An energy storage cabinet, an energy storage system and a power supply control method of the energy storage cabinet

Abstract

The application provides an energy storage cabinet, an energy storage system and a power supply control method of the energy storage cabinet, and relates to the technical field of energy storage. The energy storage cabinet comprises a direct-current power supply, an auxiliary power supply module, an energy storage converter and an auxiliary system, the input end of the auxiliary power supply module is connected to the direct-current power supply and an alternating-current power supply, the output end of the auxiliary power supply module is connected to the energy storage converter and the auxiliary system, and the auxiliary power supply module comprises a direct-current input unit, an alternating-current input unit, a path gating unit and a power supply output unit. The application adopts one auxiliary power supply module to supply power to the PCS and the auxiliary system of the energy storage cabinet simultaneously, does not need to adopt two sets of independent auxiliary power supply systems to supply power to the energy storage cabinet and the PCS respectively, avoids power supply faults, and thus improves the safety and stability of auxiliary power supply; and the switching power supply and the UPS are cancelled, and thus the cost of auxiliary power supply is reduced.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an energy storage cabinet, an energy storage system, and a power supply control method for the energy storage cabinet. Background Technology

[0002] Existing industrial and commercial energy storage systems employ two independent auxiliary power systems: one for the energy storage cabinet and the other for the power conversion system (PCS). The auxiliary power system for the energy storage cabinet powers the cabinet, while the auxiliary power system for the PCS powers the PCS. The auxiliary power system for the energy storage cabinet can include a DC 24V switching power supply and an uninterruptible power supply (UPS), meaning the energy storage cabinet is powered by both the DC 24V switching power supply and the UPS. The auxiliary power system for the PCS can include a DC 24V auxiliary power board, meaning each functional unit within the PCS is powered by the DC 24V auxiliary power board.

[0003] In existing technologies, the auxiliary power supply system of the energy storage cabinet and the auxiliary power supply system of the PCS have interactive control, which can cause grounding problems and lead to grounding failures, affecting the normal use of the energy storage cabinet and undermining the safety and stability of the auxiliary power supply. Using two independent auxiliary power supply systems increases economic costs and is not conducive to cost reduction and efficiency improvement. The auxiliary power supply system of the energy storage cabinet uses switching power supplies and UPS, which have high construction and maintenance costs. Summary of the Invention

[0004] In view of this, embodiments of this application provide an energy storage cabinet, an energy storage system, and a power supply control method for the energy storage cabinet, which reduces the cost of auxiliary power supply and improves the safety and stability of auxiliary power supply.

[0005] This application provides an energy storage cabinet, including: a DC power supply, an auxiliary power module, an energy storage converter, and an auxiliary system. The input terminal of the auxiliary power module is connected to the DC power supply and the AC power supply, and the output terminal of the auxiliary power module is connected to the energy storage converter and the auxiliary system. The auxiliary power module includes a DC input unit, an AC input unit, a path selection unit, and a power output unit. The DC input unit is used to convert the DC voltage input from the DC power supply into a DC / DC converter to generate a first DC voltage. The AC input unit is used to convert the AC voltage input by the AC power supply into AC / DC to generate a second DC voltage. The path selection unit is used to connect or disconnect the DC input unit and the power output unit under the control of the control unit, and to connect or disconnect the AC input unit and the power output unit. The power output unit is configured to supply power to the energy storage converter and the auxiliary system based on a first DC voltage output by the DC input unit when the connection between the DC input unit and the power output unit is on and the connection between the AC input unit and the power output unit is off; or, to supply power to the energy storage converter and the auxiliary system based on a second DC voltage output by the AC input unit when the connection between the AC input unit and the power output unit is on and the connection between the DC input unit and the power output unit is off; or, not to supply power to the energy storage converter and the auxiliary system when the connection between the AC input unit and the power output unit is off and the connection between the DC input unit and the power output unit is off.

[0006] In one possible implementation, the DC input unit includes a switching unit, a first inductor, and a first capacitor; a first terminal of the switching unit is connected to the DC power supply, and a second terminal of the switching unit is connected to a first terminal of the first inductor and a second terminal of the first capacitor; a second terminal of the first inductor is connected to a first terminal of the first capacitor and the path selection unit; a second terminal of the first capacitor is connected to the path selection unit. The switching unit is configured to connect the DC power supply and the first inductor under the control of the control unit, so that the DC power supply charges the first inductor and the first capacitor, and the DC power supply outputs the first DC voltage through the first inductor and the first capacitor. The switching unit is used to disconnect the connection between the DC power supply and the first inductor under the control of the control unit, so that the first inductor and the first capacitor output a first DC voltage.

[0007] In one possible implementation, the switching unit includes a first switching transistor and a second switching transistor; The control terminal of the first switching transistor is connected to the control unit, the first terminal of the first switching transistor is connected to the positive terminal of the DC power supply, and the second terminal of the first switching transistor is connected to the first terminal of the first inductor and the first terminal of the second switching transistor. The control terminal of the second switch is connected to the control unit, and the second terminal of the second switch is connected to the second terminal of the first capacitor and the path selection unit.

[0008] In one possible implementation, the AC input unit includes a step-down unit, a rectifier unit, and a filter unit. The input terminal of the step-down unit is connected to the AC power supply, the output terminal of the step-down unit is connected to the input terminal of the rectifier unit, the output terminal of the rectifier unit is connected to the input terminal of the filter unit, and the output terminal of the filter unit is connected to the path selection unit. The step-down unit is used to step down the AC voltage input from the AC power supply to generate a stepped-down AC voltage. The rectifier unit is used to rectify the stepped-down AC voltage to generate a pulsating DC voltage; The filtering unit is used to smooth the pulsating DC voltage to generate the second DC voltage.

[0009] In one possible implementation, the step-down unit includes a step-down transformer, the rectifier unit includes a first diode and a second diode, and the filter unit includes a second capacitor; The primary side of the step-down transformer is connected to the AC power supply, the first terminal of the secondary side of the step-down transformer is connected to the positive terminal of the first diode, the second terminal of the secondary side of the step-down transformer is connected to the second terminal of the second capacitor, and the third terminal of the secondary side of the step-down transformer is connected to the positive terminal of the second diode. The cathode of the first diode is connected to the first terminal of the second capacitor, and the cathode of the second diode is also connected to the first terminal of the second capacitor. The first and second terminals of the second capacitor are also connected to the path selection unit.

[0010] In one possible implementation, the path selection unit includes a first selection unit and a second selection unit, wherein the first selection unit is connected between the DC input unit and the power output unit, and the second selection unit is connected between the AC input unit and the power output unit; The first gating unit is used to connect or disconnect the DC input unit and the power output unit under the control of the control unit; The second gating unit is used to connect or disconnect the AC input unit and the power output unit under the control of the control unit.

[0011] In one possible implementation, both the first gating unit and the second gating unit include two switches.

[0012] In one possible implementation, the switch includes a mechanical switch, a relay, or a switching transistor.

[0013] In one possible implementation, the energy storage converter includes the control unit, and the energy storage cabinet includes a BCU, which is integrated into the control unit.

[0014] In one possible implementation, the auxiliary system includes at least one of an energy storage cabinet auxiliary control system, a battery management system, a fire protection system, a heat dissipation control system, and an energy management system.

[0015] This application provides an energy storage system, including: at least one energy storage cabinet as described in the first aspect or any possible implementation of the first aspect.

[0016] This application embodiment provides a power supply control method for an energy storage cabinet. The energy storage cabinet includes a DC power supply, an auxiliary power module, an energy storage converter, and an auxiliary system. The input terminal of the auxiliary power module is connected to the DC power supply and an AC power supply, and the output terminal of the auxiliary power module is connected to the energy storage converter and the auxiliary system. The auxiliary power module includes a DC input unit for converting the DC voltage input from the DC power supply into a first DC voltage via DC / DC conversion, an AC input unit for converting the AC voltage input from the AC power supply into a second DC voltage via AC / DC conversion, a path selection unit, and a power output unit. The method is implemented based on a control unit. The method includes: The control unit controls the path selection unit to connect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so that the DC input unit outputs a first DC voltage to the power output unit, and the power output unit supplies power to the energy storage converter and the auxiliary system according to the first DC voltage; or, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and connect the AC input unit and the power output unit, so that the AC input unit outputs a second DC voltage to the power output unit, and the power output unit supplies power to the energy storage converter and the auxiliary system according to the second DC voltage; or, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so that neither the DC input unit nor the AC input unit outputs voltage to the power output unit, so that the power output unit does not supply power to the energy storage converter and the auxiliary system.

[0017] In one possible implementation, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and connect the AC input unit and the power output unit, causing the AC input unit to output a second DC voltage to the power output unit. Before the power output unit supplies power to the energy storage converter and the auxiliary system based on the second DC voltage, the method further includes: The control unit determines that the detected operating state of the energy storage converter is the running state.

[0018] In one possible implementation, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit, and also disconnects the AC input unit and the power output unit, so that neither the DC input unit nor the AC input unit outputs voltage to the power output unit. Before the power output unit stops supplying power to the energy storage converter and the auxiliary system, the implementation further includes: The control unit determines that the detected energy storage converter is in standby mode. After a set time period, it executes the step of controlling the path selection unit to disconnect the DC input unit and the power output unit, and disconnect the AC input unit and the power output unit.

[0019] In one possible implementation, the control unit controls the path selection unit to connect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, causing the DC input unit to output a first DC voltage to the power output unit. After the power output unit supplies power to the energy storage converter and the auxiliary system based on the first DC voltage, the system further includes: The control unit determines whether the detected energy storage converter is in operation or standby mode.

[0020] In the technical solution provided in this application embodiment, the energy storage cabinet includes a DC power supply, an auxiliary power module, a PCS, and an auxiliary system. The auxiliary power module includes a DC input unit, an AC input unit, a path selection unit, and a power output unit. The path selection unit, under the control of the control unit, connects or disconnects the DC input unit and the power output unit, as well as the AC input unit and the power output unit. When the connection between the DC input unit and the power output unit is on and the connection between the AC input unit and the power output unit is off, the power output unit supplies power to the PCS and the auxiliary system through a first DC voltage output by the DC input unit, or... When the AC input unit and the power output unit are connected and the DC input unit and the power output unit are disconnected, the source output unit supplies power to the PCS and auxiliary system through the second DC voltage output by the AC input unit. In this embodiment, one auxiliary power module is used to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, eliminating the need for two separate auxiliary power systems to supply power to the energy storage cabinet and the PCS respectively, thus avoiding power supply failures and improving the safety and stability of the auxiliary power supply. By using one auxiliary power module to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, the switching power supply and UPS are eliminated, thereby reducing the cost of auxiliary power supply. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an energy storage cabinet provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a DC input unit provided in an embodiment of this application; Figure 3 A waveform diagram of a first DC voltage provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of an AC input unit provided in an embodiment of this application; Figure 5 This is a schematic diagram of another energy storage cabinet provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of another energy storage cabinet provided in the embodiments of this application; Figure 7 A flowchart illustrating a control method for an energy storage cabinet provided in an embodiment of this application. Detailed Implementation

[0023] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0024] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0025] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0027] Figure 1This is a schematic diagram of the structure of an energy storage cabinet provided in an embodiment of this application, as shown below. Figure 1 As shown, the energy storage cabinet may include: a DC power supply 1, an auxiliary power module 2, a PCS 3, and an auxiliary system 4. The input terminal of the auxiliary power module 2 is connected to the DC power supply 1 and the AC power supply 5, and the output terminal of the auxiliary power module 2 is connected to the PCS 3 and the auxiliary system 4. The auxiliary power module 2 includes a DC input unit 21, an AC input unit 22, a path selection unit 23, and a power output unit 24.

[0028] The DC input unit 21 is used to convert the DC voltage input from the DC power supply 1 into a DC / DC converter to generate a first DC voltage; the AC input unit 22 is used to convert the AC voltage input from the AC power supply 5 into an AC / DC converter to generate a second DC voltage; the path selection unit 23 is used to connect or disconnect the DC input unit 21 and the power output unit 24 under the control of the control unit 6, and to connect or disconnect the AC input unit 22 and the power output unit 24; the power output unit 24 is used to supply power to the PCS 3 and the auxiliary system 4 according to the first DC voltage output by the DC input unit 21 when the connection between the DC input unit 21 and the power output unit 24 is connected and the connection between the AC input unit 22 and the power output unit 24 is disconnected; or, when the connection between the AC input unit 22 and the power output unit 24 is connected and the connection between the DC input unit 21 and the power output unit 24 is disconnected, to supply power to the PCS 3 and the auxiliary system 4 according to the second DC voltage output by the AC input unit 22. PCS 3 and auxiliary system 4 are powered; or, when the connection between AC input unit 22 and power output unit 24 is disconnected and the connection between DC input unit 21 and power output unit 24 is disconnected, power is not supplied to PCS 3 and auxiliary system 4.

[0029] In this embodiment of the application, the DC power supply 1 may include a DC battery pack, and the AC power supply 5 is the AC power supply from the power grid.

[0030] As an optional solution, auxiliary system 4 may include at least one of the following: energy storage cabinet auxiliary control system, battery management system, fire protection system, heat dissipation control system, and energy management system. For example... Figure 1 As shown in the embodiments of this application, the auxiliary system 4 includes an energy storage cabinet auxiliary control system, a battery management system, a fire protection system, a heat dissipation control system, and an energy management system (EMS). In practical applications, the auxiliary system 4 may also include other systems that require auxiliary power supply, which will not be listed here.

[0031] In this embodiment, the power output unit 24 includes multiple output channels, each of which can correspond to a system requiring auxiliary power supply. For example, the first output channel is used to power the PCS, the second output channel is used to power the auxiliary control system of the energy storage cabinet, the third output channel is used to power the battery management system, the fourth output channel is used to power the fire protection system, the fifth output channel is used to power the heat dissipation control system, and the sixth output channel is used to power the energy management system.

[0032] In this embodiment of the application, the auxiliary system 4 may include multiple systems that require auxiliary power supply, thereby enabling the auxiliary power module 2 to simultaneously supply power to multiple systems that require auxiliary power supply.

[0033] In this embodiment of the application, PCS 3 includes a control unit 6, that is, the control unit 6 is disposed inside PCS 3, and the control unit 6 is the control unit of PCS 3.

[0034] As an optional solution, the energy storage cabinet includes a Battery Cluster Management Unit (BCU), which is integrated into the control unit 6. This integrates the control units of the BCU and the PCS into a single control unit. The control unit 6, which integrates the BCU, can realize the functions of the PCS and the BCU, thereby improving the integration of the energy storage cabinet, reducing costs, increasing the functions that the PCS can achieve, and improving the stability and reliability of the system.

[0035] In the technical solution provided in this application embodiment, the energy storage cabinet includes a DC power supply, an auxiliary power module, a PCS, and an auxiliary system. The auxiliary power module includes a DC input unit, an AC input unit, a path selection unit, and a power output unit. The path selection unit, under the control of the control unit, connects or disconnects the DC input unit and the power output unit, as well as the AC input unit and the power output unit. When the connection between the DC input unit and the power output unit is on and the connection between the AC input unit and the power output unit is off, the power output unit supplies power to the PCS and the auxiliary system through a first DC voltage output by the DC input unit, or... When the AC input unit and the power output unit are connected and the DC input unit and the power output unit are disconnected, the source output unit supplies power to the PCS and auxiliary system through the second DC voltage output by the AC input unit. In this embodiment, one auxiliary power module is used to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, eliminating the need for two separate auxiliary power systems to supply power to the energy storage cabinet and the PCS respectively, thus avoiding power supply failures and improving the safety and stability of the auxiliary power supply. By using one auxiliary power module to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, the switching power supply and UPS are eliminated, thereby reducing the cost of auxiliary power supply.

[0036] Figure 2 This is a schematic diagram of the structure of a DC input unit provided in an embodiment of this application, as shown below. Figure 1 and Figure 2 As shown, the DC input unit 21 includes a switching unit 211, a first inductor L1, and a first capacitor C1. The first terminal of the switching unit 211 is connected to the DC power supply 1, and the second terminal of the switching unit 211 is connected to the first terminal of the first inductor L1 and the second terminal of the first capacitor C1; the second terminal of the first inductor L1 is connected to the first terminal of the first capacitor C1 and the path selection unit 23; the second terminal of the first capacitor C1 is connected to the path selection unit 23.

[0037] Switching unit 211, under the control of control unit 6, is used to connect the DC power supply 1 and the first inductor L1, so that the DC power supply 1 charges the first inductor L1 and the first capacitor C1, and the DC power supply 1 outputs a first DC voltage through the first inductor L1 and the first capacitor C1; switching unit 211, under the control of control unit 6, is also used to disconnect the DC power supply 1 and the first inductor L1, so that the first inductor L1 and the first capacitor C1 output the first DC voltage. This achieves DC / DC conversion of the DC voltage input to the DC power supply 1 to generate the first DC voltage.

[0038] In this embodiment, the DC input unit may include a switching unit, a first inductor, and a first capacitor. The switching unit, the first inductor, and the first capacitor can be used to convert the DC voltage input by the DC power supply into a first DC voltage through DC / DC conversion, thus simplifying the structure of the DC input unit.

[0039] like Figure 1 and Figure 2 As shown, the switching unit 211 includes a first switching transistor G1 and a second switching transistor G2. The control terminal of the first switching transistor G1 is connected to the control unit 6, the first terminal of the first switching transistor G1 is connected to the positive terminal of the DC power supply 1, and the second terminal of the first switching transistor G1 is connected to the first terminal of the first inductor L1 and the first terminal of the second switching transistor G2. The control terminal of the second switching transistor G2 is connected to the control unit 6, and the second terminal of the second switching transistor G2 is connected to the second terminal of the first capacitor C1 and the path selection unit 23.

[0040] like Figure 2As shown, when the control unit 6 controls the first switch G1 to be turned on and the second switch G2 to be turned off, the DC power supply 1 charges the first inductor L1 and the first capacitor C1, and simultaneously the DC output channel of the DC input unit 21 outputs the first DC voltage. When the control unit 6 controls the first switch G1 to be turned off, the DC power supply 1 cannot charge the first inductor L1 and the first capacitor C1, and the DC output channel of the DC input unit 21 also cannot output voltage; simultaneously, the control unit 6 controls the second switch G2 to be turned on, and the first inductor L1 and the first capacitor C1 output the first DC voltage through the DC output channel. This achieves DC / DC conversion of the DC voltage input from the DC power supply 1 to generate the first DC voltage.

[0041] As an alternative, the first switch G1 and the second switch G2 may include metal-oxide-semiconductor field-effect transistors (MOSFETs). For example, the first switch G1 and the second switch G2 may be N-type MOSFETs.

[0042] In this embodiment, the switching unit includes a first switching transistor and a second switching transistor. By controlling the conduction and shutdown of the two switching transistors, it is possible to determine whether the DC power supply can charge the first inductor and the first capacitor, thereby realizing the DC / DC conversion of the DC voltage input by the DC power supply to generate the first DC voltage. This makes the structure of the DC input unit simple and the voltage conversion efficiency high.

[0043] Figure 3 A waveform diagram of a first DC voltage provided in an embodiment of this application is shown below. Figure 3 As shown, the DC input voltage of DC power supply 1 can be 800V, from which... Figure 2 The DC input unit 21 shown performs DC / DC conversion on the DC voltage, and the first output DC voltage can be 24V. The control unit 6 periodically controls the on and off of the first switch G1, so that the first DC voltage output by the DC output channel of the DC input unit 21 changes periodically, such as... Figure 3 As shown, the first DC voltage exhibits periodic changes, thus effectively stabilizing at approximately 24V after the voltage drop. This stabilization of the output first DC voltage to around 24V can be achieved by selecting the parameters of the first inductor L1 and the first capacitor C1.

[0044] Figure 4 This is a schematic diagram of the structure of an AC input unit provided in an embodiment of this application, as shown below. Figure 1 and Figure 4As shown, the AC input unit 22 includes a step-down unit 221, a rectifier unit 222, and a filter unit 223. The input terminal of the step-down unit 221 is connected to the AC power supply 5, the output terminal of the step-down unit 221 is connected to the input terminal of the rectifier unit 222, the output terminal of the rectifier unit 222 is connected to the input terminal of the filter unit 223, and the output terminal of the filter unit 223 is connected to the path selection unit 23. The step-down unit 221 is used to step down the AC voltage input from the AC power supply to generate a stepped-down AC voltage; the rectifier unit 222 is used to rectify the stepped-down AC voltage to generate a pulsating DC voltage; and the filter unit 223 is used to smooth the pulsating DC voltage to generate a second DC voltage.

[0045] In this embodiment, the AC input unit includes a step-down unit, a rectifier unit, and a filter unit. The step-down unit, rectifier unit, and filter unit can convert the AC voltage input by AC power supply into a second DC voltage, thus simplifying the structure of the AC input unit.

[0046] like Figure 1 and Figure 4 As shown, the step-down unit 221 includes a step-down transformer T, the rectifier unit 222 includes a first diode D1 and a second diode D2, and the filter unit 223 includes a second capacitor C2. The primary side A1 of the step-down transformer T is connected to the AC power supply 5. The first terminal B1 of the secondary side A2 of the step-down transformer T is connected to the positive terminal of the first diode D1, the second terminal B2 of the secondary side A2 of the step-down transformer T is connected to the second terminal of the second capacitor C2, and the third terminal B3 of the secondary side A2 of the step-down transformer T is connected to the positive terminal of the second diode D2. The negative terminal of the first diode D1 is connected to the first terminal of the second capacitor C2, and the negative terminal of the second diode D2 is connected to the first terminal of the second capacitor C2. The first and second terminals of the second capacitor C2 are also connected to the path selection unit 23.

[0047] like Figure 4As shown, AC power supply 5 inputs AC voltage to the primary side A1 of step-down transformer T. Step-down transformer T steps down the AC voltage so that the secondary side B2 of step-down transformer T outputs the stepped-down AC voltage. During the positive half-cycle of the stepped-down AC voltage, the potential of the first terminal B1 is positive, the potential of the second terminal B2 is 0, and the potential of the third terminal B3 is negative. This causes the first diode D1 to conduct in the forward direction and the second diode D2 to be reverse-biased and cut off. Therefore, during the positive half-cycle, the forward-conducting first diode D1 rectifies the stepped-down AC voltage to generate a pulsating DC voltage. Then, the second capacitor C2 rectifies the pulsating DC voltage. The voltage is smoothed to generate a second DC voltage, which is then output through the DC output channel. During the negative half-cycle of the stepped-down AC voltage, the potential of the first terminal B1 is negative, the potential of the second terminal B2 is 0, and the potential of the third terminal B3 is positive. This causes the second diode D2 to conduct in the forward direction and the first diode D1 to be reverse-biased and cut off. Therefore, during the negative half-cycle, the forward-conducting second diode D2 rectifies the stepped-down AC voltage to generate a pulsating DC voltage. Then, the second capacitor C2 smooths the pulsating DC voltage to generate the second DC voltage, which is then output through the DC output channel. It can be seen that the AC input unit 22 outputs a second DC voltage in both the positive and negative half-cycles, thus stabilizing the output DC voltage.

[0048] In this embodiment, the step-down unit includes a step-down transformer, the rectifier unit includes a first diode and a second diode, and the filter unit includes a second capacitor. The AC voltage input from the AC power supply can be converted from AC to DC to generate a second DC voltage through the step-down transformer, the first diode, the second diode, and the second capacitor. This makes the structure of the AC input unit simple and the voltage conversion efficiency high.

[0049] Figure 5 This is a schematic diagram of another energy storage cabinet provided in an embodiment of this application, as shown below. Figure 5 As shown, in Figure 1 Based on the energy storage cabinet, the path selection unit 23 includes a first selection unit 231 and a second selection unit 232. The first selection unit 231 is connected between the DC input unit 21 and the power output unit 24, and the second selection unit 232 is connected between the AC input unit 22 and the power output unit 24. The first selection unit 231 is used to connect or disconnect the connection between the DC input unit 21 and the power output unit 24 under the control of the control unit 6; the second selection unit 232 is used to connect or disconnect the connection between the AC input unit 22 and the power output unit 24 under the control of the control unit 6.

[0050] like Figure 5As shown, when the first gating unit 231 connects the DC input unit 21 and the power output unit 24 under the control of the control unit 6, and the second gating unit 232 disconnects the AC input unit 22 and the power output unit 24 under the control of the control unit 6, the DC input unit 21 outputs a first DC voltage to the power output unit 24; when the first gating unit 231 disconnects the DC input unit 21 and the power output unit 24 under the control of the control unit 6, and the second gating unit 232 connects the AC input unit 22 and the power output unit 24 under the control of the control unit 6, the AC input unit 22 outputs a second DC voltage to the power output unit 24.

[0051] In this embodiment, the path selection unit includes a first selection unit and a second selection unit. Under the control of the control unit, the first selection unit connects or disconnects the DC input unit and the power output unit. Under the control of the control unit, the second selection unit connects or disconnects the AC input unit and the power output unit. This allows the switching of voltage output between the DC input unit and the AC input unit to be realized through the first selection unit and the second selection unit. The switching method is simple and the switching efficiency is high.

[0052] Figure 6 This is a schematic diagram of the structure of another energy storage cabinet provided in the embodiments of this application, as shown below. Figure 6 As shown, in Figure 5 Based on the energy storage cabinet shown, both the first gating unit 241 and the second gating unit 242 may include at least one switch. Alternatively, both the first gating unit and the second gating unit may include two switches.

[0053] In this embodiment, the first gating unit 241 includes two switches, namely a first switch K1 and a second switch K2. The first switch K1 is connected between the first terminal of the first capacitor C1 and the power output unit 25, and the second switch K2 is connected between the second terminal of the first capacitor C1 and the power output unit 25. The second gating unit 242 includes two switches, namely a third switch K3 and a fourth switch K4. The third switch K3 is connected between the first terminal of the second capacitor C3 and the power output unit 25, and the fourth switch K4 is connected between the second terminal of the second capacitor C3 and the power output unit 25.

[0054] In this embodiment, both the first gating unit and the second gating unit include two switches, thereby improving the safety and reliability of the circuit.

[0055] As an alternative, the switches may include mechanical switches or relays; that is, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 may all include mechanical switches or relays. In this embodiment, using the above-mentioned type of switch simplifies the switch structure and reduces costs.

[0056] In practical applications, the switch may also include a switching transistor, such as a MOSFET or an insulated-gate bipolar transistor (IGBT). That is, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 can all include MOSFETs or IGBTs. In this embodiment, using MOSFETs or IGBTs as switches enables fast switching and a fast response time.

[0057] like Figure 6 As shown, a detailed description of the structure of the DC input unit 21 and the AC input unit 22 can be found in [reference needed]. Figure 2 and Figure 4 The description of the illustrated embodiments will not be repeated here. It should be noted that: Figure 6 As shown, the control unit 6 is also connected to the control terminal of the first switch G1 and the control terminal of the second switch G2. The connection lines in the figure are not specifically drawn.

[0058] This application provides an energy storage system, which may include an energy storage cabinet. A description of the energy storage cabinet can be found above. Figures 1 to 6 The descriptions in the illustrated embodiments will not be repeated here.

[0059] In this embodiment, the energy storage system can be a small-scale industrial or commercial energy storage system, and the energy storage cabinet is an integrated cabinet including a PCS. The energy storage system in this embodiment can meet the needs of long-term energy storage, achieving long-term energy storage of 4 hours or more, for example, it can be applied to energy storage scenarios such as 5 hours, 6 hours, and 8 hours. Long-term energy storage means being able to continuously discharge for 4 hours or even longer at rated power, or achieving large-scale, low-cost energy storage for several days or months.

[0060] based on Figures 1 to 6The energy storage cabinet shown in this application provides a power supply control method for the energy storage cabinet. This method may include: a control unit controlling a path selection unit to connect the DC input unit and the power output unit while disconnecting the AC input unit and the power output unit, causing the DC input unit to output a first DC voltage to the power output unit, which then supplies power to the PCS and auxiliary systems based on the first DC voltage; or, the control unit controlling the path selection unit to disconnect the DC input unit and the power output unit while connecting the AC input unit and the power output unit, causing the AC input unit to output a second DC voltage to the power output unit, which then supplies power to the PCS and auxiliary systems based on the second DC voltage; or, the control unit controlling the path selection unit to disconnect both the DC input unit and the power output unit, causing neither the DC input unit nor the AC input unit to output voltage to the power output unit, so that the power output unit does not supply power to the PCS and auxiliary systems.

[0061] As an optional solution, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and connect the AC input unit and the power output unit, so that the AC input unit outputs a second DC voltage to the power output unit. Before the power output unit supplies power to the energy storage converter and the auxiliary system according to the second DC voltage, the control unit further includes: determining that the detected working state of the energy storage converter is the running state.

[0062] As an optional solution, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit, and disconnect the AC input unit and the power output unit, so that neither the DC input unit nor the AC input unit outputs voltage to the power output unit, so that the power output unit does not supply power to the energy storage converter and the auxiliary system. Before this, the control unit further includes: determining that the detected energy storage converter is in standby mode, and after a set time period, executing the step of the control unit controlling the path selection unit to disconnect the DC input unit and the power output unit, and disconnect the AC input unit and the power output unit.

[0063] In the technical solution provided in this application embodiment, the energy storage cabinet includes a DC power supply, an auxiliary power module, a PCS, and an auxiliary system. The auxiliary power module includes a DC input unit, an AC input unit, a path selection unit, and a power output unit. The path selection unit, under the control of the control unit, connects or disconnects the DC input unit and the power output unit, as well as the AC input unit and the power output unit. When the connection between the DC input unit and the power output unit is on and the connection between the AC input unit and the power output unit is off, the power output unit supplies power to the PCS and the auxiliary system through a first DC voltage output by the DC input unit. When the connection between the AC input unit and the power output unit is made on and the connection between the DC input unit and the power output unit is made off, the power output unit supplies power to the PCS and auxiliary system through the second DC voltage output by the AC input unit. In this embodiment, one auxiliary power module is used to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, eliminating the need for two separate auxiliary power systems to supply power to the energy storage cabinet and the PCS respectively, thus avoiding power supply failures and improving the safety and stability of the auxiliary power supply. By using one auxiliary power module to supply power to the auxiliary system of the PCS and the energy storage cabinet simultaneously, the switching power supply and UPS are eliminated, thereby reducing the cost of auxiliary power supply.

[0064] Figure 7 A flowchart of a control method for an energy storage cabinet provided in an embodiment of this application is shown below. Figure 7 As shown, the method includes: Step 102: The control unit controls the path selection unit to connect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so as to output the first DC voltage to the power output unit.

[0065] Step 104: The power output unit supplies power to the PCS and auxiliary system according to the first DC voltage.

[0066] Step 106: The control unit determines whether the detected PCS is in running state or standby state. If it is in running state, proceed to step 108; if it is in standby state, proceed to step 112.

[0067] In this embodiment, the control unit determines whether to switch to AC input unit power supply and whether to continue power supply based on the operating status of the PCS, thereby achieving the purpose of saving power.

[0068] Step 108: The control unit controls the path selection unit to connect the AC input unit and the power output unit and disconnect the DC input unit and the power output unit to output the second DC voltage to the power output unit.

[0069] Step 110: The power output unit supplies power to the PCS and auxiliary system according to the second DC voltage.

[0070] When the control unit determines that the PCS is in the running state, it indicates that the PCS can work normally. At this time, the connection between the DC input unit and the power output unit can be switched to the connection between the AC input unit and the power output unit. This allows the output of the first DC voltage from the DC input unit to the output of the second DC voltage from the AC input unit, thereby enabling the AC input unit to supply power to the PCS and auxiliary systems through the power output unit, saving DC-side power.

[0071] Step 112: After a set time period, the control unit disconnects the DC input unit and the power output unit from the control path selection unit, so that the DC input unit does not output voltage to the power output unit and the power output unit does not supply power to the PCS and auxiliary system.

[0072] When the control unit determines that the PCS is in standby mode, it disconnects the DC input unit and the power output unit after a set time period, ensuring that the entire energy storage cabinet is powered off only when it does not need to be restarted. Since the control unit had already disconnected the AC input unit and the power output unit via the path selection unit in step 102, and continues to do so in step 112, neither the DC input unit nor the AC input unit outputs voltage to the power output unit. This prevents the power output unit from supplying power to the PCS and auxiliary systems, thus shutting down the PCS.

[0073] In this embodiment of the application, when it is determined that the working state of the PCS is standby, the connection between the DC input unit and the power output unit is disconnected, so that the DC input unit does not output voltage to the power output unit, thereby saving the power on the DC side.

[0074] In this embodiment, the auxiliary system may include a heat dissipation control system, and the power output unit may supply power to the heat dissipation control system according to a first DC voltage. Specifically, the power output unit supplying power to the heat dissipation control system according to the first DC voltage may include: the power output unit receiving a heat dissipation control command sent by the control unit, and responding to the heat dissipation control command by supplying power to the heat dissipation control system according to the first DC voltage.

[0075] As an optional solution, the control unit determines whether the output power of the AC output board of the PCS is greater than or equal to a set power threshold. If the output power is determined to be greater than or equal to the power threshold, a heat dissipation control command is output to the power output unit. In this embodiment, the control unit only controls the power output unit to supply power to the heat dissipation control system through the heat dissipation control command when the output power is large, so that the heat dissipation control system can work to achieve the purpose of heat dissipation.

[0076] Furthermore, if the control unit determines that the output power is less than the power threshold, it outputs a stop cooling command to the power output unit, causing the power output unit to stop supplying power to the cooling control system in response to the stop cooling command. When the output power is low, no cooling is required; therefore, the stop cooling command can be used to control the power output unit to stop supplying power to the cooling control system, thereby causing the cooling control system to stop working.

[0077] In this embodiment, the control unit determines whether to control the power output unit to supply power to the heat dissipation control system by obtaining the output power of the AC output board of the PCS. This enables the heat dissipation control system to operate only when the output power is high, thereby saving energy.

[0078] As an alternative, the control unit determines whether the temperature of the IGBT module on the PCS power board is greater than or equal to a set temperature threshold. If the temperature of the IGBT module is determined to be greater than or equal to the temperature threshold, a heat dissipation control command is output to the power output unit. In this embodiment, the control unit only controls the power output unit to supply power to the heat dissipation control system through the heat dissipation control command when the temperature of the IGBT module is high, so that the heat dissipation control system can work to achieve the purpose of heat dissipation.

[0079] Furthermore, if the control unit determines that the temperature of the IGBT module is below a temperature threshold, it outputs a stop-heat dissipation command to the power output unit, causing the power output unit to stop supplying power to the heat dissipation control system in response to the stop-heat dissipation command. When the temperature of the IGBT module is low, no heat dissipation is required; therefore, the stop-heat dissipation command can be used to control the power output unit to stop supplying power to the heat dissipation control system, thereby causing the heat dissipation control system to stop operating.

[0080] In this embodiment, the control unit determines whether to control the power output unit to supply power to the heat dissipation control system by obtaining the temperature of the IGBT module of the power board of the PCS. This enables the heat dissipation control system to operate only when the temperature is high, thereby saving energy.

[0081] Since both the auxiliary system and the PCS of the energy storage cabinet require a DC 24V auxiliary power supply as their working power, this embodiment of the application uses an auxiliary power module as the auxiliary power system of the energy storage cabinet. This auxiliary power module can supply power to both the PCS and the auxiliary system simultaneously.

[0082] In this embodiment, the auxiliary power module achieves path selection between the DC input unit and the AC input unit through the path selection unit, realizes mutual redundant switching between the DC input unit and the AC input unit, realizes redundant power supply of the auxiliary power supply, ensures uninterrupted power supply of the auxiliary power module, and thus improves the stability and reliability of the auxiliary power supply.

[0083] In this embodiment, the original switching power supply and UPS of the energy storage cabinet are eliminated, saving the economic cost of the two key components and the space occupied by the switching power supply and UPS; the two heat sources of the switching power supply and UPS are reduced, thereby reducing the energy consumption of the energy storage cabinet and improving the heat dissipation efficiency of the energy storage cabinet; eliminating the switching power supply and UPS avoids different failures under different power grid environments, which is conducive to the stable operation of the energy storage cabinet.

[0084] In this embodiment, the energy storage cabinet uses an auxiliary power module to power the PCS and auxiliary system. Compared with the original switching power supply and UPS structure of the energy storage cabinet, the auxiliary power module has a compact structure, simple wiring, and flexible control logic, which reduces the frequency of failures.

[0085] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An energy storage cabinet, characterized in that, include: The system includes a DC power supply, an auxiliary power module, an energy storage converter, and an auxiliary system. The input terminal of the auxiliary power module is connected to the DC power supply and the AC power supply, and the output terminal of the auxiliary power module is connected to the energy storage converter and the auxiliary system. The auxiliary power module includes a DC input unit, an AC input unit, a path selection unit, and a power output unit. The DC input unit is used to convert the DC voltage input from the DC power supply into a DC / DC converter to generate a first DC voltage. The AC input unit is used to convert the AC voltage input by the AC power supply into AC / DC to generate a second DC voltage. The path selection unit is used to connect or disconnect the DC input unit and the power output unit under the control of the control unit, and to connect or disconnect the AC input unit and the power output unit. The power output unit is configured to supply power to the energy storage converter and the auxiliary system based on a first DC voltage output by the DC input unit when the connection between the DC input unit and the power output unit is on and the connection between the AC input unit and the power output unit is off; or, to supply power to the energy storage converter and the auxiliary system based on a second DC voltage output by the AC input unit when the connection between the AC input unit and the power output unit is on and the connection between the DC input unit and the power output unit is off; or, not to supply power to the energy storage converter and the auxiliary system when the connection between the AC input unit and the power output unit is off and the connection between the DC input unit and the power output unit is off.

2. The energy storage cabinet according to claim 1, characterized in that, The DC input unit includes a switching unit, a first inductor, and a first capacitor; a first terminal of the switching unit is connected to the DC power supply, and a second terminal of the switching unit is connected to a first terminal of the first inductor and a second terminal of the first capacitor; a second terminal of the first inductor is connected to a first terminal of the first capacitor and the path selection unit; a second terminal of the first capacitor is connected to the path selection unit. The switching unit is configured to connect the DC power supply and the first inductor under the control of the control unit, so that the DC power supply charges the first inductor and the first capacitor, and the DC power supply outputs the first DC voltage through the first inductor and the first capacitor. The switching unit is used to disconnect the connection between the DC power supply and the first inductor under the control of the control unit, so that the first inductor and the first capacitor output a first DC voltage.

3. The energy storage cabinet according to claim 2, characterized in that, The switching unit includes a first switching transistor and a second switching transistor; The control terminal of the first switching transistor is connected to the control unit, the first terminal of the first switching transistor is connected to the positive terminal of the DC power supply, and the second terminal of the first switching transistor is connected to the first terminal of the first inductor and the first terminal of the second switching transistor. The control terminal of the second switch is connected to the control unit, and the second terminal of the second switch is connected to the second terminal of the first capacitor and the path selection unit.

4. The energy storage cabinet according to claim 1, characterized in that, The AC input unit includes a step-down unit, a rectifier unit, and a filter unit. The input terminal of the step-down unit is connected to the AC power supply, the output terminal of the step-down unit is connected to the input terminal of the rectifier unit, the output terminal of the rectifier unit is connected to the input terminal of the filter unit, and the output terminal of the filter unit is connected to the path selection unit. The step-down unit is used to step down the AC voltage input from the AC power supply to generate a stepped-down AC voltage. The rectifier unit is used to rectify the stepped-down AC voltage to generate a pulsating DC voltage; The filtering unit is used to smooth the pulsating DC voltage to generate the second DC voltage.

5. The energy storage cabinet according to claim 4, characterized in that, The step-down unit includes a step-down transformer, the rectifier unit includes a first diode and a second diode, and the filter unit includes a second capacitor; The primary side of the step-down transformer is connected to the AC power supply, the first terminal of the secondary side of the step-down transformer is connected to the positive terminal of the first diode, the second terminal of the secondary side of the step-down transformer is connected to the second terminal of the second capacitor, and the third terminal of the secondary side of the step-down transformer is connected to the positive terminal of the second diode. The cathode of the first diode is connected to the first terminal of the second capacitor, and the cathode of the second diode is also connected to the first terminal of the second capacitor. The first and second terminals of the second capacitor are also connected to the path selection unit.

6. The energy storage cabinet according to claim 1, characterized in that, The path selection unit includes a first selection unit and a second selection unit. The first selection unit is connected between the DC input unit and the power output unit, and the second selection unit is connected between the AC input unit and the power output unit. The first gating unit is used to connect or disconnect the DC input unit and the power output unit under the control of the control unit; The second gating unit is used to connect or disconnect the AC input unit and the power output unit under the control of the control unit.

7. The energy storage cabinet according to claim 6, characterized in that, Both the first gating unit and the second gating unit include two switches.

8. The energy storage cabinet according to claim 7, characterized in that, The switch may include a mechanical switch, a relay, or a switching transistor.

9. The energy storage cabinet according to any one of claims 1 to 8, characterized in that, The energy storage converter includes the control unit, and the energy storage cabinet includes a BCU, which is integrated into the control unit.

10. The energy storage cabinet according to any one of claims 1 to 8, characterized in that, The auxiliary system includes at least one of the following: energy storage cabinet auxiliary control system, battery management system, fire protection system, heat dissipation control system, and energy management system.

11. An energy storage system, characterized in that, include: At least one energy storage cabinet as described in any one of claims 1 to 10.

12. A power supply control method for an energy storage cabinet, characterized in that, The energy storage cabinet includes a DC power supply, an auxiliary power module, an energy storage converter, and an auxiliary system. The input terminal of the auxiliary power module is connected to the DC power supply and the AC power supply, and the output terminal of the auxiliary power module is connected to the energy storage converter and the auxiliary system. The auxiliary power module includes a DC input unit for converting the DC voltage input from the DC power supply into a first DC voltage via DC / DC conversion, an AC input unit for converting the AC voltage input from the AC power supply into a second DC voltage via AC / DC conversion, a path selection unit, and a power output unit. The method is implemented based on a control unit; The method includes: The control unit controls the path selection unit to connect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so that the DC input unit outputs a first DC voltage to the power output unit, and the power output unit supplies power to the energy storage converter and the auxiliary system according to the first DC voltage; or, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and connect the AC input unit and the power output unit, so that the AC input unit outputs a second DC voltage to the power output unit, and the power output unit supplies power to the energy storage converter and the auxiliary system according to the second DC voltage; or, the control unit controls the path selection unit to disconnect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so that neither the DC input unit nor the AC input unit outputs voltage to the power output unit, so that the power output unit does not supply power to the energy storage converter and the auxiliary system.

13. The power supply control method for the energy storage cabinet according to claim 12, characterized in that, The control unit controls the path selection unit to disconnect the DC input unit and the power output unit and connect the AC input unit and the power output unit, so that the AC input unit outputs a second DC voltage to the power output unit. Before the power output unit supplies power to the energy storage converter and the auxiliary system according to the second DC voltage, the following steps are also included: The control unit determines that the detected operating state of the energy storage converter is the running state.

14. The power supply control method for the energy storage cabinet according to claim 12, characterized in that, The control unit controls the path selection unit to disconnect the DC input unit and the power output unit, and also disconnect the AC input unit and the power output unit, so that neither the DC input unit nor the AC input unit outputs voltage to the power output unit. Before the power output unit stops supplying power to the energy storage converter and the auxiliary system, the system further includes: The control unit determines that the detected energy storage converter is in standby mode. After a set time period, it executes the step of controlling the path selection unit to disconnect the DC input unit and the power output unit, and disconnect the AC input unit and the power output unit.

15. The power supply control method for the energy storage cabinet according to claim 12, characterized in that, The control unit controls the path selection unit to connect the DC input unit and the power output unit and disconnect the AC input unit and the power output unit, so that the DC input unit outputs a first DC voltage to the power output unit. After the power output unit supplies power to the energy storage converter and the auxiliary system according to the first DC voltage, the system further includes: The control unit determines whether the detected energy storage converter is in operation or standby mode.

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