Household energy storage system

Abstract

The utility model provides a household energy storage system which comprises a positive electrode connector, a negative electrode connector, a plurality of battery packs, a charging and discharging total positive relay, a charging and discharging total negative relay and an isolating switch, each battery pack comprises a battery cell group, the positive electrode of the battery cell group located at the first stage is connected with the first end of the isolating switch, and the negative electrode of the battery cell group located at the second stage is connected with the second end of the isolating switch. The second end of the isolation switch is connected with the positive electrode connector through the charging and discharging main positive relay. The negative electrode of the battery cell group at the last stage is connected with the third end of the isolating switch; and the fourth end of the isolating switch is connected with the negative electrode connector through the charging and discharging general negative relay. The circulating current caused by parallel connection of the battery cell groups can be avoided, the voltage of a household energy storage system can be improved, and the loss is reduced.

Description

Technical Field

[0001] The present application relates to but is not limited to a household energy storage system. Background Art

[0002] Household energy storage refers to energy storage systems used for individual household users. Generally, household energy storage systems are usually used in conjunction with household photovoltaic systems and inverters to provide electricity to household users.

[0003] During the day, the electricity generated by the household photovoltaic system is first supplied to the family, and the excess electricity is stored in the household energy storage system, and the excess electricity is connected to the grid for sale. At night, the household energy storage system supplies electricity to the family, and the household energy storage system can be supplemented at night when the city electricity price is low, and then discharged to the outside during the day when the city electricity price is high, earning the price difference.

[0004] The present application relates to improvements to household energy storage systems. Utility Model Content

[0005] The present application provides a household energy storage system, comprising: a positive connector, a negative connector, a plurality of battery packs, a total positive charge and discharge relay, a total negative charge and discharge relay, and an isolating switch;

[0006] Each battery pack includes a cell group, the positive pole of the cell group at the first level is connected to the first end of the isolating switch, and the second end of the isolating switch is connected to the positive connector through the total positive charge and discharge relay; the negative pole of the cell group at the last level is connected to the third end of the isolating switch, and the fourth end of the isolating switch is connected to the negative connector through the total negative charge and discharge relay.

[0007] In some embodiments, the household energy storage system further includes a communication connector and a main control board, and the battery pack further includes a slave control board;

[0008] Each slave control board is provided with a communication port, the main control board is provided with a first communication port and a second communication port, the communication port of the slave control board corresponding to each battery cell group is connected to the second communication port of the main control board, and the first communication interface of the main control board is connected to the communication connector.

[0009] In some embodiments, the main control board is connected to the charge and discharge total positive relay and the charge and discharge total negative relay.

[0010] In some embodiments, the household energy storage system further includes a pre-charging resistor and a pre-charging relay; the pre-charging resistor and the pre-charging relay are connected in series, one end of which is connected to the positive connector, and the other end is connected to the second end of the total positive charge and discharge relay.

[0011] In some embodiments, the main control board is connected to the pre-charge relay.

[0012] In some embodiments, the household energy storage system also includes a power conversion module, one side of the power conversion module is connected to the main control board, one end of the other side of the power conversion module is connected to the second end of the total positive charge and discharge relay, and the other end of the other side of the power conversion module is connected to the second end of the total negative charge and discharge relay.

[0013] In some embodiments, the household energy storage system further includes a control switch, and one side of the power conversion module is connected to the main control board via the control switch.

[0014] In some embodiments, the household energy storage system further includes a current sensor; the current sensor is located near the negative electrode connector.

[0015] In some embodiments, the household energy storage system further includes a first fuse, and the isolating switch is connected to the charging and discharging total positive relay via the first fuse.

[0016] In some embodiments, the household energy storage system further includes a second fuse, and the isolating switch is connected to the charging and discharging total negative relay via the second fuse.

[0017] The household energy storage system provided by the present application can avoid the circulation caused by the parallel connection of the battery cell groups due to the series connection of multiple battery cell groups, and can also increase the voltage of the household energy storage system, reduce the energy loss during the transmission process, and the household energy storage system does not need to use a boost module for boost processing during use, which reduces power loss and improves the discharge efficiency of the household energy storage system. In addition, in order to improve the safety and reliability of the outdoor energy storage system, a total positive charge and discharge relay, a total negative charge and discharge relay, and an isolating switch are set, and the battery cell group can be disconnected from the positive connector and the negative connector in time in the event of a fault, thereby improving the safety of the household energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0019] Figure 1 It is a schematic diagram of the architecture of a household energy storage system;

[0020] Figure 2 A schematic diagram of the architecture of a household energy storage system provided in some embodiments of the present application;

[0021] Figure 3 A working principle diagram of a household energy storage system provided in some embodiments of the present application;

[0022] Figure 4 Another working principle diagram of a household energy storage system provided in some embodiments of the present application.

[0023] Reference numerals:

[0024] 110, positive connector; 120, negative connector; 130, communication connection; 140, battery cell group; 150, slave control board; 160, main control board; 190, total positive relay for charge and discharge; 170, total negative relay for charge and discharge; 180, isolating switch; 200, pre-charge relay; 210, conversion module; 220, first fuse; 230, second fuse; 240, control switch.

[0025] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0026] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application.

[0027] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0028] The power generation mode that uses household energy storage systems in conjunction with household photovoltaic systems can rationally utilize the advantages of dispersed regional resources. Household energy storage systems have become an important part of the new power system, and the industry has broad room for development.

[0029] In one implementation of a household energy storage system, the household energy storage system expands the energy storage capacity in a low-voltage parallel manner. More specifically, multiple low-voltage battery packs are connected in parallel, that is, a battery pack is 15-16 battery cells connected in series, each battery pack outputs 25-100Ah, and the capacity of each battery pack is 3-5 kWh. The capacity is expanded by connecting multiple battery packs in parallel. For example: a single battery pack is 16 battery cells connected in series, and a single battery pack outputs 100Ah, then the capacity of a single battery pack is 5 kWh. If capacity expansion is required, two or three battery packs can be connected in parallel, that is, two battery packs are connected in parallel or three battery packs are connected in parallel. The capacity after expansion is 10 kWh or 15 kWh, which can be flexibly configured according to customer needs.

[0030] Figure 1 It is a household energy storage system that uses two battery packs in parallel, such as Figure 1 As shown, each battery pack 10 includes a positive pin, a negative pin and a communication pin. The positive pins of the battery pack 10 are connected to each other as the positive port of the household energy storage system, the negative pins of the battery pack 10 are connected to each other as the negative port of the household energy storage system, and the communication pins of the battery pack 10 are connected to each other as the communication port of the household energy storage system. Each battery pack 10 includes a battery cell group, which includes a plurality of battery cells connected in series. Each battery pack is provided with a control board, which is provided with pins B0, B1+, ..., and B16+, and each pin is connected to the positive electrode of the corresponding battery cell. The charge and discharge switch tube group in the control board is used to protect the battery. The charge and discharge switch tube group includes a first switch tube S1, a first diode D1, a second switch tube S2 and a second diode D2. The power supply of the control board is provided by the battery cell in each battery pack. There is a CAN communication module in the control board of each battery pack, which transmits the collected information of the battery cell to the communication pin through the CAN communication line, and then sends it to the external energy conversion system through the communication pin. The CAN communication line includes a CAN high communication line CANH and a CAN low communication line CANL.

[0031] However, due to the different polarization internal resistance of the battery cells, the charging and discharging currents of each battery pack vary greatly. When charging and discharging stops, there will be a large circulation impact, which will cause a certain impact on the devices in the control board, such as the charging and discharging switch tube group in the control board. In severe cases, the devices may be damaged. In addition, the output voltage of the household energy storage system is also relatively low. Under the same output power, the current is large, and the energy loss in the wire is relatively large. Usually, when the household energy storage system is used for external discharge, a boost module is required for boost processing. The boost module will have power loss, and thus the discharge efficiency of the household energy storage system.

[0032] like Figure 2As shown, some embodiments of the present application provide a household energy storage system, which includes a positive connector 110, a negative connector 120, multiple battery packs, a total positive charge and discharge relay 190, a total negative charge and discharge relay 170, and an isolation switch 180.

[0033] Each battery pack includes a battery cell group 140, which refers to a plurality of battery cell units connected in series, the positive electrode of the battery cell unit at the first level is used as the positive electrode of the battery cell group 140, the negative electrode of the battery cell unit at the first level is connected to the positive electrode of the battery cell unit at the second level, the negative electrode of the battery cell unit at the second level is connected to the positive electrode of the battery cell unit at the third level, and so on, and the negative electrode of the battery cell unit at the last level is used as the negative electrode of the battery cell group 140. The isolating switch 180 is provided with a first end, a second end, a third end and a fourth end.

[0034] Multiple battery cell groups 140 are connected in series, the positive pole of the battery cell group 140 at the first level is connected to the first end of the isolating switch 180, the second end of the isolating switch 180 is connected to the positive connector 110 via the total positive charge and discharge relay 190, the negative pole of the battery cell group 140 at the last level is connected to the third end of the isolating switch 180, and the fourth end of the isolating switch 180 is connected to the negative connector 120 via the total negative charge and discharge relay 170.

[0035] Since multiple battery cell groups 140 are connected in series, the circulating current caused by the parallel connection of the battery cell groups 140 can be avoided, and the voltage of the household energy storage system can be increased, reducing the loss of energy during the transmission process. In addition, the household energy storage system does not need to use a boost module for boosting during use, which reduces power loss and improves the discharge efficiency of the household energy storage system.

[0036] In addition, in order to improve the safety and reliability of the outdoor energy storage system, a total positive charge and discharge relay 190, a total negative charge and discharge relay 170, and an isolating switch 180 are provided. In the event of a fault, the battery cell group 140 can be disconnected from the positive connector 110 and the negative connector 120 in time, thereby improving the safety of the household energy storage system.

[0037] In some embodiments, continue to refer to Figure 2 The household energy storage system also includes a communication connector 130 and a main control board 160 , and each battery pack also includes a slave control board 150 .

[0038] The slave control board 150 is provided with a communication port 151, and the main control board 160 is provided with a first communication port 161 and a second communication port 162. The communication port 151 of the slave control board 150 corresponding to each battery cell group 140 is connected to the second communication port 162 of the main control board 160, and the first communication interface 161 of the main control board 160 is connected to the communication connector 130.

[0039] The slave control board 150 corresponding to each battery cell group 140 is also connected to each battery cell unit in the battery cell group 140 for detecting the parameters of each battery cell unit. The parameters of the battery cell unit include one or more combinations of temperature, current and voltage. The parameters of the battery cell unit can also be other parameter combinations, which are not limited here.

[0040] The slave control board 150 corresponding to each battery cell group 140 reports the parameters of each battery cell unit to the main control board 160 through the communication port 151, and the main control board 160 calculates the state of charge (SOC) based on the parameters of the battery cell unit, and sends the SOC to the outside through the first communication interface 161 and the communication connector 130. Among them, the main control board 160 calculates the state of charge based on the parameters of the battery cell unit, which is an existing technology and will not be repeated here.

[0041] In the above technical solution, a main control board is provided to collect the cell parameters reported by each slave control board, and the charge state is sent to the outside through the first communication interface 161 and the communication connector 130 .

[0042] In some embodiments, the main control board 160 is connected to the total positive charge and discharge relay 190 and the total negative charge and discharge relay 170. The main control board 160 is used to control the closing or opening of the total positive charge and discharge relay 190 and the total negative charge and discharge relay 170. In the event of a fault, the battery cell group 140 can be automatically disconnected from the positive connector 110 and the negative connector 120 to improve the safety of the household energy storage system.

[0043] In some embodiments, the household energy storage system further includes a pre-charging resistor R and a pre-charging relay 200. The pre-charging resistor R and the pre-charging relay 200 are connected in series, one end of which is connected to the positive connector 110, and the other end is connected to the second end of the charge and discharge total positive relay 190.

[0044] In some embodiments, a first end of the pre-charging resistor R is connected to the positive electrode connector 110 , and a second end of the pre-charging resistor R is connected to a second end of the charge and discharge main positive relay 190 .

[0045] like Figure 3 As shown, the household energy storage system is also provided with a capacitor, and the positive connector 110 is used to connect to an external system through the capacitor. Before the household energy storage system is used, the capacitor needs to be charged first, and the pre-charging resistor and the pre-charging relay 200 are used to charge the capacitor.

[0046] In some embodiments, the main control board 160 is connected to the pre-charge relay 200. Figure 3As shown, when the external system charges the household energy storage system, the main control board 160 first controls the pre-charge relay 200 and the charge and discharge total negative relay 170 to close, so that when the external system charges the capacitor, the pre-charge resistor limits the charging current, which can reduce the initial current impact. Figure 4 As shown, after the capacitor is charged, the main control board 160 controls the pre-charging relay 200 to disconnect, controls the total positive charge and discharge relay 190 and the total negative charge and discharge relay 170 to close, and the external system charges the battery cell unit through the total positive charge and discharge relay 190 and the total negative charge and discharge relay 170.

[0047] When the household energy storage system supplies power to the outside, the main control board 160 first controls the pre-charge relay 200 and the total charge and discharge negative relay 170 to close. When the battery cell supplies power to the outside, the capacitor is charged through the pre-charge resistor. The pre-charge resistor limits the charging current, which can reduce the initial current impact. After the capacitor is pre-charged, the pre-charge relay 200 can be controlled to open, and the total charge and discharge positive relay 190 and the total charge and discharge negative relay 170 can be controlled to close. The battery cell discharges to the external system through the total charge and discharge positive relay 190 and the total charge and discharge negative relay 170.

[0048] In some embodiments, the household energy storage system further includes a power conversion module 210, one side of the power conversion module 210 is connected to the main control board 160, one end of the other side of the power conversion module 210 is connected to the second end of the total positive charge and discharge relay 190, and the other end of the other side of the power conversion module 210 is connected to the second end of the total negative charge and discharge relay 170. The power conversion module 210 takes power from the power output of the battery cell unit or the power input of the external system to supply power to the main control board 160.

[0049] In some embodiments, the household energy storage system further includes a control switch 240, and one side of the power conversion module 210 is connected to the main control board 160 through the control switch 240. Figure 3 As shown, the control switch 240 is located between the main control board 160 and the power conversion module 210. In other embodiments, the control switch 240 can also be located between the power conversion module 210 and the total positive charge and discharge relay 190, or between the power conversion module 210 and the total negative charge and discharge relay 170, which is not limited here. The control switch 240 is used to control whether to supply power to the main control board 160. Among them, the control switch 240 is a button switch.

[0050] In some embodiments, Figure 3As shown, the household energy storage system also includes a current sensor 250; the current sensor 250 is located near the negative connector 120, and is used to detect the current flowing through the negative connector 120, and the output end of the current sensor 250 is connected to the main control board 160. The main control board 160 receives the current flowing through the negative connector 120 output by the current sensor 250. When the current flowing through the negative connector 120 is greater than a preset threshold, the main control board 160 can adopt a corresponding control strategy, for example: prompting the external system to limit the current, or controlling the total positive relay 190 for charging and discharging, the total negative relay 170 for charging and discharging, and the isolating switch 180 to disconnect, and promptly disconnect the battery cell group 140 from the positive connector 110 and the negative connector 120, so as to improve the safety of the household energy storage system.

[0051] In some embodiments, Figure 3 As shown, the household energy storage system also includes a first fuse 220. The isolating switch 180 is connected to the charge and discharge total positive relay 190 through the first fuse 220. When the current flowing through the first fuse 220 is too large, the first fuse 220 melts to play a protective role.

[0052] In some embodiments, Figure 3 As shown, the household energy storage system further includes a second fuse 230, and the isolating switch 180 is connected to the charge and discharge total negative relay 170 via the second fuse 230. When the current flowing through the first fuse 220 is too large, the second fuse 230 is blown to provide protection.

[0053] The household energy storage system provided in the present application adopts a high-voltage series energy storage solution. After each battery pack is connected in series, it is connected to a high-voltage box. The high-voltage box contains a main control board, a positive connector 110, a negative connector 120, a total positive charge and discharge relay 190, and a total negative charge and discharge relay 170. There is only a slave control board in a single battery pack. The slave control board is used to collect the voltage and temperature of the battery cells. The protection of the battery cells is performed by the corresponding relays in the high-voltage box. The main control board in the high-voltage box is used to collect the information of the battery cell units collected from the slave control board, and at the same time collect the current on the negative connector 120, and also perform SOC calculations, relay control, and communication with external systems.

[0054] More specifically, the battery cells are connected to the system in series, and the slave control board is used to collect the voltage and temperature of each battery cell unit connected to the system, and transmit it to the main control board through the CAN bus. The isolation switch 180 is used to cut off the electrical connection between the battery pack and the high-voltage box. The main control board is used to receive data sent from the slave control board and communicate with external devices through the CAN communication module. At the same time, the main control board is also used to control all relays, collect current on the negative connector 120, and perform SOC calculations. The pre-charge relay 200 and the pre-charge resistor R are used to avoid the large current impact generated by the system at the moment of power-on. The total positive relay 190 for charging and discharging and the total negative relay 170 for charging and discharging are used to cut off the charging and discharging of the system. The current sensor is used to collect the current size in the circuit and transmit it to the main controller. The power conversion module is used to convert the total voltage of the battery into 24V to supply power to the main control board and the slave control board. The control switch is used to cut off or close the power supply of the main control board. The first fuse and the second fuse are used to prevent the large current impact when the positive and negative poles are short-circuited to protect the battery.

[0055] This application aims to use a high-voltage series connection method for system configuration and expansion, which has high capacity efficiency, is convenient and flexible, eliminates the need for a boost circuit, and has a low system cost. If you want to increase the capacity of a household energy storage system, you can use the method of connecting battery packs in series to avoid the circulation problem between battery packs that occurs when the capacity is increased in parallel. The larger the capacity of the household energy storage system, the more battery packs are connected in series, the higher the voltage, the smaller the line loss, and the higher the efficiency. In this way, the voltage level is increased, the energy loss in the wires is reduced, and the energy efficiency of the integrated photovoltaic storage machine is improved.

[0056] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0057] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A household energy storage system, characterized in that: include: Positive connector, negative connector, multiple battery packs, total positive charge and discharge relay, total negative charge and discharge relay, and isolating switch; Each of the battery packs includes a cell group, and multiple cell groups are connected in series. The positive electrode of the cell group at the first level is connected to the first end of the isolation switch, and the second end of the isolation switch is connected to the positive connector through the total positive charge and discharge relay; the negative electrode of the cell group at the last level is connected to the third end of the isolation switch, and the fourth end of the isolation switch is connected to the negative connector through the total negative charge and discharge relay.

2. The household energy storage system according to claim 1, characterized in that: The household energy storage system further comprises a communication connector and a main control board, and each of the battery packs comprises a slave control board; Each of the slave control boards is provided with a communication port, and the main control board is provided with a first communication port and a second communication port. The communication port of the slave control board corresponding to each battery cell group is connected to the second communication port of the main control board, and the first communication interface of the main control board is connected to the communication connector.

3. The household energy storage system according to claim 2, characterized in that: The main control board is connected to the total positive charge and discharge relay and the total negative charge and discharge relay.

4. The household energy storage system according to claim 1 or 2, characterized in that: The household energy storage system also includes a pre-charging resistor and a pre-charging relay; the pre-charging resistor and the pre-charging relay are connected in series, one end of which is connected to the positive connector, and the other end is connected to the second end of the charging and discharging total positive relay.

5. The household energy storage system according to claim 4, characterized in that: The main control board is connected with the pre-charging relay.

6. The household energy storage system according to claim 2, characterized in that: The household energy storage system also includes a power conversion module, one side of the power conversion module is connected to the main control board, one end of the other side of the power conversion module is connected to the second end of the total positive charge and discharge relay, and the other end of the other side of the power conversion module is connected to the second end of the total negative charge and discharge relay.

7. The household energy storage system according to claim 6, characterized in that: The household energy storage system further includes a control switch, and one side of the power conversion module is connected to the main control board via the control switch.

8. The household energy storage system according to claim 2, characterized in that: The household energy storage system also includes a current sensor; the current sensor is located near the negative electrode connector.

9. The household energy storage system according to claim 1 or 2, characterized in that: The household energy storage system also includes a first fuse, and the isolating switch is connected to the charging and discharging total positive relay through the first fuse.

10. The household energy storage system according to claim 1 or 2, characterized in that: The household energy storage system also includes a second fuse, and the isolation switch is connected to the charging and discharging total negative relay through the second fuse.

Images