Bidirectional conversion circuit and energy storage power supply
By employing a transformer conversion component with variable inductance in the bidirectional power supply and adjusting the inductance using a control unit, the power consumption problem of the bidirectional power supply during forward and reverse operation is solved, achieving high-efficiency optimization in different operating modes.
Patent Information
- Application Number
- CN202423264097.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-12-16
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Existing bidirectional power supplies cannot meet power consumption design requirements when operating in both forward and reverse directions, and the power consumption is fixed and cannot be adjusted.
A transformer conversion component with variable inductance is used. The inductance is adjusted by the control unit during forward and reverse operation to reduce the excitation current or voltage and reduce conduction and shutdown losses.
It achieves optimized power consumption during forward and reverse operation, reduces conduction and shutdown losses, and improves overall efficiency.
Smart Images
Figure CN223680948U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of power supply, in particular to a bidirectional conversion circuit and an energy storage power supply. BACKGROUND
[0002] The bidirectional power supply can perform bidirectional power transmission. In forward operation, the bidirectional power supply can convert larger alternating current into smaller direct current to charge an energy storage battery. In reverse operation, the bidirectional power supply can convert the electrical energy stored in the energy storage battery into larger alternating current to supply power to an electrical device.
[0003] However, the bidirectional power supply currently shares one transformer in forward and reverse operation, and the power consumption is fixed, which cannot meet the power consumption design requirements in forward and reverse operation. CONTENT OF THE UTILITY MODEL
[0004] The present application provides a bidirectional conversion circuit and an energy storage power supply to solve the problems in the prior art.
[0005] The technical solutions adopted by the embodiments of the present application are as follows:
[0006] In a first aspect, the embodiments of the present application provide a bidirectional conversion circuit, comprising: a first switch driving circuit, a second switch driving circuit, a resonant network and a transformer conversion component; wherein a first end of the first switch driving circuit is used for inputting or outputting a first direct current voltage;
[0007] A second end of the first switch driving circuit is connected to a primary side coil of the transformer conversion component through the resonant network, a secondary side coil of the transformer conversion component is connected to a first end of the second switch driving circuit, a second end of the second switch driving circuit is used for connecting an energy storage battery and outputting or inputting a second direct current voltage, and the first direct current voltage is greater than the second direct current voltage;
[0008] A control end of the first switch driving circuit and a control end of the second switch driving circuit are used for connecting a control unit, and a control end of the transformer conversion component is also used for connecting the control unit to change inductance under the control of the control unit.
[0009] In an embodiment, the transformer conversion component comprises: a first inductor, a switch unit and a transformer.
[0010] The first inductor and the switch unit are connected in series and then connected in parallel with the primary side coil of the transformer, a control end of the switch unit is the control end of the transformer conversion component and is used for connecting the control unit, and a first inductance of the first inductor is less than a second inductance of the primary side coil of the transformer.
[0011] In an embodiment, the transformer is a transformer without an open air gap.
[0012] In an embodiment, the first switch driving circuit and the second switch driving circuit are both half-bridge resonant networks.
[0013] In an embodiment, the first switch driving circuit comprises: a first switch tube and a second switch tube, a first end of the first switch tube and a second end of the second switch tube are respectively connected to a positive power supply end and a negative power supply end of the first direct current voltage;
[0014] A connection point of a second end of the first switch tube and a first end of the second switch tube is connected to a first positive connection end of the resonant network, a second end of the second switch tube is further connected to a first negative connection end of the resonant network, and a second positive connection end and a second negative connection end of the resonant network are respectively connected to two connection ends of a primary side coil of the transformer conversion component.
[0015] In an embodiment, the resonant network comprises: a second inductor and a first capacitor, one end of the second inductor is the first positive connection end of the resonant network, and is used for connecting the connection point, and one end of the first capacitor is the first negative connection end of the resonant network, and is used for connecting the second end of the second switch tube;
[0016] The other end of the second inductor is the second positive connection end of the resonant network, and the other end of the first capacitor is the second negative connection end of the resonant network, and is respectively connected to the two connection ends of the primary side coil of the transformer conversion component.
[0017] In an embodiment, the second switch driving circuit comprises: a third switch tube and a fourth switch tube, a first end of the third switch tube and a first end of the fourth switch tube are respectively connected to two connection ends of a secondary side coil of the transformer conversion component;
[0018] A second end of the third switch tube and a second end of the fourth switch tube are connected in parallel and grounded.
[0019] In an embodiment, a first end of the first switch tube is connected to a second end of the second switch tube through a second capacitor, and the second end of the second switch tube is grounded.
[0020] In an embodiment, a middle point of the secondary side coil of the transformer conversion component is further grounded through a third capacitor.
[0021] In a second aspect, the embodiments of the present application provide an energy storage power supply, comprising: the bidirectional conversion circuit, the energy storage battery and the control unit in the above embodiments.
[0022] The control unit is connected to the bidirectional conversion circuit, one end of the bidirectional conversion circuit is connected to a preset power grid transformer through a rectifier circuit and is connected to a high-voltage electrical equipment through an inverter circuit, and the other end of the bidirectional conversion circuit is connected to the energy storage battery.
[0023] The application has the beneficial effect that the bidirectional conversion circuit provided by the application has variable inductance of the voltage conversion component, and in forward operation, the inductance can be reduced to increase the excitation current, enable the first switch driving circuit to be turned on at zero voltage, and reduce the turn-on loss; in reverse operation, the inductance can be increased to reduce the excitation current, enable the second switch driving circuit to be turned off at zero current, and reduce the turn-off loss. The bidirectional conversion circuit of the application meets the power consumption requirements of forward operation and reverse operation. BRIEF DESCRIPTION OF DRAWINGS
[0024] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced below, and it should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.
[0025] Figure 1 One of the structural schematic diagrams of the bidirectional conversion circuit provided by the embodiments of the application;
[0026] Figure 2 The second structural schematic diagram of the bidirectional conversion circuit provided by the embodiments of the application;
[0027] Figure 3 The working principle schematic diagram of the first switch driving circuit in forward operation;
[0028] Figure 4 The third structural schematic diagram of the bidirectional conversion circuit provided by the embodiments of the application;
[0029] Figure 5 The working principle schematic diagram of the third switch tube in reverse operation;
[0030] Figure 6 The structural schematic diagram of the energy storage power supply provided by the embodiments of the application.
[0031] Explanation of reference numerals: 1, first switch driving circuit; 2, resonant network; 3, voltage conversion component; 4, second switch driving circuit. DETAILED DESCRIPTION
[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application but not all the embodiments of the present application.
[0033] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative work based on the embodiments in the present application are within the scope of protection of the present application.
[0034] In the description of the present application, it should be noted that if the terms "upper", "lower", etc. indicate the orientation or position relationship shown in the drawings, or the orientation or position relationship when the product of the present application is used, only for the convenience of describing the present application and simplifying the description, and it does not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0035] In addition, the terms "first", "second", etc. in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or modules does not have to be limited to those steps or modules clearly listed, but can include other steps or modules not clearly listed or inherent to these processes, methods, products or devices.
[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "set", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0037] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.
[0038] The following will specifically illustrate the bidirectional conversion circuit provided by the present application through a plurality of examples in combination with the drawings.
[0039] Figure 1 A structure diagram of a bidirectional conversion circuit provided by an embodiment of the present application is shown in FIG. 1. The bidirectional conversion circuit includes a first switch driving circuit 1, a resonance network 2, a voltage conversion component 3, and a second switch driving circuit 4. Figure 1
[0040] The first end of the first switch driving circuit is used for inputting or outputting a first direct current voltage. The second end of the first switch driving circuit is connected to a primary side coil of the voltage conversion component through the resonance network. The secondary side coil of the voltage conversion component is connected to the first end of the second switch driving circuit. The second end of the second switch driving circuit is used for connecting an energy storage battery and outputting or inputting a second direct current voltage.
[0041] The voltage conversion component is used for realizing voltage conversion, so that the first direct current voltage is greater than the second direct current voltage, that is, the primary side voltage of the voltage conversion component is greater than the secondary side voltage. The control end of the first switch driving circuit and the control end of the second switch driving circuit are used for connecting a control unit (not shown in the figure). The control unit can control the on-off of the first switch driving circuit and the second switch driving circuit. The control end of the voltage conversion component is also used for connecting the control unit, so as to change the inductance under the control of the control unit. The control unit can be a central processing unit (CPU) for example.
[0042] Specifically, when the bidirectional conversion circuit works in the forward direction, the first end of the first switch driving circuit is used for inputting the first direct current voltage. Then, the first direct current voltage passes through the first switch driving circuit, the resonance network, and the voltage conversion component in sequence, is converted into the second direct current voltage by the voltage conversion component, and is output to the energy storage battery through the second switch driving circuit, so as to charge the energy storage battery and realize energy storage of the energy storage battery. When the bidirectional conversion circuit works in the reverse direction, the energy storage battery inputs the second direct current voltage to the second end of the second switch driving circuit. Then, the second direct current voltage is converted into the first direct current voltage by the voltage conversion component, and is output to the high-voltage electrical equipment through the resonance network and the first switch driving circuit in sequence, so as to realize power supply of the high-voltage electrical equipment.
[0043] Wherein, the working frequency of the bidirectional conversion circuit is determined by the resonance network whether working forwardly or reversely; the first direct current voltage in forward working is derived from the preset power grid transformer, the preset power grid transformer outputs 220V alternating current, then converted into 400V direct current (i.e. the first direct current voltage) through the rectifier circuit, input to the first switch driving circuit, and then converted into 12V direct current (i.e. the second direct current voltage) through the voltage conversion component, input to the second switch driving circuit. Contrary to the forward working, the second direct current voltage in reverse working is derived from the energy storage battery, the energy storage battery outputs 12V direct current to the second switch driving circuit, then converted into 400V direct current through the voltage conversion component, and then converted into 220V alternating current through the inverter circuit to supply power to the high-voltage electrical equipment.
[0044] And, in forward working, the control end of the voltage conversion component changes the inductance to a smaller value under the control of the control unit to increase the excitation current, so that the first switch driving circuit is zero-voltage on, reduces the on-loss, and improves the efficiency in forward working; in reverse working, the control end of the voltage conversion component changes the inductance to a larger value under the control of the control unit to reduce the excitation current, so that the second switch driving circuit is zero-current off, reduces the off-loss, and improves the efficiency in reverse working.
[0045] In summary, the bidirectional conversion circuit provided by the application can reduce the inductance in forward working to increase the excitation current, so that the first switch driving circuit is zero-voltage on and the on-loss is reduced; and can increase the inductance in reverse working to reduce the excitation current, so that the second switch driving circuit is zero-current off and the off-loss is reduced. The bidirectional conversion circuit of the application takes into account the power consumption requirements of forward working and reverse working.
[0046] Figure 2 The second structural diagram of the bidirectional conversion circuit provided by the embodiment of the application is shown in FIG. 2, which shows that the voltage conversion component includes a first inductor L1, a switch unit K, and a transformer T. Figure 2
[0047] The first inductor L1 and the switch unit K are connected in series and then connected in parallel with the primary side coil of the transformer T, and the control end of the switch unit K, i.e. the control end of the voltage conversion component, is used to connect the control unit, and the control unit changes the inductance of the voltage conversion component by controlling the on-off of the switch unit K.
[0048] Specifically, the first inductance of the first inductor L1 is smaller than the second inductance of the primary side coil of the transformer, and the transformer is a transformer without opening air gap. When the first switch K is closed in forward operation, the first inductor L1 is connected in parallel with the primary side coil of the transformer. Since the first inductance of the first inductor L1 is smaller than the second inductance of the primary side coil of the transformer, the excitation current is large at this time, and the first switch driving circuit can be turned on at zero voltage; when the first switch is opened in reverse operation, since the transformer is a transformer without opening air gap, the inductance of the transformer without opening air gap is large, the excitation current is small at this time, and the second switch driving circuit can be turned off at zero current.
[0049] In an embodiment, the first switch driving circuit and the second switch driving circuit are both half-bridge resonant networks. The half-bridge resonant network can make the current flowing through the switch tube and the voltage drop across the switch tube be quasi-sine wave. By using certain control technology, the switching of the switch tube at the zero crossing of the current or voltage waveform can be realized, which has great benefits for reducing the size of the power supply, increasing the control ability of the power supply, improving the switching speed, and improving the ripple.
[0050] Specifically, as shown in Figure 2 The first switch driving circuit includes: a first switch tube D1 and a second switch tube D2, and the first end of the first switch tube D1 and the second end of the second switch tube D2 are respectively used to connect the positive power supply end and the negative power supply end of the first direct current voltage. The first end of the first switch tube D1 is also connected to the second end of the second switch tube D2 through a second capacitor C2, the second end of the second switch tube D2 is grounded, and the two ends of the second capacitor C2 are the positive power supply end and the negative power supply end of the first direct current voltage.
[0051] The series connection point of the second end of the first switch tube D1 and the first end of the second switch tube D2 is connected to the first positive connection end of the resonant network, and the second end of the second switch tube D2 is also connected to the first negative connection end of the resonant network. The second positive connection end and the second negative connection end of the resonant network are respectively connected to the two connection ends of the primary side coil of the transformer.
[0052] The resonant network includes a second inductor L2 and a first capacitor C1. One end of the second inductor L2 is the first positive connection end of the resonant network, used to connect the series connection point of the second end of the first switch tube D1 and the first end of the second switch tube D2. One end of the first capacitor C1 is the first negative connection end of the resonant network, used to connect the second end of the second switch tube D2.
[0053] The other end of the second inductor L2 is a second positive connection terminal of the resonance network, and the other end of the first capacitor C1 is a second negative connection terminal of the resonance network, which are respectively used for connecting two connection terminals of the primary side coil of the voltage conversion component. The working frequency F (unit: Hz) of the bidirectional conversion circuit is determined by the resonance network, F = 1 / (2Π(√LC)), wherein L is the inductance of the second inductor L2, and C is the capacitance of the first capacitor C1.
[0054] With reference to the accompanying drawings Figure 2 , the second switch driving circuit comprises a third switch tube D3 and a fourth switch tube D4, the first ends of the third switch tube D3 and the fourth switch tube D4 are respectively connected to two connection terminals of the secondary side coil of the voltage conversion component; the second ends of the third switch tube D3 and the fourth switch tube D4 are connected in parallel and grounded, the middle point of the secondary side coil of the voltage conversion component is also grounded through the third capacitor C3, and the two ends of the third switch tube D3 are respectively used for connecting the positive electrode and the negative electrode of the energy storage battery.
[0055] The working principle of the bidirectional conversion circuit will be described below Figure 2 .
[0056] Figure 3 The working principle of the first switch driving circuit in the forward working state is shown in FIG. 1. Figure 3 In the forward working state, the switch tubes D1 and D2 are alternately turned on at a frequency F = 1 / (2Π(√LC)), such as 87 kHz. Since the voltage is very high (for example, 400 V DC voltage) when the switch tube is turned off, that is, when the switch tube D1 or D2 is turned off, the voltage between the two terminals is 400 V. Taking the case that the switch tube D1 is in the stage of being turned off to being turned on as an example, if the voltage between the two terminals of D1 directly changes from 400 V to 0 V to be turned on, the power consumption in the conduction process (400 V-0)*△I (△I is the current flowing through D1 from being turned off to being turned on) is very large. The magnetizing current Ilm = 400 V / (2*Lm1) (Lm1 is the inductance of the voltage conversion component in the forward working state) discharges the junction capacitor C11 of the switch tube D3 to 0 V before D2 is turned off and D1 is turned on (dead zone), and charges the junction capacitor of the switch tube D2 to 400 V. At this time, D1 is turned on again, which realizes zero-voltage conduction, and the conduction loss of D1 becomes 0 V*△I = 0.
[0057] In this process, the magnetizing current Ilm cannot be too small, so the inductance Lm1 of the voltage conversion component needs to be kept small. Therefore, in the forward working state, the switch unit K is closed, and the first inductor L1 is connected in parallel with the primary side coil of the transformer T to reduce the inductance of the voltage conversion component. The switch tube D2 is the same, and will not be described here.
[0058] Figure 4 The third structural diagram of the bidirectional conversion circuit provided in the embodiment of the present application is shown in FIG. 3.Figure 5 This is a schematic diagram illustrating the working principle of the third switching transistor during reverse operation, as shown below. Figure 4 and Figure 5 As shown, during the reverse process, switching transistors D3 and D4 alternately conduct at a frequency F = 1 / (2π(√LC)), for example, 87kHz. Because the voltage of the secondary winding of the transformer is low during the reverse process, for example, 12V, the secondary current will be very large. If the power of the energy storage battery is 400W, the turn-off current of D3 and D4 is the secondary input current plus the magnetizing current Ils. Due to LC resonance in the primary resonant network, ideally the secondary input current is 0, but the magnetizing current Ils = 12V*n 2 / Lm2, (where n is the ratio of the number of primary windings to the number of secondary windings of the transformer, and Lm2 is the inductance of the transformer conversion component when working in reverse). If the switching transistor D3 is in the stage of conduction to turn-off at this time, the current flowing through D3 is Ils, then the power consumption during the conduction process is Ils*ΔV (ΔV is the voltage that D3 withstands from conduction to turn-off. Since the secondary voltage is only 12V, ΔV=2*12V=24V is relatively small). If the power consumption is to be small, the excitation current Ils cannot be too large at this time. Therefore, Lm2 must maintain a large inductance. The inductance of the transformer without the air gap will be very large. The large inductance brings a small excitation current, so that D3 is close to zero current turn-off when it is turned off.
[0059] Although a smaller excitation is not conducive to zero-voltage turn-on of switch D3 (the principle is the same as that of switch D1 during forward operation), the turn-on loss of D3 is actually much smaller than the turn-off loss because the secondary voltage is generally smaller. Even if zero-voltage turn-on of D3 is sacrificed, it still greatly helps the overall loss. The same applies to switch D4, so it will not be elaborated here.
[0060] It should also be noted that the second switch drive unit is also working during forward operation, serving as a rectifier; similarly, the first switch drive unit serves as a rectifier during reverse operation.
[0061] Based on the bidirectional conversion circuit provided in the above embodiments, such as Figure 6 As shown, this application also provides an energy storage power supply, including a bidirectional conversion circuit, an energy storage battery, and a control unit according to any of the above embodiments.
[0062] The control unit is connected to the bidirectional conversion circuit, which can control the on / off state of multiple switching transistors and / or switching units in the bidirectional conversion circuit. One end of the bidirectional conversion circuit is used to connect to a preset grid transformer through a rectifier circuit and to connect to high-voltage electrical equipment through an inverter circuit. The other end of the bidirectional conversion circuit is connected to an energy storage battery.
[0063] When the bidirectional conversion circuit works forwardly, the rectifier circuit converts 220V AC power outputted by the preset power grid transformer into 400V DC high voltage power, and then the voltage conversion component in the bidirectional conversion circuit can reduce the 400V DC high voltage power to 12V DC power to supply the energy storage battery, so as to realize energy storage of the energy storage battery; when the bidirectional conversion circuit works reversely, the energy storage battery outputs 12V DC power, and then the voltage conversion component in the bidirectional conversion circuit can increase the 12V DC power to 400V DC power, and the 400V DC power is converted into 220V AC power by the inverter circuit to supply the high-voltage electrical equipment.
[0064] The energy storage power supply is generally 500W-10KW high power, and its characteristics are that the primary side of the voltage conversion component has high voltage and low current, and the secondary side has low voltage and high current, for example, in the 4.8kW energy storage power supply, the average current of the primary side is 4.8kW / 400V=10.2A, and the average current of the secondary side is 4.8kW / 12V=400A. Therefore, the loss of the primary side is mainly the turn-on loss, and the voltage across the switch tubes D1 and D2 decreases from high voltage to 0 during the turn-on process, so the loss is large, and zero voltage turn-on is very important; on the contrary, the loss of the secondary side is mainly the turn-off loss, and the current flowing through the switch tubes D3 and D4 changes from large current to 0 during the turn-off process, so the loss is large, and zero current turn-off is very important. The controllable inductance transformer conversion component can realize the effect of zero voltage turn-on of the switch tubes D1 and D2 when working forwardly and zero current turn-off of the switch tubes D3 and D4 when working reversely.
[0065] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical range disclosed by the present application can be easily thought by those skilled in the art, and should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A bidirectional conversion circuit, characterized by, The application relates to a switching power supply device. The switching power supply device comprises a first switch driving circuit, a second switch driving circuit, a resonance network and a voltage conversion component; wherein a first end of the first switch driving circuit is used for inputting or outputting a first direct current voltage; a second end of the first switch driving circuit is connected with a primary side coil of the voltage conversion component through the resonance network, a secondary side coil of the voltage conversion component is connected with a first end of the second switch driving circuit, a second end of the second switch driving circuit is used for connecting an energy storage battery and is used for outputting or inputting a second direct current voltage, the first direct current voltage is greater than the second direct current voltage; a control end of the first switch driving circuit and a control end of the second switch driving circuit are used for connecting a control unit, and a control end of the voltage conversion component is also used for connecting the control unit, so that the inductance is changed under the control of the control unit.
2. The bidirectional conversion circuit of claim 1, wherein, The voltage conversion component comprises a first inductor, a switch unit and a transformer; the first inductor and the switch unit are connected in series and are connected in parallel with the primary side coil of the transformer, a control end of the switch unit is the control end of the voltage conversion component and is used for connecting the control unit, and a first inductance of the first inductor is smaller than a second inductance of the primary side coil of the transformer.
3. The bidirectional conversion circuit of claim 2, wherein, The transformer is a transformer without an opened air gap.
4. The bidirectional conversion circuit of claim 1, wherein, The first switch driving circuit and the second switch driving circuit are both half-bridge resonance networks.
5. The bidirectional conversion circuit of claim 4, wherein, The first switch driving circuit comprises a first switch tube and a second switch tube, a first end of the first switch tube and a second end of the second switch tube are respectively used for connecting a positive power supply end and a negative power supply end of the first direct current voltage; a connection point of a second end of the first switch tube and a first end of the second switch tube is connected with a first positive connection end of the resonance network, a second end of the second switch tube is also connected with a first negative connection end of the resonance network, and a second positive connection end and a second negative connection end of the resonance network are respectively connected with two connection ends of the primary side coil of the voltage conversion component.
6. The bidirectional conversion circuit of claim 5, wherein, The resonance network comprises a second inductor and a first capacitor, one end of the second inductor is the first positive connection end of the resonance network and is used for connecting the connection point, one end of the first capacitor is the first negative connection end of the resonance network and is used for connecting the second end of the second switch tube; the other end of the second inductor is the second positive connection end of the resonance network, and the other end of the first capacitor is the second negative connection end of the resonance network and is respectively connected with the two connection ends of the primary side coil of the voltage conversion component.
7. The bidirectional conversion circuit of claim 4, wherein, The second switch driving circuit comprises a third switch tube and a fourth switch tube, a first end of the third switch tube and a first end of the fourth switch tube are respectively connected with the two connection ends of the secondary side coil of the voltage conversion component; a second end of the third switch tube and a second end of the fourth switch tube are connected in parallel and are grounded.
8. The bidirectional conversion circuit of claim 5, wherein, A first end of the first switch tube is connected with a second end of the second switch tube through a second capacitor, and the second end of the second switch tube is grounded.
9. The bidirectional conversion circuit of claim 7, wherein, A middle point of the secondary side coil of the voltage conversion component is also connected with the ground through a third capacitor.
10. An energy storage power supply, characterized by, The application relates to a switching power supply device. The bidirectional conversion circuit, the energy storage battery and the control unit according to any one of claims 1-9; The control unit is connected to the bidirectional conversion circuit, one end of the bidirectional conversion circuit is used for connecting a preset power grid transformer through a rectifier circuit and is used for connecting a high-voltage electrical equipment through an inverter circuit, and the other end of the bidirectional conversion circuit is connected to the energy storage battery.