New energy power generation and energy storage device

Abstract

The utility model relates to the field of energy storage, and particularly discloses a new energy power generation and energy storage device, each phase of a power generation system is connected with three energy storage circuits, and the three energy storage circuits are in star connection; the energy storage circuit comprises a plurality of energy storage converters connected in series through alternating current ends, the direct current end of each energy storage converter is connected with a battery cluster, and the battery cluster is composed of a plurality of energy storage batteries connected in series; an A-phase energy storage battery is placed in a battery bin of the first energy storage container, a B-phase energy storage battery is placed in a battery bin of the second energy storage container, and a C-phase energy storage battery is placed in a battery bin of the third energy storage container. The liquid cooling system conveys cold water to the first energy storage container, the second energy storage container and the third energy storage container. According to the device, the SOC of the battery clusters is basically consistent, the influence of the wooden barrel effect on the overall energy storage efficiency is avoided, meanwhile, the energy storage battery of each phase is independently stored, the liquid cooling system conducts heat dissipation on the energy storage battery of each phase, the heat dissipation efficiency is improved, and the energy storage efficiency is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of energy storage, and in particular to a new energy power generation and energy storage device. Background Art

[0002] With the increasing scarcity of traditional energy and the deteriorating environment, the scale of grid-connected renewable energy generation is rapidly increasing. However, renewable energy generation depends on natural resource conditions, is volatile and intermittent, and is difficult to regulate and control. Large-scale grid-connected operation can significantly impact the safe and stable operation of the power grid. Energy storage systems, with their energy storage, rapid response, and precise power tracking, can be used as a means to improve system stability, adjust frequency, and compensate for load fluctuations.

[0003] The power grid primarily relies on thermal power generation for peak and frequency regulation. However, the introduction of new energy generation units has increased pressure on these units, causing some units to start and stop during the day, impacting their safe and efficient operation. Leveraging electrochemical energy storage, particularly lithium battery energy storage with its fast response and flexible output, to support thermal power generation in peak and frequency regulation can effectively alleviate equipment fatigue caused by frequent adjustments, ensuring safe operation, stabilizing output, and improving their availability.

[0004] Current electrochemical energy storage systems typically combine multiple battery cells connected in series and parallel to form a "large battery stack." This approach increases capacity by connecting battery clusters in parallel, with a single energy storage inverter controlling multiple battery clusters. This approach results in a state of charge (SOC) of over 90% for battery clusters with low internal resistance, while only around 50% for battery clusters with low internal resistance. This significant variation in SOC across battery clusters leads to poor balancing across the entire energy storage system (a classic "barrel effect"), significantly reducing the system's usable capacity. Furthermore, batteries generate significant heat during charging and discharging, but current liquid cooling methods concentrate all cells together, resulting in poor heat dissipation and negatively impacting energy storage efficiency. Summary of the Invention

[0005] To solve the above problems, the utility model provides a new energy power generation and energy storage device, which consists of a storage converter connected to a battery cluster to avoid the parallel use of battery cells. The active balancing function of the storage converter ensures that the SOC of the battery cluster is basically consistent, avoiding the impact of the "barrel effect" on the overall energy storage efficiency. At the same time, each phase of the energy storage battery is stored separately, and the liquid cooling system dissipates heat for each phase of the energy storage battery separately, thereby improving heat dissipation efficiency and ensuring energy storage efficiency.

[0006] The technical solution of the utility model is: a new energy power generation and energy storage device, including three energy storage circuits respectively connected to each phase of the power generation system, and the three energy storage circuits are connected in a star shape; the energy storage circuit includes a plurality of energy storage converters connected in series via the AC end, and the DC end of each energy storage converter is connected to a battery cluster, and the battery cluster is composed of a plurality of energy storage batteries connected in series;

[0007] The device also includes a first energy storage container, a second energy storage container, a third energy storage container and a liquid cooling system. The battery compartment of the first energy storage container is placed with A-phase energy storage batteries, the battery compartment of the second energy storage container is placed with B-phase energy storage batteries, and the battery compartment of the third energy storage container is placed with C-phase energy storage batteries; the liquid cooling system supplies cold water to the first energy storage container, the second energy storage container, and the third energy storage container.

[0008] As an optional embodiment, the liquid cooling system includes a chiller, the water outlet of the chiller is connected to the first main water outlet pipe, the first main water outlet pipe is respectively connected to the first outflow water pipe, the second outflow water pipe, and the third outflow water branch, the first outflow water pipe is connected to the plate heat exchanger in the first energy storage container, the second outflow water pipe is connected to the plate heat exchanger in the second energy storage container, and the third outflow water pipe is connected to the plate heat exchanger in the third energy storage container. The plate heat exchangers are respectively connected to the main return water pipe by a return water pipe, and the main return water pipe is connected to the return water outlet of the chiller; a branch circulation pump is provided on each outflow water pipe; the chiller is also connected to the cooling tower.

[0009] As an optional implementation, a branch flow solenoid valve is provided on each outgoing water pipeline, and a temperature sensor is provided on each branch return water pipeline.

[0010] As an optional implementation, a flow meter is also provided on each outgoing water pipeline.

[0011] As an optional embodiment, the liquid cooling system further includes a cold storage tank, and the chiller is connected to the cold storage tank;

[0012] The water outlet of the cold storage tank is connected to the first water outlet pipeline, the second water outlet pipeline, and the third water outlet branch pipeline respectively through the second main water outlet pipeline;

[0013] A main flow solenoid valve is respectively provided on the first main water outlet pipeline and the second main water outlet pipeline.

[0014] As an optional implementation, the chiller is a screw chiller.

[0015] The utility model provides a new energy power generation and energy storage device, which has the following beneficial effects compared with the existing technology: each phase is connected to an energy storage circuit, and multiple AC series-connected energy storage converters are provided in the energy storage circuit. Each energy storage converter is connected to a battery cluster, thereby avoiding the parallel use of battery cells. The active balancing function of the energy storage converter ensures that the SOC of the battery cluster is basically consistent, thereby avoiding the influence of the "barrel effect" on the overall energy storage efficiency, and improving the utilization rate and service life of the battery. At the same time, the energy storage batteries of each phase are stored separately, and the liquid cooling system dissipates heat for the energy storage batteries of each phase respectively, thereby improving the heat dissipation efficiency and ensuring the energy storage efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a structural diagram of a new energy power generation and energy storage device provided by an embodiment of the utility model.

[0018] Figure 2 This is a schematic diagram of the energy storage circuit structure in a new energy power generation and energy storage device provided by an embodiment of the utility model.

[0019] Figure 3 This is a schematic structural diagram of a liquid cooling system in a new energy power generation and energy storage device provided by an embodiment of the present utility model.

[0020] In the figure, 1-energy storage circuit, 2-energy storage converter, 3-energy storage battery, 4-chiller, 5-cooling tower, 6-main return water pipeline, 7-first main outlet water pipeline, 8-main flow solenoid valve, 9-cold storage tank, 10-second main outlet water pipeline, 11-first outlet water pipeline, 12-second outlet water pipeline, 13-third outlet water branch, 14-branch circulation pump, 15-branch flow solenoid valve, 16-flow meter, 17-first energy storage container, 18-second energy storage container, 19-third energy storage container, 20-plate heat exchanger, 21-temperature sensor, 22-branch return water pipeline. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are intended to explain the present invention, but the present invention is not limited to the following implementation modes.

[0022] like Figure 1 and 2As shown, this embodiment provides a new energy generation and energy storage device including three energy storage circuits 1, which are respectively connected to phases A, B, and C of the power generation system, and are connected in a star configuration. Each phase of the energy storage circuit 1 has the same structure and includes several energy storage converters 2 (Power Conversion System, PCS) connected in series via their AC terminals, achieving AC series connection of multiple energy storage converters 2. Each energy storage converter 2 is connected to a battery cluster at its DC terminal, which consists of several series-connected energy storage batteries 3 and can directly output the target voltage without a transformer. The energy storage device of this embodiment decomposes batteries into "small battery packs" that do not require parallel connection of cells. Each "small battery pack" independently exchanges electrical energy with chemical energy. The small battery packs are then aggregated through a PCS topology to form an energy storage system with the required voltage level and capacity.

[0023] like Figure 2 As shown, under charging conditions, the SOC of the first battery cluster is higher, while the SOC of the second battery cluster is lower. The charging current of the two clusters can be controlled by the first PCS and the second PCS. The first PCS controls the charging current of the first battery cluster to decrease, while the second PCS controls the charging current of the second battery cluster to increase, thereby making the SOC of the two battery clusters basically consistent. This greatly improves the consistency of the battery SOC, avoids the impact of the battery module "barrel effect" on the overall energy storage system, and improves the utilization rate and service life of the battery. This embodiment avoids the parallel use of battery cells and adopts a mode of connecting a single battery cluster to a PCS. This effectively solves the safety issues and capacity utilization issues caused by the parallel use of multiple battery cells or battery clusters, and improves the safety performance of the energy storage system and the consistency of battery operation.

[0024] like Figure 3 As shown, in order to improve the heat dissipation efficiency of the batteries, this embodiment is provided with a first energy storage container 17, a second energy storage container 18, a third energy storage container 19 and a liquid cooling system. The battery compartment of the first energy storage container 17 is used to place the A-phase energy storage battery 3, the battery compartment of the second energy storage container 18 is used to place the B-phase energy storage battery 3, and the battery compartment of the third energy storage container 19 is used to place the C-phase energy storage battery 3. The liquid cooling system supplies cold water to the first energy storage container 17, the second energy storage container 18, and the third energy storage container 19 to dissipate heat from the energy storage batteries 3 in the three energy storage containers, thereby improving the heat dissipation efficiency and ensuring the energy storage performance.

[0025] like Figure 3As shown, the liquid cooling system provided in this embodiment includes a chiller 4, which can be a screw chiller 4. The water outlet of the chiller 4 is connected to the first main water outlet pipe 7, which is respectively connected to the first outflow water pipe 11, the second outflow water pipe 12, and the third outflow water branch. The first outflow water pipe 11 is connected to the plate heat exchanger 20 in the first energy storage container 17, the second outflow water pipe 12 is connected to the plate heat exchanger 20 in the second energy storage container 18, and the third outflow water pipe 13 is connected to the plate heat exchanger 20 in the third energy storage container 19. The plate heat exchanger 20 is connected to the main return water pipe 6 by a return water pipe 22, and the main return water pipe 6 is connected to the return water outlet of the chiller 4; a branch circulation pump 14 is provided on each outflow water pipe, and the branch circulation water pump transmits cold water to the corresponding energy storage container to take away heat. The chiller 4 is connected to a cooling tower 5, which dissipates heat to the external environment.

[0026] In this embodiment, a branch flow solenoid valve 15 is installed on each outflow water pipe, and a temperature sensor 21 is installed on each branch return water pipe 22. The temperature sensor 21 is used to detect the temperature of the return water from the energy storage container. If the temperature is high, it indicates that the batteries in the energy storage container are heating up, and the cold water flow needs to be increased. The opening of the flow solenoid valve is controlled to adjust the cold water flow rate and improve the heat dissipation efficiency of the batteries. If the return water temperature is low, the opening of the branch flow solenoid valve 15 is reduced to save water resources. At the same time, a flow meter 16 can also be installed on each outflow water pipe to monitor the cold water flow to the energy storage container in real time.

[0027] In this embodiment, the liquid cooling system also includes a cold storage tank 9, which is connected to the chiller 4. The outlet of the cold storage tank 9 is connected to the first outlet water pipe 11, the second outlet water pipe 12, and the third outlet water branch pipe via a second main outlet water pipe 10. A main flow solenoid valve 8 is provided on each of the first and second main outlet water pipes 7, 10. The opening of the main flow solenoid valve 8 controls the cold water supply. When the chiller 4 releases cold water, the main flow solenoid valve 8 on the first main outlet water pipe 7 opens, while the main flow solenoid valve 8 on the second main outlet water pipe 10 closes. When the cold storage tank 9 releases cold water, the main flow solenoid valve 8 on the first main outlet water pipe 7 closes, while the main flow solenoid valve 8 on the second main outlet water pipe 10 opens. In specific implementation, the chiller 4 operates for a certain period of time to cool the refrigerant in the cold storage tank 9 to 7°C, meeting the cooling capacity required for 2 hours of battery compartment charging and discharging.

[0028] The above disclosure is only a preferred embodiment of the present invention, but the present invention is not limited thereto. Any non-creative changes that can be thought of by technicians in this field, as well as several improvements and modifications made without departing from the principles of the present invention, should fall within the scope of protection of the present invention.

Claims

1. A new energy power generation and energy storage device, characterized in that: The system comprises three energy storage circuits connected to each phase of the power generation system, with the three energy storage circuits being star-connected. The energy storage circuit comprises a plurality of energy storage converters connected in series via their AC terminals, with the DC terminal of each energy storage converter connected to a battery cluster, which is composed of a plurality of energy storage batteries connected in series. The device also includes a first energy storage container, a second energy storage container, a third energy storage container and a liquid cooling system. The battery compartment of the first energy storage container is placed with A-phase energy storage batteries, the battery compartment of the second energy storage container is placed with B-phase energy storage batteries, and the battery compartment of the third energy storage container is placed with C-phase energy storage batteries. The liquid cooling system delivers cold water to the first energy storage container, the second energy storage container, and the third energy storage container.

2. The new energy power generation and energy storage device according to claim 1, characterized in that: The liquid cooling system includes a chiller, the water outlet of the chiller is connected to the first main water outlet pipe, the first main water outlet pipe is respectively connected to the first outflow water pipe, the second outflow water pipe, and the third outflow water branch, the first outflow water pipe is connected to the plate heat exchanger in the first energy storage container, the second outflow water pipe is connected to the plate heat exchanger in the second energy storage container, and the third outflow water pipe is connected to the plate heat exchanger in the third energy storage container. The plate heat exchanger is connected to the main return water pipe by a return water pipe, and the main return water pipe is connected to the return water outlet of the chiller; a branch circulation pump is provided on each outflow water pipe; the chiller is also connected to the cooling tower.

3. The new energy power generation and energy storage device according to claim 2, characterized in that: A branch flow solenoid valve is provided on each outflow water pipe, and a temperature sensor is provided on each branch return water pipe.

4. The new energy power generation and energy storage device according to claim 3, characterized in that: Flow meters are also provided on each outflow water pipe.

5. The new energy power generation and energy storage device according to claim 4, characterized in that: The liquid cooling system also includes a cold storage tank, and the chiller is connected to the cold storage tank; The water outlet of the cold storage tank is connected to the first water outlet pipeline, the second water outlet pipeline, and the third water outlet branch pipeline respectively through the second main water outlet pipeline; A main flow solenoid valve is respectively provided on the first main water outlet pipeline and the second main water outlet pipeline.

6. The new energy power generation and energy storage device according to any one of claims 2 to 5, characterized in that: The chiller is a screw chiller.

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