An energy storage combiner cabinet with dual voltage sources and a UPS

Abstract

This utility model discloses an energy storage combiner cabinet equipped with dual voltage sources and a UPS. The main circuit draws power from the grid side or the output of the power conversion system. The front end of the combiner cabinet's control circuit is configured with a UPS, a black start button SB1, and a switching circuit consisting of relays KA2 and KA3, and contactor KM1. When mains power is available, contactor KM1 is engaged, relay KA2 remains open, and relay KA3 remains closed, switching the combiner cabinet's control circuit to mains power mode. When mains power is unavailable, contactor KM1 is disengaged, relay KA2 is engaged, and relay KA3 remains closed, switching the combiner cabinet's control circuit to UPS battery mode. The black start button SB1 can then be used to start the combiner cabinet and the external battery cabinet's control circuit. This combiner cabinet provides auxiliary power, reducing the need for long-distance power draw from the battery cabinet. Before the system is operational and in case of PCS or voltage source anomalies, it stably provides a voltage source to the combiner cabinet and battery cabinet's control circuits for a period of time to start the system or for emergency fault response.

Description

Technical Field

[0001] This utility model relates to the field of energy storage cabinet technology, and in particular to an energy storage combiner cabinet with dual voltage sources and a UPS. Background Technology

[0002] With the development of the energy storage industry, customers are increasingly demanding grid connection and off-grid operation of energy storage power stations. When switching from grid connection to off-grid operation, a backup power source is needed to supply power to the control system in order to start the energy storage system, establish AC bus voltage, and restore power supply to the load.

[0003] With the rapid development of the energy storage industry, the demand for efficient and reliable energy storage systems is constantly increasing. For any energy storage system, especially those involving multiple battery modules or photovoltaic modules, a combiner cabinet is typically required. The combiner cabinet can aggregate the current from multiple power sources, forming one or more larger current outputs for subsequent inversion, grid connection, or direct power supply, thereby improving system efficiency and reliability. Through centralized management, the combiner cabinet can effectively allocate and process the current from multiple power sources, reducing losses during current transmission and improving the overall system efficiency. Simultaneously, built-in protection devices such as circuit breakers and fuses can quickly disconnect the power supply in the event of a system fault, effectively reducing the risks of overload and short circuits and ensuring system safety. Figure 1 As shown, a typical combiner cabinet design in the energy storage industry draws power from the back end of the power conversion system (PCS) or an external voltage source. Through electrical wiring, it supplies power to the internal circuitry and provides an external AC 220V output voltage source. Some combiner cabinets even omit external voltage source distribution, only supplying power to the internal circuitry and high-voltage DC converters. In existing combiner cabinet designs, the number of power sources available to external battery cabinets is limited. A significant problem is that when the PCS or voltage source malfunctions, the combiner cabinet's control circuit goes completely black, preventing the battery cabinet's controller from issuing timely emergency commands. This can impact the PCS and the power grid, damaging the energy storage system and even the power grid system. Utility Model Content

[0004] This utility model aims to provide an energy storage combiner cabinet with dual voltage sources and a UPS, increasing the demand for multiple external power supplies. It provides two power outputs: one to supply the high-power consumption of the battery cabinet, and the other to power the combiner cabinet's control circuit. Furthermore, the addition of a UPS within the combiner cabinet allows for a stable voltage supply to the internal control circuit and combiner cabinet control circuit for a period of time before the system starts operating or in case of PCS or voltage source anomalies. This can be used for system startup or emergency fault response. The technical solution is as follows:

[0005] An energy storage combiner cabinet with dual voltage sources and a UPS, wherein the front end of the combiner cabinet control circuit is equipped with an uninterruptible power supply UPS, relays KA2 and KA3, contactor KM1 and black start button SB1, and outputs power to the external battery cabinet control circuit.

[0006] When mains power is available, the control circuit of the combiner cabinet is energized;

[0007] The coil of the contactor KM1 draws power from the combiner cabinet control circuit. When the combiner cabinet control circuit is energized, the contactor KM1 is energized. The combiner cabinet control circuit supplies power to the external battery cabinet control circuit through the normally open contact of the contactor KM1.

[0008] The uninterruptible power supply (UPS) draws power from the combiner cabinet control circuit. The output terminal of the UPS supplies power to the external battery cabinet control circuit via the normally open contact of relay KA2, the normally closed contact of contactor KM1, and the normally closed contact of relay KA3.

[0009] The normally open contacts of the black start button SB1 and the relay KA2 are connected in parallel;

[0010] The external battery cabinet control circuit supplies power to the control circuit of each battery cabinet.

[0011] The combiner cabinet control circuit includes a controller A-BMS. The controller A-BMS is powered by the combiner cabinet control circuit and is powered by the external battery cabinet control circuit. When the controller A-BMS is working, it outputs DC power to power the coil of relay KA2, driving relay KA2 to engage. It also sends a power-down signal to power the coil of relay KA3, driving relay KA3 to engage.

[0012] Furthermore, the controller A-BMS operates at a voltage of 24V.

[0013] Furthermore, the relay KA2 includes multiple normally open contacts connected in parallel; the relay KA3 includes multiple normally closed contacts connected in parallel.

[0014] Furthermore, a protective circuit breaker is installed between the control circuit of the external battery cabinet and the control circuit of each battery cabinet.

[0015] Furthermore, the main circuit of the energy storage combiner cabinet draws power from the grid side or the output terminal of the power conversion system PCS, and supplies power to the secondary circuit via the main circuit breaker QF1. The secondary circuit supplies power to the control circuit of the combiner cabinet via the circuit breaker QF2.

[0016] Furthermore, the battery cabinet is powered by a secondary circuit, and a protective circuit breaker is installed between the power circuit of each battery cabinet and the secondary circuit.

[0017] Technical effects:

[0018] In one embodiment, this combiner cabinet provides auxiliary power to reduce the need for the battery cabinet to draw power from a distance, and provides a UPS to stably provide a voltage source for a period of time to the internal control circuit of the combiner cabinet and the control circuit of the external battery cabinet before the system is running or when the PCS or voltage source is abnormal, so as to start the system or provide emergency power.

[0019] In one embodiment, this combiner cabinet provides dual voltage source outputs, each with its own circuit breaker protection, which can be used to start the energy storage system and for emergency handling. The dual voltage sources significantly reduce unnecessary power consumption, reserving UPS power functionality only for the control system, thus reducing UPS capacity and overall cost. Attached Figure Description

[0020] Figure 1 This is a typical electrical connection diagram of an existing energy storage combiner cabinet;

[0021] Figure 2 This is the electrical connection diagram of the energy storage combiner cabinet of this utility model;

[0022] Figure 3 This is an enlarged view of the electrical connections of the secondary circuit section of the energy storage combiner cabinet;

[0023] Figure 4 This is an enlarged diagram of the electrical connections of the combiner cabinet control circuit of the energy storage combiner cabinet. Detailed Implementation

[0024] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0025] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figures 2 to 4As shown, this utility model provides an embodiment of an energy storage combiner cabinet with dual voltage sources and a UPS. The main circuit draws power from the grid side or the output terminal of the power conversion system PCS, and is powered down through the main circuit breaker QF1. QF3 to QF12 serve as voltage source protection circuit breakers for the external battery cabinet. QF2 serves as a power supply protection circuit breaker for the power consumption and control circuit within the combiner cabinet. Down through QF2, power is supplied to the combiner cabinet control circuit, with Cu1 to Cu10 serving as voltage source protection circuit breakers for the external battery cabinet control circuit. Furthermore, the combiner cabinet control circuit is equipped with a UPS and circuit switching function at its front end. When mains power is available, the combiner cabinet control circuit switches to mains power mode; when mains power is unavailable, the combiner cabinet control circuit switches to UPS battery mode. The combiner cabinet and the external battery cabinet control circuit can be started via the black start button SB1. The black start button SB1 is specifically a self-resetting button.

[0027] In this embodiment, the combiner cabinet control circuit is equipped with a controller A-BMS, and its front end is equipped with an uninterruptible power supply (UPS) and a switching circuit consisting of relays KA2 and KA3 and contactor KM1, etc., which supplies power to the external battery cabinet control circuit. The connection relationship of each part is as follows:

[0028] The coil of contactor KM1 is powered by the combiner cabinet control circuit; the combiner cabinet control circuit is connected to the external battery cabinet control circuit via the normally open contact of contactor KM1.

[0029] The coil of relay KA2 is powered by the power supply of controller A-BMS.

[0030] The coil of relay KA3 is driven by the signal from controller A-BMS.

[0031] The uninterruptible power supply (UPS) draws power from the combiner cabinet control circuit. The output of the UPS is connected to the external battery cabinet control circuit via the normally open contact of relay KA2, the normally closed contact of contactor KM1, and the normally closed contact of relay KA3.

[0032] The external battery cabinet control circuit is used to supply power to the control circuits of each battery cabinet.

[0033] The controller A-BMS is powered by the main power supply of the combiner cabinet control loop and the backup power supply of the external battery cabinet control loop. When the main power fails, the backup power supply is provided by the backup power supply, which is specifically provided by the uninterruptible power supply (UPS).

[0034] The working principle of this energy storage combiner cabinet is as follows:

[0035] Power enters through the main circuit breaker QF1, equipped with a three-phase four-wire surge protector (SPD) to provide surge protection for the combiner cabinet. The secondary circuit is equipped with 10 external battery cabinet power protection circuit breakers QF3 to QF12, capable of connecting up to 10 battery cabinets, making it more convenient for energy storage systems requiring multiple battery cabinets. The design capacity of the protection circuit breakers is configured according to demand.

[0036] The power supply circuit for the external battery cabinet control circuit receives power from the secondary circuit breaker QF2 and then supplies power to the control circuit inside the combiner cabinet via a tertiary circuit. It is equipped with 10 external battery cabinet control circuit protection circuit breakers Cu1 to Cu10. This power supply is configured with a UPS and can be used for black start and emergency shutdown in case of faults. The design capacity of the protection circuit breakers Cu1 to Cu10 is determined according to requirements.

[0037] When the power grid is normal or the PCS is working, the power supply of the combiner cabinet is in the mains power state. The coil of contactor KM1 is energized, the normally open contact of KM1 is closed (KM1-3 and KM1-4 contacts are short-circuited), and the normally closed contact is open (KM1-R3 and KM1-R4 contacts are open). The system power is provided by the power grid, and the control system inside the combiner cabinet and the control circuit of the external battery cabinet are both in normal condition.

[0038] When the power grid is not connected and the energy storage system is not started, the combiner cabinet is in a completely dark state, the contactor KM1 coil is not energized, and the system power will be provided by the UPS system. Press the black start button SB1 for about 1 second, and after the combiner cabinet control system is powered on, release the black start button SB1. The control system inside the combiner cabinet starts to operate. After the controller A-BMS starts operating, the controller A-BMS provides 24V power to the relay KA2. The coil of the relay KA2 is energized and energized. The contacts of KA2-11, KA2-14, KA2-21, KA2-24, KA2-41, and KA2-44 change from normally open to normally closed, realizing interlocking. The control system inside the combiner cabinet and the external battery cabinet control circuit are both in a normal power supply state.

[0039] When the energy storage system malfunctions or the power grid experiences an anomaly, the contactor KM1 coil switches from the energized state to the de-energized state. Because the 24V power supply of the controller A-BMS has a delayed power-off function, the system power immediately switches to UPS power, ensuring the control system can continue to operate normally and preventing the energy storage system from going completely black. When the controller A-BMS detects a system fault, it promptly issues a derating or shutdown command to maintain the safety of the energy storage system. After the command is issued, the controller A-BMS can control relay KA3 to energize, and the contacts of KA3-11, KA3-12, KA3-21, KA3-22, KA3-41, and KA3-42 change from normally closed to normally open, cutting off the UPS power supply circuit and powering down the system.

[0040] This combiner cabinet provides dual voltage sources: one supply powers high-power devices in the battery cabinet (such as chillers), and the other supplies power to both the combiner cabinet control system and the battery cabinet control system. This can be used for black start and fault handling in energy storage systems. When a fault occurs in the energy storage system, the control circuit can immediately switch to UPS power, extending the operating time and allowing the controller to handle anomalies promptly. It also provides operators or maintenance personnel with as much response time as possible to locate the cause of the anomaly. Compared to a conventional single-channel voltage source, it provides a stable operating condition for the energy storage system, better ensuring the safety of the PCS and the power grid.

[0041] In summary, this combiner cabinet has the following technical advantages:

[0042] (1) This combiner cabinet provides auxiliary power to reduce the need for the battery cabinet to draw power from a distance. Before the system is running and when the PCS or voltage source is abnormal, it provides a stable voltage source to the control circuit of the combiner cabinet and battery cabinet for a period of time to start the system or for emergency fault response.

[0043] (2) This combiner cabinet provides dual voltage source outputs, each with its own circuit breaker protection, and can be used to start energy storage systems and for emergency handling. The dual voltage sources significantly reduce unnecessary power consumption, allowing for the reservation of UPS power supply functionality only for the control system, thus reducing UPS capacity and overall cost.

[0044] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. An energy storage combiner cabinet equipped with dual voltage sources and a UPS, characterized in that: Its combiner cabinet control circuit is equipped with an uninterruptible power supply (UPS), relays KA2 and KA3, contactor KM1 and black start button SB1 at the front end, and outputs power to the external battery cabinet control circuit. When mains power is available, the control circuit of the combiner cabinet is energized; The coil of the contactor KM1 draws power from the combiner cabinet control circuit. When the combiner cabinet control circuit is energized, the contactor KM1 is energized. The combiner cabinet control circuit supplies power to the external battery cabinet control circuit through the normally open contact of the contactor KM1. The uninterruptible power supply (UPS) draws power from the combiner cabinet control circuit. The output terminal of the UPS supplies power to the external battery cabinet control circuit via the normally open contact of relay KA2, the normally closed contact of contactor KM1, and the normally open contact of relay KA3. The normally open contacts of the black start button SB1 and the relay KA2 are connected in parallel; The external battery cabinet control circuit supplies power to the control circuit of each battery cabinet. The combiner cabinet control circuit is equipped with a controller A-BMS. The controller A-BMS is powered by the combiner cabinet control circuit and is powered by the external battery cabinet control circuit. When the controller A-BMS is working, it outputs DC power to power the coil of relay KA2, driving relay KA2 to engage. It also sends a power-down signal to power the coil of relay KA3, driving relay KA3 to engage.

2. The energy storage busbar cabinet with dual voltage source and UPS according to claim 1, characterized in that: The controller A-BMS operates at a voltage of 24V.

3. The energy storage busbar cabinet with dual voltage source and UPS according to claim 1, characterized in that: The relay KA2 includes multiple normally open contacts connected in parallel; the relay KA3 includes multiple normally closed contacts connected in parallel.

4. The energy storage combiner cabinet with dual voltage sources and UPS as described in claim 1, wherein a protective circuit breaker is provided between the control circuit of the external battery cabinet and the control circuit of each battery cabinet.

5. The energy storage busbar cabinet with dual voltage source and UPS according to claim 1, characterized in that: The main circuit of the energy storage combiner cabinet draws power from the grid side or the output terminal of the power conversion system PCS, and supplies power to the secondary circuit through the main circuit breaker QF1. The secondary circuit supplies power to the control circuit of the combiner cabinet through the circuit breaker QF2.

6. The energy storage busbar cabinet with dual voltage source and UPS according to claim 5, characterized in that: The battery cabinet is powered by a secondary circuit, and a protective circuit breaker is installed between the power circuit of each battery cabinet and the secondary circuit.

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