Converter circuit, energy storage module and system

Abstract

The invention relates to a commutation circuit and an energy storage module and system, the commutation circuit comprises a full-bridge module, and the full-bridge module is connected with an external energy storage module; the full-bridge module comprises four switch units, and at least one switch unit in the four switch units comprises at least one semi-control switch device; at least two of the four switch units comprise at least one full-control switch device; and in the same switch unit, the full-control switch device and / or the half-control switch device are sequentially connected in series. Because the half-control switching device can only control the conduction and cannot control the turn-off, when the half-control switching device is arranged in the switch unit, other full-control switching devices can be controlled to be turned off, so that the half-control switching device is turned off. Therefore, on the basis that the original functions of the full-bridge module are realized and the performance is not influenced, the manufacturing cost of the circuit is reduced, and the control complexity of the full-bridge module can also be reduced because the half-control switching device does not need to be controlled to be switched off.

Description

Technical Field

[0001] The present disclosure relates to the technical field of direct current power transmission, and particularly to a commutation circuit, an energy storage module, and a system. Background Art

[0002] A converter is a device that can realize the conversion between different forms of electric energy and is one of the core circuits of a new power system. The Modular Multilevel Converter (MMC) is a common converter, which has the advantages of high control flexibility, good reliability, and no consumption of reactive power. However, it has a large number of device requirements and high costs. Therefore, how to reduce the cost of the circuit on the basis of ensuring the working performance of the modular multilevel converter has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0003] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a commutation circuit, an energy storage module, and a system, which can reduce the cost of the commutation circuit without affecting the circuit performance.

[0004] The present disclosure provides a commutation circuit, which includes a full-bridge module;

[0005] The full-bridge module is connected to an external energy storage module; the full-bridge module includes four switching units, and at least one of the four switching units includes at least one semi-controlled switching device; at least two of the four switching units include at least one fully-controlled switching device;

[0006] In the same switching unit, the fully-controlled switching device and / or the semi-controlled switching device are connected in series in sequence;

[0007] Wherein, the energy storage module is used to output a sinusoidal half-wave voltage to the full-bridge module.

[0008] Optionally, the full-bridge module includes a first bridge arm group and a second bridge arm group;

[0009] The first bridge arm group includes a first switching unit and a second switching unit, and the second bridge arm group includes a third switching unit and a fourth switching unit;

[0010] The first switching unit and the second switching unit are connected to the midpoint of the bridge arm of the first bridge arm group, and the third switching unit and the fourth switching unit are connected to the midpoint of the bridge arm of the second bridge arm group;

[0011] Wherein, the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit all include fully-controlled switching devices, and at least one of the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit includes at least one semi-controlled switching device.

[0012] Optionally, three of the first switch unit, the second switch unit, the third switch unit, and the fourth switch unit include only fully controlled switch devices, and the other one includes a semi-controlled switch device and a fully controlled switch device.

[0013] Or,

[0014] two of the first switch unit, the second switch unit, the third switch unit, and the fourth switch unit include only fully controlled switch devices, and the other two both include a semi-controlled switch device and a fully controlled switch device.

[0015] Or,

[0016] one of the first switch unit, the second switch unit, the third switch unit, and the fourth switch unit includes only fully controlled switch devices, and the other three both include a semi-controlled switch device and a fully controlled switch device.

[0017] Or,

[0018] the first switch unit, the second switch unit, the third switch unit, and the fourth switch unit all include a semi-controlled switch device and a fully controlled switch device.

[0019] Optionally, the full-bridge module includes a third bridge arm group and a fourth bridge arm group;

[0020] the third bridge arm group includes a fifth switch unit and a sixth switch unit, and the fourth bridge arm group includes a seventh switch unit and an eighth switch unit;

[0021] the fifth switch unit and the sixth switch unit are connected to the midpoint of the bridge arm of the third bridge arm group, and the seventh switch unit and the eighth switch unit are connected to the midpoint of the bridge arm of the fourth bridge arm group;

[0022] wherein, at least one of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit includes only a semi-controlled switch device, and at least two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit include at least one fully controlled switch device.

[0023] Optionally, one of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit includes only a semi-controlled switch device, and the other three both include a semi-controlled switch device and a fully controlled switch device.

[0024] Or,

[0025] one of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit includes only a semi-controlled switch device, two of the other three both include a semi-controlled switch device and a fully controlled switch device, and the last one includes only a fully controlled switch device.

[0026] Or,

[0027] One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes semi-controlled switch devices, one of the other three includes semi-controlled switch devices and fully-controlled switch devices, and the last two only include fully-controlled switch devices.

[0028] Or,

[0029] One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes semi-controlled switch devices, and the other three only include fully-controlled switch devices.

[0030] Optionally, two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include semi-controlled switch devices, and the other two both include semi-controlled switch devices and fully-controlled switch devices.

[0031] Or,

[0032] Two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include semi-controlled switch devices, one of the other two includes semi-controlled switch devices and fully-controlled switch devices, and the last one only includes fully-controlled switch devices.

[0033] Or,

[0034] Two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include semi-controlled switch devices, and the other two only include fully-controlled switch devices.

[0035] Optionally, the semi-controlled switch devices include thyristors and first diodes;

[0036] The positive terminal of the thyristor is connected to the negative terminal of the first diode, and the negative terminal of the thyristor is connected to the positive terminal of the first diode.

[0037] Optionally, the fully-controlled switch devices include IGBTs,

[0038] Or,

[0039] IGCTs and second diodes;

[0040] The positive terminal of the IGCT is connected to the negative terminal of the second diode, and the negative terminal of the IGCT is connected to the positive terminal of the second diode.

[0041] The present disclosure also provides an energy storage module, and the energy storage module is connected to any of the above commutation circuits;

[0042] The energy storage module includes a plurality of battery units, and the plurality of battery units are connected in series in sequence;

[0043] The battery unit includes: a DC power supply unit and a half-bridge unit;

[0044] The half-bridge unit includes a first transistor and a second transistor; a first end of the first transistor is connected to a first end of the DC power supply unit, a second end of the first transistor is connected to a first end of the second transistor, and a second end of the second transistor is connected to a second end of the DC power supply unit; the second end of the first transistor is connected to a first end of the commutation circuit or an adjacent battery unit, and the second end of the second transistor is connected to a second end of the commutation circuit or an adjacent battery unit;

[0045] Wherein, the half-bridge unit is configured to output a sinusoidal half-wave voltage according to the DC voltage provided by the DC power supply unit when the first transistor receives a pulse width modulation signal.

[0046] The present disclosure also provides an energy storage system, including at least one commutation circuit as described above and at least one energy storage module as described above;

[0047] The commutation circuits and the energy storage modules are connected in one-to-one correspondence, and the commutation circuits are connected to the power grid.

[0048] The present disclosure provides a commutation circuit, an energy storage module, and a system. The commutation circuit includes a full-bridge module, and the full-bridge module is connected to an external energy storage module. Two switch units are respectively connected to two bridge arms of the full-bridge module, for a total of four switch units. Among the four switch units, at least one switch unit includes at least one semi-controlled switch device, and at least two switch units include at least one fully-controlled switch device. That is to say, at least two of the four switch units can control the turn-off of the fully-controlled switch device inside through a control signal provided by an external control module. The semi-controlled switch devices provided in each switch unit can be turned off when the fully-controlled switch unit is controlled to turn off. Since the semi-controlled switch device can only control conduction and cannot control turn-off, while the fully-controlled switch device can control both conduction and turn-off, the semi-controlled switch unit is simpler in structural design than the fully-controlled switch device, and thus the cost of the semi-controlled switch unit is lower than that of the fully-controlled switch device. By providing a semi-controlled switch device in the full-bridge module that can be turned off when the fully-controlled switch device is turned off, the present disclosure enables the full-bridge module to achieve its original functions without affecting its performance, reduces the circuit cost, and also reduces the control complexity of the full-bridge module since the semi-controlled switch device does not require control for turning off. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0050] Figure 1 Structural schematic diagram of a commutation circuit provided by an embodiment of the present disclosure.

[0051] Figure 2 Structural schematic diagram of a switching unit provided by an embodiment of the present disclosure.

[0052] Figure 3 Another structural schematic diagram of a commutation circuit provided by an embodiment of the present disclosure.

[0053] Figure 4 Another structural schematic diagram of a commutation circuit provided by an embodiment of the present disclosure.

[0054] Figure 5 Structural schematic diagram of an energy storage module provided by an embodiment of the present disclosure.

[0055] Figure 6 Structural schematic diagram of an energy storage system provided by an embodiment of the present disclosure. Detailed implementation manners

[0056] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced without some of these specific details. The following description of the embodiments is only provided to provide a better understanding of the present application by showing examples of the present application.

[0057] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.

[0058] Figure 1 Structural schematic diagram of a commutation circuit provided by an embodiment of the present disclosure. As Figure 1 shown, the commutation circuit includes a full-bridge module 100.

[0059] The full-bridge module 100 is connected to an external energy storage module 200; the full-bridge module 100 includes four switching units 101, at least one of the four switching units 101 includes at least one semi-controlled switching device; at least two of the four switching units 101 include at least one fully-controlled switching device.

[0060] Among them, the energy storage module 200 is used to output a sinusoidal half-wave voltage to the full-bridge module 100.

[0061] Exemplarily, the full-bridge module 100 is also connected to the transformer 300. The external energy storage module 200 can supply power to the full-bridge module 100, so as to supply power to the transformer 300. When the energy storage module 200 supplies power, it provides a sinusoidal half-wave voltage that is twice the frequency of the AC voltage in the transformer 300 to the full-bridge module 100. When supplying power to the transformer 300, it is necessary to convert the sinusoidal half-wave voltage generated by the energy storage module 200 into an AC voltage with the same frequency as the AC voltage in the transformer 300. The full-bridge module 100 includes two bridge arm groups. Two switching units 101 are respectively arranged on each bridge arm group. The midpoints of the bridge arms of the two bridge arm groups are connected to the transformer 300. The AC voltage provided by the energy storage module 200 is output to the transformer 300 through the midpoints of the bridge arms. The external control module (not shown in the figure) is connected to each switching unit 101. By controlling the conduction sequence of the switching units 101 on each bridge arm group, the forward output and the reverse output of the full-bridge module 100 are realized. Therefore, when the full-bridge module 100 works, it outputs the sinusoidal half-wave voltage provided by the energy storage module 200 in the forward direction, and outputs a sinusoidal half-wave voltage that is opposite in phase to the sinusoidal half-wave voltage provided by the energy storage module 200 in the reverse direction, so as to output an AC voltage with a complete cycle to the transformer 300, that is, an AC voltage with the same frequency as the AC voltage in the transformer 300.

[0062] In the switching unit 101, there may be only fully controlled switching devices, or only semi-controlled switching devices, or there may be both fully controlled switching devices and semi-controlled switching devices.

[0063] Since the semi-controlled switching device can only control conduction and cannot control turn-off, it is necessary to indirectly control the turn-on and turn-off of the semi-controlled switching device by controlling the turn-off of the fully controlled switching device. Therefore, in an output loop of the full-bridge module 100, at least one switching unit 101 is provided with a fully controlled switching device, so that this switching unit 101 can be controlled to turn off, thereby indirectly controlling that another switching unit 101 only provided with a semi-controlled switching device in this output loop can be turned off. Also, because the full-bridge module 100 has a forward output loop and a reverse output loop, there are at least two switching units 101 in the full-bridge module that are provided with fully controlled switching devices, and only one switching unit 101 in these two output loops is only provided with a semi-controlled switching device.

[0064] For the case where both fully controlled switching devices and semi - controlled switching devices are provided in the switching unit 101, an external control module can turn off the fully controlled switching devices in this switching unit 101, thereby indirectly turning off other semi - controlled switching devices in this switching unit 101. Also, because semi - controlled switching devices can only control conduction and cannot control turn - off, while fully controlled switching devices can control both conduction and turn - off, the semi - controlled switching unit is simpler in structural design than fully controlled switching devices, which will result in the cost of the semi - controlled switching unit being lower than that of fully controlled switching devices. Therefore, the present disclosure reduces the circuit cost by setting semi - controlled switching devices in the full - bridge module that can be turned off when the fully controlled switching devices are turned off, and on the basis of being able to achieve the original functions without affecting the performance. And because the semi - controlled switching devices do not need to be controlled to turn off, it can also reduce the control complexity of the full - bridge module, thereby reducing the cost of the inverter circuit and reducing the control complexity of the inverter circuit.

[0065] Figure 2 FIG. is a schematic structural diagram of a switching unit provided by an embodiment of the present disclosure, as Figure 2 shown, in the same switching unit 101, the fully controlled switching devices 103, and / or, the semi - controlled switching devices 102 are connected in series in sequence.

[0066] Exemplarily, in the switching unit 101, there may be only fully controlled switching devices 103, only semi - controlled switching devices 102, or both fully controlled switching devices 103 and semi - controlled switching devices 102. In the switching unit 101 where both fully controlled switching devices 103 and semi - controlled switching devices 102 are provided, different arrangement orders between the fully controlled switching devices 103 and the semi - controlled switching devices 102 do not affect the switching function of the switching unit 101. The series connection of each fully controlled switching device 103 and semi - controlled switching device 102 can increase the high - voltage withstand ability of the switching unit 101, thereby meeting the high - voltage withstand requirements of the commutation circuit.

[0067] In some embodiments, Figure 3 FIG. is a schematic structural diagram of another commutation circuit provided by an embodiment of the present disclosure, as Figure 3 shown, the full - bridge module includes a first bridge - arm group 110 and a second bridge - arm group 120.

[0068] The first bridge - arm group 110 includes a first switching unit 111 and a second switching unit 112, and the second bridge - arm group 120 includes a third switching unit 121 and a fourth switching unit 122.

[0069] The first switching unit 111 and the second switching unit 112 are connected to the arm mid - point A of the first bridge - arm group 110, and the third switching unit 121 and the fourth switching unit 122 are connected to the arm mid - point B of the second bridge - arm group 120.

[0070] Among them, the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 all include fully controlled switching devices, and at least one of the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 includes at least one semi-controlled switching device.

[0071] Specifically, the first end of the first switching unit 111 is connected to the energy storage module 200, the second end of the first switching unit 111 is connected to the first end of the second switching unit 112 at the arm midpoint A of the first arm group 110, and the second end of the second switching unit 112 is connected to the energy storage module 200. The first end of the third switching unit 121 is connected to the energy storage module 200, the second end of the third switching unit 121 is connected to the first end of the fourth switching unit 122 at the arm midpoint B of the second arm group 120, and the second end of the fourth switching unit 122 is connected to the energy storage module 200. The arm midpoint A of the first arm group 110 is connected to the transformer 300, and the arm midpoint B of the second arm group 120 is connected to the transformer 300.

[0072] When the energy storage module 200 supplies power to the transformer 300 through the full-bridge module, the full-bridge module first adopts a forward output mode, and the control module controls the first switching unit 111 and the fourth switching unit 122 to conduct. At this time, the second switching unit 112 and the third switching unit 121 remain off, and the sinusoidal half-wave voltage provided by the energy storage module 200 is directly output to the transformer 300. After that, when the full-bridge module adopts a reverse output mode, the control module controls the second switching unit 112 and the third switching unit 121 to conduct, and the first switching unit 111 and the fourth switching unit 122 are disconnected. At this time, the fully controlled switching devices in the first switching unit 111 and the fourth switching unit 122 turn off after receiving the control signal from the control module, and when there is a semi-controlled switching device in the first switching unit 111 or the fourth switching unit 122, after the fully controlled switching device is disconnected, the semi-controlled switching device turns off due to the decrease in current, so as to realize the disconnection of the first switching unit 111 and the fourth switching unit 122. At this time, the sinusoidal half-wave voltage provided by the energy storage module 200 is inverted by the full-bridge circuit and then output to the transformer 300, thereby realizing the output of a complete AC voltage to the transformer 300.

[0073] Exemplarily, for the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 all including fully controlled switching devices, and at least one of the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 including at least one semi-controlled switching device, the following several situations are included:

[0074] Three of the first switch unit 111, the second switch unit 112, the third switch unit 121, and the fourth switch unit 122 include only fully controlled switch devices, and the other one includes a semi-controlled switch device and fully controlled switch devices. For example, the first switch unit 111, the second switch unit 112, and the third switch unit 121 include only fully controlled switch devices, and the fourth switch unit 122 includes a semi-controlled switch device and fully controlled switch devices.

[0075] Alternatively, two of the first switch unit 111, the second switch unit 112, the third switch unit 121, and the fourth switch unit 122 include only fully controlled switch devices, and the other two both include a semi-controlled switch device and fully controlled switch devices. For example, the first switch unit 111 and the second switch unit 112 include only fully controlled switch devices, and the third switch unit 121 and the fourth switch unit 122 include a semi-controlled switch device and fully controlled switch devices.

[0076] Alternatively, one of the first switch unit 111, the second switch unit 112, the third switch unit 121, and the fourth switch unit 122 includes only fully controlled switch devices, and the other three both include a semi-controlled switch device and fully controlled switch devices. For example, the first switch unit 111 includes only fully controlled switch devices, and the second switch unit 112, the third switch unit 121, and the fourth switch unit 122 include a semi-controlled switch device and fully controlled switch devices.

[0077] Alternatively, the first switch unit 111, the second switch unit 112, the third switch unit 121, and the fourth switch unit 122 all include a semi-controlled switch device and fully controlled switch devices.

[0078] For the case where both fully controlled switch devices and semi-controlled switch devices are provided in each switch unit, the external control module can indirectly turn off the other semi-controlled switch devices in this switch unit by controlling the fully controlled switch devices in the switch unit to turn off. By providing semi-controlled switch devices that can be turned off as the fully controlled switch devices are turned off in the full-bridge module, the present disclosure enables the full-bridge module to achieve the original functions without affecting the performance, reduces the circuit cost, and since the semi-controlled switch devices do not need to be controlled to turn off, it can also reduce the control complexity of the full-bridge module, thereby reducing the cost of the inverter circuit and reducing the control complexity of the inverter circuit.

[0079] It should be noted that the above situations are all examples. Since the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 all include fully controlled switching devices, the first switching unit 111, the second switching unit 112, the third switching unit 121, and the fourth switching unit 122 can all be provided with semi-controlled switching devices to achieve the purpose of cost reduction. The number of switching units with semi-controlled switching devices and the data of the semi-controlled switching units set in the switching units need to be set according to the actual situation, as long as it is ensured that fully controlled switching devices are provided in each switching unit, and no specific limitations are made here.

[0080] In some embodiments, Figure 4 is a schematic structural diagram of another commutation circuit provided by an embodiment of the present disclosure. As Figure 4 shown, the full-bridge module includes a third bridge arm group 130 and a fourth bridge arm group 140.

[0081] The third bridge arm group 130 includes a fifth switching unit 131 and a sixth switching unit 132, and the fourth bridge arm group 140 includes a seventh switching unit 141 and an eighth switching unit 142.

[0082] The fifth switching unit 131 and the sixth switching unit 132 are connected to the midpoint C of the bridge arm of the third bridge arm group 130, and the seventh switching unit 141 and the eighth switching unit 142 are connected to the midpoint D of the bridge arm of the fourth bridge arm group 140.

[0083] Among them, at least one of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 only includes semi-controlled switching devices, and at least two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include at least one fully controlled switching device.

[0084] Exemplarily, the first end of the fifth switching unit 131 is connected to the energy storage module 200, the second end of the fifth switching unit 131 is connected to the first end of the sixth switching unit 132 at the midpoint C of the bridge arm of the third bridge arm group 130, and the second end of the sixth switching unit 132 is connected to the energy storage module 200. The first end of the seventh switching unit 141 is connected to the energy storage module 200, the second end of the seventh switching unit 141 is connected to the first end of the eighth switching unit 142 at the midpoint D of the bridge arm of the fourth bridge arm group 140, and the second end of the eighth switching unit 142 is connected to the energy storage module 200. The midpoint C of the third bridge arm group 130 is connected to the transformer 300, and the midpoint D of the fourth bridge arm group 140 is connected to the transformer 300.

[0085] The fifth switching unit 131 and the eighth switching unit 142 are used in the output loop for the forward output of the full-bridge module.

[0086] The sixth switching unit 132 and the seventh switching unit 141 are used in the output loop of the full-bridge module for reverse output. Since in one output loop of the full-bridge module, only one switching unit can include only semi-controlled switching devices, the seventh switching unit 141 and the eighth switching unit 142 are taken as examples where they only include semi-controlled switching devices for introduction.

[0087] When the energy storage module 200 supplies power to the transformer 300 through the full-bridge module, the full-bridge module first adopts the forward output mode, and the control module controls the fifth switching unit 131 and the eighth switching unit 142 to conduct. At this time, the sixth switching unit 132 and the seventh switching unit 141 remain off, and the sinusoidal half-wave voltage provided by the energy storage module 200 is directly output to the transformer 300. After that, when the full-bridge module adopts the reverse output mode, the control module controls the sixth switching unit 132 and the seventh switching unit 141 to conduct, and controls the fifth switching unit 131 to disconnect. At this time, the fully controlled switching device in the fifth switching unit 131 turns off after receiving the control signal from the control module. According to Kirchhoff's current law, the current of the eighth switching unit 142 is the same as the current of the fifth switching unit 131. Therefore, during the process of the current gradually decreasing after the fifth switching unit 131 disconnects, the current of the eighth switching unit 142 also gradually decreases. Thus, it is achieved that the eighth switching unit 142 disconnects as the fifth switching unit 131 disconnects. At this time, the sinusoidal half-wave voltage provided by the energy storage module 200 is inverted by the full-bridge circuit and then output to the transformer 300, thereby achieving the output of a complete AC voltage to the transformer 300.

[0088] Moreover, when the full-bridge module switches from the reverse output mode to the forward output mode, the control module controls the fifth switching unit 131 and the eighth switching unit 142 to conduct, and controls the sixth switching unit 132 to disconnect. At this time, the fully controlled switching device in the sixth switching unit 132 turns off after receiving the control signal from the control module. According to Kirchhoff's current law, the current of the seventh switching unit 141 is the same as the current of the sixth switching unit 132. Therefore, during the process of the current gradually decreasing after the sixth switching unit 132 disconnects, the current of the seventh switching unit 141 also gradually decreases. Thus, it is achieved that the seventh switching unit 141 disconnects as the sixth switching unit 132 disconnects.

[0089] It should be noted that the seventh switching unit 141 and the eighth switching unit 142 only including semi-controlled switching devices are only examples and are not specifically limited here.

[0090] Exemplarily, at least one of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices, and at least two of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 include at least one fully-controlled switch device.

[0091] The situation where only one of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices includes the following cases:

[0092] One of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices, and the other three all include semi-controlled switch devices and fully-controlled switch devices. For example, the fifth switch unit 131 only includes semi-controlled switch devices, and the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 all include semi-controlled switch devices and fully-controlled switch devices.

[0093] Or one of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices, two of the other three all include semi-controlled switch devices and fully-controlled switch devices, and the last one only includes fully-controlled switch devices. For example, the fifth switch unit 131 only includes semi-controlled switch devices, the sixth switch unit 132 and the seventh switch unit 141 include semi-controlled switch devices and fully-controlled switch devices, and the eighth switch unit 142 only includes fully-controlled switch devices.

[0094] Or one of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices, one of the other three includes semi-controlled switch devices and fully-controlled switch devices, and the last two only include fully-controlled switch devices. For example, the fifth switch unit 131 only includes semi-controlled switch devices, the sixth switch unit 132 includes semi-controlled switch devices and fully-controlled switch devices, and the seventh switch unit 141 and the eighth switch unit 142 only include fully-controlled switch devices.

[0095] Or one of the fifth switch unit 131, the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only includes semi-controlled switch devices, and the other three only include fully-controlled switch devices. For example, the fifth switch unit 131 only includes semi-controlled switch devices, and the sixth switch unit 132, the seventh switch unit 141, and the eighth switch unit 142 only include fully-controlled switch devices.

[0096] Since in an output loop of the full-bridge module, only one switching unit can include only semi-controlled switching devices, there can only be the fifth switching unit 131 and the sixth switching unit 132 including only semi-controlled switching devices, or the sixth switching unit 132 and the eighth switching unit 142 including only semi-controlled switching devices, or the seventh switching unit 141 and the eighth switching unit 142 including only semi-controlled switching devices, or the fifth switching unit 131 and the seventh switching unit 141 including only semi-controlled switching devices. On this basis, there are the following cases where only two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include only semi-controlled switching devices:

[0097] Two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include only semi-controlled switching devices, and the other two both include semi-controlled switching devices and fully-controlled switching devices. For example, the fifth switching unit 131 and the sixth switching unit 132 include only semi-controlled switching devices, and the seventh switching unit 141 and the eighth switching unit 142 include semi-controlled switching devices and fully-controlled switching devices.

[0098] Or two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include only semi-controlled switching devices, one of the other two includes semi-controlled switching devices and fully-controlled switching devices, and the last one includes only fully-controlled switching devices. For example, the fifth switching unit 131 and the sixth switching unit 132 include only semi-controlled switching devices, the seventh switching unit 141 includes semi-controlled switching devices and fully-controlled switching devices, and the eighth switching unit 142 includes only fully-controlled switching devices.

[0099] Or two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include only semi-controlled switching devices, and the other two include only fully-controlled switching devices. For example, the fifth switching unit 131 and the sixth switching unit 132 include only semi-controlled switching devices, and the seventh switching unit 141 and the eighth switching unit 142 include only fully-controlled switching devices.

[0100] For multiple switching units, there is a case where only semi-controlled switching devices are provided. The external control module can turn off the fully-controlled switching devices in other switching units, so that the switching units with fully-controlled switching devices in the output loop are turned off, thereby reducing the current in this output loop. When the current decreases, the switching unit with only semi-controlled switching devices is disconnected accordingly, thus realizing the disconnection of all the switching units that need to be disconnected. By providing semi-controlled switching devices in the full-bridge module that can be disconnected following the disconnection of the fully-controlled switching devices, the full-bridge module can achieve the original functions without being affected in performance, while reducing the circuit cost. Moreover, since the semi-controlled switching devices do not need to be controlled to be disconnected, the control complexity of the full-bridge module can also be reduced, thereby realizing the reduction of the cost of the inverter circuit and the control complexity of the inverter circuit.

[0101] It should be noted that the above situations are all examples. Since in an output loop of the full-bridge module, only one switching unit can include only semi-controlled switching devices, when only one of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 includes only semi-controlled switching devices, the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 can all include only semi-controlled switching devices. When two of the fifth switching unit 131, the sixth switching unit 132, the seventh switching unit 141, and the eighth switching unit 142 include only semi-controlled switching devices, as long as these two switching units are not in the same output loop, no specific limitation is made here.

[0102] In some embodiments, the semi-controlled switching device includes a thyristor and a first diode; the positive terminal of the thyristor is connected to the negative terminal of the first diode, and the negative terminal of the thyristor is connected to the positive terminal of the first diode.

[0103] Specifically, when the energy storage module supplies power to the transformer through the full-bridge circuit, the control module controls the fully controlled switch devices of each switch unit to disconnect, so that the current flowing through the thyristor gradually decreases. When the current decreases below the latching current of the thyristor, the thyristor disconnects. After the thyristor disconnects, it enters the reverse recovery period. After a period of reverse recovery time, the thyristor completes the reverse recovery process, thereby restoring the forward blocking ability. When the transformer charges the energy storage module through the full-bridge circuit and the DC voltage just drops to 0, the current will flow through the first diode reversely connected in parallel with the disconnected thyristor for freewheeling until the switch unit in another output loop conducts. Then, the current flowing through the first diode flows through the conducting switch unit in another output loop to the energy storage module. It should be noted that after the thyristor disconnects, it is necessary to ensure that after a period of reverse recovery time of the thyristor, the energy storage module can start working again, so as to avoid the problem that the thyristor is re-conducted when it receives a positive voltage before completing the reverse recovery process, and further avoid the problem of chaotic conduction output logic of the full-bridge circuit.

[0104] In some embodiments, the fully controlled switch device includes an Insulated-Gate Bipolar Transistor (IGBT).

[0105] Or it includes an Integrated Gate-Commutated Thyristor (IGCT) and a second diode.

[0106] The positive terminal of the IGCT is connected to the negative terminal of the second diode, and the negative terminal of the IGCT is connected to the positive terminal of the second diode.

[0107] Specifically, since a body diode is provided in the IGBT, when the IGBT is used as the fully controlled switch device, there is no need to additionally set other diodes, so the complexity of the circuit can be reduced. For the IGCT, the IGCT has a stronger voltage withstand effect than the IGBT. Therefore, the IGCT can be used as the fully controlled switch device in high-voltage devices. When the transformer charges the energy storage module through the full-bridge circuit and the DC voltage just drops to 0, the current will flow through the second diode reversely connected in parallel with the disconnected IGCT, or the body diode in the IGBT for freewheeling until the switch unit in another output loop conducts. Then, the current flowing through the second diode or the body diode flows through the conducting switch unit in another output loop to the energy storage module.

[0108] Figure 5 The figure is a schematic structural diagram of an energy storage module provided by an embodiment of the present disclosure. The energy storage module is connected to the commutation circuit provided in any of the above embodiments, as Figure 5 shown. The energy storage module includes a plurality of battery units 210, and the plurality of battery units 210 are connected in series in sequence.

[0109] The battery cell 210 includes: a DC power supply unit 211 and a half-bridge unit 212.

[0110] The half-bridge unit 212 includes a first transistor Q1 and a second transistor Q2; a first end of the first transistor Q1 is connected to a first end of the DC power supply unit 211, a second end of the first transistor Q1 is connected to a first end of the second transistor Q2, and a second end of the second transistor Q2 is connected to a second end of the DC power supply unit 211; the second end of the first transistor Q1 is connected to a first end of the commutation circuit 400 or an adjacent battery cell 210, and the second end of the second transistor Q2 is connected to a second end of the commutation circuit 400 or an adjacent battery cell 210;

[0111] Wherein, the half-bridge unit 212 is configured to output a sinusoidal half-wave voltage according to the DC voltage provided by the DC power supply unit 211 when the first transistor Q1 receives a pulse width modulation signal.

[0112] Specifically, the DC power supply unit 211 can be a battery or a super capacitor. The working states of the battery cell 210 include three states: a locked state, an input state, and a cut-off state. The control module controls the working modes of the battery cell 210 in different working states through the on-off states of the first transistor Q1 and the second transistor Q2.

[0113] In the locked state, the control module controls the first transistor Q1 and the second transistor Q2 to be turned off. When the current flow direction is from the first end of the commutation circuit 400 to the second end of the commutation circuit 400, the current flow direction in the battery cell 210 is from the first end of the commutation circuit 400, through the body diode of the first transistor Q1 to the DC power supply unit 211, and then through the DC power supply unit 211 to the second end of the commutation circuit 400, and at this time, the DC power supply unit 211 is charged. When the current flow direction is from the second end of the commutation circuit 400 to the first end of the commutation circuit 400, the current flow direction in the battery cell 210 is from the second end of the commutation circuit 400, through the body diode of the second transistor Q2 to the second end of the commutation circuit 400. At this time, the DC power supply unit 211 in the battery cell 210 is not connected to the loop, and the battery cell 210 serves as a bypass.

[0114] In the input state, the control module controls the first transistor Q1 to conduct and the second transistor Q2 to disconnect. When the current flow direction is from the first end of the commutation circuit 400 to the second end of the commutation circuit 400, the current flow direction in the battery unit 210 is from the first end of the commutation circuit 400, through the conducting first transistor Q1, to the DC power supply unit 211, and then through the DC power supply unit 211 to the second end of the commutation circuit 400. At this time, the DC power supply unit 211 is charged. When the current flow direction is from the second end of the commutation circuit 400 to the first end of the commutation circuit 400, the current flow direction in the battery unit 210 is from the second end of the commutation circuit 400 through the DC power supply unit 211 to the conducting first transistor Q1, and then through the conducting first transistor Q1 to the first end of the commutation circuit 400. At this time, the DC power supply unit 211 in the battery unit 210 provides a DC voltage.

[0115] In the cut-off state, the control module controls the first transistor Q1 to disconnect and the second transistor Q2 to conduct. At this time, regardless of the current flow direction, the battery unit 210 acts as a bypass and neither discharges nor charges.

[0116] Therefore, the present disclosure can, in the input state of the battery unit 210, control the charging or discharging of the DC power supply unit 211 by controlling the current flow direction, and further realize the power supply from the energy storage module to the transformer 300 or the charging of the energy storage module by the transformer 300. When n DC power supply units 211 in the battery unit 210 are in the discharging state and the supply voltage of the DC power supply unit 211 is U, since n battery units 210 are connected in series, the energy storage module can provide a voltage of 0 to nU to the commutation circuit 400, and the provided voltage is a sine half-wave voltage.

[0117] In some embodiments, the energy storage system includes at least one commutation circuit provided in any of the above embodiments and at least one energy storage module provided in the above embodiments. The commutation circuits and the energy storage modules are connected in one-to-one correspondence, and the commutation circuits are connected to the power grid.

[0118] Exemplarily, Figure 6 is a schematic structural diagram of an energy storage system provided by an embodiment of the present disclosure. As Figure 6 shown, the energy storage system includes three commutation circuits 400, three energy storage modules 200, and three inductors L.

[0119] The three commutation circuits 400 are connected to the three energy storage modules 200 in one-to-one correspondence. The first ends of the three commutation circuits 400 are all connected to the power grid 500 through inductors L, and the second ends of the three commutation circuits 400 are all connected to the neutral line.

[0120] It can be understood that the energy storage system provided by the embodiments of the present application can achieve the corresponding beneficial effects of the commutation circuit and the energy storage module provided by the above embodiments, which will not be elaborated herein.

[0121] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0122] The above are only specific embodiments of the present disclosure, enabling those skilled in the art to understand or implement the present disclosure. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A commutation circuit, characterized in that, Comprising: A full-bridge module, connected to an external energy storage module; the full-bridge module includes four switching units, at least one of the four switching units includes at least one semi-controlled switching device; at least two of the four switching units include at least one fully-controlled switching device; In the same switching unit, the fully-controlled switching device, and / or, the semi-controlled switching device are connected in series in sequence; Wherein, the energy storage module is used to output a sinusoidal half-wave voltage to the full-bridge module.

2. The commutation circuit according to claim 1, wherein The full-bridge module includes a first bridge arm group and a second bridge arm group; The first bridge arm group includes a first switching unit and a second switching unit, and the second bridge arm group includes a third switching unit and a fourth switching unit; The first switching unit and the second switching unit are connected to the midpoint of the bridge arm of the first bridge arm group, and the third switching unit and the fourth switching unit are connected to the midpoint of the bridge arm of the second bridge arm group; Wherein, the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit all include the fully-controlled switching device, and at least one of the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit includes at least one of the semi-controlled switching devices.

3. The commutation circuit according to claim 2, wherein Three of the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit only include the fully-controlled switching device, and the other one includes the semi-controlled switching device and the fully-controlled switching device, Or, Two of the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit only include the fully-controlled switching device, and the other two both include the semi-controlled switching device and the fully-controlled switching device, Or, One of the first switching unit, the second switching unit, the third switching unit, and the fourth switching unit only includes the fully-controlled switching device, and the other three both include the semi-controlled switching device and the fully-controlled switching device, Or, The first switching unit, the second switching unit, the third switching unit, and the fourth switching unit all include the semi-controlled switching device and the fully-controlled switching device.

4. The commutation circuit according to claim 1, characterized in that The full-bridge module includes a third bridge arm group and a fourth bridge arm group; The third bridge arm group includes a fifth switching unit and a sixth switching unit, and the fourth bridge arm group includes a seventh switching unit and an eighth switching unit; The fifth switching unit and the sixth switching unit are connected to the midpoint of the bridge arm of the third bridge arm group, and the seventh switching unit and the eighth switching unit are connected to the midpoint of the bridge arm of the fourth bridge arm group; Wherein, at least one of the fifth switching unit, the sixth switching unit, the seventh switching unit, and the eighth switching unit only includes the semi-controlled switching device, and at least two of the fifth switching unit, the sixth switching unit, the seventh switching unit, and the eighth switching unit include at least one of the fully-controlled switching devices.

5. The commutation circuit according to claim 4, wherein One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes the semi-controlled switch device, and the other three all include the semi-controlled switch device and the fully-controlled switch device. Or, One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes the semi-controlled switch device, two of the other three all include the semi-controlled switch device and the fully-controlled switch device, and the last one only includes the fully-controlled switch device. Or, One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes the semi-controlled switch device, one of the other three includes the semi-controlled switch device and the fully-controlled switch device, and the last two only include the fully-controlled switch device. Or, One of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only includes the semi-controlled switch device, and the other three only include the fully-controlled switch device.

6. The commutation circuit according to claim 4, wherein Two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include the semi-controlled switch device, and the other two all include the semi-controlled switch device and the fully-controlled switch device. Or, Two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include the semi-controlled switch device, one of the other two includes the semi-controlled switch device and the fully-controlled switch device, and the last one only includes the fully-controlled switch device. Or, Two of the fifth switch unit, the sixth switch unit, the seventh switch unit, and the eighth switch unit only include the semi-controlled switch device, and the other two only include the fully-controlled switch device.

7. The commutation circuit according to any one of claims 1-6, characterized in that, The semi-controlled switch device includes a thyristor and a first diode; The positive terminal of the thyristor is connected to the negative terminal of the first diode, and the negative terminal of the thyristor is connected to the positive terminal of the first diode.

8. The commutation circuit according to any one of claims 1-6, characterized in that, The fully-controlled switch device includes an IGBT, Or, IGCT and a second diode; The positive terminal of the IGCT is connected to the negative terminal of the second diode, and the negative terminal of the IGCT is connected to the positive terminal of the second diode.

9. A energy storage module, characterized in that, Connected to the commutation circuit according to any one of claims 1-8; The energy storage module includes a plurality of battery units, and the plurality of battery units are connected in series in sequence; The battery unit includes: A DC power supply unit; A half-bridge unit, including a first transistor and a second transistor; the first end of the first transistor is connected to the first end of the DC power supply unit, the second end of the first transistor is connected to the first end of the second transistor, and the second end of the second transistor is connected to the second end of the DC power supply unit; the second end of the first transistor is connected to the first end of the commutation circuit or an adjacent battery unit, and the second end of the second transistor is connected to the second end of the commutation circuit or an adjacent battery unit; Among them, the half-bridge unit is configured to output a sinusoidal half-wave voltage according to the DC voltage provided by the DC power supply unit when the first transistor receives a pulse width modulation signal.

10. A energy storage system, characterized in that, Comprising at least one commutation circuit as described in any one of claims 1-8 and at least one energy storage module as described in claim 9; The commutation circuits are connected to the energy storage modules in a one-to-one correspondence, and the commutation circuits are connected to the power grid.

Images