Resonance circuit, power supply module and V2G charging equipment

Abstract

The invention discloses a resonance circuit, a power supply module and V2G charging equipment, and relates to the field of charge and discharge control, the resonance circuit is applied to a bidirectional DC-DC conversion circuit of the power supply module, when a power grid charges an electric load through the power supply module, parallel resonance is formed between a first inductor and a first capacitor, and between a second inductor and a second capacitor; the influence of electricity load change on the circuit stability is reduced, and the circuit stability is improved; when the electric load discharges to the power grid through the power supply module, series resonance is formed between the first inductor and the first capacitor and between the second inductor and the second capacitor, the frequency stability is high, the harmonic content of grid-connected current is low, and the quality of electric energy fed back to the power grid is high. According to the scheme, automatic switching between series resonance and parallel resonance can be achieved according to the current charging and discharging state, and bidirectional energy transmission between the electricity load and the power grid can be better achieved.

Description

Technical Field

[0001] The present invention relates to the field of charge and discharge control technology, and in particular to a resonant circuit, a power module and a V2G charging device. Background Art

[0002] With the large-scale promotion and application of electric vehicles, the demand for electricity load is increasing. In order to adapt to this trend and change, V2G (Vehicle to Grid) technology has been applied. That is, electric vehicles in a parked state are used as mobile energy storage devices to respond on the demand side of the grid, provide emergency power supply and maintain grid stability, and ultimately achieve two-way charging and discharging between electric vehicles and the grid.

[0003] Specifically, in order to achieve two-way interaction between electric vehicles and the power grid, and to use the energy storage of electric vehicles as a supplement to the power grid and renewable energy, a module that can achieve two-way energy transfer between electric vehicles and the power grid is needed, that is, a power module using V2G technology, which can draw electricity from the power grid to charge electric vehicles, and can also draw electricity from electric vehicles and transmit it to the power grid to relieve the pressure on the power grid. At present, the power module using V2G technology consists of two parts, namely the grid-side conversion circuit part and the bidirectional DC-DC conversion circuit (Direct Converter-Direct Converter, DC-DC) part, to achieve two-way energy flow. However, in actual applications, it is found that the poor quality of the power transmitted by electric vehicles to the power grid will pollute the power grid and have an adverse impact on the power grid. Therefore, it is necessary to improve the quality of the power connected to the power grid; in addition, when the power grid charges electric vehicles, it is necessary to reduce the impact of load changes such as electric vehicles on the power grid.

[0004] Therefore, how to provide an effective solution to better realize the two-way energy transfer between electric vehicles and the power grid is an urgent problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a resonant circuit, a power module and a V2G charging device, which can automatically switch between series resonance and parallel resonance according to the current charging and discharging status, thereby better realizing the two-way energy transfer between the power load and the power grid.

[0006] To solve the above technical problems, the present application provides a resonant circuit, which is applied to a power supply module. The power supply module includes a control module and a grid-side conversion circuit and a bidirectional DC-DC conversion circuit connected in sequence; the bidirectional DC-DC conversion circuit includes a first conversion circuit, a transformer, and a second conversion circuit connected in sequence; the resonant circuit includes a first inductor, a first capacitor, a second inductor, a second capacitor, and a first switch module, a second switch module, a third switch module, and a fourth switch module, all of which have control ends connected to the control module;

[0007] One end of the first inductor is connected to the midpoint of the first bridge arm in the first conversion circuit, and the other end is connected to the second end of the first switch module and one end of the first winding of the transformer respectively;

[0008] The third end of the first switch module is connected to the midpoint of the second bridge arm of the first conversion circuit, and the first end of the first switch module is connected to one end of the first capacitor, so that when the grid charges the electrical load through the power module, the first end of the first switch module is electrically connected to the second end of the first switch module; when the electrical load discharges to the grid through the power module, the first end of the first switch module is electrically connected to the third end of the first switch module;

[0009] A first end of the second switch module is connected to the midpoint of the second bridge arm, and a second end of the second switch module is connected to the other end of the first capacitor and the other end of the first winding, and is configured to be turned on when charging the electrical load and turned off when discharging to the power grid;

[0010] One end of the second inductor is connected to the midpoint of the third bridge arm in the second conversion circuit, and the other end is connected to the second end of the third switch module and one end of the second winding of the transformer respectively;

[0011] The third end of the third switch module is connected to the midpoint of the fourth bridge arm of the second conversion circuit, and the first end of the third switch module is connected to one end of the second capacitor, so that when charging the electrical load, the first end of the third switch module is electrically connected to the second end of the third switch module; when discharging to the grid, the first end of the third switch module is electrically connected to the third end of the third switch module;

[0012] The first end of the fourth switch module is connected to the midpoint of the fourth bridge arm, and the second end of the fourth switch module is connected to the other end of the second capacitor and the other end of the second winding, and is configured to be turned on when charging the electrical load and turned off when discharging to the power grid.

[0013] Furthermore, the first switch module includes a first controllable switch and a second controllable switch, both control ends of which are connected to the control module;

[0014] The first end of the first controllable switch is connected to the first end of the second controllable switch, and the common end of the connections serves as the first end of the first switch module, and the second end of the first controllable switch serves as the second end of the first switch module, and is configured to be turned on when the grid charges the power load through the power module, and turned off when the power load discharges to the grid through the power module;

[0015] The second end of the second controllable switch serves as the third end of the first switch module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

[0016] Furthermore, the first controllable switch and the second controllable switch are MOSFETs or IGBTs.

[0017] Furthermore, the second switch module includes a third controllable switch;

[0018] The first end of the third controllable switch serves as the first end of the second switch module, the second end of the third controllable switch serves as the second end of the second switch module, and the control end of the third controllable switch serves as the control end of the second switch module.

[0019] Furthermore, the first switch module includes a first electromagnetic switch and a fourth controllable switch;

[0020] The common contact of the first electromagnetic switch serves as the first end of the first switch module, the normally closed contact of the first electromagnetic switch serves as the second end of the first switch module, and the normally open contact of the first electromagnetic switch serves as the third end of the first switch module;

[0021] One end of the first coil of the first electromagnetic switch is connected to a DC power supply, and the other end is grounded through the fourth controllable switch;

[0022] The control end of the fourth controllable switch is connected to the control module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

[0023] Furthermore, the first electromagnetic switch is a relay.

[0024] Furthermore, the second switch module includes a second electromagnetic switch and a fifth controllable switch;

[0025] One end of the normally closed switch of the second electromagnetic switch serves as the first end of the second switch module, and the other end of the normally closed switch of the second electromagnetic switch serves as the second end of the second switch module;

[0026] One end of the second coil of the second electromagnetic switch is connected to a DC power supply, and the other end is grounded via the fifth controllable switch;

[0027] The control end of the fifth controllable switch is connected to the control module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

[0028] Furthermore, the fourth controllable switch is a normally open switch of the second electromagnetic switch.

[0029] To solve the above technical problems, the present invention further provides a power supply module, comprising a control module, a grid-side conversion circuit and a bidirectional DC-DC conversion circuit connected in sequence, and also comprising the resonant circuit as described above;

[0030] The resonant circuit is connected to the bidirectional DC-DC conversion circuit.

[0031] In order to solve the above technical problems, the present invention also provides a V2G charging device, including the power module as described above.

[0032] The present application provides a resonant circuit, a power module and a V2G charging device, wherein the resonant circuit is applied to a bidirectional DC-DC conversion circuit of the power module, the resonant circuit includes a first inductor, a first capacitor, a second inductor, a second capacitor and a first switch module, a second switch module, a third switch module and a fourth switch module, all of which have control ends connected to the control module. When the power grid charges the power load through the power module, the second switch module, the fourth switch module, the first end and the second end of the first switch module, and the first end and the second end of the third switch module are connected, so that the first inductor and the first capacitor, the second inductor and the second capacitor are connected, and the first inductor and the first capacitor are connected. A parallel resonance is formed between the second inductor and the second capacitor. For changes in the power load, the load circuit can be automatically tuned, which is beneficial to reducing the impact of the power load change on the circuit stability and improving the circuit stability. When the power load discharges to the power grid through the power module, the first end and the third end of the first switch module, and the first end and the third end of the third switch module are connected, and the second switch module and the fourth switch module are turned off, so that a series resonance is formed between the first inductor and the first capacitor, and between the second inductor and the second capacitor, with high frequency stability, low grid-connected current harmonic content, and high quality of electric energy fed back to the power grid. It can be seen that the solution in this application can realize automatic switching between series resonance and parallel resonance according to the current charging and discharging state, which is beneficial to better realize the two-way energy transfer between the power load and the power grid, and is beneficial to practical application.

[0033] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1 A schematic structural diagram of a resonant circuit provided by the present invention;

[0036] Figure 2 A schematic structural diagram of a power module provided by the present invention;

[0037] Figure 3 A schematic structural diagram of another resonant circuit provided by the present invention;

[0038] Figure 4 This is a schematic structural diagram of another resonant circuit provided by the present invention. DETAILED DESCRIPTION

[0039] The core of the present invention is to provide a resonant circuit, a power module and a V2G charging device, which can realize automatic switching between series resonance and parallel resonance according to the current charging and discharging status, thereby better realizing the two-way energy transfer between the power load and the power grid.

[0040] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0041] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0042] Please refer to Figure 1, Figure 1 This is a structural schematic diagram of a resonant circuit provided by the present invention.

[0043] The resonant circuit is applied to a power module, which includes a control module and a grid-side conversion circuit 1 and a bidirectional DC-DC conversion circuit 2 connected in sequence; the bidirectional DC-DC conversion circuit 2 includes a first conversion circuit, a transformer, and a second conversion circuit connected in sequence; the resonant circuit includes a first inductor L1, a first capacitor C1, a second inductor L2, a second capacitor C2, and a first switch module 51, a second switch module 52, a third switch module 53, and a fourth switch module 54, all of which have control ends connected to the control module;

[0044] One end of the first inductor L1 is connected to the midpoint of the first bridge arm 21 in the first conversion circuit, and the other end is connected to the second end of the first switch module 51 and one end of the first winding of the transformer T respectively;

[0045] The third end of the first switch module 51 is connected to the midpoint of the second bridge arm 22 in the first conversion circuit, and the first end of the first switch module 51 is connected to one end of the first capacitor C1, so that when the power grid charges the power load through the power module, the first end of the first switch module 51 and the second end of the first switch module 51 are electrically connected; when the power load discharges to the power grid through the power module, the first end of the first switch module 51 and the third end of the first switch module 51 are electrically connected;

[0046] A first end of the second switch module 52 is connected to the midpoint of the second bridge arm 22, and a second end of the second switch module 52 is connected to the other end of the first capacitor C1 and the other end of the first winding, and is configured to be turned on when charging the load and turned off when discharging to the grid;

[0047] One end of the second inductor L2 is connected to the midpoint of the third bridge arm 23 in the second conversion circuit, and the other end is connected to the second end of the third switch module 53 and one end of the second winding of the transformer T respectively;

[0048] The third end of the third switch module 53 is connected to the midpoint of the fourth bridge arm 24 in the second conversion circuit, and the first end of the third switch module 53 is connected to one end of the second capacitor C2, so that when charging the electrical load, the first end of the third switch module 53 and the second end of the third switch module 53 are electrically connected; when discharging to the grid, the first end of the third switch module 53 and the third end of the third switch module 53 are electrically connected;

[0049] The first end of the fourth switch module 54 is connected to the midpoint of the fourth bridge arm 24, and the second end of the fourth switch module 54 is connected to the other end of the second capacitor C2 and the other end of the second winding, and is configured to be turned on when charging the electrical load and turned off when discharging to the grid.

[0050] In this embodiment, please first refer to Figure 2 , Figure 2 This is a structural schematic diagram of a power module provided by the present invention. Specifically, the power module may include a first terminal 3, a grid-side conversion circuit 1, a bidirectional DC-DC conversion circuit 2 and a second terminal 4 connected in sequence, wherein the first terminal 3 is used to connect to the grid, and the first terminal 3 is connected to each phase of the three-phase electricity in sequence from top to bottom, and the last terminal is used to connect to the neutral wire; the second terminal 4 is used to connect to the electrical load, and the first terminal 4 from top to bottom can be the DC positive terminal DC+ and the last terminal can be the DC negative terminal DC-. The electrical load here includes but is not limited to electric vehicles.

[0051] The grid-side conversion circuit 1 may include an inductor L3, an inductor L4, an inductor L5, a controllable switch Q1, a controllable switch Q2, a controllable switch Q3, a controllable switch Q4, a controllable switch Q5, a controllable switch Q6, a controllable switch Q7, a controllable switch Q8, a controllable switch Q9, a controllable switch Q10, a controllable switch Q11, a controllable switch Q12, a capacitor C3, and a capacitor C4 to form a T-type three-level topology; it should be noted that the control end of each of the controllable switches is connected to the control module. Figure 2 Due to image limitations and to avoid confusing wiring, the control module configuration diagram is omitted for now. Each controllable switch described herein may be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) or an IGBT (Insulate-Gate Bipolar Transistor), without specific limitations. The grid-side conversion circuit 1 is used to achieve rectification when the grid charges the electrical load through the power module, and to achieve inversion when the electrical load discharges to the grid through the power module.

[0052] The bidirectional DC-DC conversion circuit 2 includes a first conversion circuit, a transformer T and a second conversion circuit connected in sequence. Figure 2 As shown, the first conversion circuit includes a first bridge arm 21 and a second bridge arm 22, the first bridge arm 21 includes a controllable switch Q13 and a controllable switch Q15, and the second bridge arm 22 includes a controllable switch Q14 and a controllable switch Q16; the second conversion circuit includes a third bridge arm 23 and a fourth bridge arm 24, the third bridge arm 23 includes a controllable switch Q17 and a controllable switch Q19, and the fourth bridge arm 24 includes a controllable switch Q18 and a controllable switch Q20. It should be noted that the control end of each controllable switch is connected to the control module. Figure 2Due to the limitation of the focus of the picture and to avoid confusion in the connection, the setting diagram of the control module is temporarily omitted; and the controllable switches here can be MOSFET or IGBT, which is not particularly limited here; the bidirectional DC-DC conversion circuit 2 can also include capacitors C5 and C6 to achieve filtering; the controllable switches in the bidirectional DC-DC conversion circuit 2 are used to perform voltage conversion according to the voltage and / or current required for charging when the power grid charges the power load through the power module; when the power load discharges to the power grid through the power module, the voltage and / or current that the power load can provide, that is, DC power, is converted into stable DC power, so as to be provided to the grid-side conversion circuit 1 for inversion into the power grid to achieve bidirectional conversion; the transformer T is used for voltage conversion and electrical isolation.

[0053] Figure 1 Due to image focus and to avoid confusion regarding wiring, the control module setup diagram is omitted for now. Furthermore, the control module can determine whether the grid is charging the load or discharging the load back to the grid. This determination is made by, but is not limited to, determining the power quality based on power information (including current and / or voltage amplitude, frequency, phase, etc.) input from the grid to the power module, and then switching between series resonance and parallel resonance based on the power quality.

[0054] It should also be noted that the midpoint of the first bridge arm 21 is the midpoint where the controlled switch Q13 and the controlled switch Q15 are connected, the midpoint of the second bridge arm 22 is the midpoint where the controlled switch Q14 and the controlled switch Q16 are connected, the midpoint of the third bridge arm 23 is the midpoint where the controlled switch Q17 and the controlled switch Q19 are connected, and the midpoint of the fourth bridge arm 24 is the midpoint where the controlled switch Q18 and the controlled switch Q20 are connected; the first winding of the transformer T is the primary winding of the transformer T, and the second winding is the secondary winding of the transformer T.

[0055] In summary, the present application provides a resonant circuit, which applies the resonant circuit to the bidirectional DC-DC conversion circuit 2 of the power module. When the power grid charges the power load through the power module, the second switch module 52, the fourth switch module 54, the first end and the second end of the first switch module 51, and the first end and the second end of the third switch module 53 are turned on, so that parallel resonance is formed between the first inductor L1 and the first capacitor C1, and between the second inductor L2 and the second capacitor C2. When the power load changes or fluctuates, the load circuit can be automatically tuned, which is beneficial to reducing reactive power and reducing the power load. The impact of changes on circuit stability improves circuit stability; when the electrical load discharges to the power grid through the power module, the first end and the third end of the first switch module 51, the first end and the third end of the third switch module 53 are connected, and the second switch module 52 and the fourth switch module 54 are turned off, so that series resonance is formed between the first inductor L1 and the first capacitor C1, and between the second inductor L2 and the second capacitor C2, with high frequency stability, and the frequency and phase are conducive to following the power grid, and the grid-connected current has low harmonic content, high quality factor, and high quality of electric energy fed back to the power grid, which will not have an adverse effect on the power grid. It can be seen that the solution in this application can simply and reliably realize automatic switching between series resonance and parallel resonance according to the current charge and discharge state, which is conducive to better realizing the two-way energy transfer between the electrical load and the power grid, alleviating the pressure on the power grid, and facilitating practical applications.

[0056] Based on the above embodiment:

[0057] In some embodiments, the first switch module 51 includes a first controllable switch and a second controllable switch, both control ends of which are connected to the control module;

[0058] The first end of the first controllable switch is connected to the first end of the second controllable switch, and the common end of the connections serves as the first end of the first switch module 51. The second end of the first controllable switch serves as the second end of the first switch module 51, and is configured to be turned on when the grid charges the electrical load through the power module, and turned off when the electrical load discharges to the grid through the power module.

[0059] The second end of the second controllable switch serves as the third end of the first switch module 51 , and is configured to be turned off when charging the electrical load and turned on when discharging to the grid.

[0060] It should also be noted that the third switch module 53 may include a sixth controllable switch and a seventh controllable switch, both control ends of which are connected to the control module; the first end of the sixth controllable switch is connected to the first end of the seventh controllable switch, and the common end of the connection serves as the first end of the third switch module 53, and the second end of the sixth controllable switch serves as the second end of the third switch module 53; the second end of the seventh controllable switch serves as the third end of the third switch module 53.

[0061] The sixth controllable switch is used to be turned on when charging the electrical load and turned off when discharging to the grid; the seventh controllable switch is used to be turned off when charging the electrical load and turned on when discharging to the grid.

[0062] In some embodiments, the first controllable switch and the second controllable switch are MOSFETs or IGBTs.

[0063] It can be seen that the above configuration can simply and reliably realize the control of the first controllable switch and the second controllable switch. In addition, similarly, the sixth controllable switch and the seventh controllable switch described in the above embodiment can be MOSFETs or IGBTs.

[0064] In some embodiments, the second switch module 52 includes a third controllable switch;

[0065] The first end of the third controllable switch serves as the first end of the second switch module 52 , the second end of the third controllable switch serves as the second end of the second switch module 52 , and the control end of the third controllable switch serves as the control end of the second switch module 52 .

[0066] Specifically, the third controllable switch is used to be turned on when charging the electrical load and turned off when discharging to the grid; the third controllable switch may be a MOSFET or an IGBT.

[0067] In addition, the fourth switch module 54 may include an eighth controllable switch, the first end of the eighth controllable switch serving as the first end of the fourth switch module 54, the second end serving as the second end of the fourth switch module 54, and the control end serving as the control end of the fourth switch module 54, for being turned on when charging the electrical load and turned off when discharging to the grid; the eighth controllable switch may be a MOSFET or an IGBT.

[0068] In some embodiments, the first switch module 51 includes a first electromagnetic switch and a fourth controllable switch;

[0069] The common contact c1 of the first electromagnetic switch serves as the first end of the first switch module 51 , the normally closed contact b1 of the first electromagnetic switch serves as the second end of the first switch module 51 , and the normally open contact a1 of the first electromagnetic switch serves as the third end of the first switch module 51 ;

[0070] One end of the first coil of the first electromagnetic switch is connected to the DC power supply, and the other end is grounded through the fourth controllable switch;

[0071] The control end of the fourth controllable switch is connected to the control module, and is configured to be turned off when charging the electrical load and turned on when discharging to the grid.

[0072] Specifically, from the implementation principle, when charging the electrical load, the fourth controllable switch is turned off and the first coil is not energized, then the common contact c1 of the first electromagnetic switch remains connected to the normally closed contact b1; when discharging to the power grid, the fourth controllable switch is turned on and the first coil is energized, then the common contact c1 of the first electromagnetic switch is connected to the normally open contact a1.

[0073] Furthermore, the third switch module 53 may include a third electromagnetic switch and a ninth controllable switch. The third electromagnetic switch's common contact c2 serves as the first end of the third switch module 53, the normally open contact a2 serves as the second end of the third switch module 53, and the normally closed contact b2 serves as the third end of the third switch module 53. One end of the third coil of the third electromagnetic switch is connected to the DC power supply, and the second end is grounded via the ninth controllable switch. The ninth controllable switch's control end is connected to the control module, configured to be turned on when charging the load and turned off when discharging the load to the grid. It is understood that when charging the load, the ninth controllable switch is turned on, energizing the third coil, and the common contact c2 of the third electromagnetic switch is connected to the normally open contact a2. When discharging the load to the grid, the ninth controllable switch is turned off, de-energizing the third coil, and the common contact c2 of the third electromagnetic switch remains connected to the normally closed contact b2.

[0074] For further information, please refer to Figure 3 and Figure 4 , Figure 3 A schematic diagram of the structure of another resonant circuit provided by the present invention, Figure 4 A schematic diagram of another resonant circuit provided by the present invention; wherein, Figure 3 and Figure 4 Due to the limitation of the focus of the picture, the arrangement diagrams of the control module, the first coil and the DC power supply, the fourth controllable switch, the third coil and the ninth controllable switch are omitted for the time being. Figure 3 Schematic diagram of the contact action results of the first electromagnetic switch and the third electromagnetic switch when the power grid charges the power load through the power module; Figure 4 The diagram shows the contact action results of the first electromagnetic switch and the third electromagnetic switch when the electrical load discharges to the grid through the power module.

[0075] It should be noted that the fourth controllable switch and the ninth controllable switch here can be MOSFET or IGBT.

[0076] In some embodiments, the first electromagnetic switch is a relay.

[0077] Specifically, considering that the relay has advantages such as high reliability, ease of expansion, and electrical isolation, a relay is selected as the first electromagnetic switch.

[0078] In addition, the third electromagnetic switch may also be a relay.

[0079] In some embodiments, the second switch module 52 includes a second electromagnetic switch and a fifth controllable switch;

[0080] One end of the normally closed switch K1 of the second electromagnetic switch serves as the first end of the second switch module 52 , and the other end of the normally closed switch K1 of the second electromagnetic switch serves as the second end of the second switch module 52 ;

[0081] One end of the second coil of the second electromagnetic switch is connected to the DC power supply, and the other end is grounded via the fifth controllable switch;

[0082] The control end of the fifth controllable switch is connected to the control module, and is used to be turned off when charging the power load and turned on when discharging to the power grid.

[0083] Exemplarily, the fourth switch module 54 may include a fourth electromagnetic switch and a tenth controllable switch, one end of the first normally closed switch K2 of the fourth electromagnetic switch serves as the first end of the fourth switch module 54, and the other end of the first normally closed switch K2 serves as the second end of the fourth switch module 54; one end of the fourth coil of the fourth electromagnetic switch is connected to the DC power supply, and the other end is grounded through the tenth controllable switch; the control end of the tenth controllable switch is connected to the control module, and is used to be turned off when charging the power load and turned on when discharging to the power grid.

[0084] Specifically, from the implementation principle, when charging the electrical load, the fifth controllable switch is turned off, the second coil is not energized, and the normally closed switch K1 of the second electromagnetic switch remains closed. Figure 3 When discharging to the grid, the fifth controllable switch is turned on, the second coil is energized, and the normally closed switch K1 is opened, as shown in FIG. Figure 4 As shown; it should be noted that, similarly, due to the limitations of the picture display focus, Figure 3 and Figure 4 The arrangement diagrams of the second coil and the fifth controllable switch, and the fourth coil and the tenth controllable switch are temporarily omitted.

[0085] The fifth controllable switch and the tenth controllable switch here may be MOSFET or IGBT.

[0086] In some embodiments, the fourth controllable switch is a normally open switch of the second electromagnetic switch.

[0087] Specifically, the normally open switch of the second electromagnetic switch is expanded to be the fourth controllable switch, which is conducive to reducing costs and realizing linkage control; similarly, the ninth controllable switch can be the second normally closed switch of the third electromagnetic switch.

[0088] The present invention also provides a power supply module, comprising a control module, a grid-side conversion circuit 1 and a bidirectional DC-DC conversion circuit 2 connected in sequence, and further comprising the resonant circuit as described above;

[0089] The resonant circuit is connected to the bidirectional DC-DC converter circuit 2 .

[0090] For an introduction to the power supply module provided in this application, please refer to the above-mentioned embodiment of the resonant circuit, which will not be repeated here.

[0091] The present invention also provides a V2G charging device, comprising the power module as described above.

[0092] For the introduction of the V2G charging device provided in this application, please refer to the embodiment of the resonant circuit above, which will not be repeated here. It should be noted that the V2G charging device here includes but is not limited to a V2G charging pile.

[0093] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. Relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements limited by the sentence "comprising a" do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0094] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is to be construed in the widest manner consistent with the principles and novel features disclosed herein.

Claims

1. A resonant circuit, characterized in that: Applicable to a power supply module, the power supply module includes a control module and a grid-side conversion circuit and a bidirectional DC-DC conversion circuit connected in sequence; the bidirectional DC-DC conversion circuit includes a first conversion circuit, a transformer, and a second conversion circuit connected in sequence; the resonant circuit includes a first inductor, a first capacitor, a second inductor, a second capacitor, and a first switch module, a second switch module, a third switch module, and a fourth switch module, all of which have control ends connected to the control module; One end of the first inductor is connected to the midpoint of the first bridge arm in the first conversion circuit, and the other end is connected to the second end of the first switch module and one end of the first winding of the transformer respectively; The third end of the first switch module is connected to the midpoint of the second bridge arm of the first conversion circuit, and the first end of the first switch module is connected to one end of the first capacitor, so that when the grid charges the electrical load through the power module, the first end of the first switch module is electrically connected to the second end of the first switch module; when the electrical load discharges to the grid through the power module, the first end of the first switch module is electrically connected to the third end of the first switch module; A first end of the second switch module is connected to the midpoint of the second bridge arm, and a second end of the second switch module is connected to the other end of the first capacitor and the other end of the first winding, and is configured to be turned on when charging the electrical load and turned off when discharging to the power grid; One end of the second inductor is connected to the midpoint of the third bridge arm in the second conversion circuit, and the other end is connected to the second end of the third switch module and one end of the second winding of the transformer respectively; The third end of the third switch module is connected to the midpoint of the fourth bridge arm of the second conversion circuit, and the first end of the third switch module is connected to one end of the second capacitor, so that when charging the electrical load, the first end of the third switch module is electrically connected to the second end of the third switch module; when discharging to the grid, the first end of the third switch module is electrically connected to the third end of the third switch module; The first end of the fourth switch module is connected to the midpoint of the fourth bridge arm, and the second end of the fourth switch module is connected to the other end of the second capacitor and the other end of the second winding, and is configured to be turned on when charging the electrical load and turned off when discharging to the power grid.

2. The resonant circuit according to claim 1, wherein The first switch module includes a first controllable switch and a second controllable switch, both control ends of which are connected to the control module; The first end of the first controllable switch is connected to the first end of the second controllable switch, and the common end of the connections serves as the first end of the first switch module, and the second end of the first controllable switch serves as the second end of the first switch module, and is configured to be turned on when the grid charges the power load through the power module, and turned off when the power load discharges to the grid through the power module; The second end of the second controllable switch serves as the third end of the first switch module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

3. The resonant circuit according to claim 2, wherein: The first controllable switch and the second controllable switch are MOSFETs or IGBTs.

4. The resonant circuit according to claim 1, wherein: The second switch module includes a third controllable switch; The first end of the third controllable switch serves as the first end of the second switch module, the second end of the third controllable switch serves as the second end of the second switch module, and the control end of the third controllable switch serves as the control end of the second switch module.

5. The resonant circuit according to any one of claims 1 to 3, characterized in that: The first switch module includes a first electromagnetic switch and a fourth controllable switch; The common contact of the first electromagnetic switch serves as the first end of the first switch module, the normally closed contact of the first electromagnetic switch serves as the second end of the first switch module, and the normally open contact of the first electromagnetic switch serves as the third end of the first switch module; One end of the first coil of the first electromagnetic switch is connected to a DC power supply, and the other end is grounded through the fourth controllable switch; The control end of the fourth controllable switch is connected to the control module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

6. The resonant circuit according to claim 5, wherein: The first electromagnetic switch is a relay.

7. The resonant circuit according to claim 5, wherein: The second switch module includes a second electromagnetic switch and a fifth controllable switch; One end of the normally closed switch of the second electromagnetic switch serves as the first end of the second switch module, and the other end of the normally closed switch of the second electromagnetic switch serves as the second end of the second switch module; One end of the second coil of the second electromagnetic switch is connected to a DC power supply, and the other end is grounded via the fifth controllable switch; The control end of the fifth controllable switch is connected to the control module, and is configured to be turned off when charging the electrical load and turned on when discharging to the power grid.

8. The resonant circuit according to claim 7, wherein: The fourth controllable switch is a normally open switch of the second electromagnetic switch.

9. A power module, characterized in that: It comprises a control module, a grid-side conversion circuit and a bidirectional DC-DC conversion circuit connected in sequence, and also comprises a resonant circuit according to any one of claims 1 to 8; The resonant circuit is connected to the bidirectional DC-DC conversion circuit.

10. A V2G charging device, characterized in that: Comprising the power module as claimed in claim 9.

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