each with its own advantages and disadvantages. Batteries can store a large amount of energy and provide backup power for extended periods, but their charge / discharge rate is low and their cycle life is limited. Supercapacitors, on the other hand, have the advantages of a high charge / discharge rate and a high cycle life, but their disadvantage is low energy density, meaning they store less energy per unit weight or volume. Therefore, their advantages and disadvantages can complement each other.

[0003] To meet energy storage needs in different scenarios, batteries (BAT) and supercapacitors (SC) are generally used. Currently, the industry typically employs four methods: two parallel connections and two series connections. Regardless of the method, a drawback is that two topologies with the same power are required, resulting in higher costs. Summary of the Invention

[0004] This application provides a switching power supply and an energy storage device to reduce the cost of the energy storage device while meeting energy storage needs in multiple scenarios.

[0005] In a first aspect, embodiments of this application provide a switching power supply that can be applied to devices with energy storage functions, such as UPS and new energy grid-connected equipment. The switching power supply may include: a first switching circuit, a second switching circuit, a bidirectional converter, and a controller.

[0006] In this system, the first terminal of the first switching circuit is connected to the battery pack, and the second terminal of the first switching circuit is connected to the first terminal of the bidirectional converter. The first terminal of the second switching circuit is connected to the energy storage element, and the second terminal of the second switching circuit is connected to the first terminal of the bidirectional converter. The second terminal of the bidirectional converter is connected to a load or power source to convert electrical energy obtained from the first terminal of the bidirectional converter and then power the connected downstream equipment, or to convert electrical energy obtained from the second terminal of the bidirectional converter and then charge the energy storage element or the battery pack. The controller is connected to the first switching circuit and the second switching circuit respectively, and controls the state of the first switching circuit and the second switching circuit according to charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the equipment connected to the second terminal of the bidirectional converter. The energy storage element is a component with storage function and capable of rapid charging and discharging, such as a supercapacitor. The power source connected to the second terminal of the bidirectional converter is a power source other than the supercapacitor and the battery pack, such as the power grid.

[0007] With the above design, the energy storage element and the battery pack are each connected to the bidirectional converter via a switching circuit. By controlling the closing and opening of each switching circuit, the charging and discharging times of the energy storage element and the battery pack can be controlled. For scenarios requiring frequent charging and discharging, such as grid connection of new energy sources, when a discharge or charging command is received, the switching circuit connected to the energy storage element can be closed first to meet the device's demand for energy storage devices. When the device's power demand is low, the energy storage element can meet the device's power requirements, thus reducing the number of charge-discharge cycles of the battery pack and extending its lifespan. For scenarios requiring long-term backup power, when a discharge or charging command is received, the switching circuit connected to the battery pack can be closed to fulfill the device's demand for energy storage devices. Since the lifespan of the energy storage element is less affected by the number of charge-discharge cycles, both switching circuits can be closed, allowing both the battery pack and the energy storage element to participate in the device's energy storage process, thereby meeting the device's demand for energy storage devices. Therefore, with the above design, while meeting the energy storage needs of multiple scenarios, the sharing of a bidirectional converter between the energy storage element and the battery pack also helps to reduce the cost of energy storage equipment.

[0008] In one possible design, the controller is specifically used to: control the second switching circuit to close when a discharge command is received; and control the first switching circuit to close and the second switching circuit to open when the remaining capacity of the energy storage element is detected to be less than a first preset threshold. With this design, since the lifespan of the energy storage element is less affected by the number of charge-discharge cycles, when a discharge command is received, the second switching circuit connected to the energy storage element can be preferentially closed to control the energy storage element to discharge first. When the energy stored in the energy storage element is insufficient, the battery pack is then started to discharge, and the energy storage element is controlled to stop discharging.

[0009] In one possible design, the controller is specifically used to: control the second switching circuit to close when a discharge command is received; and control the first switching circuit to close when the remaining capacity of the energy storage element is detected to be less than a first preset threshold. With this design, since the lifespan of the energy storage element is less affected by the number of charge-discharge cycles, when a discharge command is received, the second switching circuit connected to the energy storage element can be controlled to prioritize the discharge of the energy storage element. When the energy stored in the energy storage element is insufficient, the first switching circuit is then controlled to close to start the battery pack for discharge. As the discharge time increases, the battery pack voltage gradually decreases; when the battery pack voltage is the same as the energy storage element voltage, the battery pack and the energy storage element discharge together.

[0010] In one possible design, the controller is specifically used to: close the second switching circuit upon receiving a discharge command; and open the second switching circuit upon detecting that the device connected to the second end of the bidirectional converter has stopped using power. With this design, since the lifespan of the energy storage element is less affected by the number of charge-discharge cycles, the second switching circuit connected to the energy storage element can be controlled upon receiving a discharge command to prioritize the discharge of the energy storage element. For short-term power consumption scenarios, if the device connected to the back end of the bidirectional converter has already stopped using power before the energy stored in the energy storage element is fully released, the battery pack's lifespan is improved because it does not participate in the charge-discharge process.

[0011] In one possible design, the controller is specifically configured to: when a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is less than a third preset threshold, control the second switching circuit to close; when it is determined that the energy storage element has finished charging, control the second switching circuit to open and control the first switching circuit to close; when it is determined that the battery pack has finished charging, control the first switching circuit to open.

[0012] In one possible design, the controller is specifically used to: when a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is equal to a third preset threshold, control the second switching circuit to close; and when it is determined that the energy storage element has finished charging, control the second switching circuit to open.

[0013] In one possible design, the first switching circuit includes a first switching transistor and a second switching transistor, and the second switching circuit includes a third switching transistor and a fourth switching transistor.

[0014] Specifically, the first terminal of the first switching transistor is connected to the battery pack, and the second terminal of the first switching transistor is connected to the first terminal of the bidirectional converter; the first terminal of the second switching transistor is connected to the first terminal of the bidirectional converter, and the second terminal of the second switching transistor is connected to the battery pack; the first terminal of the third switching transistor is connected to the energy storage element, and the second terminal of the third switching transistor is connected to the first terminal of the bidirectional converter; the first terminal of the fourth switching transistor is connected to the first terminal of the bidirectional converter, and the second terminal of the fourth switching transistor is connected to the energy storage element. The switching transistors in the first and second switching circuits are semi-controlled switching transistors. With this design, since semi-controlled switching transistors, such as thyristors, have unidirectional conductivity, the ports of the two switching transistors in the switching circuit can be connected in reverse, allowing the two switching transistors to serve as the charging and discharging paths for the connected device, respectively. Furthermore, it avoids mutual charging between the battery pack and the energy storage element caused by both switching circuits being simultaneously active.

[0015] In one possible design, the first switching circuit includes a first diode, a second diode, a fifth switching transistor, and a sixth switching transistor, and the second switching circuit includes a third diode, a fourth diode, a seventh switching transistor, and an eighth switching transistor.

[0016] Specifically, the anode of the first diode is connected to the battery pack, and the cathode of the first diode is connected to the first terminal of the bidirectional converter through the fifth switching transistor; the cathode of the second diode is connected to the battery pack, and the anode of the second diode is connected to the first terminal of the bidirectional converter through the sixth switching transistor; the anode of the third diode is connected to the energy storage element, and the cathode of the third diode is connected to the first terminal of the bidirectional converter through the seventh switching transistor; the cathode of the fourth diode is connected to the energy storage element, and the anode of the fourth diode is connected to the first terminal of the bidirectional converter through the eighth switching transistor. The switching transistors in the first and second switching circuits are fully controlled switching transistors. With this design, each switching circuit has two switching transistors connected in series with a diode of opposite polarities. Based on the unidirectional conductivity of diodes, the two switching transistors can serve as the charging and discharging paths for the connected device, respectively, and can also prevent mutual charging between the battery pack and the energy storage element from occurring when both switching circuits are simultaneously turned on.

[0017] In one possible design, the switching power supply further includes a first capacitor connected in parallel with the battery pack and a second capacitor connected in parallel with the energy storage element. With this design, for scenarios requiring port capacitors, if the required port capacitor value is large, the port capacitor needs to be placed at the first end of the bidirectional converter. If the required port capacitor value is small, the port capacitor can be placed at both ends of the supercapacitor and the battery pack.

[0018] Secondly, embodiments of this application provide an energy storage device that can be applied to equipment requiring energy storage functions, including UPS and new energy power generation systems. The energy storage device may include a battery pack, energy storage elements, and a switching power supply provided in the first aspect of this application and any possible design thereof.

[0019] Thirdly, embodiments of this application provide a charging and discharging control method, which can be applied to the switching power supply provided in the first aspect of this application and any possible design therein, and is executed by the controller in the switching power supply, specifically including the following steps:

[0020] The remaining capacity of the energy storage element and the battery pack is detected; based on the charging command, the discharging command, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second end of the bidirectional converter, the states of the first switching circuit and the second switching circuit are controlled.

[0021] In one possible design, controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes:

[0022] When a discharge command is received, the second switching circuit is controlled to close; when the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close and the second switching circuit is controlled to open.

[0023] In one possible design, controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes:

[0024] When a discharge command is received, the second switching circuit is controlled to close; when the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close.

[0025] In one possible design, controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes:

[0026] Upon receiving a discharge command, the second switching circuit is controlled to close; when it is detected that the device connected to the second end of the bidirectional converter has stopped using power, the second switching circuit is controlled to open.

[0027] In one possible design, controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes:

[0028] When a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is less than a third preset threshold, the second switch circuit is controlled to close; when it is determined that the energy storage element has finished charging, the second switch circuit is controlled to open and the first switch circuit is controlled to close; when it is determined that the battery pack has finished charging, the first switch circuit is controlled to open.

[0029] In one possible design, controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes:

[0030] When a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is equal to a third preset threshold, the second switch circuit is controlled to close; when it is determined that the energy storage element has finished charging, the second switch circuit is controlled to open.

[0031] Furthermore, the technical effects of the second to third aspects and any possible design can be found in the technical effects of different designs in the first aspect of the embodiments of this application, and will not be repeated here. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of a switching power supply provided in this application embodiment. Figure 1 ;

[0034] Figure 2 A schematic diagram of the structure of a first switching circuit provided in an embodiment of this application. Figure 1 ;

[0035] Figure 3 A schematic diagram of the structure of a first switching circuit provided in an embodiment of this application. Figure 2 ;

[0036] Figure 4 A schematic diagram of the structure of a second switching circuit provided in an embodiment of this application. Figure 1 ;

[0037] Figure 5 A schematic diagram of the structure of a second switching circuit provided in this application embodiment. Figure 2 ;

[0038] Figure 6 A schematic flowchart of a discharge control method for a battery pack and a supercapacitor provided in this application embodiment. Figure 1 ;

[0039] Figure 7 A flowchart illustrating a discharge control method for a battery pack and a supercapacitor provided in this application embodiment. Figure 2 ;

[0040] Figure 8 A flowchart illustrating a discharge control method for a battery pack and a supercapacitor provided in this application embodiment. Figure 3 ;

[0041] Figure 9 A flowchart illustrating a charging control method for a battery pack and a supercapacitor provided in this application embodiment. Figure 1 ;

[0042] Figure 10 A flowchart illustrating a charging control method for a battery pack and a supercapacitor provided in this application embodiment. Figure 2 ;

[0043] Figure 11 A schematic diagram of a switching power supply provided in this application embodiment. Figure 2 . Detailed Implementation

[0044] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0045] The terminology used in the implementation section of this application is only for explaining specific embodiments of this application and is not intended to limit this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0046] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0047] The following explanations of some terms used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0048] (1) In the embodiments of this application, the term "multiple" refers to two or more, and other quantifiers are similar.

[0049] (2) The switching transistors in this application embodiment can be one or more of various types of switching transistors, such as relays, metal oxide semiconductor field effect transistors (MOSFETs), bipolar junction transistors (BJTs), and insulated gate bipolar transistors (IGBTs). These types will not be listed individually in this application embodiment. Each switching transistor may include a first terminal, a second terminal, and a control terminal, wherein the control terminal is used to control the switching transistor to turn on or off. When the switching transistor is on, current can be transmitted between the first terminal and the second terminal; when the switching transistor is off, current cannot be transmitted between the first terminal and the second terminal. Taking a MOSFET as an example, the control terminal of the switching transistor is the gate, the first terminal of the switching transistor can be the source, and the second terminal can be the drain, or the first terminal can be the drain and the second terminal can be the source.

[0050] (3) In the embodiments of this application, "connection" can be understood as electrical connection or communication connection. The electrical connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components, such as the connection between A and B. Alternatively, it can be a direct connection between A and C, a direct connection between C and B, with A and B connected through C.

[0051] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The switching power supply provided in this application has an external energy storage device, and the switching power supply can be applied to devices with energy storage requirements, meeting the energy storage needs of devices in different scenarios. For example, the switching power supply can be applied to UPS and new energy power generation systems. When the switching power supply is applied to a UPS, it can convert the voltage of the UPS's internal DC bus to the charging voltage of the energy storage device when the external AC power supply to the UPS is normal, and charge the connected energy storage device. The switching power supply can also convert the stored electrical energy into the DC bus voltage and supply power to the DC bus when the AC power supply fails, thereby supplying power to the load connected to the downstream of the DC bus. Because the UPS has a large power supply capacity and the AC power supply is in normal condition most of the time, the energy storage device connected to the switching power supply is in a standby state for a long time, and the energy storage device connected to the switching power supply needs to have a large capacity to store electrical energy.

[0052] When a switching power supply is used in a renewable energy generation system and the system is connected to the grid, the power supply can participate in grid frequency regulation. When the grid frequency drops, the power supply can output energy stored in the energy storage devices of the connected renewable energy generation system to the grid until the grid frequency returns to normal. When the grid frequency rises, the power supply can obtain energy from the renewable energy generation system or from the grid until the grid frequency returns to normal. Therefore, the energy storage devices connected to the switching power supply need to have the ability to charge and discharge frequently to meet the grid frequency regulation requirements. The following detailed explanation, with reference to embodiments, illustrates the process by which a switching power supply meets energy storage requirements in different scenarios.

[0053] See Figure 1 The diagram shown is a structural schematic of a switching power supply provided in an embodiment of this application. Figure 1 As shown, a switching power supply may include: a first switching circuit, a second switching circuit, a bidirectional converter, and a controller.

[0054] In this system, the first terminal of the first switching circuit is connected to the battery pack (BAT), and the second terminal is connected to the first terminal of the bidirectional converter. The first terminal of the second switching circuit is connected to the energy storage element, and the second terminal is connected to the first terminal of the bidirectional converter. The second terminal of the bidirectional converter is connected to a load or power source to convert electrical energy from the first terminal of the bidirectional converter to power connected downstream devices, or to convert electrical energy from the second terminal of the bidirectional converter to charge the energy storage element or battery pack. A controller is connected to both the first and second switching circuits and controls their states based on charging commands, discharging commands, the remaining capacity of the energy storage element and the battery pack, and the power consumption of the devices connected to the second terminal of the bidirectional converter. The power source connected to the second terminal of the bidirectional converter is a power source other than the energy storage element and battery pack, such as the power grid. The energy storage element is a commonly used component with fast charging and discharging capabilities and a lifespan minimally affected by the number of charge and discharge cycles. The following embodiments use a supercapacitor (SC) as the energy storage element.

[0055] It should be understood that, Figure 1 The switching power supply structure shown is for illustrative purposes only. In practical applications, switching power supplies can have more advanced features than... Figure 1 The power supply may also include other components, such as overload protection devices and short-circuit protection devices. Of course, the power supply may also include other functional devices, which will not be described in detail here.

[0056] In practical applications, the switching power supply can be externally connected to a battery pack (BAT) and a supercapacitor (SC). The battery pack (BAT) can be connected to a bidirectional converter via a first switching circuit, and the supercapacitor (SC) can be connected to the bidirectional converter via a second switching circuit. Therefore, the controller can control the charging and discharging times of the supercapacitor (SC) and the battery pack (BAT) by controlling the closing and opening of each switching circuit.

[0057] use Figure 1 The switching power supply shown can utilize a bidirectional converter to convert the voltage of the battery pack (BAT) or supercapacitor (SC) to the voltage of the connected devices, thus powering them. The bidirectional converter can also convert the voltage of the connected devices to the charging voltage of the supercapacitor (SC) or battery pack (BAT), thus charging them. If the devices connected to the bidirectional converter transmit AC power, a bidirectional AC converter can be used. If the devices connected to the bidirectional converter transmit DC power, a bidirectional DC converter can be used.

[0058] See also Figure 1 The switching power supply shown is suitable for scenarios requiring frequent charging and discharging, such as grid connection of new energy sources. Since the lifespan of the supercapacitor SC is less affected by the number of charge / discharge cycles and its charging speed is relatively fast, when a charging or discharging command is received, the switching circuit connected to the supercapacitor SC can be prioritized to close, meeting the energy storage needs of the device. When the device's energy demand is low, the supercapacitor SC can meet the device's power requirements, thus avoiding the battery pack's involvement in the charging and discharging process and extending the battery pack's lifespan. For scenarios requiring long-term backup power, when a charging or discharging command is received, the switching circuit connected to the battery pack BAT can be closed to meet the device's energy storage capacity requirements. Alternatively, both switching circuits can be closed, allowing both the battery pack BAT and the supercapacitor SC to participate in the device's energy storage process, thereby meeting the device's energy storage needs. Therefore, this design not only meets the energy storage needs of multiple scenarios but also helps reduce the cost of energy storage equipment because the supercapacitor SC and the battery pack BAT share a single bidirectional converter.

[0059] In practical applications, both the first and second switching circuits include multiple switching devices, all of which are electrically controlled switching devices. The controller is connected to these electrically controlled switching devices and controls their on / off states by sending voltage or current signals of corresponding levels. In practical applications, these electrically controlled switching devices can be semi-controlled or fully controlled switching devices. Depending on the type of switching device, the first and second switching circuits provided in this application embodiment can have different structural topologies. The charging and discharging processes of the supercapacitor SC and the battery pack BAT will be described in detail below, based on the circuit topologies of the first and second switching circuits.

[0060] I. First Switching Circuit

[0061] The first terminal of the first switching circuit is connected to the battery pack BAT, and the second terminal of the first switching circuit is connected to the first terminal of the bidirectional converter. When the first switching circuit is closed, it forms an electrical connection between the battery pack BAT and the bidirectional converter, thus forming the discharge and charging paths for the battery pack BAT. When the first switching circuit is open, it disconnects the electrical connection between the battery pack BAT and the bidirectional converter.

[0062] In one possible implementation, the first switching circuit includes a first switching transistor Q1 and a second switching transistor Q2. See also... Figure 2 As shown, the first terminal of the first switch Q1 is connected to the battery pack BAT, and the second terminal of the first switch Q1 is connected to the first terminal of the bidirectional converter. The first terminal of the second switch Q2 is connected to the first terminal of the bidirectional converter, and the second terminal of the second switch Q2 is connected to the battery pack BAT.

[0063] use Figure 2 The first switching circuit structure shown can be a semi-controlled switch, such as a thyristor, where the first switch Q1 and the second switch Q2 are semi-controlled switches. Since semi-controlled switches have unidirectional conductivity, the first switch Q1 and the second switch Q2 can be used as the charging path and the discharging path of the battery pack BAT, respectively. This also avoids mutual charging between the battery pack BAT and the supercapacitor SC when both the first and second switching circuits are closed.

[0064] In one possible implementation, if the electrical control device in the first switching circuit is a fully controlled switching device, see [reference needed]. Figure 3 As shown, the first switching circuit includes a first diode D1, a second diode D2, a fifth switching transistor Q5, and a sixth switching transistor Q6.

[0065] Specifically, the anode of the first diode D1 is connected to the battery pack BAT, and the cathode of the first diode D1 is connected to the first terminal of the bidirectional converter through the fifth switch Q5. The cathode of the second diode D2 is connected to the battery pack BAT, and the anode of the second diode D2 is connected to the first terminal of the bidirectional converter through the sixth switch Q6. The switching transistors in both the first and second switching circuits are fully controlled switches.

[0066] See Figure 3 The first switching circuit shown has the following characteristics: since the diode has unidirectional conductivity, the branch where the first diode D1 is located can only be used as the discharge path of the battery pack BAT, and the branch where the second diode D2 is located can only be used as the charging path of the battery pack BAT. It can also prevent mutual charging between the battery pack BAT and the supercapacitor SC when both the first and second switching circuits are closed.

[0067] It should be noted that the above structure of the first switching circuit is only an example. The first switching circuit can also use a chip with the above functions, and the first switching circuit can also include other functional devices, such as overcurrent protection devices and short-circuit protection devices. This application does not impose any further limitations here.

[0068] II. Second Switching Circuit

[0069] The first terminal of the second switching circuit is connected to the supercapacitor SC, and the second terminal of the second switching circuit is connected to the first terminal of the bidirectional converter. When the second switching circuit is closed, it forms an electrical connection between the supercapacitor SC and the bidirectional converter, thus creating a charging and discharging path for the supercapacitor SC. When the second switching circuit is open, it disconnects the electrical connection between the supercapacitor SC and the bidirectional converter.

[0070] In one possible implementation, the second switching circuit includes a third switch Q3 and a fourth switch Q4, see [link to relevant documentation]. Figure 4 As shown, the first terminal of the third switch Q3 is connected to the supercapacitor SC, and the second terminal of the third switch Q3 is connected to the first terminal of the bidirectional converter. The first terminal of the fourth switch Q4 is connected to the first terminal of the bidirectional converter, and the second terminal of the fourth switch Q4 is connected to the supercapacitor SC.

[0071] use Figure 4 The second switching circuit shown can use semi-controlled switching transistors, such as thyristors, for the third and fourth switching transistors, Q3 and Q4. Since semi-controlled switching transistors have unidirectional conductivity, Q3 and Q4 can be used as the charging and discharging paths of the supercapacitor SC, respectively. This also avoids mutual charging between the battery pack BAT and the supercapacitor SC when both the first and second switching circuits are closed.

[0072] In one possible implementation, if the electrical control device in the second switching circuit is a fully controlled switching device, see [reference needed]. Figure 5 As shown, the second switching circuit may include a third diode D3, a fourth diode D4, a seventh switch Q7, and an eighth switch Q8. The anode of the third diode D3 is connected to the supercapacitor SC, and the cathode of the third diode D3 is connected to the first terminal of the bidirectional converter through the seventh switch Q7. The cathode of the fourth diode D4 is connected to the supercapacitor SC, and the anode of the fourth diode D4 is connected to the first terminal of the bidirectional converter through the eighth switch Q8. The switching transistors in both the first and second switching circuits are fully controlled switches.

[0073] See Figure 5 The second switching circuit shown has the following characteristics: since the diode has unidirectional conductivity, the branch where the first diode D1 is located can only be used as the discharge path of the battery pack BAT, and the branch where the second diode D2 is located can only be used as the charging path of the battery pack BAT. It can also prevent mutual charging between the battery pack BAT and the supercapacitor SC when both the first and second switching circuits are closed.

[0074] It should be noted that the above-described structure of the second switching circuit is merely an example. The first switching circuit may also use a chip with the above-mentioned functions, and the second switching circuit may also include devices with other functions, such as overcurrent protection devices and short-circuit protection devices. This application does not impose any further limitations on these aspects.

[0075] In practical applications, the control terminals of the switching transistors in the first and second switching circuits are connected to the controller. The controller can send corresponding drive signals to the switching transistors in the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, as well as the power consumption of the device connected to the second terminal of the bidirectional converter, to control the state of the first and second switching circuits. The following section combines... Figures 2 to 5 The first and second switching circuit structures shown are illustrated, and the discharge and charging processes of the battery pack BAT and the supercapacitor SC are explained in detail with reference to the embodiments.

[0076] like Figure 6 As shown, a discharge process of the supercapacitor SC and the battery pack BAT is illustrated. The discharge control process of the supercapacitor SC and the battery pack BAT can be executed by the controller in the switching power supply, such as... Figure 6 As shown, the main steps include:

[0077] S601. When a discharge command is received, the second switch circuit is closed.

[0078] Specifically, the controller can send a drive signal to the switch transistor in the discharge path of the second switching circuit to drive the switch transistor in the second switching circuit to conduct, thereby controlling the second switching circuit to close. For example, for Figure 4 The second switching circuit shown can send a drive signal to the third switching transistor Q3 to turn it on. The conduction of the third switching transistor Q3 forms the discharge path of the supercapacitor SC. For Figure 5 The second switching circuit shown can send a drive signal to the seventh switch Q7 to turn on the seventh switch Q7. The turning on of the seventh switch Q7 forms the discharge path of the supercapacitor SC.

[0079] S602. When the device connected to the second end of the bidirectional converter is detected to have stopped using power, the second switching circuit is controlled to disconnect.

[0080] Specifically, in scenarios involving frequent charging and discharging in the short term, since the supercapacitor SC discharges first, the discharge operation ends before the electrical energy stored in the supercapacitor SC is completely released. This can effectively avoid starting the battery pack BAT for charging and discharging, which is beneficial to improving the service life of the battery pack BAT.

[0081] It should be noted that the above Figure 6 The discharge process of the supercapacitor SC and battery pack shown is mainly applicable to short-term frequent charge and discharge scenarios. If the switching power supply is used in a long-term backup power scenario, the supercapacitor SC has limited energy storage capacity and cannot meet the power supply requirements of the back-end connected equipment. Therefore, both the battery pack and the supercapacitor SC and the battery pack need to participate in the discharge process.

[0082] See Figure 7 The diagram illustrates a discharge process for the supercapacitor SC and the battery pack BAT in a long-term backup power scenario using a switching power supply. The discharge control process for the supercapacitor SC and the battery pack BAT can be executed by the controller in the switching power supply. Figure 7 As shown, the main steps include:

[0083] S701. When a discharge command is received, the second switch circuit is closed.

[0084] It should be noted that the closing process of the second switching circuit is described in detail above, and will not be repeated here.

[0085] S702. When the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close and the second switching circuit is controlled to open. The first preset threshold can be the discharge cutoff threshold of the supercapacitor SC. This value can be configured according to the specifications of the supercapacitor and the power consumption of the downstream equipment; this application does not impose further limitations on this.

[0086] Specifically, as the power consumption time of the equipment connected to the back end of the bidirectional converter increases, the energy stored in the supercapacitor SC gradually decreases. When the energy stored in the supercapacitor SC reaches the discharge cutoff threshold and a discharge command is still received, a drive signal can be sent to the switch in the discharge path of the first switching circuit to drive the switch in the first switching circuit to conduct, thereby controlling the first switching circuit to close and controlling the second switching circuit to open. At this time, the discharge of the supercapacitor SC is switched to the discharge of the battery pack BAT.

[0087] For practical applications, please refer to Figure 4 The first switching circuit structure shown can send a drive signal to the control terminal of the first switching transistor Q1 to drive Q1 to conduct. The conduction of the first switching transistor Q1 forms the discharge path of the battery pack BAT. Because the first switch Q1 clamps the potential at the second terminal of the third switching transistor Q3 after it conducts, the current in the circuit containing the third switching transistor Q3 becomes zero, and the third switching transistor Q3 automatically turns off, thus disconnecting the second switching circuit. For Figure 5 The first switching circuit structure shown can send a drive signal to the control terminal of the fifth switching transistor Q5 to drive the fifth switching transistor Q5 to conduct. The conduction of the fifth switching transistor Q5 forms the discharge path of the battery pack BAT. The controller stops sending drive signals to the seventh switching transistor Q7 to drive the seventh switching transistor Q7 to turn off, thereby controlling the second switching circuit to open.

[0088] like Figure 8 As shown, this is an alternative discharge process for the supercapacitor SC and the battery pack BAT in a long-term backup power scenario. The discharge process of the supercapacitor SC and the battery pack BAT is executed by the controller. Figure 8 As shown, the main steps include:

[0089] S801. When a discharge command is received, the second switch circuit is closed.

[0090] It should be noted that the closing process of the second switching circuit is described in detail above, and will not be repeated here.

[0091] S802. When the remaining capacity of the energy storage element is detected to be less than the first preset threshold, the first switch circuit is controlled to close.

[0092] Specifically, as the power consumption time of the equipment connected to the back end of the bidirectional converter increases, the energy stored in the supercapacitor SC gradually decreases. When the energy stored in the supercapacitor SC reaches the discharge cutoff threshold and a discharge command is still received, a drive signal can be sent to the switch in the discharge path of the first switching circuit to drive the switch in the first switching circuit to conduct, thereby controlling the first switching circuit to close. At this time, the discharge from the supercapacitor SC is switched to the discharge from the battery pack. As the discharge time of the battery pack increases, the voltage across the battery pack BAT gradually decreases. When the voltage across the battery pack BAT is the same as the voltage across the supercapacitor SC, the discharge from the supercapacitor SC is switched to the joint discharge of the supercapacitor SC and the battery pack BAT.

[0093] Therefore, the charging process of the battery pack BAT and the supercapacitor SC will be introduced below in conjunction with the structure of the switching power supply.

[0094] like Figure 9 As shown, this illustrates a charging process for the battery pack BAT and the supercapacitor SC, controlled by a controller in the switching power supply. Figure 9 As shown, it includes the following steps:

[0095] Step 901: When a charging command is received, if the remaining capacity of the energy storage element is less than the second preset threshold and the remaining capacity of the battery pack is less than the third preset threshold, control the second switch circuit to close.

[0096] The second preset threshold can be the remaining capacity of the supercapacitor SC after it has been fully charged, and the third preset threshold can be the remaining capacity of the battery pack BAT after it has been fully charged. The specific values ​​of the second and third preset thresholds can be configured according to the models of the supercapacitor SC and the battery pack BAT, which will not be discussed in detail here.

[0097] Specifically, for long-term backup power supply scenarios, the discharge process of the supercapacitor SC and the battery pack BAT can be found in [reference needed]. Figures 6 to 8 As shown, since both the supercapacitor SC and the battery pack BAT participate in the discharge operation, the remaining capacity of both the supercapacitor SC and the battery pack BAT is lower than the remaining capacity when fully charged. Both the supercapacitor SC and the battery pack BAT need to be charged. Since the service life of the supercapacitor SC is less affected by the number of charge and discharge cycles, the second switch circuit connected to the supercapacitor SC can be closed first to charge the supercapacitor SC.

[0098] Step 902: When it is determined that the energy storage element has finished charging, control the second switch circuit to open and control the first switch circuit to close.

[0099] Step 903: When it is determined that the battery pack is fully charged, the first switch circuit is turned off.

[0100] See Figure 10 As shown, a charging process for the battery pack BAT and the supercapacitor SC is executed by the controller in the switching power supply, such as... Figure 10 As shown, it includes the following steps:

[0101] Step 1001: When a charging command is received, if the remaining capacity of the energy storage element is less than the second preset threshold and the remaining capacity of the battery pack is equal to the third preset threshold, control the second switch circuit to close.

[0102] Specifically, for scenarios involving short-term, frequent charge-discharge cycles, the discharge process of the supercapacitor (SC) and the battery pack (BAT) can be found in [reference needed]. Figures 6 to 8 As shown, since the equipment connected to the back end of the bidirectional converter has stopped using power before the electrical energy stored in the supercapacitor SC is completely released, only the remaining capacity of the supercapacitor SC is lower than the remaining capacity value required for full charge. That is, only the supercapacitor SC needs to be charged. Therefore, the second switch circuit connected to the supercapacitor SC can be closed to charge the supercapacitor SC.

[0103] Step 1002: When it is determined that the energy storage element has finished charging, the second switch circuit is turned off.

[0104] In practical applications, for bidirectional converters requiring port capacitors with relatively small capacitance values, to avoid affecting the normal charging and discharging of the battery pack (BAT) and supercapacitor (SC), the port capacitors can be configured across the battery pack (BAT) and supercapacitor (SC). For example, see [reference needed]. Figure 11 As shown, the switching power supply provided in this application embodiment also includes a first capacitor C1 connected in parallel with the battery pack BAT and a second capacitor C2 connected in parallel with the supercapacitor SC.

[0105] It should be noted that, Figure 11 The circuit topology shown is adopted Figure 4 The first and second switching circuits shown are one circuit topology of a switching power supply. Depending on the types of devices in the first and second switching circuits, the switching power supply may have other circuit topologies, which will not be described in detail here.

[0106] In practical applications, all components of the switching power supply can be integrated into a single cabinet. The cabinet is equipped with power interfaces for connecting the battery pack (BAT) and the supercapacitor (SC). The supercapacitor (SC) and battery pack (BAT) can connect to the switching power supply through these power interfaces. The cabinet may also include other interfaces, allowing other components within the same device to connect to the switching power supply.

[0107] In one embodiment, multiple devices in a switching power supply may be located on the same printed circuit board (PCB). If multiple devices in a switching power supply are located on different PCBs, then multiple PCBs are provided with connectors, and the multiple devices in the switching power supply can be connected through these connectors.

[0108] Based on the above description, this application also provides an energy storage device that can be integrated into equipment requiring energy storage functions, such as UPS and new energy power generation systems. The energy storage device may include a battery pack (BAT), a supercapacitor (SC), and the aforementioned switching power supply. Details regarding the internal structure of the switching power supply and its relationship with the supercapacitor (SC) and battery pack (BAT) can be found in the foregoing description and will not be repeated here.

[0109] Based on the above embodiments and the same concept, this application also provides a computer-readable storage medium storing a computer-readable program. When the computer-readable program is run on a computer, it causes the computer to execute the method steps applied to the controller provided in the above embodiments.

[0110] The methods provided in this application can be implemented, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, they can be implemented, in whole or in part, in the form of a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of the present invention is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. A computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. Available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs), or semiconductor media (e.g., SSDs), etc.

[0111] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0112] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0113] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0114] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A switching power supply, characterized in that, include: The system comprises a first switching circuit, a second switching circuit, a bidirectional converter, and a controller. The first terminal of the first switching circuit is used to connect to the battery pack, and the second terminal of the first switching circuit is connected to the first terminal of the bidirectional converter. The first terminal of the second switching circuit is used to connect to the energy storage element, and the second terminal of the second switching circuit is connected to the first terminal of the bidirectional converter. The second end of the bidirectional converter is used to connect to a load or a power source, and is used to convert the electrical energy obtained from the first end of the bidirectional converter to power the connected equipment, or to convert the electrical energy obtained from the second end of the bidirectional converter to charge the energy storage element or the battery pack. The controller is connected to the first switching circuit and the second switching circuit respectively, and is used to control the state of the first switching circuit and the second switching circuit according to the charging command, the discharging command, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second end of the bidirectional converter.

2. The switching power supply according to claim 1, characterized in that, The controller is specifically used for: When a discharge command is received, the second switching circuit is controlled to close. When the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close and the second switching circuit is controlled to open.

3. The switching power supply according to claim 1, characterized in that, The controller is specifically used for: When a discharge command is received, the second switching circuit is controlled to close. When the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close.

4. The switching power supply according to claim 1, characterized in that, The controller is specifically used for: Upon receiving a discharge command, the second switching circuit is controlled to close. When the device connected to the second end of the bidirectional converter is detected to have stopped using power, the second switching circuit is controlled to disconnect.

5. The switching power supply according to any one of claims 2 to 4, characterized in that, The controller is specifically used for: When a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is less than a third preset threshold, the second switch circuit is controlled to close. When it is determined that the energy storage element is fully charged, the second switching circuit is controlled to open and the first switching circuit is controlled to close. When it is determined that the battery pack is fully charged, the first switching circuit is turned off.

6. The switching power supply according to any one of claims 2 to 4, characterized in that, The controller is specifically used for: When a charging command is received, if the remaining capacity of the energy storage element is less than the second preset threshold and the remaining capacity of the battery pack is equal to the third preset threshold, the second switch circuit is controlled to close. When the energy storage element is determined to be fully charged, the second switching circuit is controlled to disconnect.

7. The switching power supply according to claim 1, characterized in that, The first switching circuit includes a first switching transistor and a second switching transistor, and the second switching circuit includes a third switching transistor and a fourth switching transistor; The first end of the first switching transistor is used to connect to the battery pack, and the second end of the first switching transistor is connected to the first end of the bidirectional converter. The first end of the second switching transistor is used to connect to the first end of the bidirectional converter, and the second end of the second switching transistor is used to connect to the battery pack. The first end of the third switching transistor is used to connect to the energy storage element, and the second end of the third switching transistor is connected to the first end of the bidirectional converter; The first end of the fourth switching transistor is used to connect to the first end of the bidirectional converter, and the second end of the fourth switching transistor is used to connect to the energy storage element. In this circuit, the switching transistors of the first and second switching circuits are semi-controlled switching transistors.

8. The switching power supply according to claim 1, characterized in that, The first switching circuit includes a first diode, a second diode, a fifth switching transistor, and a sixth switching transistor; the second switching circuit includes a third diode, a fourth diode, a seventh switching transistor, and an eighth switching transistor. The anode of the first diode is used to connect to the battery pack, and the cathode of the first diode is connected to the first end of the bidirectional converter through the fifth switching transistor; The cathode of the second diode is connected to the battery pack, and the anode of the second diode is connected to the first terminal of the bidirectional converter through the sixth switching transistor. The anode of the third diode is used to connect to the energy storage element, and the cathode of the third diode is connected to the first end of the bidirectional converter through the seventh switch. The cathode of the fourth diode is connected to the energy storage element, and the anode of the fourth diode is connected to the first end of the bidirectional converter through the eighth switching transistor. In this circuit, the switching transistors of the first and second switching circuits are fully controlled switching transistors.

9. An energy storage device, characterized in that, include: Battery pack, energy storage element, and switching power supply as described in any one of claims 1 to 8.

10. A charging and discharging control method, characterized in that, Applied to the switching power supply as described in any one of claims 1 to 8, the method comprises: Detect the remaining capacity of the energy storage element and the battery pack; The states of the first switching circuit and the second switching circuit are controlled according to the charging command, the discharging command, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, as well as the power consumption of the device connected to the second end of the bidirectional converter.

11. The method according to claim 10, characterized in that, The step of controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes: When a discharge command is received, the second switching circuit is controlled to close. When the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close and the second switching circuit is controlled to open.

12. The method according to claim 10, characterized in that, The step of controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes: When a discharge command is received, the second switching circuit is controlled to close. When the remaining capacity of the energy storage element is detected to be less than a first preset threshold, the first switching circuit is controlled to close.

13. The method according to claim 10, characterized in that, The step of controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes: Upon receiving a discharge command, the second switching circuit is controlled to close. When it is detected that the device connected to the second end of the bidirectional converter has stopped using power, the second switching circuit is controlled to disconnect.

14. The method according to claim 10, characterized in that, The step of controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes: When a charging command is received, if the remaining capacity of the energy storage element is less than a second preset threshold and the remaining capacity of the battery pack is less than a third preset threshold, the second switch circuit is controlled to close. When it is determined that the energy storage element is fully charged, the second switching circuit is controlled to open and the first switching circuit is controlled to close. When it is determined that the battery pack is fully charged, the first switching circuit is turned off.

15. The method according to claim 10, characterized in that, The step of controlling the states of the first and second switching circuits based on charging commands, discharging commands, the remaining capacity of the energy storage element and the remaining capacity of the battery pack, and the power consumption of the device connected to the second terminal of the bidirectional converter includes: When a charging command is received, if the remaining capacity of the energy storage element is less than the second preset threshold and the remaining capacity of the battery pack is equal to the third preset threshold, the second switch circuit is controlled to close. When the energy storage element is determined to be fully charged, the second switching circuit is controlled to disconnect.

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