A new energy storage device, energy storage system and charging pile

Abstract

This invention provides a novel energy storage device, energy storage system, and charging pile. The novel energy storage device includes an external power grid, an energy storage converter compartment, and a battery compartment. The energy storage converter compartment consists of a circuit breaker, a voltage regulating transformer, a first energy storage converter, and a second energy storage converter. The AC side of the first energy storage converter and the AC side of the second energy storage converter are connected in parallel to the low-voltage side of the voltage regulating transformer. The high-voltage side of the voltage regulating transformer is connected to one end of the circuit breaker, and the external power grid is connected to the other end of the circuit breaker to supply power to the energy storage converter compartment. The battery compartment is composed of multiple stacked battery cells, and its external interfaces are connected to the DC sides of the first and second energy storage converters, respectively. This invention reduces the number of circuit components required for the energy storage device and simplifies its overall structure.

Description

Technical Field

[0001] This utility model belongs to the field of electrical technology, specifically relating to a novel energy storage device, energy storage system, and charging pile. Background Technology

[0002] With the widespread application of renewable energy and the continuous growth of electricity demand, energy storage technology plays an increasingly important role in power systems. Energy storage devices, especially electrochemical energy storage systems, have become an important means of balancing power supply and demand, improving energy utilization efficiency, and promoting power system stability. Currently, energy storage devices on the market are mainly divided into lithium batteries, lead-acid batteries, and supercapacitors, each type of energy storage device has certain advantages in different application scenarios.

[0003] In the design of traditional energy storage devices, especially in large battery pack systems, multi-stage circuit designs are often employed to achieve functions such as battery management, charge / discharge control, and fault protection. To ensure efficient system operation, multiple circuit components are typically required, including a battery management system (BMS), current sensors, voltage monitoring modules, and switching control modules. Furthermore, to ensure battery safety and extend its lifespan, energy storage devices often also require complex cooling systems, equalization charging modules, and overcurrent protection functions.

[0004] However, existing energy storage devices face several significant problems in their design and implementation:

[0005] Complex Structure: Due to the need for multiple circuit components for control and management, the overall structure of existing energy storage devices is quite complex. The interaction between each functional module makes system assembly, debugging, and maintenance cumbersome. In addition, the connection and wiring design between modules requires a large space and precise manufacturing processes, further increasing the complexity of energy storage devices.

[0006] Numerous circuit components: In existing technologies, energy storage systems typically require multiple independent circuit components to achieve functions such as battery protection, monitoring, power management, and equalization charging. For example, multiple sensors are used to monitor parameters such as battery voltage, current, and temperature, while multiple control chips are also needed to coordinate their operation. This increase in components not only raises the system's cost but also reduces its reliability and stability. Too many circuit components also increase the risk of potential malfunctions, and make fault location and repair more difficult when system failures occur.

[0007] Large size and weight: Due to the need for multiple functional modules and circuit components, existing energy storage devices are typically large in size and weight. Especially in mobile applications (such as electric vehicles, drones, etc.), the constraints of device size and weight require energy storage devices to be more compact and lightweight. However, existing technologies struggle to meet these requirements, limiting the application of energy storage devices in specific situations.

[0008] In summary, existing energy storage device designs suffer from problems such as complex structures, numerous circuit components, and large size. These issues not only affect the performance, reliability, and maintainability of energy storage systems but also increase manufacturing and operating costs. Therefore, there is an urgent need for a simpler, more reliable, and more efficient energy storage device design to address one or more of the aforementioned shortcomings and meet the multiple requirements of modern energy storage systems in terms of performance, cost, and space. Utility Model Content

[0009] The technical problem to be solved by this utility model is to provide a new type of energy storage device, energy storage system and charging pile, so as to reduce the number of circuit components required for the energy storage device and simplify the overall structure of the energy storage device.

[0010] On the one hand, the novel energy storage device provided by this utility model includes an external power grid, an energy storage converter compartment, and a battery compartment;

[0011] The energy storage converter compartment consists of a circuit breaker, a voltage regulating transformer, a first energy storage converter, and a second energy storage converter. The AC side of the first energy storage converter and the AC side of the second energy storage converter are connected in parallel and then connected to the low-voltage side of the voltage regulating transformer. The high-voltage side of the voltage regulating transformer is connected to one end of the circuit breaker, and the external power grid is connected to the other end of the circuit breaker to supply power to the energy storage converter compartment.

[0012] The battery compartment is composed of multiple stacked battery cells, and the external interfaces of the battery compartment are connected to the DC side of the first energy storage converter and the DC side of the second energy storage converter, respectively.

[0013] Preferably, the circuit breaker is a vacuum circuit breaker, used to cut off the power supply from the external power grid and provide overcurrent protection.

[0014] Preferably, the AC side of the first energy storage converter and the AC side of the second energy storage converter are connected in parallel and then connected in a star configuration to the low-voltage side of the voltage regulating transformer.

[0015] Preferably, the high-voltage side of the voltage regulating transformer is connected to one end of the circuit breaker in a delta configuration.

[0016] Preferably, a fuse is also provided between the external interface of the battery compartment and the multiple battery cells to provide overcurrent protection for the multiple battery cells.

[0017] Preferably, the battery compartment is also equipped with a surge protector.

[0018] Secondly, this utility model also provides an energy storage system, including the novel energy storage device described above.

[0019] Thirdly, this utility model also provides a charging pile, including the above-mentioned energy storage system.

[0020] The beneficial effects of this utility model are:

[0021] The novel energy storage device provided by this utility model connects the AC sides of two energy storage converters in parallel to the low-voltage side of a voltage regulating transformer, enabling the exchange of electrical energy from the external power grid between the two energy storage converters. This reduces the demand for power capacity, decreases the number of energy storage converters, and lowers material costs. Compared to traditional energy storage devices, the modular design of the energy storage converter compartment and battery compartment significantly reduces the structural complexity of the energy storage device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the energy storage converter in this utility model. Detailed Implementation

[0024] To address the issues of numerous circuit components and complex overall structure in traditional energy storage devices, this invention provides a novel energy storage device, energy storage system, and charging pile.

[0025] like Figures 1 to 2 As shown, the novel energy storage device provided by this utility model includes an external power supply 101, an energy storage converter 102, and a battery compartment 103.

[0026] Specifically, the energy storage converter compartment 102 consists of a circuit breaker 201, a voltage regulating transformer 202, a first energy storage converter 203, and a second energy storage converter 204. The AC side of the first energy storage converter 203 and the AC side of the second energy storage converter 204 are connected in parallel and then connected to the low-voltage side of the voltage regulating transformer 202. The high-voltage side of the voltage regulating transformer 202 is connected to one end of the circuit breaker 201, and the external power supply 101 is connected to the other end of the circuit breaker 201 to supply power to the energy storage converter compartment 102.

[0027] Taking a battery compartment with a rated power of 5MWh as an example, in this embodiment, the rated power of the first energy storage converter 203 and the second energy storage converter 204 is 2.5MW.

[0028] In this utility model, the circuit breaker 201 is a vacuum circuit breaker 201, which is used to cut off the power supply of the external power source 101 and provide overcurrent protection.

[0029] It should be noted that the AC side of the first energy storage converter 203 and the AC side of the second energy storage converter 204 are connected in parallel and then star-connected to the low-voltage side of the voltage regulating transformer 202. Specifically, the parallel connection of the AC sides of the energy storage converters means that the input terminals of the two converters are connected. This enables the energy storage system to operate in parallel, allowing the electrical energy from the external power supply 101 to be exchanged between the two energy storage converters, thereby reducing the power capacity requirement. The parallel connection helps to balance the system load and provide higher power and more stable voltage. Compared with traditional energy storage devices, the new energy storage device provided by this invention reduces the number of energy storage converters and lowers material costs. Since energy storage converters have been well-researched, this invention will not elaborate on them here. Typically, energy storage converters are equipped with high-voltage circuit breakers, disconnect switches, and surge arresters.

[0030] The high-voltage side of the voltage regulating transformer 202 is delta-connected to one end of the circuit breaker 201. It should be understood that in a delta connection, the three ends of the windings of the voltage regulating transformer 202 are connected to form a closed triangle, with the endpoint of each winding connected to the endpoint of another winding. This allows it to handle larger load currents and is suitable for receiving high-voltage current from an external power source 101.

[0031] The battery compartment 103 is composed of multiple stacked battery cells, and the doors of the battery compartment 103 are respectively connected to the DC side of the first energy storage converter and the DC side of the second energy storage converter.

[0032] Specifically, the DC side of the first energy storage converter and the DC side of the second energy storage converter output DC power to charge the batteries in the battery compartment 103, storing electrical energy in the batteries. To improve circuit safety, in some embodiments of this utility model, fuses and surge arresters are also provided between the door of the battery compartment 103 and the multiple battery cells for overcurrent protection of the multiple battery cells.

[0033] In practical applications, taking a 0.5P project with a 5MWh battery compartment as an example, if the traditional dual-branch connection method is used, each battery compartment needs to connect two 1.25MWPCS units. The maximum current of the battery compartment is approximately 2100~2500A. Based on the DC cable current carrying capacity, each compartment needs to be connected with six positive and six negative 185mm DC cables and two communication lines. Each 5MW / 10MWh energy storage unit requires 12 185mm DC cables and four communication lines. If a single-branch connection method is used, each 5MW battery compartment connects to one 2.5MWPCS unit. Based on the cable current carrying capacity, six positive and six negative 185mm DC cables and two communication lines can be used. Each 5MW / 10MWh energy storage unit requires two 185mm DC cables and two communication lines, which can reduce the consumption of communication wiring harnesses.

[0034] Meanwhile, in the battery compartment and PCS section, dual-branch wiring requires fuses, disconnect switches and surge arresters to be installed on each outgoing line. Single-branch wiring only requires a higher-specification switch on one outgoing line, which is more cost-effective than dual-branch wiring.

[0035] It should be noted that in other embodiments of this utility model, battery compartments with different rated power can be adapted by stacking the number of the above-mentioned energy storage devices.

[0036] The above is the wiring scheme for a 0.5P project. For a 1P project, a single branch PCS is often insufficient to meet the charging and discharging power of a battery compartment. In this case, the batteries inside the battery compartment need to be divided into two piles, with each pile corresponding to one PCS. Based on the 0.5P, an additional communication harness can be added to meet the usage requirements.

[0037] In some other embodiments, as a further improvement to the above technical solution, an isolation switch inside the battery compartment can be added according to the actual needs of the project to increase the convenience of inspection and maintenance.

[0038] As can be seen from the above, the novel energy storage device provided by this utility model connects the AC sides of two energy storage converters in parallel to the low-voltage side of a voltage regulating transformer, enabling the exchange of electrical energy from the external power grid between the two energy storage converters. This reduces the demand for power capacity, decreases the number of energy storage converters, and lowers material costs. Compared with traditional energy storage devices, the modular design of the energy storage converter compartment and battery compartment significantly reduces the structural complexity of the energy storage device.

[0039] This invention also provides an energy storage system, including the novel energy storage device described above. This energy storage system possesses the same beneficial effects as the novel energy storage device described above.

[0040] In addition, this utility model also provides a charging pile, which includes the above-mentioned energy storage system and has the same beneficial effects.

[0041] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0042] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. A novel energy storage device, characterized in that, Includes external power grid, energy storage converter compartment and battery compartment; The energy storage converter compartment consists of a circuit breaker, a voltage regulating transformer, a first energy storage converter, and a second energy storage converter. The AC side of the first energy storage converter and the AC side of the second energy storage converter are connected in parallel and then connected to the low-voltage side of the voltage regulating transformer. The high-voltage side of the voltage regulating transformer is connected to one end of the circuit breaker, and the external power grid is connected to the other end of the circuit breaker to supply power to the energy storage converter compartment. The battery compartment is composed of multiple stacked battery cells, and the external interfaces of the battery compartment are respectively connected to the DC side of the first energy storage converter and the DC side of the second energy storage converter.

2. The novel energy storage device according to claim 1, characterized in that, The circuit breaker is a vacuum circuit breaker, used to cut off the power supply to the external power grid and provide overcurrent protection.

3. The novel energy storage device according to claim 1, characterized in that, The AC side of the first energy storage converter and the AC side of the second energy storage converter are connected in parallel and then connected in a star configuration to the low-voltage side of the voltage regulating transformer.

4. The novel energy storage device according to claim 1, characterized in that, The high-voltage side of the voltage regulating transformer is connected in a delta configuration to one end of the circuit breaker.

5. The novel energy storage device according to claim 1, characterized in that, A fuse is also provided between the external interface of the battery compartment and the plurality of battery cells for overcurrent protection of the plurality of battery cells.

6. The novel energy storage device according to claim 1, characterized in that, The battery compartment is also equipped with a lightning arrester.

7. An energy storage system, characterized in that, Including the novel energy storage device as described in any one of claims 1-6.

8. A charging pile, characterized in that, Including the energy storage system as described in claim 7.

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