Energy storage valve device, operation method thereof and energy storage system

Abstract

The invention relates to an energy storage valve device, an operation method thereof and an energy storage system, the energy storage valve device is provided with a main power supply module and a redundant power supply module, and the main power supply module is respectively connected with a direct current support capacitor and a power control board card, obtains energy from the direct current support capacitor and supplies power to the power control board card. And the redundant power supply module is respectively connected with the energy storage module and the power control board card, and obtains energy from the energy storage module to supply power to the power control board card. By means of the scheme, the power control board card can take energy from the direct current supporting capacitor and the energy storage module, redundant power supply operation is achieved, the possibility of power failure of the power control board card of the energy storage valve device can be reduced, and therefore the phenomenon that an energy storage system or an electric power system is stopped due to the power failure of the power control board card is relieved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an energy storage valve device and an operating method thereof, and an energy storage system. Background Art

[0002] Energy storage provides frequency regulation and peak regulation in all aspects of power generation, transmission, distribution and use, and plays a role in stabilizing the frequency of the power grid, alleviating grid congestion, and improving the flexibility of power generation and use. The cascade energy storage system has the advantages of modular design, high capacity utilization, high conversion efficiency, fast dynamic response, low harmonic content, and stable system operation. It has become a current research hotspot and has broad application prospects.

[0003] The energy storage valve device of the cascade energy storage system is generally constructed by cascading multiple energy storage valve submodules that integrate the power part and the energy storage part. The safe and stable operation of the energy storage valve device is of great significance to the energy storage system and even the power system. However, in the related art, the energy storage valve device can easily cause the energy storage system or even the power system to shut down due to power failure of the power control board. Summary of the invention

[0004] Based on this, it is necessary to provide an energy storage valve device and its operating method, and an energy storage system to reduce the possibility of power failure of the power control board of the energy storage valve device, thereby alleviating the phenomenon of the energy storage system or power system being shut down due to power failure of the power control board.

[0005] The present application provides an energy storage valve device, including a power module, a power control board, a DC support capacitor, a main power module, a redundant power module and an energy storage module, wherein the DC support capacitor is connected in parallel with the power module, the power control board is connected to the power module, the main power module is respectively connected to the DC support capacitor and the power control board, the redundant power module is respectively connected to the energy storage module and the power control board, and the energy storage module is connected to the power module and the DC support capacitor.

[0006] In the above scheme, a main power module and a redundant power module are provided in the energy storage valve device. The main power module is respectively connected to the DC support capacitor and the power control board, and takes energy from the DC support capacitor to supply power to the power control board. The redundant power module is respectively connected to the energy storage module and the power control board, and takes energy from the energy storage module to supply power to the power control board. Through this scheme, the power control board can take energy from the DC support capacitor and the energy storage module to achieve redundant power supply operation, which can reduce the possibility of power failure of the power control board of the energy storage valve device, thereby alleviating the phenomenon of the energy storage system or the power system being shut down due to power failure of the power control board.

[0007] In some embodiments, the energy storage valve device includes more than two energy storage valve sub-modules, each of the energy storage valve sub-modules includes the power module, the DC support capacitor, the power control board and the energy storage module, and the redundant power supply module is connected to the energy storage module in the same energy storage valve sub-module as the power module.

[0008] In the above scheme, the redundant power supply module obtains energy from the energy storage module which belongs to the same energy storage valve submodule as the power module, that is, the redundant power supply of the power control board is realized through the energy storage valve submodule controlled by the power control board. The power supply method is simple and the complexity of the circuit layout is effectively reduced.

[0009] In some embodiments, the energy storage valve device includes more than two energy storage valve sub-modules, each of the energy storage valve sub-modules includes the power module, the DC support capacitor, the power control board and the energy storage module, and the redundant power supply module is connected to the energy storage module in the energy storage valve sub-module other than the energy storage valve sub-module to which the power module belongs.

[0010] In the above scheme, the redundant power supply module obtains energy from the energy storage modules of other energy storage valve submodules other than the energy storage valve submodule where the power module is located. After the energy storage valve submodule where the power module is located is bypassed, there is no need for the energy storage module of the energy storage valve submodule where the power module is located to continuously discharge, thereby improving the operating reliability of the energy storage valve device.

[0011] In some embodiments, the power module comprises a full-bridge power module or a half-bridge power module.

[0012] In the above scheme, the power module includes a bridge power module or a half-bridge power module. Power modules with different structures can be selected according to actual needs, which can effectively improve the applicability of the energy storage valve device.

[0013] In some embodiments, the energy storage valve device further includes a voltage-equalizing resistor, the voltage-equalizing resistor is connected in parallel with the DC support capacitor, and the energy storage module is connected to the voltage-equalizing resistor.

[0014] In the above scheme, equalizing resistors are connected in parallel at both ends of the DC support capacitor. During the operation of the power module, the equalizing effect of the equalizing resistors improves the operation reliability. After the power module is bypassed, the equalizing resistors can also discharge the capacitors to improve the discharge efficiency.

[0015] In some embodiments, the power module includes a power unit and a bypass switch, the first AC end of the power unit is used to connect the first end of the bypass switch and to be cascaded with other power modules, the second AC end of the power unit is used to connect the second end of the bypass switch and to be cascaded with other power modules, the first DC end and the second DC end of the power unit are respectively connected to the DC support capacitor, and the control end of the power unit is connected to the power control board.

[0016] In the above scheme, a power unit and a bypass switch are provided at the power module. When the energy storage valve device fails, the power unit can be bypassed through the bypass switch, thereby improving the operational safety of the energy storage valve device.

[0017] In some embodiments, the energy storage valve device further includes an isolating switch, and the energy storage module is connected to the DC support capacitor via the isolating switch.

[0018] The above solution realizes electrical isolation between the power module and the energy storage module through the isolating switch, thereby further improving the operational safety of the energy storage valve device.

[0019] In some embodiments, the power control board includes a main control board, a bypass switch driver board and a power switch driver board, the main control board is connected to the bypass switch driver board and the power switch driver board respectively, the bypass switch driver board and the power switch driver board are connected to the power module respectively, the main power supply module and the redundant power supply module are connected to the main control board respectively, the main power supply module and the redundant power supply module are connected to the bypass switch driver board respectively, and the main power supply module and the redundant power supply module are connected to the power switch driver board respectively.

[0020] In the above scheme, the power control board includes a main control board, a bypass switch driver board and a power switch driver board. Different driving functions are respectively realized by the bypass switch driver board and the power switch driver board, thereby effectively improving the control reliability of the power control board.

[0021] The present application also provides an operating method based on the above-mentioned energy storage valve device, including: when the startup conditions are met, taking energy from the redundant power supply module to control the operation of the power module; when the capacitor voltage of the DC support capacitor is greater than the preset main power supply startup voltage, taking energy according to the redundant power supply module and the main power supply module to control the operation of the power module.

[0022] In the above scheme, when the startup conditions are met, the power control board takes energy from the redundant power supply module and controls the operation of the power module without waiting for the DC support capacitor to be charged. This can achieve full-controlled charging of the energy storage valve device and improve the startup speed of the energy storage valve device.

[0023] In some embodiments, the operating method further includes: when the power module enters a bypass operating state, obtaining energy from the redundant power supply module to monitor the operating state of the power module.

[0024] In the above scheme, after the power module is bypassed, the redundant power supply can also be used to monitor the operating status of the power module, support the power control board to be always powered, and further improve the operating reliability of the energy storage valve device.

[0025] In some embodiments, a voltage-equalizing resistor is also arranged in parallel between the DC support capacitor and the energy storage module, and the operating method further includes: when the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than a preset lockout time, obtaining the maximum allowable discharge resistance value; and determining the resistance parameter of the voltage-equalizing resistor based on the maximum discharge resistance value.

[0026] The above scheme, combined with the maximum discharge resistance value required when the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than the preset locking time, is used to determine the resistance parameters of the equalizing resistor, so that the equalizing resistor is more matched with the energy storage valve device, further improving the operating reliability of the energy storage valve device.

[0027] In some embodiments, the discharge duration includes the sum of a first discharge duration and a second discharge duration, wherein the first discharge duration includes: when the DC support capacitor discharges from a preset rated operating voltage to reach a preset shutdown voltage threshold, the duration of the main power supply module and the equalizing resistor discharging together; the second discharge duration includes: when the DC support capacitor discharges from the preset shutdown voltage threshold to reach a preset safety voltage threshold, the duration of the equalizing resistor discharging alone.

[0028] The above scheme combines the first discharge duration of the stage in which the main power module and the equalizing resistor discharge together, and the second discharge duration of the stage in which the equalizing resistor discharges alone, to obtain an accurate discharge duration, thereby improving the accuracy of the resistance parameter finally determined.

[0029] The present application also provides an energy storage system, comprising the above-mentioned energy storage valve device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0031] Figure 1 This is a schematic diagram of the structure of an energy storage valve device in one embodiment of the present application;

[0032] Figure 2 This is a schematic structural diagram of an energy storage valve device in another embodiment of the present application;

[0033] Figure 3 This is a structural schematic diagram of an energy storage valve device in another embodiment of the present application;

[0034] Figure 4 This is a schematic diagram of the equivalent circuit structure of the energy storage valve submodule in one embodiment of the present application;

[0035] Figure 5 This is a schematic flow chart of an operating method of an energy storage valve device in one embodiment of the present application;

[0036] Figure 6 This is a schematic flow chart of the operating method of the energy storage valve device in another embodiment of the present application. DETAILED DESCRIPTION

[0037] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0039] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0042] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0043] At present, from the perspective of the development of the market situation, the application of energy storage systems is becoming more and more extensive, which has brought great convenience to daily production and life. High-voltage direct-mounted energy storage has a highly modular structure and can meet the needs of high efficiency, high reliability, economy and safety, and has gradually been developed and applied. In the high-voltage direct-mounted energy storage system, the core part is the energy storage valve submodule. Each energy storage valve submodule includes an integrated power part and an energy storage part. Multiple energy storage valve submodules are connected to form an energy storage valve device, and then the energy storage valve device is combined with a converter to finally form an energy storage system. Typically, the energy storage valve submodules are cascaded to form a cascaded energy storage valve device. The reliable operation of the energy storage valve device will directly affect the energy storage system or the power system. How to improve the operating reliability of the energy storage valve device is particularly important.

[0044] However, the energy storage valve submodule of the energy storage valve device often loses power during operation. The power failure of any energy storage valve submodule will directly affect the stable operation of the energy storage system. In severe cases, it will cause the entire energy storage system or even the power system to shut down. Through research, it is found that the power failure of the energy storage valve submodule is often caused by the power failure of the power control board. How to alleviate the power failure of the power control board is an effective means to improve the reliability of the energy storage system.

[0045] Based on the above considerations, in order to alleviate the phenomenon of power failure of the power control board, a redundant power supply can be designed for the power control board, that is, the power control board of the energy storage valve device is designed to be powered by power supply devices that draw energy from different positions. In the event of a power failure in one of the power supply devices, another power supply device is switched to supply power, thereby improving the power supply reliability of the power control board.

[0046] More specifically, each power control board in the energy storage valve device can be designed with a main power module and a redundant power module. Taking one of the energy storage valve submodules as an example, the power control board used for power module operation control in the energy storage valve submodule is connected to the main power module and the redundant power module respectively, the main power module draws energy from the DC support capacitor of the energy storage valve submodule, and the redundant power module draws energy from the energy storage module of the energy storage valve submodule.

[0047] Considering that after the power module is bypassed, the energy storage module corresponding to the energy storage valve submodule stores limited electrical energy. If the energy storage module is continuously discharged to achieve redundant power supply, the energy storage valve submodule may be exhausted and the power supply may be interrupted. In another embodiment, taking one of the energy storage valve submodules as an example, the power control board used for power module operation control in the energy storage valve submodule is connected to the main power module and the redundant power module respectively. The main power module draws energy from the DC support capacitor of the energy storage valve submodule, and the redundant power module draws energy from the energy storage module of another energy storage valve submodule.

[0048] By adopting the above scheme, when each energy storage valve submodule is started and operated, it can first draw energy from its own energy storage module through the redundant power supply module to power the power control board; or draw energy from the energy storage module of another energy storage valve submodule to power the power control board. After the DC support capacitor is charged, it switches to drawing energy from its own DC support capacitor through the main power supply module to power the power control board. In the subsequent operation process, if the main power supply module fails, it can also switch again to draw energy from its own energy storage module or the energy storage module of other energy storage valve submodules. Through this power supply switching method, the possibility of power failure of the power control board can be effectively reduced, that is, the possibility of power failure of the energy storage valve submodule can be reduced, thereby improving the operation reliability of the energy storage valve device.

[0049] The energy storage valve device provided in the present application is applied to an energy storage system. Specifically, it can be a battery energy storage, supercapacitor energy storage, flywheel energy storage, or gas compression energy storage type energy storage system, without specific limitation. The following takes the energy storage system in which the energy storage valve device is applied to battery energy storage as an example. The type of battery energy storage system is not unique. As long as it is a battery energy storage system that needs to be built using an energy storage valve device, it can be used. For example, in a more detailed embodiment, the battery energy storage system includes a high-voltage direct-hung energy storage system. In order to facilitate the understanding of the technical solution of the present application, the following embodiments can all be understood as the energy storage valve device being applied to a high-voltage direct-hung energy storage system.

[0050] See also Figure 1The present application provides an energy storage valve device, including a power module 101, a power control board 109, a DC support capacitor C, a main power module 105, a redundant power module 107 and an energy storage module 103, the power control board 109 is connected to the power module 101 (not shown), the DC support capacitor C is connected to the power module in parallel, the main power module 105 is respectively connected to the DC support capacitor C and the power control board 109, the redundant power module 107 is respectively connected to the energy storage module 103 and the power control board 109, and the energy storage module 103 is connected to the power module 101 and the DC support capacitor C.

[0051] Specifically, the power module 101 is a device for realizing the power conversion function. The power control board 109 is a device for controlling the power module 101 to perform power conversion. The main power supply module 105 is a device for storing and converting the electric energy of the DC support capacitor C, and transmitting it to the power control board for power supply. The redundant power supply module 107 is a device for storing and converting the electric energy of the energy storage module 103, and transmitting it to the power control module for power supply. The energy storage module 103 is a device for storing electric energy, and under the action of the power module 101, it can realize the storage and release of electric energy.

[0052] The energy storage valve device includes multiple energy storage valve submodules. Taking the cascade energy storage valve system as an example, multiple energy storage valve submodules are cascaded, specifically, the power modules 101 of the energy storage valve submodules are cascaded, and an energy storage valve device can be constructed. Therefore, in the same energy storage valve device, the number of power modules 101, power control board 109, main power module 105, redundant power module 107 and energy storage module 103 is not unique. By connecting a power module 101, a power control board 109, a main power module 105, a redundant power module 107 and an energy storage module 103, an energy storage valve submodule can be constructed, and multiple energy storage valve submodules are further constructed to form an energy storage valve device by cascading.

[0053] In the same energy storage valve submodule, the power control board 109 is used to control the operation of the power module 101. The main power supply module 105 obtains energy from the DC support capacitor C, and after storing and converting it, it can power the power control board 109. The redundant power supply module 107 obtains energy from the energy storage module 103. Specifically, it can obtain energy from any energy storage module 103 in the energy storage valve device, and after storing and converting it, it can power the power control board 109.

[0054] In the solution of this embodiment, when the energy storage valve device meets the startup conditions, the power control board 109 first obtains energy from the redundant power supply module 107, outputs the corresponding control signal to the power module 101, and controls the operation of the power module 101. In this process, the energy storage module 103 will continue to charge the DC support capacitor C. When the capacitor voltage of the DC support capacitor C is greater than the preset main power startup voltage, the power control board 109 is powered by the main power supply module 105 and the redundant power supply module 107 to achieve control of the power module 101.

[0055] Specifically, when the capacitor voltage of the DC support capacitor C is greater than the preset main power startup voltage, the power control board 109 switches to taking energy from the main power module 105, and completes power supply through the electric energy stored in the DC support capacitor C. When a power failure occurs in the main power module 105 or the capacitor voltage drops below the preset main power startup voltage, the power control board 109 will switch to taking energy from the redundant power module 107 until the main power module 105 resumes operation, and then switches to taking energy from the main power module 105 again, thereby realizing power supply.

[0056] The specific structures of the main power module 105 and the redundant power module 107 are not unique. The structures of the main power module 105 and the redundant power module 107 can be set to be the same or different, and the specific selection can be made in combination with actual needs. For example, in a more detailed embodiment, the main power module 105 and the redundant power module 107 have the same structure, both including an energy storage unit and a DC conversion unit. The energy storage unit is connected to the power module 101, or connected to the energy storage module 103, and the energy storage unit is connected to the DC conversion unit, and the DC conversion unit is connected to the power control board 109. More specifically, the energy storage unit can be a battery, a capacitor, etc., which is not specifically limited.

[0057] It should be noted that the number of main power modules 105 and redundant power modules 107 is not unique. In one embodiment, one main power module 105 and one redundant power module 107 may be respectively provided, and the power control board 109 may be powered by energy access position redundancy. In another embodiment, two or more main power modules 105 may be provided, and in the case of energy access position redundancy, the power control board 109 may be powered by power supply number redundancy. And / or, in another embodiment, two or more redundant power modules 107 may be provided, and in the case of energy access position redundancy, the power control board 109 may be powered by power supply number redundancy.

[0058] In the above scheme, the energy storage valve device is provided with a main power supply module 105 and a redundant power supply module 107, and the main power supply module 105 is respectively connected to the DC support capacitor C and the power control board 109, and takes energy from the DC support capacitor C to supply power to the power control board 109. The redundant power supply module 107 is respectively connected to the energy storage module 103 and the power control board 109, and takes energy from the energy storage module 103 to supply power to the power control board 109. Through this scheme, the power control board 109 can take energy from the DC support capacitor C and the energy storage module 103 to achieve redundant power supply operation, which can reduce the possibility of power failure of the power control board 109 of the energy storage valve device, thereby alleviating the phenomenon of the energy storage system or the power system being shut down due to power failure of the power control board 109.

[0059] In some embodiments, please refer to Figure 1 The redundant power supply module 107 is connected to the energy storage module 103 in the same energy storage valve submodule as the power module 101 .

[0060] Specifically, the energy storage valve device includes more than two energy storage valve submodules, and each energy storage valve submodule includes a power module 101, a DC support capacitor C, a power control board 109 and an energy storage module 103. In the solution of this embodiment, in the energy storage valve device, the power control board 109 of the same energy storage valve submodule is obtained by the energy storage valve submodule. Specifically, in the same energy storage valve submodule, the main power module 105 obtains energy from the DC support capacitor C, and the redundant power module 107 obtains energy from the energy storage module 103, so as to realize the redundant power supply operation of the power control board 109. In this way, the power supply line routing of the same energy storage valve submodule is realized inside the energy storage valve submodule, the power supply line will not cross the energy storage valve submodule, the routing method is simple, and there are no problems such as insulation and interference.

[0061] In the above scheme, the redundant power supply module 107 obtains energy from the energy storage module 103 which belongs to the same energy storage valve submodule as the power module 101, that is, the redundant power supply of the power control board 109 is realized through the energy storage valve submodule controlled by the power control board 109. The power supply method is simple and the complexity of the circuit layout is effectively reduced.

[0062] Please refer to Figure 2 In some embodiments, the redundant power supply module 107 is connected to the energy storage module 103 in the energy storage valve submodule other than the energy storage valve submodule to which the power module 101 belongs.

[0063] Specifically, the energy storage valve device includes more than two energy storage valve submodules, and each energy storage valve submodule includes a power module 101, a DC support capacitor C, a power control board 109 and an energy storage module 103. During operation, the energy storage valve device often controls each energy storage valve submodule to switch on and off according to actual operation requirements, and the power module 101 of the energy storage valve submodule is in bypass operation. When the energy storage valve submodule enters the bypass operation state, the connection between the energy storage module 103 and the power module 101 will be cut off, for example, by disconnecting the isolating switch, etc., the energy storage module 103 cannot exchange energy with the power module 101, the DC support capacitor C is discharged quickly, and the main power module 105 stops running.

[0064] In order to realize the real-time monitoring of the power module 101, the power control board 109 needs to be always powered on, and at this time, it will switch to the redundant power supply module 107 for energy. Since the energy storage module 103 cannot exchange energy with the grid side, the energy stored in the energy storage module 103 is limited. In order to improve the endurance of the power control board 109, in the solution of this embodiment, the redundant power supply module 107 is connected to the energy storage module 103 of other energy storage valve submodules other than the energy storage valve submodule to which it belongs, and other energy storage modules 103 are used for power supply.

[0065] It can be understood that when the redundant power supply module 107 is connected to the energy storage module 103 of other energy storage valve submodules other than the energy storage valve submodule to which it belongs, the specific access position is not unique. In a more detailed embodiment, in order to minimize the routing of the power supply line and alleviate the complexity of the line, the redundant power supply module 107 can be connected to the energy storage module 103 of the energy storage valve submodule adjacent to the energy storage valve submodule to which it belongs, and draw energy from the energy storage module 103 of the adjacent energy storage valve submodule.

[0066] In the above scheme, the redundant power supply module 107 draws energy from the energy storage modules 103 of other energy storage valve submodules other than the energy storage valve submodule where the power module 101 is located. After the energy storage valve submodule where the power module 101 is located is bypassed, there is no need for the energy storage module 103 of the energy storage valve submodule where the power module 101 is located to continuously discharge, thereby improving the operating reliability of the energy storage valve device.

[0067] Please refer to Figure 3 In some embodiments, the power module 101 includes a power unit 301 , and the power unit 301 is connected to a DC support capacitor C in parallel.

[0068] Specifically, the power unit 301 is a device for power conversion in the power module 101, and the DC support capacitor C is a device for storing the electric energy released by the energy storage module 103. The power unit 301 is connected to the power control board 109, and under the action of the power control board 109, the start and stop of the power conversion function can be realized.

[0069] It should be noted that the specific structure of the power unit 301 is not unique, and a full-bridge structure or a half-bridge structure can be selected according to actual needs, and there is no specific limitation. In this way, the applicability of the energy storage valve device can be improved.

[0070] For more details, please continue reading Figure 3 Taking the half-bridge structure as an example, the power unit 301 includes a first power switch T1 and a second power switch T2. The input end of the first power switch T1 serves as the first DC end of the power unit 301, connecting the first end of the DC support capacitor C and the main power module 105. The output end of the first power switch T1 is connected to the input end of the second power switch T2, and the common end of the two serves as the first AC end of the power unit 301, connected to other power modules 101. The output end of the second power switch T2 serves as the second DC end and the second AC end of the power unit 301. The second AC end of other power modules 101 is connected to the external circuit, the second DC end is connected to the second end of the DC support capacitor C and the main power module 105, and the control ends of the first power switch T1 and the second power switch T2 serve as the control ends of the power unit 301, connected to the power control board 109 (not shown).

[0071] In the above scheme, the power module 101 includes a power unit 301, the main power module 105 obtains energy from the DC support capacitor C, and the power unit 301 is connected to the power control board 109. Power conversion is achieved under the control of the power control board 109, thereby improving the power supply reliability of the main power module 105.

[0072] See also Figure 3 In some embodiments, the energy storage valve device further includes a voltage-equalizing resistor R, which is connected in parallel with the DC support capacitor C, and the energy storage module 103 is connected to the voltage-equalizing resistor R.

[0073] Specifically, the voltage-equalizing resistor R is a resistor that realizes the voltage-equalizing function by using the resistor voltage-dividing principle. In the solution of this embodiment, for each energy storage valve submodule in the energy storage valve device, a voltage-equalizing resistor R is provided in parallel between the DC support capacitor C and the energy storage module 103, and the voltage-equalizing effect of the voltage-equalizing resistor R improves the operating reliability of the energy storage valve submodule.

[0074] The resistance parameters of the equalizing resistor R are not unique. In one embodiment, when the discharge time required for the DC support capacitor C to discharge to a preset safety voltage threshold is less than a preset lockout time, the maximum allowable discharge resistance value is obtained; based on the maximum discharge resistance value, the resistance parameters of the equalizing resistor R are determined.

[0075] The preset safety voltage threshold is the preset voltage threshold at which the DC support capacitor C is discharged without affecting the safe cloud operation of the energy storage valve submodule. Its value is not unique. In a more detailed embodiment, it can be set to 20V (volts). The preset lockout duration refers to the preset maximum duration allowed from the energy storage valve submodule triggering the lockout to completing the lockout.

[0076] Considering that the energy storage valve device proposed in this application can operate under the control of the power control module during the entire operation process, the power module 101 can realize the fully controlled charging of the energy storage valve. Therefore, the selection of the resistance parameter of the equalizing resistor R mainly considers two constraints. First, after the energy storage valve submodule is shut down, the equalizing resistor R acts as a discharge resistor. It is necessary to discharge the DC support capacitor C before the shutdown time reaches the preset lock time, that is, the DC support capacitor C discharges to the preset safety voltage threshold; second, in order to reduce the power consumption of the energy storage valve submodule and the load on the water cooling system in the application scenario of the energy storage system, the equalizing resistor R should try to select a larger resistance value.

[0077] Taking the above factors into consideration, the solution of this embodiment first calculates the conditions that the resistance parameters of the equalizing resistor R need to meet when the discharge time required for the DC support capacitor C to discharge to a preset safety voltage threshold is less than the preset lockout time. Then, when the equalizing resistor R meets the above conditions, the largest maximum discharge resistance value is selected to determine the resistance parameters of the equalizing resistor R.

[0078] More specifically, according to the maximum discharge resistance value, the resistance parameter of the voltage-equalizing resistor R is determined, including: setting the resistance parameter of the voltage-equalizing resistor R to the maximum discharge resistance value. In another embodiment, the maximum discharge resistance value may be appropriately increased or decreased and used as the resistance parameter of the piezoresistance to eliminate errors caused by measurement and calculation, and further improve the accuracy of the resistance parameter.

[0079] Please refer to Figure 4 In some embodiments, after the energy storage valve device stops operating, the energy storage valve submodule is locked, and the locking time is determined by the discharge time of the DC support capacitor C. After the connection between the energy storage module 103 and the power module 101 is disconnected, the voltage of the DC support capacitor C begins to decrease. The discharge process includes two stages. One is that the main power module 105 works (equivalent to the figure r) and discharges together with the equalizing resistor R; the other is that the main power module 105 is turned off, and the equalizing resistor R discharges alone.

[0080] Therefore, the discharge time includes: when the DC support capacitor C discharges from the preset rated working voltage to reach the preset shutdown voltage threshold, the main power supply module 105 and the equalizing resistor R discharge together for the first discharge time; and when the DC support capacitor C discharges from the preset shutdown voltage threshold to reach the preset safety voltage threshold, the equalizing resistor R discharges alone for the second discharge time.

[0081] The preset rated working voltage is the preset rated working voltage of the energy storage valve submodule when it is in operation. The preset cut-off voltage threshold refers to the preset voltage threshold at which the main power supply module 105 cuts off the power supply.

[0082] At this time, T1+T2=T, where T represents the discharge time, T1 represents the first discharge time, and T2 represents the second discharge time. In the selection process, it is necessary to satisfy T1+T2=T<T Off , T Off Indicates the preset lockout duration. According to the circuit principle analysis, μ represents the efficiency of the main power module 105, R represents the resistance of the voltage balancing resistor R, C represents the capacitance of the DC support capacitor C, and U C represents the voltage of the DC support capacitor C, P represents the power of the power control board of the energy storage valve submodule, U N Indicates the preset rated operating voltage, U off Indicates the preset shutdown voltage threshold, U o Indicates the preset safety voltage threshold. Off Solving under this constraint, we can get R<R1. Further, considering the influence of the power consumption of the voltage-equalizing resistor R on the load of the water cooling system, the larger the resistance, the smaller the power consumption, so the final heating resistance parameter of the voltage-equalizing resistor R can be taken as R1.

[0083] In the above scheme, a voltage-equalizing resistor R is connected in parallel at both ends of the DC support capacitor C. During the operation of the power module 101, the voltage-equalizing effect of the voltage-equalizing resistor R improves the operation reliability. After the power module 101 is bypassed, the voltage-equalizing resistor R can also discharge the DC support capacitor C to improve the discharge efficiency.

[0084] Please refer to Figure 3 In some embodiments, the power module includes a power unit 301 and a bypass switch P, the first AC end of the power unit 301 is used to connect the first end of the bypass switch P and to be cascaded with other power modules, the second AC end of the power unit 301 is used to connect the second end of the bypass switch P and to be cascaded with other power modules, the first DC end and the second DC end of the power unit 301 are respectively connected to the DC support capacitor C, and the control end of the power unit 301 is connected to the power control board 109.

[0085] Specifically, the bypass switch P is used to bypass the power unit 301 when there is a bypass demand. Taking the cascade energy storage valve device as an example, each energy storage valve submodule is cascaded through the first AC end and the second AC end of the power unit 301 to form an energy storage valve device. In the case of a bypass demand, in the corresponding energy storage valve submodule, the bypass switch P of the power unit 301 under the power module 101 is closed, and the power unit 301 of the energy storage valve submodule is equivalent to being short-circuited. At this time, the upper-level energy storage valve submodule and the lower-level energy storage valve submodule are connected through the bypass switch P, and the intermediate-level energy storage valve submodule is equivalent to being cut off.

[0086] In the above solution, a bypass switch P is provided at the power module 101. When the energy storage valve device fails, the power unit 301 can be bypassed through the bypass switch P, thereby improving the operational safety of the energy storage valve device.

[0087] See also Figure 3 In some embodiments, the energy storage valve device further includes an isolating switch K, and the energy storage module 103 is connected to the DC support capacitor C via the isolating switch K.

[0088] Specifically, the isolating switch K is a switch device for achieving electrical isolation. More specifically, in one embodiment, the positive end and the negative end of the energy storage module 103 are respectively connected to the power module 101. To improve the reliability of electrical isolation between the energy storage module 103 and the power module 101, an isolating switch K is respectively provided between the positive end of the energy storage module 103 and the power module 101, and between the negative end of the energy storage module 103 and the power module 101. When there is a need for isolation, the two isolating switches K can be controlled at the same time.

[0089] In the above solution, the power module 101 and the energy storage module 103 are electrically isolated by the isolation switch K, thereby further improving the operational safety of the energy storage valve device.

[0090] Please refer to Figure 3 In some embodiments, the power control board 109 includes a main control board 302, a bypass switch driver board 303 and a power switch driver board 304, the main control board 302 is connected to the bypass switch driver board 303 and the power switch driver board 304 respectively, the bypass switch driver board 303 and the power switch driver board 304 are respectively connected to the power module 101 (not shown in the figure), the main power supply module 105 and the redundant power supply module 107 are respectively connected to the main control board 302 (not shown in the figure), the main power supply module 105 and the redundant power supply module 107 are respectively connected to the bypass switch driver board 303 (not shown in the figure), and the main power supply module 105 and the redundant power supply module 107 are respectively connected to the power switch driver board 304 (not shown in the figure).

[0091] Specifically, the main control board 302, that is, the power module 101 controller (Sub-module controller, SMC) board, is used to receive the status information of the bypass switch P of the power module 101 and the status information of the power switch device of the power unit 301, and upload it to the upper processor; it is also used to control the operation of the bypass switch driver board 303 and the power switch driver board 304 according to the signal sent by the upper processor.

[0092] The bypass switch driving board 303 is used to drive the bypass switch P to be turned on and off, so the bypass switch driving board 303 is connected to the control end of the bypass switch P of the power module 101, and sends a corresponding control signal when there is a bypass demand to control the bypass switch P to be turned on. The power switch driving board 304 is used to drive the power unit 301 of the power module 101. When there is a power conversion demand, it only needs to output a corresponding control signal to control the power switch device in the power unit 301 to be turned on and off.

[0093] In the solution of this embodiment, the main control board 302, the bypass switch driver board 303 and the power switch driver board 304 are respectively connected to the main power supply module 105 and the redundant power supply module 107, and each board is independently and redundantly powered, with high power supply reliability.

[0094] In the above scheme, the power control board 109 includes a main control board 302, a bypass switch driving board 303 and a power switch driving board 304. Different driving functions are respectively realized by the bypass switch driving board 303 and the power switch driving board 304, thereby effectively improving the control reliability of the power control board 109.

[0095] In order to facilitate understanding of the technical solution of the present application, the present application is explained below in conjunction with more detailed embodiments.

[0096] The energy storage valve device includes a plurality of cascaded energy storage valve submodules, each of which includes a power module 101, a DC support capacitor C, a voltage balancing resistor R, a power control board 109, a main power module 105, a redundant power module 107, an isolation switch K and an energy storage module 103, wherein the main power module 105 takes energy from its own DC support capacitor C, and the redundant power module 107 takes energy from the energy storage module 103 of the adjacent energy storage valve submodule, and the main power module 105 and the redundant power module 107 are both connected to the power control board 109 for power supply. The power module 101 includes a power unit 301 of a half-bridge structure and a bypass switch P, and the power control board 109 includes a main control board 302, a bypass switch driver board 303 and a power switch driver board 304.

[0097] Taking one of the energy storage valve submodules as an example, when the energy storage valve device meets the startup conditions, the isolation switch K is closed, and the redundant power supply module 107 takes energy from the energy storage module 103 of the adjacent energy storage valve submodule to supply power to the main control board 302, the bypass switch driver board 303, and the power switch driver board 304. The main control board 302 sends relevant instructions to the power switch driver board 304 to control the on and off of the switch device of the power unit 301, and the energy storage module 103 starts to charge the DC support capacitor C to achieve full control charging of the energy storage valve submodule. When the capacitor voltage reaches the preset main power startup voltage, the main power supply module 105 is switched to supply power to the main control board 302, the bypass switch driver board 303, and the power switch driver board 304, and the power conversion function continues to be executed.

[0098] When the energy storage valve submodule needs to be bypassed, the isolation switch K is disconnected, and the main control board 302 controls the bypass switch driving board 303 to send a corresponding control signal to control the bypass switch P to close. At this time, the redundant power supply will be switched to ensure that the power control board 109 is always powered on and continuously monitors the operating status of the power module 101.

[0099] At the same time, the resistance parameters of the equalizing resistor R are selected mainly considering two constraints. When the discharge time required for the DC support capacitor C to discharge to the preset safety voltage threshold is less than the preset lockout time, the maximum allowable discharge resistance value is obtained; based on the maximum discharge resistance value, the resistance parameters of the equalizing resistor R are determined.

[0100] The discharge time required for the DC support capacitor C to discharge to reach a preset safety voltage threshold includes: when the DC support capacitor C discharges from a preset rated operating voltage to reach a preset shutdown voltage threshold, the main power supply module 105 and the equalizing resistor R discharge together for a first discharge time; and when the DC support capacitor C discharges from a preset shutdown voltage threshold to reach a preset safety voltage threshold, the equalizing resistor R discharges alone for a second discharge time.

[0101] Combined with T1+T2=T<T Off , T represents the discharge time, T1 represents the first discharge time, T2 represents the second discharge time, T Off Indicates the preset lockout duration. And μ represents the efficiency of the main power module 105, R represents the resistance of the voltage balancing resistor R, C represents the capacitance of the DC support capacitor C, and U C represents the voltage of the DC support capacitor C, P represents the power of the power control board of the energy storage valve submodule, U N Indicates the preset rated operating voltage, U off Indicates the preset shutdown voltage threshold, U oRepresents the preset safety voltage threshold. By solving, we get R<R1. Further, considering the influence of the power consumption of the voltage-equalizing resistor R on the load of the water cooling system, the larger the resistance, the smaller the power consumption. Therefore, the final heating resistance parameter of the voltage-equalizing resistor R can be taken as R1.

[0102] See also Figure 5 The present application also provides an operating method based on the above-mentioned energy storage valve device, including step 502 and step 504.

[0103] Step 502: When the startup conditions are met, energy is obtained from the redundant power supply module to control the operation of the power module.

[0104] Step 504: when the capacitor voltage of the DC support capacitor is greater than the preset main power startup voltage, power is taken from the redundant power module and the main power module to control the operation of the power module.

[0105] Specifically, the energy storage valve device operates as shown in the above embodiments and drawings, which will not be described in detail here. In the above scheme, when the startup conditions are met, the power control board takes energy from the redundant power module to control the operation of the power module without waiting for the DC support capacitor to charge, which can realize full control charging of the energy storage valve device and improve the startup speed of the energy storage valve device.

[0106] See also Figure 6 In some embodiments, the operating method further includes step 602.

[0107] Step 602: When the power module enters the bypass operation state, energy is obtained from the redundant power supply module to monitor the operation state of the power module.

[0108] Specifically, when there is a bypass demand, in the corresponding energy storage valve submodule, the bypass switch of the power unit under the power module is closed, and the power unit of the energy storage valve submodule is equivalent to being short-circuited. At this time, the upper-level energy storage valve submodule and the lower-level energy storage valve submodule are connected through the bypass switch, and the intermediate-level energy storage valve submodule is equivalent to being cut off. In order to realize the constant power operation of the power control board, the redundant power supply module will be switched to supply power, so as to continuously monitor the operating status of the power module.

[0109] In the above scheme, after the power module is bypassed, the redundant power supply can also be used to monitor the operating status of the power module, support the power control board to be always powered, and further improve the operating reliability of the energy storage valve device.

[0110] In some embodiments, the power module includes a voltage-equalizing resistor, and the operating method further includes: when the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than a preset lockout time, obtaining the maximum allowable discharge resistance value; and determining the resistance parameters of the voltage-equalizing resistor based on the maximum discharge resistance value.

[0111] Specifically, the preset safety voltage threshold is a preset voltage threshold at which the capacitor discharges and does not affect the safe cloud operation of the energy storage valve submodule. Its value is not unique. In a more detailed embodiment, it can be set to 20V (volts). The preset lockout time refers to the preset maximum time allowed for the energy storage valve submodule to trigger the lockout and complete the lockout.

[0112] Taking into account that during the entire operation process of the energy storage valve device proposed in the application, the power module can operate under the control of the power control module to realize fully controlled charging of the energy storage valve, the resistance parameters of the equalizing resistor are selected mainly considering two constraints. First, after the energy storage valve submodule is shut down, the equalizing resistor acts as a discharge resistor. The DC support capacitor needs to be discharged before the shutdown time reaches the preset lockout time, that is, the capacitor discharge reaches the preset safety voltage threshold; second, in order to reduce the power consumption of the energy storage valve submodule and the load on the water cooling system in the application scenario of the energy storage system, the equalizing resistor should be selected with a larger resistance value as much as possible.

[0113] Taking the above factors into consideration, the solution of this embodiment first calculates the conditions that the resistance parameters of the equalizing resistor need to meet when the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than the preset lockout time. Then, when the equalizing resistor meets the above conditions, the largest maximum discharge resistance value is selected to determine the resistance parameters of the equalizing resistor.

[0114] The above scheme, combined with the maximum discharge resistance value required when the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than the preset locking time, is used to determine the resistance parameters of the equalizing resistor, so that the equalizing resistor is more matched with the energy storage valve device, further improving the operating reliability of the energy storage valve device.

[0115] In some embodiments, the discharge duration includes: a first discharge duration when the capacitor discharges from a preset rated operating voltage to a preset shutdown voltage threshold, during which the main power supply module and the equalizing resistor discharge together; and a second discharge duration when the capacitor discharges from a preset shutdown voltage threshold to a preset safety voltage threshold, during which the equalizing resistor discharges alone.

[0116] For details, please refer to Figure 4After the energy storage valve device stops operating, the energy storage valve submodule is locked. The locking time is determined by the discharge time of the DC support capacitor. After the energy storage module and the power module are disconnected, the voltage of the capacitor begins to decrease. The discharge process includes two stages. One is that the main power module works (equivalent to the figure r) and discharges together with the equalizing resistor; the other is that the main power module is turned off and the equalizing resistor discharges alone.

[0117] The preset rated operating voltage is the preset rated operating voltage of the energy storage valve submodule when it is in operation. The preset shutoff voltage threshold refers to the preset voltage threshold at which the main power module shuts off the power supply.

[0118] At this time, T1+T2=T, where T represents the discharge time, T1 represents the first discharge time, and T2 represents the second discharge time. In the selection process, it is necessary to satisfy T1+T2=T<T Off , T Off Indicates the preset lockout duration. According to the circuit principle analysis, μ represents the efficiency of the main power module, R represents the resistance of the voltage-equalizing resistor, C represents the capacitance of the capacitor, and U C represents the voltage of the capacitor, P represents the power of the power control board of the energy storage valve submodule, and U N Indicates the preset rated operating voltage, U off Indicates the preset shutdown voltage threshold, U o Indicates the preset safety voltage threshold. Off Solving under this constraint, we can get R<R1. Furthermore, considering the influence of the power consumption of the voltage-equalizing resistor on the load of the water cooling system, the larger the resistance, the smaller the power consumption, so the final heating resistance parameter of the voltage-equalizing resistor can be taken as R1.

[0119] The above scheme combines the first discharge duration of the stage in which the main power module and the equalizing resistor discharge together, and the second discharge duration of the stage in which the equalizing resistor discharges alone, to obtain an accurate discharge duration, thereby improving the accuracy of the resistance parameter finally determined.

[0120] The present application also provides an energy storage system, comprising the above-mentioned energy storage valve device.

[0121] Specifically, the energy storage system can be a battery energy storage, supercapacitor energy storage, flywheel energy storage or gas compression energy storage type energy storage system, which is not specifically limited. The energy storage valve device and its operation method are shown in the above-mentioned embodiments and drawings, and will not be repeated here. In this solution, a main power module and a redundant power module are provided in the energy storage valve device. The main power module is respectively connected to the power module and the power control board, and energy is taken from the DC support capacitor to supply power to the power control board. The redundant power module is respectively connected to the energy storage module and the power control board, and energy is taken from the energy storage module to supply power to the power control board. Through this solution, the power control board can take energy from the DC support capacitor and the energy storage module to realize redundant power supply operation, which can reduce the possibility of power failure of the energy storage valve device, thereby alleviating the phenomenon that the energy storage system or the power system is shut down due to power failure of the energy storage valve device.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A storage valve device, characterized in that: include: Power module; A power control board connected to the power module; A DC support capacitor connected in parallel with the power module; A main power supply module is connected to the DC support capacitor and the power control board respectively; A redundant power supply module is connected to the energy storage module and the power control board respectively; An energy storage module is connected to the power module and the DC support capacitor.

2. The energy storage valve device according to claim 1, characterized in that: The energy storage valve device includes more than two energy storage valve sub-modules, each of the energy storage valve sub-modules includes the power module, the DC support capacitor, the power control board and the energy storage module, and the redundant power supply module is connected to the energy storage module in the same energy storage valve sub-module as the power module.

3. The energy storage valve device according to claim 1, characterized in that: The energy storage valve device includes more than two energy storage valve sub-modules, each of the energy storage valve sub-modules includes the power module, the DC support capacitor, the power control board and the energy storage module, and the redundant power supply module is connected to the energy storage module in the energy storage valve sub-module other than the energy storage valve sub-module to which the power module belongs.

4. The energy storage valve device according to any one of claims 1 to 3, characterized in that: The power module includes a full-bridge power module or a half-bridge power module.

5. The energy storage valve device according to any one of claims 1 to 3, characterized in that: It also includes a voltage-equalizing resistor, which is connected in parallel with the DC support capacitor, and the energy storage module is connected to the voltage-equalizing resistor.

6. The energy storage valve device according to any one of claims 1 to 3, characterized in that: The power module includes a power unit and a bypass switch, the first AC end of the power unit is used to connect the first end of the bypass switch and to be cascaded with other power modules, the second AC end of the power unit is used to connect the second end of the bypass switch and to be cascaded with other power modules, the first DC end and the second DC end of the power unit are respectively connected to the DC support capacitor, and the control end of the power unit is connected to the power control board.

7. The energy storage valve device according to any one of claims 1 to 3, characterized in that: It also includes an isolating switch, and the energy storage module is connected to the DC support capacitor through the isolating switch.

8. The energy storage valve device according to any one of claims 1 to 3, characterized in that: The power control board includes a main control board, a bypass switch driving board and a power switch driving board. The main control board is connected to the bypass switch driving board and the power switch driving board respectively. The bypass switch driving board and the power switch driving board are connected to the power module respectively. The main power supply module and the redundant power supply module are connected to the main control board respectively. The main power supply module and the redundant power supply module are connected to the bypass switch driving board respectively. The main power supply module and the redundant power supply module are connected to the power switch driving board respectively.

9. An operating method of the energy storage valve device according to any one of claims 1 to 8, characterized in that: include: When the startup conditions are met, taking energy from the redundant power supply module to control the operation of the power module; When the capacitor voltage of the DC support capacitor is greater than the preset main power startup voltage, energy is taken from the redundant power module and the main power module to control the operation of the power module.

10. The operating method according to claim 9, characterized in that: Also includes: When the power module enters the bypass operation state, energy is obtained from the redundant power supply module to monitor the operation state of the power module.

11. The operating method according to claim 9, characterized in that: A voltage-equalizing resistor is also connected in parallel between the DC support capacitor and the energy storage module, and the operation method further includes: When the discharge time required for the DC support capacitor to discharge to reach a preset safety voltage threshold is less than a preset lockout time, obtaining a maximum allowable discharge resistance value; The resistance parameter of the voltage balancing resistor is determined according to the maximum discharge resistance value.

12. The operating method according to claim 11, characterized in that: The discharge duration includes the sum of a first discharge duration and a second discharge duration, wherein the first discharge duration includes: when the DC support capacitor discharges from a preset rated working voltage to reach a preset shutdown voltage threshold, the duration during which the main power supply module and the grading resistor discharge together; the second discharge duration includes: when the DC support capacitor discharges from the preset shutdown voltage threshold to reach a preset safety voltage threshold, the duration during which the grading resistor discharges alone.

13. An energy storage system, characterized in that: The energy storage valve device comprises any one of claims 1 to 8.

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