Energy storage converter, energy storage system and power supply method

Abstract

The application discloses an energy storage converter, an energy storage system and a power supply method. The energy storage converter comprises a battery management board and an auxiliary power supply. The positive electrode of the auxiliary power supply is used for connecting the positive electrode of a battery cluster, taking electricity from the battery cluster, transforming the electricity taken from the battery cluster, and supplying power to the battery management board and internal loads of the energy storage converter. The battery management board collects the voltage and current of the battery cluster and controls the charging and discharging of the battery cluster according to the voltage and current. Only one auxiliary power supply is arranged in the energy storage converter, and the battery cluster part can not be provided with an auxiliary power supply. The auxiliary power supply directly takes electricity from the positive electrode of the battery cluster, uninterruptedly supplies power to the battery management board, and can also supply power to the controller in the energy storage converter. The number of auxiliary power supplies is saved, and the hardware architecture of the entire energy storage system is simplified. The auxiliary power supply needs to take electricity from the battery cluster all the time, and therefore, an auxiliary power supply contactor needs not to be specially arranged for the auxiliary power supply, and the number of hardware is further reduced.

Description

Technical Field

[0001] This application relates to the field of new energy technology, specifically to an energy storage converter, an energy storage system, and a power supply method. Background Technology

[0002] The function of a power conversion system (PCS) is to convert the current during the charging and discharging of a battery. Currently, energy storage systems mainly consist of batteries, switch boxes, and power conversion systems.

[0003] The battery primarily stores and releases energy. The switch box typically includes a shunt, fuses, contactors, load switches, and a battery management system (BMS) board. The BMS board is responsible for energy management at the battery cluster level, voltage and current sampling, and communication with the energy storage converter. It also controls the engagement of the internal main contactors. The switch box includes an auxiliary power supply to power the BMS board. The DC side of the energy storage converter typically includes a soft-start circuit, bus capacitors, and an auxiliary power supply. The auxiliary power supply inside the energy storage converter draws power from the converter's ports; therefore, the auxiliary power supply inside the energy storage converter is energized when the positive and negative contactors in the switch box are engaged.

[0004] The auxiliary power supply inside the switch box needs to be constantly working to ensure that the battery management board is powered and can operate. In addition, the switch box occupies a certain amount of space in the energy storage system, making the overall energy storage system architecture less streamlined. Summary of the Invention

[0005] In view of this, this application provides an energy storage converter, an energy storage system, and a power supply method, which can simplify the architecture of the energy storage system.

[0006] This application discloses an energy storage converter, including: a battery management board and an auxiliary power supply;

[0007] The positive terminal of the auxiliary power supply is used to connect to the positive terminal of the battery cluster, to draw power from the battery cluster, and to convert the power drawn from the battery cluster to power the battery management board and the internal load of the energy storage converter.

[0008] The battery management board is used to collect the voltage and current of the battery clusters and control the charging and discharging of the battery clusters based on the voltage and current.

[0009] Preferably, it further includes: a positive electrode fuse, a negative electrode fuse, and a load switch;

[0010] The first end of the positive electrode fuse is used to connect to the positive electrode of the battery cluster, and the first end of the negative electrode fuse is used to connect to the negative electrode of the battery cluster.

[0011] The positive switch of the load switch is connected in series between the second end of the positive fuse and the positive terminal of the DC bus capacitor;

[0012] The negative switch of the load switch is connected in series between the second end of the negative fuse and the negative terminal of the DC bus capacitor;

[0013] The negative terminal of the auxiliary power supply is connected to the negative terminal of the load switch.

[0014] Preferably, it further includes a main contactor connected in series between the positive switch of the positive fuse and the load switch.

[0015] Preferably, it further includes: a positive soft-start circuit connected in parallel across the two ends of the main contactor;

[0016] The positive terminal soft-start circuit includes a soft-start contactor and a soft-start resistor connected in series.

[0017] Preferably, it further includes a shunt connected in series between the positive electrode fuse and the main contactor.

[0018] Preferably, the number of positive electrode fuses corresponds one-to-one with the number of battery clusters;

[0019] When there are multiple battery clusters, the positive terminal of each battery cluster is connected to the positive switch of the load switch through the corresponding positive terminal fuse, and the negative terminals of the multiple battery clusters are connected together and connected to the negative switch of the load switch through a common negative terminal fuse.

[0020] Preferably, it further includes a negative terminal soft-start circuit connected in series between the negative switch of the load switch and the negative terminal of the DC bus capacitor.

[0021] Preferably, it also includes a main contactor connected in series with the negative terminal soft-start circuit.

[0022] This application also provides an energy storage system, including: the energy storage converter described above, and further including: at least one battery cluster;

[0023] The battery cluster is connected to the input of the energy storage converter.

[0024] This application also provides a power supply method for a battery management board in an energy storage converter, the energy storage converter including: a battery management board and an auxiliary power supply;

[0025] The auxiliary power supply draws power from the battery clusters to power the battery management board.

[0026] Therefore, this application has the following beneficial effects:

[0027] The energy storage converter provided in this application only requires one auxiliary power supply within the converter itself. The battery cluster section does not require an auxiliary power supply; instead, the auxiliary power supply draws power directly from the positive terminal of the battery cluster. This provides uninterrupted power to the battery management board and also powers the controller within the converter. This reduces the number of auxiliary power supplies, simplifying the overall hardware architecture of the energy storage system. Since the auxiliary power supply continuously draws power from the battery cluster, there is no need for a dedicated auxiliary power contactor, further reducing the amount of hardware required. Attached Figure Description

[0028] Figure 1 A schematic diagram of an energy storage converter provided in an embodiment of this application;

[0029] Figure 2 A schematic diagram of another energy storage converter provided in the embodiments of this application;

[0030] Figure 3 A schematic diagram of another energy storage converter provided in the embodiments of this application;

[0031] Figure 4 This is a schematic diagram of an energy storage system provided in an embodiment of this application. Detailed Implementation

[0032] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the embodiments of this application will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] The energy storage converter provided in this embodiment includes an auxiliary power supply, which powers the battery management board inside the energy storage converter. This energy storage converter eliminates the switch box and integrates the battery management board inside the energy storage converter's cabinet. Furthermore, the battery section does not have an auxiliary power supply. The battery management board is not powered by the auxiliary power supply of the battery section, but by the auxiliary power supply inside the energy storage converter. In addition, the auxiliary power supply inside the energy storage converter can also power the internal load of the energy storage converter. This allows for the use of only one auxiliary power supply instead of two, simplifying the hardware architecture and reducing the overall size of the energy storage system.

[0034] Since only one auxiliary power supply is set up, which needs to continuously power the battery management board, the previous auxiliary power contactor is not needed and can be eliminated.

[0035] The energy storage converter provided in the embodiments of this application is described in detail below with reference to the accompanying drawings.

[0036] See Figure 1 The figure is a schematic diagram of an energy storage converter provided in an embodiment of this application.

[0037] For ease of explanation, this application only illustrates the architecture and connection relationship between the battery cluster and the DC side of the energy storage converter.

[0038] The energy storage converter 1000 provided in this embodiment includes: a battery management board and an auxiliary power supply 20;

[0039] The positive terminal of the auxiliary power supply 20 is used to connect to the positive terminal of the battery cluster, to draw power from the battery cluster, and to convert the power drawn from the battery cluster to power the battery management board 10 and the internal load of the energy storage converter 1000.

[0040] The energy storage converter 1000 provided in this application embodiment can be applied to one battery cluster or two battery clusters. In this embodiment, the input terminal of the energy storage converter 1000 is connected to two battery clusters, namely the first battery cluster RACK1 and the second battery cluster RACK2.

[0041] The auxiliary power supply 20 can draw power from one of the battery clusters, for example, from RACK1. The positive terminal of the auxiliary power supply 20 is connected to the positive terminal of the first battery cluster RACK1. It should be understood that the auxiliary power supply 20 can also draw power from the second battery cluster RACK2. The negative terminal of the first battery cluster RACK1 is connected to the positive terminal of the DC bus capacitor Cbus through a first soft-start circuit, and the negative terminal of the second battery cluster RACK2 is connected to the positive terminal of the DC bus capacitor Cbus through a second soft-start circuit.

[0042] Since both the first and second slow-start circuits are connected to the positive terminal of the battery cluster, they are positive terminal slow-start circuits.

[0043] The battery management board 10 is used to collect the voltage and current of the battery cluster and control the charging and discharging of the battery cluster based on the voltage and current.

[0044] The battery management board 10 collects the voltage and current of the first battery cluster RACK1 and the voltage and current of the second battery cluster RACK2.

[0045] For example, the energy storage converter 1000 is compatible with 0.25C / 4h charging and discharging. It can achieve 0.5C charging and discharging of the energy storage system when a single RACK is connected, or 0.25C charging and discharging of the energy storage system when two RACKs are connected, demonstrating strong compatibility.

[0046] Specifically, by detecting the SOC value of each battery cluster through the battery management board 10, and then controlling the charging and discharging of each branch, the remaining SOC of the battery cluster can be balanced, reducing the weakest link effect.

[0047] In addition, the auxiliary power supply 20 is also used to power the controllers inside the energy storage converter 1000, such as the ARM / DSP 40. Both the ARM and DSP are controllers of the energy storage converter 1000.

[0048] The battery management board 10 also communicates with the ARM / DSP40 to receive instructions and report charging and discharging information.

[0049] Since the energy storage converter 1000 is connected to the battery cluster, the battery cluster section does not require an auxiliary power supply. Only one auxiliary power supply is needed within the energy storage converter 1000. This auxiliary power supply draws power directly from the positive terminal of the battery cluster, providing uninterrupted power to the battery management board and also powering the controller inside the energy storage converter. This reduces the number of auxiliary power supplies, simplifying the overall hardware architecture of the energy storage system. Because the auxiliary power supply 20 continuously draws power from the battery cluster, an auxiliary power contactor is unnecessary, further reducing the number of hardware components.

[0050] See Figure 2 The figure is a schematic diagram of another energy storage converter provided in an embodiment of this application.

[0051] The energy storage converter provided in this application embodiment also includes a load switch 32.

[0052] Load switch 32 is connected between the first soft-start circuit and the DC bus capacitor Cbus. Simultaneously, load switch 32 is connected between the second soft-start circuit and the DC bus capacitor Cbus. That is, load switch 32 is connected after the junction of the two battery clusters, allowing the disconnection of both battery clusters using a single load switch 32. Specifically, when load switch 32 is open, RACK1 is disconnected from Cbus, and RACK2 is also disconnected from Cbus.

[0053] The negative terminal of the auxiliary power supply 20 draws power from the negative terminal of the battery pack through the load switch 32. That is, the negative terminal of the auxiliary power supply 20 is connected between the load switch 32 and the DC bus capacitor Cbus, and is connected to the rear end of the load switch 32.

[0054] The negative terminal of the auxiliary power supply 20 is connected to the back end of the load switch 32. This ensures that when the load switch 32 is disconnected during operation and maintenance, the auxiliary power supply 20 is also de-energized, thereby ensuring that the battery management board 10 is also de-energized. This avoids the problem of the entire circuit board being electrified during operation and maintenance, thus ensuring safety during operation and maintenance.

[0055] If the negative terminal of the auxiliary power supply 20 is connected to the front end of the load switch 32, the auxiliary power supply 20 cannot be guaranteed to be de-energized when the load switch is disconnected during operation and maintenance, which poses a potential hazard to operation and maintenance.

[0056] To ensure circuit safety, the energy storage converter provided in this application embodiment also includes fuses and shunts, which will be described in detail below with reference to the accompanying drawings.

[0057] See Figure 3 This figure is a schematic diagram of another energy storage converter provided in the embodiments of this application.

[0058] The energy storage converter provided in this embodiment also includes: a positive electrode fuse and a negative electrode fuse;

[0059] The first end of the positive electrode fuse is used to connect to the positive electrode of the battery cluster, and the first end of the negative electrode fuse is used to connect to the negative electrode of the battery cluster.

[0060] The positive switch of the load switch is connected in series between the second end of the positive fuse and the positive terminal of the DC bus capacitor.

[0061] The negative switch of the load switch is connected in series between the second end of the negative fuse and the negative terminal of the DC bus capacitor.

[0062] The energy storage converter provided in this embodiment further includes: a main contactor connected in series between the positive fuse and the positive switch of the load switch; in addition, it also includes: a positive soft-start circuit, which is connected in parallel across the two ends of the main contactor.

[0063] The positive terminal soft-start circuit includes a soft-start contactor and a soft-start resistor connected in series.

[0064] In addition, the energy storage converter also includes a shunt connected in series between the positive fuse and the soft-start circuit. The function of the shunt is to collect current, that is, to perform current sampling.

[0065] The number of positive electrode fuses corresponds one-to-one with the number of battery clusters;

[0066] When there are multiple battery clusters, the positive terminal of each battery cluster is connected to the positive switch of the load switch through the corresponding positive terminal fuse, and the negative terminals of the multiple battery clusters are connected together and connected to the negative switch of the load switch through a common negative terminal fuse.

[0067] The following example illustrates how an energy storage converter 1000 connects two battery clusters.

[0068] Each battery cluster corresponds to a fuse, a shunt, a soft-start circuit, and a main contactor.

[0069] The positive terminal of the first battery cluster RACK1 is connected to the positive switch of the load switch 32 via fuse 21, shunt 24 and the first soft-start circuit; it should be understood that the positive and negative terminals of the load switch each correspond to a switch.

[0070] In addition, each branch also includes a main contactor, with the first battery cluster RACK1 corresponding to the main contactor 28. The main contactor 28 is connected in parallel with the first soft-start circuit, which includes a soft-start contactor 27 and a soft-start resistor 26 connected in series.

[0071] The positive terminal of the second battery cluster RACK2 is connected to the positive switch of the load switch 32 via fuse 22, shunt 25 and the first soft-start circuit.

[0072] Additionally, the second battery cluster RACK2 corresponds to the main contactor 31, which is connected in parallel with the second soft-start circuit. The second soft-start circuit includes a soft-start contactor 29 and a soft-start resistor 30 connected in series.

[0073] It should be understood that the function of the slow-start circuit is to mitigate the impact of inrush current on the devices when the energy storage system starts up. Once the slow start is successful, the slow-start circuit can be deactivated, i.e., the main contactor closes and the slow-start contactor opens, thus avoiding additional power consumption caused by the slow-start resistor.

[0074] Corresponding to the positive terminal, the energy storage converter provided in this application embodiment further includes: a main contactor 35 connected in series between the negative switch of the load switch and the negative terminal of the DC bus capacitor, and a negative terminal soft-start circuit connected in parallel across the main contactor 35. For example... Figure 3 As shown, the negative terminal slow-start circuit includes a slow-start contactor 33 and a slow-start resistor 34 connected in series. When slow-starting occurs, the slow-start contactor 33 closes. After successful slow-starting, the slow-start contactor 33 opens and the main contactor 35 closes.

[0075] In addition, a fuse 23 is connected between the negative switch of the load switch 32 and the negative terminal of RACK1.

[0076] The negative terminal of the auxiliary power supply 20 is connected between the negative switch of the load switch 32 and the main contactor 35.

[0077] Based on the energy storage converter provided in the above embodiments, this application also provides an energy storage system, which will be described in detail below with reference to the accompanying drawings.

[0078] See Figure 4 The figure is a schematic diagram of an energy storage system provided in an embodiment of this application.

[0079] The energy storage system provided in this embodiment includes the energy storage converter 1000 described in the above embodiments, and also includes at least one battery cluster 100;

[0080] Battery cluster 100 is connected to the input terminal of energy storage converter 1000.

[0081] It should be understood that the energy storage converter 1000 can charge and discharge the battery cluster 100. It can both convert the electrical energy of the battery cluster 100 and feed it back to the grid, and charge the battery cluster 100 with the grid's electrical energy at appropriate times.

[0082] Because the energy storage converter provided in this application embodiment has a simplified internal structure and includes only one auxiliary power supply, the size of the entire energy storage system can be reduced. Due to the reduction in hardware circuitry, the reliability is also improved.

[0083] Based on the energy storage converter and energy storage system provided in the above embodiments, this application also provides a power supply method for the battery management board in the energy storage converter. The energy storage converter includes a battery management board and an auxiliary power supply; the auxiliary power supply is used to draw power from the battery cluster to power the battery management board. That is, in the power supply method provided in this application, the battery management board is located inside the energy storage converter, and the battery management board is powered by the auxiliary power supply located inside the energy storage converter, and directly draws power from the positive terminal of the battery cluster, thereby saving an auxiliary power supply and the auxiliary contactor connected to the auxiliary power supply, reducing costs.

[0084] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems or apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0085] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An energy storage converter, characterized in that, include: Battery management board, load switch, positive fuse, negative fuse, and auxiliary power supply; The positive terminal of the auxiliary power supply is used to connect to the positive terminal of the battery cluster, and is used to draw power from the battery cluster. The power drawn from the battery cluster is converted to power the battery management board and the internal load of the energy storage converter. The first end of the positive electrode fuse is used to connect to the positive electrode of the battery cluster, and the first end of the negative electrode fuse is used to connect to the negative electrode of the battery cluster; The positive switch of the load switch is connected in series between the second end of the positive fuse and the positive terminal of the DC bus capacitor; the negative switch of the load switch is connected in series between the second end of the negative fuse and the negative terminal of the DC bus capacitor. The negative terminal of the auxiliary power supply is connected to the negative terminal of the load switch; The battery management board is used to collect the voltage and current of the battery cluster and control the charging and discharging of the battery cluster based on the voltage and current.

2. The energy storage converter according to claim 1, characterized in that, Also includes: The main contactor is connected in series between the positive fuse and the positive switch of the load switch.

3. The energy storage converter according to claim 2, characterized in that, Also includes: A positive soft-start circuit connected in parallel across the two ends of the main contactor; The positive electrode soft-start circuit includes a soft-start contactor and a soft-start resistor connected in series.

4. The energy storage converter according to claim 2, characterized in that, Also includes: A shunt connected in series between the positive electrode fuse and the main contactor.

5. The energy storage converter according to any one of claims 1-3, characterized in that, The number of positive electrode fuses corresponds one-to-one with the number of battery clusters; When there are multiple battery clusters, the positive terminal of each battery cluster is connected to the positive switch of the load switch through a corresponding positive fuse, and the negative terminals of the multiple battery clusters are connected together and connected to the negative switch of the load switch through a common negative fuse.

6. The energy storage converter according to any one of claims 1-3, characterized in that, Also includes: A negative soft-start circuit is connected in series between the negative switch of the load switch and the negative terminal of the DC bus capacitor.

7. The energy storage converter according to claim 6, characterized in that, It also includes a main contactor connected in series with the negative terminal soft-start circuit.

8. An energy storage system, characterized in that, include: The energy storage converter according to any one of claims 1-7 further includes: at least one battery cluster; The battery cluster is connected to the input terminal of the energy storage converter.

9. A power supply method for a battery management board in an energy storage converter, characterized in that, The energy storage converter includes: a battery management board, a load switch, a positive fuse, a negative fuse, and an auxiliary power supply; The first end of the positive electrode fuse is used to connect to the positive electrode of the battery cluster, and the first end of the negative electrode fuse is used to connect to the negative electrode of the battery cluster; The positive switch of the load switch is connected in series between the second end of the positive fuse and the positive terminal of the DC bus capacitor. The negative switch of the load switch is connected in series between the second end of the negative fuse and the negative terminal of the DC bus capacitor. The negative terminal of the auxiliary power supply is connected to the negative terminal of the load switch; the power supply method includes: the auxiliary power supply draws power from the battery cluster to supply power to the battery management board.

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