Energy storage converter circuit and energy storage converter system

Abstract

The utility model relates to the technical field of energy storage, and discloses an energy storage converter circuit and an energy storage converter system, a controllable power switch circuit is connected in series on each branch battery pack on the direct current side of a conversion circuit to realize the charge and discharge control of the branch battery packs, so that the circuit module is simple in structure, does not need redundant circuit arrangement, and is convenient to use. Compared with the prior art, according to the scheme provided by the utility model, the circuit structure of the direct current side is simplified, and the controllable power switch circuit is in one-way conduction, so that the problem of circulating current among the multi-branch battery pack is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to an energy storage converter circuit and an energy storage converter system. Background Art

[0002] At present, with the support of the national policy of promoting the development of clean energy, energy storage converter technology has been rapidly developed and promoted. The existing energy storage converter circuit is divided into a DC side and an AC side. Multiple groups of batteries are provided on the DC side. Each battery group is provided with a soft start switch, and the soft start switch includes: a first contactor and a first circuit breaker connected to the first side of each battery group, and a second circuit breaker connected in series to the second side of the first battery; the DC bus is connected with a bus capacitor, and the AC measurement circuit after the full-bridge conversion is connected in series with a filter unit, a switch module, a fuse and an isolator in turn, so as to realize the charging of multi-branch battery groups and the discharge to the power grid. The soft start switch of the first contactor + the first circuit breaker requires the addition of additional cables and connection contacts, and when the multi-way battery groups are connected for charging and discharging, the battery groups are connected in parallel, and a circulating current will be generated through the first contactor and the first circuit breaker. Utility Model Content

[0003] The utility model provides an energy storage converter circuit and an energy storage converter system, which are used to solve the problems that the existing energy storage converter circuit has complex lines and circulating current exists during charging and discharging.

[0004] The first aspect of the utility model provides an energy storage converter circuit, comprising:

[0005] A conversion circuit, a grid-connected circuit, a plurality of branch battery groups and a controllable power switch circuit, wherein the grid-connected circuit is connected to the AC side of the conversion circuit, and the plurality of branch battery groups are connected in parallel to the positive and negative electrodes of the DC side of the conversion circuit;

[0006] The conversion circuit is used to convert the electric energy provided by the battery pack or the power grid into AC and DC;

[0007] The grid-connected circuit is used to filter, step up or step down the AC power output by the power grid or the conversion circuit;

[0008] The branch battery pack is used to store or provide electrical energy;

[0009] The controllable power switch circuit is connected in series in the branch battery group and is located on one side of the branch battery group, and is used to control the charging and discharging of the corresponding branch battery group or to perform gradient charging and discharging of the corresponding branch battery group with other branch battery groups when the controllable power switch circuit is turned on.

[0010] In a feasible implementation manner, the controllable power switch circuit is a combination circuit composed of at least one controllable power switch tube, and the combination circuit is connected in series to the positive electrode or the negative electrode in the branch battery pack.

[0011] In a feasible implementation manner, the controllable power switch tube is a power diode or a power triode.

[0012] In a feasible implementation manner, if the at least one controllable power switch tube is two controllable power triodes, the two controllable power triodes are connected to each other in series or in parallel.

[0013] In a feasible implementation manner, if the controllable power transistors are connected to each other in series, two controllable power transistors are connected in series in a common emitter or common collector manner.

[0014] In a feasible implementation manner, if the controllable power transistors are connected to each other in parallel, two controllable power transistors are connected in parallel by connecting their emitters and collectors in common.

[0015] In a feasible implementation manner, if there are at least three controllable power switch tubes, the controllable power switch tubes are connected to each other in series and parallel.

[0016] In a feasible implementation, the at least three controllable power switch tubes include at least two combined branches, the branches are connected in parallel by connecting the emitter and the collector in common, and the controllable power switch tubes in each branch are connected in series by connecting the emitter or the collector in common.

[0017] In a feasible implementation manner, the grid-connected circuit includes an inductor, an AC filter, an AC circuit breaker, an isolation transformer, an AC fuse, and an AC isolation switch connected in sequence;

[0018] During grid-connected power generation, the AC power output by the conversion circuit is filtered by the inductor and the AC filter, connected to the AC circuit breaker, boosted by the isolation transformer, and then connected to the AC fuse. After the isolation switch is controlled to close, the AC power is connected to the grid.

[0019] A second aspect of the utility model provides an energy storage converter system, comprising the energy storage converter circuit as described above, and a control unit and a communication unit connected by a bus;

[0020] The control unit is respectively connected to the grid-connected circuit, the conversion circuit and the controllable power switch circuit for outputting corresponding drive signals for each circuit;

[0021] The communication unit is respectively connected to the grid-connected circuit and each of the branch battery packs for communication, and is used to collect current and voltage of the grid-connected circuit and each of the branch battery packs.

[0022] In a feasible implementation manner, it further includes: an AC monitoring unit and a DC monitoring unit;

[0023] The AC monitoring unit is arranged between the communication unit and the grid-connected circuit, and is used to collect the current and voltage of the grid-connected circuit;

[0024] The DC monitoring unit is arranged between the communication unit and each branch battery pack, and is used for collecting the current and voltage of each branch battery pack.

[0025] In the technical solution provided by the utility model, the charge and discharge control of the branch battery group is realized by connecting a controllable power switch circuit in series to each branch battery group on the DC side of the conversion circuit. Such a circuit module has a simple structure and does not require redundant line settings. Compared with the prior art, the solution provided by the utility model simplifies the circuit structure on the DC side, and the controllable power switch circuit is unidirectional, avoiding the circulation problem between multiple branch battery groups. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an existing energy storage converter circuit;

[0027] Figure 2 This is a schematic diagram of the first structure of the energy storage converter circuit in the embodiment of the utility model;

[0028] Figure 3 This is a second structural schematic diagram of the energy storage converter circuit in the embodiment of the utility model;

[0029] Figure 4 This is a first schematic diagram of a controllable power switch circuit in an embodiment of the utility model;

[0030] Figure 5 This is a second schematic diagram of the controllable power switch circuit in the embodiment of the utility model;

[0031] Figure 6 This is a third schematic diagram of the controllable power switch circuit in the embodiment of the utility model;

[0032] Figure 7 This is a third structural schematic diagram of the energy storage converter circuit in the embodiment of the utility model;

[0033] Figure 8 This is a fourth structural schematic diagram of the energy storage converter circuit in the embodiment of the utility model;

[0034] Fig. 9This is a fifth structural schematic diagram of the energy storage converter circuit in the embodiment of the utility model;

[0035] Fig.10 A schematic diagram of the structure of the energy storage converter system in the embodiment of the utility model;

[0036] Fig.11 It is another structural schematic diagram of the energy storage converter system in the embodiment of the utility model. DETAILED DESCRIPTION

[0037] The utility model provides an energy storage converter circuit and an energy storage converter system, which are used to set a controllable power switch circuit in series on each branch battery group on the DC side of the conversion circuit in the energy storage converter circuit. When grid-connected power generation or charging of each branch battery group is required, the controllable power switch circuit is controlled to be turned on. The circuit structure of the controllable power switch circuit is simple, thereby simplifying the overall circuit and line design of the energy storage converter circuit and avoiding the circulation problem between each branch battery group.

[0038] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here, for example, can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] In the existing solution, the DC side of the energy storage converter is connected to multiple groups of batteries via a DC bus and a soft start switch, such as Figure 1 As shown, the soft start switch includes: a first contactor and a first circuit breaker connected to the first side of each battery group, and a second circuit breaker connected in series to the second side of the first battery; the DC bus is connected to a bus capacitor, and the AC measurement circuit after full-bridge conversion is sequentially connected in series with a filter unit, a switch module, a fuse and an isolator to realize the charging of multi-branch battery groups and the discharge to the power grid. This contactor + circuit breaker topology increases the number of components and the material cost. Whether it is a common positive electrode combination connection or a common negative electrode combination connection, it increases the connection cost of cables, copper bars, or aluminum bars; it increases the number of transfer points and the complexity of the installation layout, and it is also easy to cause circulation problems when multiple DC branch battery groups are connected in parallel.

[0040] In order to solve the above problems, the present invention provides an energy storage converter circuit. Figure 2 As shown, specifically including:

[0041] A conversion circuit 210, a grid-connected circuit 220, a plurality of branch battery groups 230 and a controllable power switch circuit 240, wherein the grid-connected circuit 220 is connected to the AC side of the conversion circuit 210, and the plurality of branch battery groups 230 are connected in parallel to the positive and negative electrodes of the DC side of the conversion circuit 210;

[0042] The conversion circuit 210 is used to convert the electric energy provided by the battery pack or the power grid into AC and DC;

[0043] The grid-connected circuit 220 is used to filter, step up or down the AC power output by the grid or the conversion circuit 210;

[0044] The branch battery group 230 is used to store or provide electrical energy;

[0045] The controllable power switch circuit 240 is connected in series in the branch battery group 230 and is located on one side of the branch battery group 230, and is used to control the charging and discharging of the corresponding branch battery group 230 or the gradient charging and discharging of the corresponding branch battery group 230 and other branch battery groups when the controllable power switch circuit 240 is turned on.

[0046] In this embodiment, the control of gradient graded charging and discharging is specifically to detect the voltage in each branch battery pack, generate a switch signal based on the voltage to control the conduction of the power switch tube on the corresponding branch battery pack, thereby realizing the control of charging and discharging. The gradient grade can be controlled by setting the priority and voltage level of each branch battery pack.

[0047] In practical applications, based on the actual needs of charging and discharging or the power supply needs in the photovoltaic system, a system is constructed for controlling the single charging voltage and discharging voltage of each branch battery group, as well as the priority level of each branch battery group. Based on the priority level and the single charging voltage and discharging voltage of each branch battery group, a control signal sequence is generated. Based on the control signal sequence, the conduction direction of each controllable power switch in the controllable power switch circuit is controlled. After the charging and discharging of the corresponding branch battery group reaches a preset gradient value, the next branch battery group is charged and discharged, thereby realizing gradient graded charging and discharging.

[0048] like Figure 2 As shown, the controllable power switch circuit 240 is a combination circuit composed of at least one controllable power switch tube 241 , and the combination circuit is connected in series to the positive electrode or the negative electrode in the branch battery group 230 .

[0049] It should be noted that when the branch battery group needs to be charged or discharged, a driving signal is input and output to each controllable power switch tube in the controllable power switch circuit to control the conduction and disconnection of each controllable power switch tube, so as to connect the corresponding branch battery group to the conversion circuit to realize charging or discharging.

[0050] In a feasible implementation, the grid-connected circuit 220 includes an inductor, an AC filter, an AC circuit breaker, an isolation transformer, an AC fuse, and an AC isolation switch connected in sequence;

[0051] During grid-connected power generation, the AC power output by the conversion circuit 210 is filtered by the inductor and the AC filter, connected to the AC circuit breaker, boosted by the isolation transformer, and then connected to the AC fuse. After the isolation switch is controlled to close, the AC power is connected to the grid.

[0052] like Figure 2 As shown, the energy storage converter circuit is composed of a branch battery group; a controllable power switch tube; positive and negative fuses; a three-phase full bridge (that is, a conversion circuit); an inductor; an AC filter; an AC circuit breaker; an isolation transformer; an AC fuse; an AC isolation switch, etc.

[0053] Its working principle: each branch battery group, each group is connected in series with each controllable power switch tube, and the positive and negative poles of the DC side of the access circuit are concentrated and converged. After the DC protection fuse and the DC bus capacitor group, the three-phase full bridge converts the DC power into AC power, and after filtering by the inductor and AC filter, it is connected to the controllable AC circuit breaker, boosted by the isolation transformer, and then connected to the AC side protection fuse. After the electric control isolation switch is closed, it is connected to the public power grid to achieve grid-connected power generation. Conversely, the power grid can charge each battery group string. Through the intelligent management and control of the controllable power switch tubes of each branch, it is possible to flexibly realize the charging of single battery groups of each branch battery group, or gradient charging of multiple battery groups, as well as centralized parallel unified charging.

[0054] In a feasible implementation, the controllable power switch tube 241 is a controllable power diode or a controllable power transistor, wherein the controllable power diode includes at least one of a dual-controlled power diode, a single-controlled power diode, and a general-purpose power diode, and the controllable power transistor is an IGBT power switch tube.

[0055] It should be noted that the controllable power switch circuit 240 can be obtained by combining controllable power switch tubes 241 of the same specifications, for example, only two dual-control type power diodes are connected in parallel to obtain the controllable power switch circuit 240. Of course, different specifications can also be used for combination, such as a dual-control type power diode and an IGBT power switch tube are connected in parallel to obtain the controllable power switch circuit 240. And the combined controllable power switch circuit 240 is only connected to one side of the branch battery group 230, that is, it is only set on the positive electrode or negative electrode of the branch battery group 230.

[0056] In a feasible implementation, the controllable power switch circuit 240 can be implemented by using only one controllable power switch tube, in which case the collector of the controllable power switch tube is connected to the positive electrode of the branch battery group 230, and the emitter of the controllable power switch tube is connected to the positive electrode of the inverter circuit 210 through a fuse. Alternatively, the emitter of the controllable power switch tube is connected to the negative electrode of the branch battery group 230, and the collector of the controllable power switch tube is connected to the negative electrode of the inverter circuit 210 through a fuse.

[0057] In a possible implementation, Figure 3 As shown, the controllable power switch circuit 240 can be realized by only two controllable power switch tubes connected in series or in parallel. In this case, the collector of the controllable power switch circuit 240 is connected to the positive electrode of the branch battery group 230, and the emitter of the controllable power switch circuit 240 is connected to the positive electrode of the inverter circuit 210 through a fuse. Alternatively, the emitter of the controllable power switch circuit 240 is connected to the negative electrode of the branch battery group 230, and the collector of the controllable power switch circuit 240 is connected to the negative electrode of the inverter circuit 210 through a fuse.

[0058] In a feasible implementation manner, if the at least one controllable power switch tube is two controllable power triodes, the two controllable power triodes are connected to each other in series or in parallel.

[0059] If the controllable power transistors are connected to each other in series, two controllable power transistors are connected in series in a common emitter or common collector manner.

[0060] If the controllable power transistors are connected to each other in parallel, two controllable power transistors are connected in parallel by connecting the emitter and the collector in common.

[0061] In practical applications, when the controllable power switch circuit 240 uses only two controllable power switch tubes and the controllable power switch tubes are IGBT power switch tubes, they can be connected in series or in parallel. Figure 4As shown, two controllable power switch tubes are connected in parallel by connecting the emitter and the collector together. Figure 5 and 6 As shown, two controllable power switch tubes are connected in series through a common emitter or common collector mode.

[0062] In a possible implementation, Figure 7 As shown, when the controllable power switch circuit 240 is designed by a dual-control type power diode, the anode of the dual-control type power diode is connected to the positive electrode of the conversion circuit 210, and the cathode of the dual-control type power diode is connected to the positive electrode of the branch battery group 230; or the anode of the dual-control type power diode is connected to the negative electrode of the branch battery group 230, and the cathode of the dual-control type power diode is connected to the negative electrode of the conversion circuit 210. Similarly, the connection method for a single-control type power diode and a general-purpose power diode is the same as the connection method for a dual-control type power diode, and will not be repeated here. Figure 8 and 9 shown.

[0063] In a feasible implementation manner, if there are at least three controllable power switch tubes, the controllable power switch tubes are connected to each other in series and parallel.

[0064] Specifically, the at least three controllable power switch tubes include at least two combined branches, the branches are connected in parallel by connecting the emitter and the collector in common, and the controllable power switch tubes in each branch are connected in series by connecting the emitter or the collector in common.

[0065] The utility model realizes the charge and discharge control of the branch battery groups by connecting the controllable power switch circuit in series to each branch battery group on the DC side of the conversion circuit. Such a circuit module has a simple structure and does not require redundant line settings. Compared with the prior art, the solution provided by the utility model simplifies the circuit structure on the DC side, and the controllable power switch circuit is unidirectional, avoiding the circulation problem between multiple branch battery groups.

[0066] See also Fig.10 , is a schematic diagram of the structure of an energy storage converter system provided by the utility model, the system includes the energy storage converter circuit 1010 provided in the above embodiment, and a control unit 1020 and a communication unit 1030 connected by a bus;

[0067] The control unit 1020 is respectively connected to the grid-connected circuit 220, the conversion circuit 210 and the controllable power switch circuit 240 for outputting corresponding driving signals for each circuit;

[0068] The communication unit 1030 is respectively connected to the grid-connected circuit 220 and each of the branch battery groups 230 for communication, and is used to collect current and voltage of the grid-connected circuit 220 and each of the branch battery groups 230 .

[0069] In a feasible implementation, the system further includes: an AC monitoring unit 1040 and a DC monitoring unit 1050;

[0070] The AC monitoring unit 1040 is provided between the communication unit 1030 and the grid-connected circuit 220 and is used to collect the current and voltage of the grid-connected circuit 220;

[0071] The DC monitoring unit 1050 is disposed between the communication unit 1030 and each of the branch battery groups 230 , and is used to collect the current and voltage of each of the branch battery groups 230 .

[0072] In practical applications, the system also includes a host computer, which sets the control parameters of the energy storage converter circuit. Then, the control unit 1020 outputs a corresponding drive signal based on the voltage and current collected in real time by the AC monitoring unit 1040 and the DC monitoring unit 1050 to achieve charge and discharge control.

[0073] like Fig.11 As shown, the energy storage converter has a complete grid-connected operation function and can flexibly adapt to the charging and discharging control of different branch battery groups. The charging and discharging mode and charging and discharging instructions are set by the PC host computer or the LCD screen display user interface. The specific grid-connected operation charging and discharging mode is as follows:

[0074] Constant power (AC) power generation mode, constant voltage source power generation mode, constant current source power generation mode; constant power (DC) charging mode, constant voltage charging mode, constant current charging mode are set according to the dispatching instructions, and these modes can all be operated in the grid-connected state. The energy storage converter system can be well adapted to application scenarios such as power peak regulation, frequency regulation, peak elimination and valley filling, and new energy grid-connected smoothing.

[0075] In this embodiment, the energy storage converter system includes a PC host computer / LCD screen, a central integrated control unit (i.e., the control unit 1020), an intelligent communication unit (i.e., the communication unit 1030), a current and voltage monitoring unit (including an AC monitoring unit 1040 and a DC monitoring unit 1050) arranged on each branch battery pack 230, a control unit of a controllable power switch tube arranged before each branch battery pack and the control unit 1020, a DSP-SVPWM modulation algorithm and a converter power tube drive signal unit, and an AC side current and voltage monitoring electric energy metering unit, etc. The functional units mainly communicate through RS485 or optical fiber communication to exchange digital information or perform operations on various control commands. The PC host computer / LCD screen can mainly set the voltage, current, power, and frequency parameters on both sides of the AC and DC, and can select and set the charging / discharging mode. The central integrated unit mainly collects the DC bus current, voltage, AC side current, voltage parameters, and after obtaining the information parameters of each functional unit, the integrated control dispatches the operation of each DC branch switch tube, and sends digital program commands to the drive unit to drive the power tube of the converter circuit to work, and executes the closing or opening operation of the AC side circuit breaker and the disconnector. The intelligent communication unit receives the LCD screen parameter settings, collects the current and voltage information of each group of strings, collects the status of the AC circuit breaker and the main disconnector, and then communicates with the central control unit. The current and voltage monitoring units of each battery string collect the voltage and current parameters of each branch battery group and exchange information with the intelligent unit. The control unit of each group of controllable switch tubes executes the control command issued by the integrated unit to control each DC branch switch tube in real time. The DSP-SVPWM modulation algorithm and converter power tube drive signal unit mainly execute the modulation algorithm to drive the six main power tubes to work for power conversion. The AC side current and voltage monitoring and energy metering unit collects the current and voltage of the grid-connected side. After the power generation meter communicates with the intelligent communication unit, it can be displayed intuitively on the LCD screen in a timely manner.

[0076] Specifically, each controllable power switch tube on the DC side is connected to a branch battery group; they are centrally connected to the positive and negative fuses, and the control unit controls the energy storage converter circuit to charge the DC bus capacitor. The central integrated control unit detects the current and voltage of the DC bus, and the current and voltage detection units of each branch battery group are used to detect the current and voltage of each branch battery group. The central integrated control unit controls the opening or closing of the controllable power switch tube of the corresponding branch battery group according to the energy difference between the collected DC bus current and voltage and the current and voltage collected by the current and voltage monitoring unit;

[0077] When the system needs to be charged, the closing logic flow of the controllable power switch tube of the branch is as follows: at the beginning, the controllable power switch tubes are all in the disconnected state; the battery groups are sorted according to the power level according to the power parameters of the battery groups collected by the current and voltage monitoring unit; the battery group with the lowest power is ranked as the lowest energy battery group, and the battery group with the second lowest power is ranked as the second lowest energy battery group; the DC bus capacitor is charged by the central integrated control unit, the DC bus capacitor voltage is increased to the same voltage as the lowest energy battery group, and then the power switch tube of this branch is closed, so that the lowest energy battery group is connected to the DC side of the energy storage converter; the DC bus voltage and the voltage of the lowest energy battery group are increased to the same voltage as the second lowest energy battery group by the central integrated control unit, and then the switch tube corresponding to the second lowest energy battery group is closed, so that the second lowest energy battery group is connected to the DC side of the energy storage converter circuit; and so on, until all battery groups in series are connected to the DC side of the energy storage converter circuit for charging;

[0078] The energy storage converter system also includes a closing logic flow of the controllable power switch tube during discharge: at the beginning, the power switch tubes of the branch are all in the disconnected state; the battery groups are sorted according to the power level using the power parameters of the battery groups collected by the battery string detection unit; the battery group with the highest power is ranked as the highest energy battery group, and the battery group with the second highest power is ranked as the second highest energy battery group; the DC bus voltage is increased to the same voltage as the highest energy battery group through the integrated control unit, and then the power switch tube of this branch is closed, so that the highest energy battery group is connected to the DC side of the energy storage converter; the DC bus capacitor and the highest energy battery group are discharged until the DC bus capacitor voltage and the voltage of the highest energy battery group drop to the same voltage as the second highest energy battery group, and then the switch tube corresponding to the second highest energy battery group is closed, so that the second highest energy battery group is connected to the DC side of the energy storage converter circuit; and so on, until all battery strings are connected to the DC side of the energy storage converter circuit for discharge.

[0079] In summary, this system performs pre-charging of each branch battery pack through a controllable power switch tube, and can also realize grid-connected power generation of the energy storage inverter circuit. It solves the problem of how to connect multiple battery packs in parallel; simplifies the device connection path, reduces the circulation problem when multiple battery packs are connected in series and parallel, and effectively reduces the number of parallel battery packs in each branch, reduces the maintenance difficulty when large-scale battery packs are used, and enhances the flexibility and reliability of the system. The use of the energy storage inverter circuit of this application can effectively improve the high-efficiency operating time of the energy storage power station, bring considerable power generation premium benefits to energy storage power generation users, and help maximize investment benefits.

[0080] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0081] In addition, in the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the utility model can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the utility model. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0083] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0084] Finally, it should be noted that the above embodiments are only specific implementation methods of the utility model, which are used to illustrate the technical solution of the utility model, rather than to limit it. The protection scope of the utility model is not limited thereto. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art should understand that any technician familiar with the technical field can still modify the technical solution recorded in the above embodiments within the technical scope disclosed by the utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the utility model, and should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. A storage converter circuit, characterized in that: include: A conversion circuit, a grid-connected circuit, a plurality of branch battery groups and a controllable power switch circuit, wherein the grid-connected circuit is connected to the AC side of the conversion circuit, and the plurality of branch battery groups are connected in parallel to the positive and negative electrodes of the DC side of the conversion circuit; The conversion circuit is used to convert the electric energy provided by the battery pack or the power grid into AC and DC; The grid-connected circuit is used to filter, step up or step down the AC power output by the power grid or the conversion circuit; The branch battery pack is used to store or provide electrical energy; The controllable power switch circuit is connected in series in the branch battery group and is located on one side of the branch battery group, and is used to control the charging and discharging of the corresponding branch battery group or to perform gradient charging and discharging of the corresponding branch battery group with other branch battery groups when the controllable power switch circuit is turned on.

2. The energy storage converter circuit according to claim 1, characterized in that: The controllable power switch circuit is a combination circuit composed of at least one controllable power switch tube, and the combination circuit is connected in series to the positive electrode or the negative electrode in the branch battery group.

3. The energy storage converter circuit according to claim 2, characterized in that: The controllable power switch tube is a controllable power diode or a controllable power triode.

4. The energy storage converter circuit according to claim 3, characterized in that: If the at least one controllable power switch tube is two controllable power triodes, the two controllable power triodes are connected to each other in series or in parallel.

5. The energy storage converter circuit according to claim 4, characterized in that: If the controllable power transistors are connected to each other in series, two controllable power transistors are connected in series in a common emitter or common collector manner.

6. The energy storage converter circuit according to claim 4, characterized in that: If the controllable power transistors are connected to each other in parallel, two controllable power transistors are connected in parallel by connecting the emitter and the collector in common.

7. The energy storage converter circuit according to claim 3, characterized in that: If there are at least three controllable power switch tubes, the controllable power switch tubes are connected to each other in series and parallel.

8. The energy storage converter circuit according to claim 7, characterized in that: The at least three controllable power switch tubes include at least two combined branches, each of the branches is connected in parallel by connecting the emitter and the collector in common, and each of the controllable power switch tubes in each branch is connected in series by connecting the emitter in common or the collector in common.

9. The energy storage converter circuit according to any one of claims 1 to 8, characterized in that: The grid-connected circuit comprises an inductor, an AC filter, an AC circuit breaker, an isolation transformer, an AC fuse and an AC isolation switch connected in sequence; During grid-connected power generation, the AC power output by the conversion circuit is filtered by the inductor and the AC filter, connected to the AC circuit breaker, boosted by the isolation transformer, and then connected to the AC fuse. After the isolation switch is controlled to close, the AC power is connected to the grid.

10. An energy storage converter system, characterized in that: The invention comprises an energy storage converter circuit as claimed in any one of claims 1 to 9, and a control unit and a communication unit connected by a bus; The control unit is respectively connected to the grid-connected circuit, the conversion circuit and the controllable power switch circuit for outputting corresponding drive signals for each circuit; The communication unit is respectively connected to the grid-connected circuit and each of the branch battery packs for communication, and is used to collect current and voltage of the grid-connected circuit and each of the branch battery packs.

11. The energy storage converter system according to claim 10, characterized in that: Also includes: an AC monitoring unit and a DC monitoring unit; The AC monitoring unit is arranged between the communication unit and the grid-connected circuit, and is used to collect the current and voltage of the grid-connected circuit; The DC monitoring unit is arranged between the communication unit and each branch battery pack, and is used for collecting the current and voltage of each branch battery pack.

Images