Power supply output circuit and power supply system

Abstract

The utility model belongs to the technical field of power supply devices, and particularly relates to a power supply output circuit and a power supply system. The power supply system comprises at least two battery clusters and further comprises AC / DC conversion modules and high-voltage boxes used for being correspondingly connected with the battery clusters, the power supply output end of at least one high-voltage box is provided with an interface used for being connected with a direct-current load, and the power supply output ends of the at least two high-voltage boxes are connected with the direct-current sides of the corresponding AC / DC conversion modules. AC sides of the AC / DC conversion modules or at least two AC / DC conversion modules are connected in parallel and then are used for connecting an AC load; the high-voltage box is provided with a switch used for controlling power output of the battery clusters, a pre-charging circuit does not need to be designed in the high-voltage box, use of electrical parts such as contactors and resistors is reduced, the size of the high-voltage box is reduced, a confluence cabinet does not need to be configured for confluence between the clusters, and the space occupancy and cost of the power system are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of power supply devices, and particularly relates to a power output circuit and a power system. Background Art

[0002] The endurance of new energy rail locomotives depends on the power of the power system, and the carrying capacity depends on the output capacity of the power system. The loads include DC loads (such as DC motors) and AC loads (such as air conditioners). The load composition is complex, and the capacity requirements and output requirements are large. Conventional battery series-parallel connections cannot meet the requirements. Therefore, in the prior art, the power systems of rail locomotives generally adopt an energy storage architecture. As Figure 1 shown, two clusters of battery boxes are respectively controlled and output through high-voltage boxes and then are connected in parallel and converged in a busbar cabinet, and after convergence, they are connected to the load. Since two battery clusters are directly connected in parallel on the busbar of the busbar cabinet, there may be a pressure difference between the clusters. And the internal resistance of the battery itself is small. In this case, a large inter-cluster circulating current may occur. When the inter-cluster circulating current is too large, the system will be damaged. Therefore, a pre-charge circuit including electrical components such as contactors and resistors is designed in the high-voltage box. When there is a pressure difference between the clusters, the pre-charge circuit is controlled according to the inter-cluster balancing strategy to reduce the pressure difference. The entire power system has a large space occupancy rate and high cost. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a power output circuit and a power system to solve the problem of large space occupancy rate of the existing power system.

[0004] The utility model provides a power system for solving the above technical problems. The power system includes at least two battery clusters, and also includes an AC / DC conversion module and a high-voltage box used for corresponding connection with the battery clusters. The power output end of at least one high-voltage box is provided with an interface for connecting a DC load. The power output ends of at least two high-voltage boxes are connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module or at least two of the AC / DC conversion modules are connected in parallel and used for connecting an AC load; the high-voltage box is provided with a switch for controlling the power output of the battery cluster.

[0005] Further, the number of the battery clusters is two, which are a first battery cluster and a second battery cluster respectively. The first battery cluster is connected to a first high-voltage box, and the second battery cluster is connected to a second high-voltage box. The power output ends of the first high-voltage box and the second high-voltage box are both provided with interfaces for connecting a DC load; the power output end of the first high-voltage box is further connected to the DC side of a first AC / DC conversion module, and the power output end of the second high-voltage box is further connected to the DC side of a second AC / DC conversion module. The AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel and used for connecting an AC load.

[0006] Further, the number of the battery clusters is greater than two. Each battery cluster is connected to a high-voltage box. An interface for connecting a DC load is provided at the power output end of each high-voltage box. The power output ends of the high-voltage boxes are also connected to the DC side of the corresponding AC / DC conversion module. The AC sides of the AC / DC conversion modules are connected in parallel and used to connect to an AC load.

[0007] Further, the power supply system further includes a control module. The control module includes a BMM and a BCM. The BMM is used to upload the information of the single cells in the battery cluster collected to the BCM, and the BCM processes the information of the single cells in the battery cluster and then uploads it to the vehicle controller.

[0008] Further, the AC side of the AC / DC conversion module is also used to connect to an AC power supply. The AC / DC conversion module converts the AC power supply into DC power and charges the corresponding connected battery cluster.

[0009] Further, the high-voltage box is also provided with a charging interface for connecting a charging power supply. The charging power supply charges the battery cluster through the charging interface.

[0010] The beneficial effects of the above technical solutions are as follows: The present utility model is an improved invention. The high-voltage boxes corresponding to at least two battery clusters are connected to the DC side of the corresponding AC / DC conversion modules. The AC sides of multiple AC / DC conversion modules are connected in parallel and then used to connect to an AC load to supply power to the AC load. Since the parallel connection position is in the middle of the AC / DC and the AC load, and the AC / DC is of the isolated type, parallel connection will not cause an inter-cluster circulating current problem. Therefore, there is no need to design a pre-charge circuit in the high-voltage box, reducing the use of electrical components such as contactors and resistors, thereby reducing the size of the high-voltage box, lowering the space occupancy rate and cost of the power supply system, and not requiring a busbar cabinet to conduct inter-cluster busbar connection, further reducing the space occupancy rate of the power supply system and optimizing the space layout of the system.

[0011] To solve the above technical problems, the present utility model also provides a power output circuit, including an AC / DC conversion module and a high-voltage box for corresponding connection with a battery cluster. An interface for connecting a DC load is provided at the power output end of at least one high-voltage box. The power output ends of at least two high-voltage boxes are connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module or at least two of the AC / DC conversion modules are connected in parallel and used to connect to an AC load; the high-voltage box is provided with a switch for controlling the power output of the battery cluster.

[0012] Further, the number of high-voltage boxes is two, namely the first high-voltage box and the second high-voltage box. Interfaces for connecting DC loads are provided at the power output ends of the first high-voltage box and the second high-voltage box; the power output end of the first high-voltage box is also connected to the DC side of the first AC / DC conversion module, and the power output end of the second high-voltage box is also connected to the DC side of the second AC / DC conversion module. The AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel and then used to connect an AC load.

[0013] Further, the number of high-voltage boxes is greater than two. Interfaces for connecting DC loads are provided at the power output ends of each high-voltage box. The power output end of each high-voltage box is also connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module are connected in parallel and then used to connect an AC load.

[0014] Further, the AC side of the AC / DC conversion module is also used to connect an AC power supply. The AC / DC conversion module converts the AC power supply into direct current and then charges the corresponding connected battery cluster.

[0015] The beneficial effects of the above technical solutions are as follows: The present utility model is an improved invention. The high-voltage boxes corresponding to at least two battery clusters are connected to the DC sides of the corresponding AC / DC conversion modules. The AC sides of multiple AC / DC conversion modules are connected in parallel and then used to connect an AC load to supply power to the AC load. Since the parallel connection position is in the middle between the AC / DC and the AC load, and the AC / DC is an isolation type, parallel connection will not cause inter-cluster circulating current problems. Therefore, there is no need to design a pre-charge circuit in the high-voltage box, reducing the use of electrical components such as contactors and resistors, thereby reducing the size of the high-voltage box, lowering the space occupancy rate and cost of the power supply system, and not requiring a busbar cabinet to conduct inter-cluster busbar connection, further reducing the space occupancy rate of the power supply system and optimizing the space layout of the system. Description of the Drawings

[0016] Figure 1 is the framework diagram of the power supply system in the prior art;

[0017] Figure 2 is the framework diagram of the power output circuit in the power supply system embodiment of the present utility model;

[0018] Figure 3 is the architecture diagram of the control module in the power supply system embodiment of the present utility model;

[0019] Figure 4 is the architecture diagram of the power supply system control module in the prior art. Detailed Embodiments

[0020] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following further describes the detailed embodiments of the present utility model with reference to the drawings.

[0021] The high-voltage output terminal of the high-voltage box connecting the battery clusters of the present utility model is divided into two-way load outputs to provide power for DC loads and AC loads respectively, and the busbar cabinet is no longer used to converge the outputs of all battery clusters for unified power supply; when AC output is performed, the power output terminal of the battery cluster corresponding to the high-voltage box is connected to the DC side of the corresponding AC / DC conversion module, and the AC sides of multiple AC / DC conversion modules are connected in parallel and then connected to the AC load to supply power to the AC load at the same time. Since the parallel connection position is in the middle of the AC / DC and the AC load, and the AC / DC is isolated, parallel connection will not cause the problem of inter-cluster circulating current. Therefore, there is no need to design a pre-charge circuit in the high-voltage box, reducing the use of electrical components such as contactors and resistors, thereby reducing the size of the high-voltage box, lowering the space occupancy rate and cost of the power supply system, and not requiring the configuration of a busbar cabinet for inter-cluster convergence, further reducing the space occupancy rate of the power supply system and optimizing the space layout of the system.

[0022] Power supply system embodiment

[0023] A power supply system of the present utility model can be applied to all power supply systems with specific load attributes of rail locomotives (referring to both DC and AC loads at the rear end), including at least two battery clusters, and also includes a power output circuit and a control module. The power output circuit includes a high-voltage box for corresponding connection with the battery clusters. The power output terminal of at least one high-voltage box is provided with an interface for connecting a DC load. The power output terminals of at least two high-voltage boxes are connected to the DC sides of the corresponding AC / DC conversion modules. The AC sides of the AC / DC conversion modules are connected in parallel for connecting an AC load; the high-voltage box is provided with a switch for controlling the power output of the battery cluster. Inside the high-voltage box, there are a switch for controlling the power output of the battery cluster, a current sensor for detecting the magnitude of the current, and a fuse for over-current protection. Among them, the power input terminal of each high-voltage box is connected to a corresponding battery cluster, and the number of battery clusters and high-voltage boxes can be set according to the usage requirements. The AC side of the AC / DC conversion module is also used to connect an AC power supply, and the AC / DC conversion module converts the AC power supply into a DC power supply to charge the corresponding connected battery cluster. The high-voltage box is also provided with a charging interface, and the charging power supply charges the battery cluster through the charging interface.

[0024] In one embodiment, the number of battery clusters and high-voltage boxes is two. At this time, it is a dual-power parallel connection. The first battery cluster is connected to the first high-voltage box, the second battery cluster is connected to the second high-voltage box, and the power output terminals of the first high-voltage box and the second high-voltage box are both provided with interfaces for connecting a DC load; the power output terminal of the first high-voltage box is also connected to the DC side of the first AC / DC conversion module, the power output terminal of the second high-voltage box is also connected to the DC side of the second AC / DC conversion module, and the AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel for connecting an AC load.

[0025] AsFigure 2 As shown in the figure: The first battery cluster (battery cluster 1 in the figure) is connected to the power input terminal of the first high-voltage box (high-voltage box 1 in the figure), and the second battery cluster (battery cluster 2 in the figure) is connected to the power input terminal of the second high-voltage box (high-voltage box 2 in the figure). The first high-voltage box and the second high-voltage box are respectively provided with fuses 1-FU1 and 2-FU1 at the positive power output terminal, switches 1-KM2 and 2-KM2, and current sensors 1-HALL and 2-HALL at the negative power output terminal. The power output terminal of each high-voltage box is divided into two paths. One path of the power output terminal of the first high-voltage box is connected to the first DC load (load 1 in the figure), and the other path is connected to the DC side of the first AC / DC conversion module. One path of the power output terminal of the second high-voltage box is connected to the second DC load (load 3 in the figure), and the other path is connected to the DC side of the second AC / DC conversion module. The AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel and then connected to the AC load (load 2 in the figure). At this time, the first DC load is powered by the first battery cluster alone, the second DC load is powered by the second battery cluster alone, the first DC load and the second DC load are DC motors, and the AC load is powered by the first battery cluster and the second battery cluster through AC / DC conversion and parallel connection at the same time, meeting the charging requirements of the power system in different situations. Since the parallel position of the power system is located in the middle of the AC / DC and the AC load, and the AC / DC is isolated, there will be no inter-cluster circulating current problem between the battery clusters. Therefore, there is no need to design a pre-charge circuit in the high-voltage box, reducing the use of electrical components such as contactors and resistors, reducing the size of the high-voltage box, and there is no need to configure a busbar cabinet for inter-cluster busbar connection. The circuit architecture is simpler and the structure layout is less, reducing the space occupancy of the power system, and it can also be used in projects with limited product structures, optimizing the space layout of the power system. And when controlling, there is no need to design an inter-cluster balancing strategy corresponding to the pre-charge circuit, simplifying the control strategy.

[0026] In another embodiment, the number of battery clusters is greater than two, for example, 3. Each battery cluster is connected to the corresponding high-voltage box. The power output terminals of two of the high-voltage boxes are also connected to the DC sides of the corresponding AC / DC conversion modules. The AC sides of these two AC / DC conversion modules are connected in parallel and then connected to the AC load. The power output terminal of the remaining one high-voltage box is not connected to the AC / DC conversion module and only powers the DC load. The other two high-voltage boxes can also be provided with interfaces for connecting the DC load.

[0027] In other embodiments, the number of high-voltage boxes is greater than two. The power input terminals of each high-voltage box are connected to the corresponding battery clusters. The power output terminals of each high-voltage box are provided with interfaces for connecting the DC load. The power output terminals of each high-voltage box are also connected to the DC sides of the corresponding AC / DC conversion modules. The AC sides of each AC / DC conversion module are connected in parallel and used to connect the AC load. All battery clusters power the AC load at the same time.

[0028] The power supply system control module is as follows Figure 3 shown, including: a battery management unit BMM and a battery cluster management unit BCM. The BMM is a slave controller, and the BCM is a master controller. The BMM collects the information of individual batteries in the battery cluster, including the voltage and temperature of the individual batteries, etc., and then uploads the information of the individual batteries in the collected battery cluster to the BCM through the CAN bus. The master controller BCM is used to interact with the vehicle controller, and uploads the processed information of the individual batteries in the collected battery cluster to the vehicle controller VCU. The controller executes the control strategy according to the information uploaded by the BCM to control the power output of the high-voltage box. The BCMs between different battery clusters can also communicate through the CAN bus, and the BMMs between each battery box can also communicate with each other. As shown in Figure 3 in, the master BCM1 of the first battery cluster and the master BCM2 of the second battery cluster can interact through the CAN bus to obtain the battery cluster information of each other. The control strategy is the control strategy in the design of the conventional power supply system, and only the power and capacity need to be matched according to the requirements, without the need to redesign the power supply system control strategy, saving the design cycle and meeting the requirements of short development cycle, fast delivery and stable system.

[0029] The existing power supply control module of the rail locomotive adopts an energy storage BMS architecture, as shown in Figure 4 shown. The slave BMM collects the voltage and temperature information of the individual batteries and uploads them to the master BCM. After being collected by the master BCM, it is sent to the display and control ESMU. The display and control ESMU processes the data and sends it to the energy management system EMS for interaction, and executes the corresponding strategy according to the interaction result. The control strategy is complex, and in this application, the BMS architecture is reduced from three levels to two levels. The reduction of the architecture corresponds to the reduction of the corresponding BMS hardware. The control strategy and software writing are simpler, further reducing the cost of the power supply system; and there will be no circulating current problem in the power supply system, and there is no need to set up a pre-charge circuit and an inter-cluster balancing strategy, reducing the status judgment of the contactor. The more contactors there are, the more adhesion judgments need to be made, and the master BMS also needs more IO interfaces and more voltage acquisition interfaces, which requires simple hardware for the master BMS, and the unit price of the master BMS will also be relatively low. Simplifying the BMS control logic further reduces the project cost.

[0030] Embodiment of the power output circuit

[0031] The present utility model provides a power output circuit, which is the power output circuit introduced in the embodiment of the power supply system, and will not be described in detail here.

Claims

1. A power supply system, comprising at least two battery clusters, characterized in that, It also includes an AC / DC conversion module and a high-voltage box for corresponding connection with the battery cluster. The power output end of at least one high-voltage box is provided with an interface for connecting a DC load. The power output ends of at least two high-voltage boxes are connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module or at least two of them are connected in parallel for connecting an AC load; the high-voltage box is provided with a switch for controlling the power output of the battery cluster.

2. The power supply system according to claim 1, wherein The number of the battery clusters is two, namely the first battery cluster and the second battery cluster. The first battery cluster is connected to the first high-voltage box, and the second battery cluster is connected to the second high-voltage box. The power output ends of the first high-voltage box and the second high-voltage box are both provided with interfaces for connecting a DC load; the power output end of the first high-voltage box is also connected to the DC side of the first AC / DC conversion module, and the power output end of the second high-voltage box is also connected to the DC side of the second AC / DC conversion module. The AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel for connecting an AC load.

3. The power supply system according to claim 1, characterized in that, The number of the battery clusters is greater than two. Each battery cluster is connected to a high-voltage box. The power output ends of each high-voltage box are all provided with interfaces for connecting a DC load. The power output ends of each high-voltage box are also connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module are connected in parallel for connecting an AC load.

4. The power supply system according to claim 1, wherein The power system also includes a control module. The control module includes a BMM and a BCM. The BMM is used to upload the information of the single cells in the battery cluster collected to the BCM, and the BCM processes the information of the single cells in the battery cluster and then uploads it to the vehicle controller.

5. The power supply system according to any one of claims 1-4, characterized in that, The AC side of the AC / DC conversion module is also used to connect an AC power supply. The AC / DC conversion module converts the AC power supply into DC power to charge the corresponding connected battery cluster.

6. The power supply system according to any one of claims 1-4, characterized in that, The high-voltage box is also provided with a charging interface for connecting a charging power supply. The charging power supply charges the battery cluster through the charging interface.

7. A power output circuit, characterized in that, It includes an AC / DC conversion module and a high-voltage box for corresponding connection with the battery cluster. The power output end of at least one high-voltage box is provided with an interface for connecting a DC load. The power output ends of at least two high-voltage boxes are connected to the DC side of the corresponding AC / DC conversion module. The AC sides of each AC / DC conversion module or at least two of them are connected in parallel for connecting an AC load; the high-voltage box is provided with a switch for controlling the power output of the battery cluster.

8. The power output circuit according to claim 7, wherein The number of the high-voltage boxes is two, namely the first high-voltage box and the second high-voltage box. The power output ends of the first high-voltage box and the second high-voltage box are both provided with interfaces for connecting a DC load; the power output end of the first high-voltage box is also connected to the DC side of the first AC / DC conversion module, and the power output end of the second high-voltage box is also connected to the DC side of the second AC / DC conversion module. The AC sides of the first AC / DC conversion module and the second AC / DC conversion module are connected in parallel for connecting an AC load.

9. The power output circuit according to claim 7, wherein The number of high-voltage boxes is greater than two. An interface for connecting a DC load is provided at the power output end of each high-voltage box. The power output end of each high-voltage box is also connected to the DC side of the corresponding AC / DC conversion module. The AC sides of the AC / DC conversion modules are connected in parallel and used to connect an AC load.

10. The power output circuit according to any one of claims 7-9, characterized in that The AC side of the AC / DC conversion module is also used to connect an AC power supply. The AC / DC conversion module converts the AC power supply into DC power and charges the corresponding connected battery cluster.

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