Fusion version group string type energy storage system

Abstract

The utility model discloses a fusion plate string type energy storage system, and belongs to the technical field of energy storage, and the fusion plate string type energy storage system comprises a battery cluster formed by connecting a plurality of single battery cells in series; the fusion PCS module is connected with the battery cluster and used for collecting operation information of the battery cluster and converting output current of the battery cluster into three-phase alternating current; the alternating current confluence cabinet is connected with the plurality of fusion PCS modules and is used for collecting the three-phase alternating current output by the plurality of fusion PCS modules to obtain target collected current; and the energy management module is connected with the alternating current confluence cabinet and is used for connecting the output current of the alternating current confluence cabinet into a power grid and managing the plurality of fusion PCS modules and the alternating current confluence cabinet. By means of the fusion version group string type energy storage system, the technical problems that in the prior art, a centralized energy storage system is poor in safety performance, low in operation efficiency and complex in operation and maintenance can be solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of energy storage, particularly relates to a fusion version group string type energy storage system. BACKGROUND

[0002] Because the structure of centralized energy storage system is compact, capacity is big, control logic is simple, and easy to deploy and optimize, therefore, centralized energy storage system has been very widely used in actual life. Figure 1 , Figure 1 It is the structure diagram of centralized energy storage system in prior art. In centralized energy storage system, the output current of each battery cluster will be input to DC bus cabinet through a high voltage box, then DC bus cabinet will input the output current of each battery cluster to centralized PCS (Power Conversion System, energy storage converter), and is merged into high voltage cabinet via step-up transformer, finally, high voltage cabinet will merge the output voltage of step-up transformer into power grid. In this process, EMS (Energy Management System, energy management system) will also manage the energy of DC bus cabinet, centralized PCS and high voltage cabinet to ensure the smooth execution of centralized energy storage system energy conversion process.

[0003] However, centralized energy storage system is prone to exponential decay phenomenon in the running process, the bucket effect is obvious, and the overall life of energy storage system depends on the battery cluster with the shortest life among all battery clusters. The discharge depth of each battery cluster is inconsistent, which will also cause the circulating current phenomenon of battery cluster, so as to not only affect the charge and discharge efficiency of centralized energy storage system, but also affect its safety in the running process. And when centralized energy storage system fails, the manufacturer needs to debug and repair on site, so as to cause the longer downtime of centralized energy storage system and higher operation and maintenance cost. At the same time, because the capacity of single battery in centralized energy storage system is large, once centralized energy storage system fails, its influence range is wide, so as to put forward higher repair requirements to operation and maintenance personnel. In summary, centralized storage system has the problems of poor safety operation performance, low charge and discharge efficiency and complex operation and maintenance. At present, there is no effective solution to this technical problem. UTILITY MODEL CONTENT

[0004] Therefore, the utility model aims at providing a fusion version group string type energy storage system to solve the technical problems of poor safety operation performance, low charge and discharge efficiency and complex operation and maintenance of centralized energy storage system in prior art. The specific scheme is as follows:

[0005] In order to solve the above technical problems, the utility model provides a fusion version group string type energy storage system, which comprises:

[0006] a battery cluster composed of a plurality of single cells connected in series;

[0007] a fusion PCS module connected with the battery cluster, configured to collect operation information of the battery cluster and convert output current of the battery cluster into three-phase alternating current;

[0008] an alternating current busbar connected with a plurality of the fusion PCS modules, configured to collect three-phase alternating current output by the plurality of the fusion PCS modules to obtain target collection current;

[0009] an energy management module connected with the alternating current busbar, configured to integrate output current of the alternating current busbar into a power grid and manage the plurality of the fusion PCS modules and the alternating current busbar.

[0010] Preferably, the energy management module comprises a step-up transformer, a high-voltage cabinet and an EMS energy management unit.

[0011] Preferably, an output end of the alternating current busbar is connected with a first input end of the high-voltage cabinet through the step-up transformer, a communication interface of the alternating current busbar is connected with a first communication interface of the EMS energy management unit, a communication interface of the fusion PCS module is connected with a second communication interface of the EMS energy management unit, a third communication interface of the EMS energy management unit is connected with a communication interface of the high-voltage cabinet, and an output end of the high-voltage cabinet is connected with the power grid.

[0012] Preferably, the fusion PCS module comprises:

[0013] an isolation protection unit configured to electrically isolate the battery cluster and electrically protect each electronic component inside the fusion PCS module;

[0014] a busbar capacitor unit connected in parallel between the positive electrode and the negative electrode of the battery cluster;

[0015] a charge-discharge control unit connected with the isolation protection unit, configured to pre-charge the busbar capacitor unit and control charge and discharge of the busbar capacitor unit;

[0016] a power conversion unit configured to convert input current;

[0017] a filter unit connected with the power conversion unit, configured to filter current output by the power conversion unit;

[0018] a soft start unit connected with the filter unit, configured to buffer power supply signals of a load connected with the fusion PCS module;

[0019] A grid-connected contactor connected to the filter unit and configured to perform grid-connected control on an output current of the filter unit;

[0020] A fuse unit connected to the soft-start unit and the grid-connected contactor and configured to provide over-current protection;

[0021] A BCU master unit configured to collect operation information of the battery cluster;

[0022] A control board connected to the BCU master unit and configured to control the power conversion unit according to the operation information of the battery cluster, an output current of the bus capacitor unit, and an output current of the power conversion unit.

[0023] Preferably, the isolation protection unit comprises:

[0024] An electrical isolation device connected in parallel between the positive electrode and the negative electrode of the battery cluster; the electrical isolation device is specifically a DC circuit breaker or a disconnector;

[0025] A DC fuse connected to the electrical isolation device and configured to provide electrical protection for each electronic component inside the fusion PCS module.

[0026] Preferably, the charge-discharge control unit comprises a first pre-charge resistor, a second pre-charge resistor, a first pre-charge relay, a second pre-charge relay, a main positive relay, and a main negative relay.

[0027] The first end of the first pre-charge resistor and the first end of the main positive relay are both connected to the output end of the DC fuse, the second end of the first pre-charge resistor is connected to the first end of the first pre-charge relay, and the second end of the first pre-charge relay is connected to the second end of the main positive relay; the first end of the second pre-charge resistor and the first end of the main negative relay are both connected to the second output end of the electrical isolation device, the second end of the second pre-charge resistor is connected to the first end of the second pre-charge relay, and the second end of the second pre-charge relay is connected to the second end of the main negative relay.

[0028] Preferably, the bus capacitor unit comprises a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, and a tenth capacitor.

[0029] The first end of the first capacitor, the first end of the second capacitor, the first end of the third capacitor, the first end of the fourth capacitor and the first end of the fifth capacitor are connected with the positive electrode of the battery cluster, the common end composed of the second end of the first capacitor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor is connected with the common end composed of the first end of the sixth capacitor, the first end of the seventh capacitor, the first end of the eighth capacitor, the first end of the ninth capacitor and the first end of the tenth capacitor, and the common end composed of the second end of the sixth capacitor, the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth capacitor and the second end of the tenth capacitor is connected with the negative electrode of the battery cluster.

[0030] Preferably, the power conversion unit comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube.

[0031] The common end composed of the second end of the first capacitor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor is connected with the first end of the first switch tube, the first end of the third switch tube and the first end of the fifth switch tube respectively, the second end of the first switch tube is connected with the second end of the second switch tube, the second end of the third switch tube is connected with the second end of the fourth switch tube, and the second end of the fifth switch tube is connected with the second end of the sixth switch tube.

[0032] Correspondingly, the first end of the second switch tube, the first end of the fourth switch tube and the first end of the sixth switch tube are output ends of the power conversion unit.

[0033] Preferably, the filter unit comprises a first reactor, a second reactor, a third reactor, a fourth reactor, a fifth reactor, a sixth reactor, an eleventh capacitor, a twelfth capacitor and a thirteenth capacitor.

[0034] The first end of the first electric reactor is connected with the first end of the second switch tube, the second end of the first electric reactor is connected with the first end of the second electric reactor and the first end of the eleventh capacitor respectively, the first end of the third electric reactor is connected with the first end of the fourth switch tube, the second end of the third electric reactor is connected with the first end of the fourth electric reactor and the first end of the twelfth capacitor respectively, the first end of the fifth electric reactor is connected with the first end of the sixth switch tube, the second end of the fifth electric reactor is connected with the first end of the sixth electric reactor and the first end of the thirteenth capacitor respectively, and the second end of the eleventh capacitor, the second end of the twelfth capacitor and the second end of the thirteenth capacitor jointly constitute the N line of three-phase four-wire.

[0035] Preferably, the AC busbar cabinet comprises:

[0036] The BAU master unit is used for collecting the three-phase AC power output by the plurality of fusion PCS modules to obtain the target collected current.

[0037] The AC circuit breaker is connected with the BAU master unit and is used for cutting off the fault.

[0038] Beneficial effects: In the fusion version group string type energy storage system, the battery cluster, the fusion PCS module, the AC busbar cabinet and the energy management module are arranged. The battery cluster is composed of a plurality of single cells connected in series, the fusion PCS module is connected with the battery cluster, is used for collecting the operation information of the battery cluster, and converts the output current of the battery cluster into three-phase AC power. The AC busbar cabinet is connected with the plurality of fusion PCS modules, is used for collecting the three-phase AC power output by the plurality of fusion PCS modules to obtain the target collected current. The energy management module is connected with the AC busbar cabinet, is used for merging the output current of the AC busbar cabinet into the power grid, and manages the plurality of fusion PCS modules and the AC busbar cabinet.

[0039] Compared with the prior art, the energy storage system with the setting architecture can utilize a fusion PCS module to manage a single battery cluster, thereby realizing a cluster management function of the energy storage system, each battery cluster can independently execute charging and discharging logic, thereby avoiding circulating current problems between the battery clusters, which can significantly prolong the service life of the battery cluster in the energy storage system, and thereby improve the safety and reliability of the entire energy storage system during operation. Under the setting architecture, the capacity attenuation of a single battery cluster only affects the performance of a certain battery cluster, and has little effect on the charging and discharging efficiency of the entire energy storage system, thereby improving the charging and discharging efficiency of the entire energy storage system. Moreover, the cluster management mode of the energy storage system can quickly locate a fault and accurately locate a certain battery cluster when the energy storage system fails, so that the maintenance personnel can more quickly process and replace the faulty components, thereby significantly shortening the downtime of the energy storage system when the energy storage system fails, and greatly reducing the operation and maintenance complexity of the energy storage system. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0041] Figure 1 is a structural diagram of a centralized energy storage system in the prior art;

[0042] Figure 2 is a structural diagram of a fusion battery string type energy storage system provided by an embodiment of the present application;

[0043] Figure 3 is a structural diagram of another fusion battery string type energy storage system provided by an embodiment of the present application;

[0044] Figure 4 is a structural diagram of a fusion PCS module provided by an embodiment of the present application;

[0045] Figure 5 is a whole structural diagram of the fusion battery string type energy storage system. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0047] Please refer to Figure 2 , Figure 2 The structure diagram of the fusion version group string type energy storage system provided by the embodiment of the present application, the fusion version group string type energy storage system comprises:

[0048] The battery cluster 11 formed by a plurality of single battery cells connected in series;

[0049] The fusion PCS module 12 connected with the battery cluster 11, used for collecting the operation information of the battery cluster 11, and converting the output current of the battery cluster 11 into three-phase alternating current;

[0050] The alternating current busbar cabinet 13 connected with a plurality of fusion PCS modules 12, used for collecting the three-phase alternating current output by the plurality of fusion PCS modules 12 to obtain a target collection current;

[0051] The energy management module 14 connected with the alternating current busbar cabinet 13, used for merging the output current of the alternating current busbar cabinet 13 into a power grid, and managing the plurality of fusion PCS modules 12 and the alternating current busbar cabinet 13.

[0052] In the embodiment, a fusion version group string type energy storage system is provided, which has good safety performance, high operation efficiency and simple operation and maintenance. In the fusion version group string type energy storage system, the battery cluster 11, the fusion PCS module 12, the alternating current busbar cabinet 13 and the energy management module 14 are arranged.

[0053] The battery cluster 11 is formed by a plurality of single battery cells connected in series, the fusion PCS module 12 is connected with the battery cluster 11, used for collecting the operation information of the battery cluster 11, and converting the output current of the battery cluster 11 into three-phase alternating current. The alternating current busbar cabinet 13 is connected with a plurality of fusion PCS modules 12, used for collecting the three-phase alternating current output by the plurality of fusion PCS modules 12 to obtain a target collection current. The energy management module 14 is connected with the alternating current busbar cabinet 13, used for merging the output current of the alternating current busbar cabinet 13 into a power grid, and managing the plurality of fusion PCS modules 12 and the alternating current busbar cabinet 13.

[0054] It should be noted that in actual application, the single cells in each battery cluster 11 in the energy storage system can be mixed in new and old, and the number of battery clusters 11 in the energy storage system can also be expanded or reduced according to actual needs, thereby matching to form energy storage submodules of various capacities, thereby greatly improving the flexibility of the energy storage system setting structure, and the setting architecture of the energy storage system also has the advantages of convenient transportation and quick installation.

[0055] The energy storage system adopts a modular design, each battery cluster 11 is connected with a fusion PCS module 12, so that each battery cluster 11 has independent control logic, thereby making the entire energy storage system highly flexible and scalable. This decentralized architecture can be applied to industrial and commercial user side, zero-carbon park, new energy storage, and transformer area energy storage scenarios, and is suitable for strong grid, weak grid and off-grid application scenarios, and has the same ability as the same capacity synchronous generator in supporting voltage stability, frequency stability, power angle stability, etc. In addition, this architecture also helps to improve the grid connection and consumption of new energy. A large amount of test data shows that the performance of the energy storage system exceeds the existing level of the industry.

[0056] When a battery cluster 11 is connected with a fusion PCS module 12, it is equivalent to managing each battery cluster 11 in the energy storage system one cluster at a time. Under this setting architecture, the charging and discharging efficiency of each battery cluster 11 can be improved. Moreover, under this setting architecture, different battery clusters 11 can be combined, which not only enables efficient energy storage of the battery cluster 11, but also enables rational allocation of energy. In addition, the energy management module 14 can be used to monitor and dispatch each battery cluster 11, enabling intelligent control of the energy storage system, thereby improving the utilization efficiency of the entire energy storage system.

[0057] Since each battery cluster 11 has independent charging and discharging control logic, problems such as cell consistency mismatch caused by circulating current can be avoided, thereby making the temperature uniformity of the energy storage system better. The capacity attenuation of a single battery cluster 11 only affects the working performance of that battery cluster 11, and does not exist the wooden barrel effect in centralized energy storage systems, having less impact on the charging and discharging of other battery clusters in the energy storage system, which can further prolong the service life of the energy storage system.

[0058] Moreover, because each battery cluster 11 has independent charging and discharging control logic, the faults of each battery cluster 11 can be isolated. When the energy storage system fails, the maintenance personnel can accurately locate a certain battery cluster 11 in the energy storage system, and process and repair the faulty battery cluster 11, quickly replace the faulty parts, and shorten the downtime of the energy storage system, which can significantly reduce the operation and maintenance cost of the energy storage system.

[0059] In other words, since the energy storage system adopts a modular design, when the energy storage system fails, the failed module (including the battery cluster 11 and the fusion PCS module 12) can be cut off individually without affecting the normal work of other modules in the energy storage system, the system availability is as high as 99.9%, flexible deployment and smooth capacity expansion can be achieved, the influence range of failure is greatly reduced, and the difficulty of maintenance of the energy storage system by the operation and maintenance personnel is reduced.

[0060] In addition, under this setting architecture, each battery cluster 11 has independent control logic, which reduces the risk of thermal runaway of the battery cluster 11, thereby avoiding the expansion of thermal runaway and the occurrence of large-scale fires. Once the energy storage system fails, the failed area in the energy storage system can be quickly cut off, which further improves the safety and reliability of the energy storage system during operation.

[0061] In addition, in actual application, AI (Artificial Intelligence) technology or cloud management technology can be used to detect failed devices in the fusion battery string type energy storage system to reduce the probability of fire accidents. At the same time, an artificial intelligence model can be built using AI technology, and the health of each battery cluster in the fusion battery string type energy storage system can be predicted using the artificial intelligence model. Alternatively, the artificial intelligence model can find the best balance point between the attenuation of the battery cluster and the temperature control energy consumption, so that the LCOS (Levelized Cost of Storage) of the energy storage system is optimized.

[0062] Compared with the prior art, through the setting architecture of the energy storage system, one fusion PCS module can be used to manage a single battery cluster, which realizes the one-cluster management function of the energy storage system, and each battery cluster can independently execute the charging and discharging logic, thereby avoiding the circulating current problem between the battery clusters, which can significantly prolong the service life of the battery cluster in the energy storage system and improve the safety and reliability of the entire energy storage system during operation. Under this setting architecture, the capacity attenuation of a single battery cluster only affects the performance of the battery cluster, and has little effect on the charging and discharging efficiency of the entire energy storage system, which can improve the charging and discharging efficiency of the energy storage system. In addition, the one-cluster management mode of the energy storage system can quickly locate the failure and accurately locate a certain battery cluster when the energy storage system fails, so that the operation and maintenance personnel can more quickly process and replace the failed components, thereby significantly shortening the downtime when the energy storage system fails and greatly reducing the operation and maintenance complexity of the energy storage system.

[0063] Based on the above embodiment, the technical solutions are further described and optimized in this embodiment, please refer to Figure 3 , Figure 3 The structure diagram of another fusion version group string type energy storage system is provided in the embodiment of the utility model. As a preferred implementation, the energy management module 14 comprises: a step-up transformer 141, a high-voltage cabinet 142 and an EMS energy management unit 143.

[0064] Among them, the output end of the AC bus cabinet 13 is connected with the first input end of the high-voltage cabinet 142 through the step-up transformer 141, the communication interface of the AC bus cabinet 13 is connected with the first communication interface of the EMS energy management unit 143, the communication interface of the fusion PCS module 12 is connected with the second communication interface of the EMS energy management unit 143, the third communication interface of the EMS energy management unit 143 is connected with the communication interface of the high-voltage cabinet 142, and the output end of the high-voltage cabinet 142 is connected with the power grid.

[0065] In this embodiment, the energy management module 14 is specifically described. The step-up transformer 141, the high-voltage cabinet 142 and the EMS (Energy Management System, battery management system) energy management unit 143 are arranged in the energy management module 14. The step-up transformer 141 can perform step-up processing on the voltage output by the AC bus cabinet 13 and transmit the stepped-up voltage to the high-voltage cabinet 142. After the high-voltage cabinet 142 receives the voltage sent by the step-up transformer 141, the high-voltage cabinet 142 will integrate the energy output by the entire energy storage system into the power grid.

[0066] At the same time, the EMS energy management unit 143 also interacts with each fusion PCS module 12 and AC bus cabinet 13 in the energy storage system and collects the data information of each fusion PCS module 12 and AC bus cabinet 13. Then, the EMS energy management unit 143 will manage each fusion PCS module 12 according to the data information of each fusion PCS module 12 collected, so that each battery cluster connected in front of the fusion PCS module 12 can execute normal charging and discharging logic. Similarly, the EMS energy management unit 143 will also control the output voltage of the AC bus cabinet 13 according to the data information of the AC bus cabinet 13 collected.

[0067] Obviously, through the technical solutions provided in this embodiment, not only can the energy output by the energy storage system be successfully integrated into the power grid, but also the control logic of each fusion PCS module and AC bus cabinet in the energy storage system can be managed.

[0068] Based on the above embodiment, the technical solutions are further described and optimized in this embodiment, please refer to Figure 4 ,Figure 4 A structure diagram of the fusion PCS module is provided in the embodiments of the utility model. As a preferred implementation, the fusion PCS module 12 comprises:

[0069] An isolation protection unit 101 for electrically isolating the battery cluster 11 and electrically protecting each electronic component inside the fusion PCS module 12;

[0070] A bus capacitor unit 103 connected in parallel between the positive and negative poles of the battery cluster 11;

[0071] A charge-discharge control unit 102 connected to the isolation protection unit 101, for pre-charging the bus capacitor unit 103 and controlling the charge and discharge of the bus capacitor unit 103;

[0072] A power conversion unit 104 for power conversion of input current;

[0073] A filter unit 106 connected to the power conversion unit 104, for filtering the current output by the power conversion unit 104;

[0074] A soft start unit 107 connected to the filter unit 106, for buffering the power supply signal of the load connected to the fusion PCS module 12;

[0075] A grid-connected contactor KM01 connected to the filter unit 106, for grid-connected control of the output current of the filter unit 106;

[0076] A fuse unit 110 connected to the soft start unit 107 and the grid-connected contactor KM01, for providing overcurrent protection;

[0077] A BCU master unit 108 for collecting the running information of the battery cluster;

[0078] A control panel 109 connected to the BCU master unit 108, for controlling the power conversion unit 104 according to the running information of the battery cluster 11, the output current of the bus capacitor unit 103, and the output current of the power conversion unit 104.

[0079] In this embodiment, the internal structure of the fusion PCS module 12 is specifically described. In the fusion PCS module 12, the isolation protection unit 101, the bus capacitor unit 103, the charge-discharge control unit 102, the power conversion unit 104, the filter unit 106, the soft start unit 107, the grid-connected contactor KM01, the fuse unit 110, the BCU (Battery Control Unit) master unit 108, and the control panel 109 are provided.

[0080] The isolation protection unit 101 is used to electrically isolate the battery cluster 11 and protect the electronic components in the fusion PCS module 12 from short circuit or overload to avoid safety accidents. The bus capacitor unit 103 is used to store the power transmitted by the battery cluster 11, and is connected to the DC side to filter high-frequency noise in the current. The charge and discharge control unit 102 is used to control the bus capacitor unit 103 to charge or discharge.

[0081] The control board 109 is used to provide a PWM (Pulse Width Modulation) driving signal to the power conversion unit 104 and control the power conversion unit 104 to convert the voltage output by the bus capacitor unit 103 into three-phase alternating current. Since the three-phase alternating current output by the power conversion unit 104 is not smooth and contains high-order harmonics, the filter unit 106 can be used to filter the high-order harmonics in the three-phase alternating current output by the power conversion unit 104, so that the three-phase alternating current output by the filter unit 106 becomes a smooth sine wave.

[0082] The soft start unit 107 is used to buffer the power supply signal of the load connected to the fusion PCS module 12 to avoid damage to the load caused by large current. The grid-connected contactor KM01 is used to connect the output current of the filter unit 106 to the grid. The grid-connected contactor KM01 is a contactor with three auxiliary contacts on the input and output ends, and the three auxiliary contacts on the input and output ends of the grid-connected contactor KM01 are connected to the A-phase, B-phase and C-phase lines on the AC side, respectively. The fuse unit 110 is used to provide overcurrent protection to avoid safety accidents. Figure 4 In the above, the first fuse FU1, the second fuse FU2 and the third fuse FU3 constitute the fuse unit 110, the first ends of the first fuse FU1, the second fuse FU2 and the third fuse FU3 are connected to the three auxiliary contacts on the output end of the grid-connected contactor KM01, and the second ends of the first fuse FU1, the second fuse FU2 and the third fuse FU3 constitute the A-phase output end, the B-phase output end and the C-phase output end of the fusion PCS module, respectively.

[0083] The BCU master unit 108 is configured to collect the operation information of the battery cluster 11 through the daisy chain, and the operation information of the battery cluster 11 includes voltage information, current information, temperature information and the like of the battery cluster 11. After the BCU master unit 108 collects the operation information of the battery cluster 11, the operation information of the battery cluster 11 is sent to the control panel 109. The control panel 109 controls the power conversion unit according to the operation information of the battery cluster 11, the output current of the bus capacitor unit 103 and the output current of the power conversion unit 105, so that the current output by the power conversion unit 105 can successfully complete the grid-connected operation.

[0084] Obviously, through the technical scheme provided by the embodiment, the output current of the battery cluster can be safely and reliably converted into three-phase alternating current by the fusion PCS module.

[0085] Please continue to refer to Figure 4 As a preferred embodiment, the isolation protection unit 101 includes:

[0086] An electrical isolation device connected in parallel between the positive electrode and the negative electrode of the battery cluster 11; the electrical isolation device is specifically a DC circuit breaker QF0 or a disconnector;

[0087] A DC fuse FU0 connected to the electrical isolation device and configured to electrically protect each electronic component inside the fusion PCS module 12.

[0088] Specifically, the isolation protection unit 101 is provided with the electrical isolation device and the DC fuse FU0. The electrical isolation device can be a DC circuit breaker QF0 or a disconnector. The DC circuit breaker QF0 is configured to protect and isolate the battery cluster 11, and cut off the electrical circuit when the battery cluster 11 is overloaded or short-circuited, so as to protect each component in the fusion PCS module. The disconnector is configured to isolate the electrical circuit of the battery cluster 11 and the PCS side. The DC fuse FU0 is configured to protect each electronic component in the fusion PCS module from short circuit.

[0089] Obviously, through the technical scheme provided by the embodiment, each component in the fusion PCS module can be electrically protected on the DC side.

[0090] Please continue to refer to Figure 4 As a preferred embodiment, the charge and discharge control unit 102 includes a first pre-charging resistor R01, a second pre-charging resistor R02, a first pre-charging relay KM1, a second pre-charging relay KM2, a main positive relay KM3 and a main negative relay KM4.

[0091] The first end of the first pre-charge resistor R01 and the first end of the main positive relay KM3 are connected with the output end of the DC fuse FU0, the second end of the first pre-charge resistor R01 is connected with the first end of the first pre-charge relay KM1 respectively, and the second end of the first pre-charge relay KM1 is connected with the second end of the main positive relay KM3; the first end of the second pre-charge resistor R02 and the first end of the main negative relay KM4 are connected with the second output end of the electrical isolation device, the second end of the second pre-charge resistor R02 is connected with the first end of the second pre-charge relay KM2, and the second end of the second pre-charge relay KM2 is connected with the second end of the main negative relay KM4.

[0092] Since the bus capacitor unit 103 cannot be directly charged with a large current, the service life of the bus capacitor unit 103 will be seriously affected, and therefore, the pre-charge circuit needs to be arranged in the charge-discharge control unit 102. The first pre-charge resistor R01, the second pre-charge resistor R02, the first pre-charge relay KM1 and the second pre-charge relay KM2 constitute the pre-charge circuit. When the bus capacitor unit 103 is charged to a certain extent by using the pre-charge circuit, the main positive relay KM3 and the main negative relay KM4 can be used to control the charge-discharge logic of the bus capacitor unit 103.

[0093] Obviously, by using the technical scheme provided in the embodiment, the safety and reliability in the charge-discharge control of the bus capacitor unit can be further ensured.

[0094] Please continue to refer to Figure 4 As a preferred embodiment, the bus capacitor unit 103 comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a tenth capacitor C10.

[0095] The first end of the first capacitor C1, the first end of the second capacitor C2, the first end of the third capacitor C3, the first end of the fourth capacitor C4 and the first end of the fifth capacitor C5 are connected with the positive electrode of the battery cluster 11, the common end composed of the second end of the first capacitor C1, the second end of the second capacitor C2, the second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the fifth capacitor C5 is connected with the common end composed of the first end of the sixth capacitor C6, the first end of the seventh capacitor C7, the first end of the eighth capacitor C8, the first end of the ninth capacitor C9 and the first end of the tenth capacitor C10, and the common end composed of the second end of the sixth capacitor C6, the second end of the seventh capacitor C7, the second end of the eighth capacitor C8, the second end of the ninth capacitor C9 and the second end of the tenth capacitor C10 is connected with the negative electrode of the battery cluster 11.

[0096] In the embodiment, the structure of the bus capacitor unit 103 is specifically described. The bus capacitor unit 103 is used to store electric quantity, and plays a role of energy buffer when the power conversion unit 105 performs power conversion.

[0097] Please continue to see Figure 4 As a preferred embodiment, the power conversion unit 104 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a fifth switch tube Q5 and a sixth switch tube Q6.

[0098] The second end of the first capacitor C1, the second end of the second capacitor C2, the second end of the third capacitor C3, the second end of the fourth capacitor C4 and the second end of the fifth capacitor C5 form a common end, which is connected to the first end of the first switch tube Q1, the first end of the third switch tube Q3 and the first end of the fifth switch tube Q5, the second end of the first switch tube Q1 is connected to the second end of the second switch tube Q2, the second end of the third switch tube Q3 is connected to the second end of the fourth switch tube Q4, and the second end of the fifth switch tube Q5 is connected to the second end of the sixth switch tube Q6.

[0099] Correspondingly, the first end of the second switch tube Q2, the first end of the fourth switch tube Q4 and the second end of the sixth switch tube Q6 are output ends of the power conversion unit 104.

[0100] In the embodiment, six switch tubes are arranged in the power conversion unit 104, and the six switch tubes can convert the output voltage of the battery cluster into three-phase alternating current by the power conversion unit.

[0101] In actual application, the six switch tubes can be set as the same type of switch tube. For example, the first switch tube can be set as an NMOS (N Metal Oxide Semiconductor, N-type metal oxide semiconductor) tube, the gate of the NMOS tube is set as the control end of the first switch tube Q1, and the source and drain of the NMOS tube are set as the first end and the second end of the first switch tube Q1, respectively.

[0102] Please continue to see Figure 4 As a preferred embodiment, the filter unit 106 includes a first reactor L1, a second reactor L2, a third reactor L3, a fourth reactor L4, a fifth reactor L5, a sixth reactor L6, an eleventh capacitor C11, a twelfth capacitor C12 and a thirteenth capacitor C13.

[0103] The first end of the first reactor L1 is connected with the first end of the second switch tube Q2, the second end of the first reactor L1 is connected with the first end of the second reactor L2 and the first end of the eleventh capacitor C11 respectively, the first end of the third reactor L3 is connected with the first end of the fourth switch tube Q4, the second end of the third reactor L3 is connected with the first end of the fourth reactor L4 and the first end of the twelfth capacitor C12 respectively, the first end of the fifth reactor L5 is connected with the first end of the sixth switch tube Q1, the second end of the fifth reactor L5 is connected with the first end of the sixth reactor L6 and the first end of the thirteenth capacitor C13 respectively, and the second end of the eleventh capacitor C11, the second end of the twelfth capacitor C12 and the second end of the thirteenth capacitor C13 together constitute the N line of the three-phase four-wire.

[0104] In the embodiment, the first reactor L1, the second reactor L2, the third reactor L3, the fourth reactor L4, the fifth reactor L5, the sixth reactor L6, the eleventh capacitor C11, the twelfth capacitor C12 and the thirteenth capacitor C13 are arranged in the filter unit 106. The filter unit 106 can filter out the high-order harmonic wave in the three-phase alternating current output by the power conversion unit 105, thereby ensuring the stability of the output current of the fusion PCS module 12 on the alternating current side.

[0105] Please continue to refer to Figure 5 As a preferred embodiment, the soft start unit 107 includes the first resistor R1, the second resistor R2, the third resistor R3 and the alternating current contactor KM02.

[0106] The first end of the first resistor R1, the first end of the second resistor R2 and the first end of the third resistor R3 are connected with the second end of the second reactor, the second end of the fourth reactor and the second end of the sixth reactor respectively, the second end of the first resistor R1, the second end of the second resistor R2 and the second end of the third resistor R3 are connected with the three auxiliary contacts of the input end of the alternating current contactor KM02 respectively, and the three auxiliary contacts of the output end of the alternating current contactor KM02 are connected with the three auxiliary contacts of the output end of the grid-connected contactor KM01 respectively.

[0107] In actual application, if the three-phase alternating current output by the filter unit 106 is directly provided to the load, it is very likely that the load will be damaged due to the too large instantaneous power supply energy. In order to avoid this situation, the first resistor R1, the second resistor R2, the third resistor R3 and the alternating current contactor KM02 can be arranged in the soft start unit 107, and the resistors can be introduced into the electric circuit through the conduction of each switch, so as to reduce the energy impact on the load, thereby achieving the purpose of protecting the load connected with the fusion PCS module 12.

[0108] Obviously, through the technical solutions provided by the embodiment, the safety of the fusion PCS module when supplying power to the load can be further improved.

[0109] Based on the above embodiment, the technical solutions are further described and optimized in this embodiment, please refer to Figure 5 , ​ The overall structure diagram of the fusion version group string energy storage system is shown in FIG. 1. As a preferred embodiment, the AC bus cabinet 13 includes:

[0110] The BAU master unit 131 is used to collect the three-phase AC power output by the plurality of fusion PCS modules to obtain the target collection current.

[0111] The AC circuit breaker QF1 is connected to the BAU master unit 131 and is used to cut off the fault.

[0112] In this embodiment, the AC bus cabinet 13 is specifically described. The AC bus cabinet 13 is provided with the BAU master unit 131 and the AC circuit breaker QF1. The BAU master unit 131 is used to collect the three-phase AC power output by the plurality of fusion PCS modules 12 to obtain the target collection current. The AC circuit breaker QF1 is used to cut off the fault when the AC bus cabinet 13 fails, so as to ensure the safe and stable operation of the AC bus cabinet 13.

[0113] In actual application, a plurality of DI / DO interfaces can be arranged at the input end of the BAU master unit 131, and these DI / DO interfaces are used to collect the fire alarm signal, emergency stop signal, water immersion signal, access control signal, opening signal, closing signal and the like in the energy storage system. At the same time, a plurality of RS485 communication interfaces can be arranged at the output end of the BAU master unit 131, and these RS485 communication interfaces are used to communicate with other devices (such as temperature and humidity sensors, video monitors, liquid cooling machines) in the energy storage system. In addition, a LAN (Local Area Network) communication interface can be arranged on the BAU master unit 131, and a switch is connected to the LAN communication interface, so as to communicate with the EMS energy management unit 143 through the switch, and to accept the control of the EMS energy management unit 143.

[0114] Obviously, through the technical solutions provided by the embodiment, the safety and reliability of the AC bus cabinet during use can be further ensured.

[0115] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended 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. A fused group string energy storage system, characterized by, The application relates to a battery cluster, a fusion PCS module, an AC busbar cabinet and an energy management module. The battery cluster comprises a plurality of single battery cells connected in series. The fusion PCS module is connected with the battery cluster, used for collecting operation information of the battery cluster and converting output current of the battery cluster into three-phase alternating current. The AC busbar cabinet is connected with the fusion PCS module, used for collecting three-phase alternating current output by the fusion PCS module to obtain target collection current. The energy management module is connected with the AC busbar cabinet, used for merging output current of the AC busbar cabinet into a power grid and managing the fusion PCS module and the AC busbar cabinet. The fusion PCS module comprises an isolation protection unit, a bus capacitor unit, a charge-discharge control unit, a power conversion unit, a filter unit, a soft start unit, a grid-connected contactor, a fuse unit, a BCU master unit and a control board. The isolation protection unit is used for electrically isolating the battery cluster and electrically protecting each electronic component in the fusion PCS module. The bus capacitor unit is connected in parallel between the positive electrode and the negative electrode of the battery cluster. The charge-discharge control unit is connected with the isolation protection unit, used for pre-charging the bus capacitor unit and controlling charge and discharge of the bus capacitor unit. The power conversion unit is used for power conversion of input current. The filter unit is connected with the power conversion unit, used for filtering current output by the power conversion unit. The soft start unit is connected with the filter unit, used for buffering power supply signals of a load connected with the fusion PCS module. The grid-connected contactor is connected with the filter unit, used for grid-connected control of output current of the filter unit. The fuse unit is connected with the soft start unit and the grid-connected contactor, used for over-current protection. The BCU master unit is used for collecting operation information of the battery cluster. The control board is connected with the BCU master unit, used for controlling the power conversion unit according to operation information of the battery cluster, output current of the bus capacitor unit and output current of the power conversion unit.

2. A fused bank energy storage system according to claim 1, wherein, The energy management module comprises a step-up transformer, a high-voltage cabinet and an EMS energy management unit. The output end of the AC busbar cabinet is connected with the first input end of the high-voltage cabinet through the step-up transformer, the communication interface of the AC busbar cabinet is connected with the first communication interface of the EMS energy management unit, the communication interface of the fusion PCS module is connected with the second communication interface of the EMS energy management unit, the third communication interface of the EMS energy management unit is connected with the communication interface of the high-voltage cabinet, and the output end of the high-voltage cabinet is connected with the power grid.

3. A fused bank energy storage system according to claim 1, wherein, The isolation protection unit comprises an electrical isolation device connected in parallel between the positive electrode and the negative electrode of the battery cluster. The electrical isolation device is a DC circuit breaker or a disconnector. The charge-discharge control unit comprises a first pre-charging resistor, a second pre-charging resistor, a first pre-charging relay, a second pre-charging relay, a main positive relay and a main negative relay.

4. A fused bank energy storage system according to claim 3, wherein, ​ The first end of the first pre-charging resistor and the first end of the main positive relay are connected with the output end of the DC fuse, the second end of the first pre-charging resistor is connected with the first end of the first pre-charging relay respectively, and the second end of the first pre-charging relay is connected with the second end of the main positive relay; the first end of the second pre-charging resistor and the first end of the main negative relay are connected with the second output end of the electrical isolation device, the second end of the second pre-charging resistor is connected with the first end of the second pre-charging relay, and the second end of the second pre-charging relay is connected with the second end of the main negative relay.

5. The fused bank energy storage system of claim 1, wherein, The bus capacitor unit comprises a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a tenth capacitor. The first end of the first capacitor, the first end of the second capacitor, the first end of the third capacitor, the first end of the fourth capacitor and the first end of the fifth capacitor are connected with the positive electrode of the battery cluster, the second end of the first capacitor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor constitute a common end, which is connected with the common end of the first end of the sixth capacitor, the first end of the seventh capacitor, the first end of the eighth capacitor, the first end of the ninth capacitor and the first end of the tenth capacitor, and the common end of the second end of the sixth capacitor, the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth capacitor and the second end of the tenth capacitor is connected with the negative electrode of the battery cluster.

6. A fused bank energy storage system according to claim 5, wherein, The power conversion unit comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth switch tube and a sixth switch tube. The second end of the first capacitor, the second end of the second capacitor, the second end of the third capacitor, the second end of the fourth capacitor and the second end of the fifth capacitor constitute a common end, which is connected with the first end of the first switch tube, the first end of the third switch tube and the first end of the fifth switch tube respectively, the second end of the first switch tube is connected with the second end of the second switch tube, the second end of the third switch tube is connected with the second end of the fourth switch tube, and the second end of the fifth switch tube is connected with the second end of the sixth switch tube. Correspondingly, the first end of the second switch tube, the first end of the fourth switch tube and the first end of the sixth switch tube are output ends of the power conversion unit.

7. A fused bank energy storage system according to claim 6, wherein, The filter unit comprises a first reactor, a second reactor, a third reactor, a fourth reactor, a fifth reactor, a sixth reactor, an eleventh capacitor, a twelfth capacitor and a thirteenth capacitor. The first end of the first electric reactor is connected with the first end of the second switch tube, the second end of the first electric reactor is connected with the first end of the second electric reactor and the first end of the eleventh capacitor respectively, the first end of the third electric reactor is connected with the first end of the fourth switch tube, the second end of the third electric reactor is connected with the first end of the fourth electric reactor and the first end of the twelfth capacitor respectively, the first end of the fifth electric reactor is connected with the first end of the sixth switch tube, the second end of the fifth electric reactor is connected with the first end of the sixth electric reactor and the first end of the thirteenth capacitor respectively, and the second end of the eleventh capacitor, the second end of the twelfth capacitor and the second end of the thirteenth capacitor jointly constitute the N line of the three-phase four-wire system.

8. The fused bank energy storage system of claim 1, wherein, The AC bus cabinet comprises: a BAU master control unit for collecting the three-phase AC power output by the plurality of fusion PCS modules to obtain the target collected current; an AC circuit breaker connected with the BAU master control unit and used for cutting off the fault.

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