Energy storage-direct current charging pile integrated system

Abstract

The utility model discloses an energy storage-direct current charging pile integrated system, which belongs to the technical field of charging piles, comprises a direct current charging system, an energy storage converter PCS and an energy storage battery pack BAT, and solves the technical problem of integrated efficient power supply of an energy storage and charging system based on a shared direct current bus. According to the utility model, the energy storage battery pack and the direct-current charging system are uniformly connected to the direct-current side of the energy storage PCS to construct a shared direct-current bus structure, so that the energy storage battery can directly supply power to the fast charging terminal without an alternating-current link; therefore, the energy path is obviously simplified, the power conversion loss is reduced, the system configuration redundancy is reduced, and the overall operation efficiency and reliability are improved.

Description

Technical Field

[0001] This utility model belongs to the field of charging pile technology, and in particular relates to an integrated system of energy storage-DC charging pile. Background Technology

[0002] With the widespread adoption of new energy vehicles, the construction of charging infrastructure has become a key factor restricting the industry's development. DC fast charging, due to its advantages of high power and short charging time, is widely deployed in highway service areas, urban charging stations, and other scenarios. At the same time, energy storage systems are also being introduced into charging scenarios to peak shaving, load balancing, and improve grid stability. This has led to the development of a composite application structure: the "energy storage-DC charging pile system."

[0003] Currently, the most mainstream energy storage-charging integrated solutions on the market adopt a distributed structure: the energy storage system is connected to the AC bus via an energy storage converter (PCS), and the fast-charging DC charging pile (usually the fast-charging host) is also independently connected to the AC bus. Figure 3 As shown, in this structure, the DC energy of the energy storage battery needs to be converted into AC by the PCS first, and then converted into DC by the AC-DC converter (AC / DC) inside the charging pile, and finally output to the electric vehicle.

[0004] However, traditional technologies have the following drawbacks:

[0005] The energy path is lengthy, and the DC power output from the energy storage battery needs to undergo a two-stage power conversion process of "DC → AC → DC", which leads to a significant increase in conversion losses.

[0006] Fast charging systems require additional AC / DC power conversion modules, resulting in complex system structures, high costs, and large space requirements.

[0007] Multi-stage transformation also increases the pressure of equipment operation and maintenance and the potential for failure, affecting system stability and economy. Utility Model Content

[0008] The purpose of this invention is to provide an integrated energy storage-DC charging pile system, which solves the technical problem of efficient power supply for the integrated energy storage and charging system based on a shared DC bus.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] An integrated energy storage-DC charging pile system includes a DC charging system, an energy storage converter PCS, and an energy storage battery pack BAT. The power input terminal of the energy storage converter PCS is connected to the AC power grid, and the power output terminal outputs a DC bus.

[0011] The busbar of the energy storage battery pack BAT is connected to the DC busbar;

[0012] The power supply terminal of the DC charging system is connected to the DC bus.

[0013] Preferably, the DC charging system includes a DC / DC converter, an energy storage management unit (ESMU), an energy management system (EMS), and multiple fast charging interfaces (DC).

[0014] The DC / DC converter's power supply terminal is connected to the DC bus, and its output terminal provides DC power to each fast charging interface.

[0015] The DC / DC converter communicates with the Energy Storage Management Unit (ESMU) via a CAN bus; the ESMU communicates with the Energy Management System (EMS) via a LAN bus; the EMS communicates with the Energy Storage Converter (PCS) via a LAN bus; and the PCS communicates with the ESMU via a CAN bus.

[0016] The Energy Storage Management Unit (ESMU) communicates with the Battery Management System (BMS) of the Energy Storage Battery Pack (BAT) via a CAN bus.

[0017] Preferably, the energy storage battery pack BAT is connected to the DC bus via a bidirectional DC contactor BDCC; a current detection unit CDU and an overcurrent protection unit OPU are also provided between the energy storage battery pack BAT and the DC bus, and the bidirectional DC contactor BDCC, the current detection unit CDU, and the overcurrent protection unit OPU are all connected to the battery management system BMS.

[0018] Preferably, the energy storage converter PCS is equipped with an independent AC / DC isolation transformer and a synchronous rectifier module to electrically isolate the power grid from the DC bus.

[0019] Preferably, the energy storage management unit (ESMU) is further equipped with a bus voltage detection module (VDM) for detecting the DC bus voltage.

[0020] The energy storage-DC charging pile integrated system described in this utility model solves the technical problem of efficient power supply for integrated energy storage and charging systems based on a shared DC bus. This utility model constructs a shared DC bus structure by connecting the energy storage battery pack and the DC charging system to the DC side of the energy storage PCS, enabling the energy storage battery to directly power the fast charging terminal without going through an AC link. This significantly simplifies the energy path, reduces power conversion losses, reduces system configuration redundancy, and improves overall operating efficiency and reliability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the busbar connection of this utility model;

[0022] Figure 2This is a system architecture diagram of this utility model;

[0023] Figure 3 This is a schematic diagram of the existing system architecture in the background technology. Detailed Implementation

[0024] Depend on Figures 1-2 The energy storage-DC charging pile integrated system shown includes a DC charging system, an energy storage converter PCS and an energy storage battery pack BAT. The power supply input terminal of the energy storage converter PCS is connected to the AC power grid, and the power supply output terminal outputs a DC bus.

[0025] The energy storage converter PCS is equipped with an independent AC / DC isolation transformer and a synchronous rectifier module, which are used to electrically isolate the power grid from the DC bus.

[0026] The power input terminal of the energy storage converter PCS is connected to the AC power grid, and bidirectional conversion and safe isolation of electrical energy are achieved through the built-in AC / DC isolation transformer and synchronous rectification module.

[0027] In this embodiment, the energy storage converter PCS can be a 100kW-500kW bidirectional energy storage converter, supporting functions such as V / f control, PQ control, islanding mode and grid-connected switching.

[0028] The converter outputs a stable DC bus at its DC output terminal (i.e., as shown in the example). Figure 1 and Figure 2 The DC-Bus shown can have a voltage level of 1500V depending on the specific application. The DC bus serves as the core power channel of the system, connecting the energy storage battery pack and the DC charging system.

[0029] The bus of the energy storage battery pack BAT is connected to the DC bus; the energy storage battery pack BAT is connected to the DC bus through a bidirectional DC contactor BDCC; a current detection unit CDU and an overcurrent protection unit OPU are also provided between the energy storage battery pack BAT and the DC bus, and the bidirectional DC contactor BDCC, the current detection unit CDU and the overcurrent protection unit OPU are all connected to the battery management system BMS.

[0030] The energy storage battery pack BAT is connected to the DC bus via a bidirectional DC contactor BDCC. The bidirectional DC contactor BDCC is used to realize the isolation and emergency power cut-off of the energy storage system. The EV-DC500 series high-voltage DC contactor can be selected.

[0031] Meanwhile, to ensure the safe operation of the battery, a current detection unit (CDU) and an overcurrent protection unit (OPU) are set in the access path in this embodiment. The current sensor can be a Hall effect current sensor, and the overcurrent protection adopts an electronic fuse or a fusible module.

[0032] The energy storage battery pack is equipped with a battery management system (BMS) to monitor and balance the cell voltage, current, and temperature.

[0033] The power supply terminal of the DC charging system is connected to the DC bus.

[0034] This embodiment uses a shared DC bus (i.e., DC bus) as the core connection structure, and can achieve efficient collaboration between the energy storage system and the charging terminal through hardware integration.

[0035] The DC charging system includes a DC / DC converter, an energy storage management unit (ESMU), an energy management system (EMS), and multiple fast charging interfaces (DC).

[0036] The DC / DC converter's power supply terminal is connected to the DC bus, and its output terminal provides DC power to each fast charging interface.

[0037] The DC / DC converter communicates with the Energy Storage Management Unit (ESMU) via a CAN bus; the ESMU communicates with the Energy Management System (EMS) via a LAN bus; the EMS communicates with the Energy Storage Converter (PCS) via a LAN bus; and the PCS communicates with the ESMU via a CAN bus.

[0038] The Energy Storage Management Unit (ESMU) communicates with the Battery Management System (BMS) of the Energy Storage Battery Pack (BAT) via a CAN bus.

[0039] The energy storage management unit (ESMU) is also equipped with a bus voltage detection module (VDM) for detecting DC bus voltage.

[0040] The DC / DC converter is used to convert the bus voltage to a charging voltage (usually 800Vdc) that is compatible with different charging interface standards (such as GB / T, CCS, CHAdeMO). Each fast charging interface is equipped with an independent DC / DC module to support independent power control.

[0041] A high-frequency DC conversion module can be selected for the DC / DC converter.

[0042] The Energy Storage Management Unit (ESMU) is the control core of this system. It communicates with the DC / DC converter via the CAN bus to achieve power allocation and status monitoring for each fast charging interface.

[0043] The Energy Storage Management Unit (ESMU) also communicates with the Energy Management System (EMS) via a LAN bus. The EMS communication is used to coordinate the operating status of the PCS, grid power demand, and power scheduling of the energy storage system.

[0044] The Energy Storage Management Unit (ESMU) communicates with the Energy Storage Converter (PCS) via CAN to coordinate the control of the PCS's charging and discharging modes, power flow, etc.

[0045] In this embodiment, the Energy Storage Management Unit (ESMU) communicates with the BMS system inside the Energy Storage Battery Pack (BAT) via a CAN bus. This enables user-customized functions to obtain key parameters such as the State of Charge (SOC) and State of Health (SOH) of the battery pack in real time, which can be used to assess whether power can be supplied or whether the PCS needs to replenish power from the grid.

[0046] The Energy Storage Management Unit (ESMU) also includes a Bus Voltage Detection Module (VDM), which can be used to detect in real time whether the DC bus voltage is within a set threshold range. The VDM is constructed using high-voltage sampling devices (such as isolated voltage sampling resistor arrays or voltage sensing chips). When the voltage is lower than the critical value, it can trigger a switching mechanism such as relay switching, so that the power supply path can be switched from the energy storage battery to the PCS.

[0047] The energy storage-DC charging pile integrated system described in this utility model solves the technical problem of efficient power supply for integrated energy storage and charging systems based on a shared DC bus. This utility model constructs a shared DC bus structure by connecting the energy storage battery pack and the DC charging system to the DC side of the energy storage PCS, enabling the energy storage battery to directly power the fast charging terminal without going through an AC link. This significantly simplifies the energy path, reduces power conversion losses, reduces system configuration redundancy, and improves overall operating efficiency and reliability.

Claims

1. An integrated system for energy storage and DC charging piles, characterized in that: It includes a DC charging system, an energy storage converter PCS, and an energy storage battery pack BAT. The power input terminal of the energy storage converter PCS is connected to the AC power grid, and the power output terminal outputs a DC bus. The busbar of the energy storage battery pack BAT is connected to the DC busbar; The power supply terminal of the DC charging system is connected to the DC bus.

2. The energy storage-DC charging pile integrated system as described in claim 1, characterized in that: The DC charging system includes a DC / DC converter, an energy storage management unit (ESMU), an energy management system (EMS), and multiple fast charging interfaces (DC). The DC / DC converter's power supply terminal is connected to the DC bus, and its output terminal provides DC power to each fast charging interface. The DC / DC converter communicates with the Energy Storage Management Unit (ESMU) via a CAN bus; the ESMU communicates with the Energy Management System (EMS) via a LAN bus; the EMS communicates with the Energy Storage Converter (PCS) via a LAN bus; and the PCS communicates with the ESMU via a CAN bus. The Energy Storage Management Unit (ESMU) communicates with the Battery Management System (BMS) of the Energy Storage Battery Pack (BAT) via a CAN bus.

3. The energy storage-DC charging pile integrated system as described in claim 2, characterized in that: The energy storage battery pack BAT is connected to the DC bus via a bidirectional DC contactor BDCC. A current detection unit CDU and an overcurrent protection unit OPU are also provided between the energy storage battery pack BAT and the DC bus. The bidirectional DC contactor BDCC, the current detection unit CDU, and the overcurrent protection unit OPU are all connected to the battery management system BMS.

4. The energy storage-DC charging pile integrated system as described in claim 2, characterized in that: The energy storage converter PCS is equipped with an independent AC / DC isolation transformer and a synchronous rectifier module, which are used to electrically isolate the power grid from the DC bus.

5. The energy storage-DC charging pile integrated system as described in claim 2, characterized in that: The energy storage management unit (ESMU) is also equipped with a bus voltage detection module (VDM) for detecting DC bus voltage.

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