Novel hybrid energy storage system

Abstract

The utility model discloses a novel hybrid energy storage system, comprising a power generation system connected with a DC bus through a first DC / DC converter; the direct current bus is connected with the hybrid energy storage unit and is connected with a power grid through the DC / AC converter; the hybrid energy storage unit comprises a super capacitor energy storage system, a storage battery energy storage system and a controller; the super capacitor energy storage system is connected with the direct current bus through a second DC / DC converter; the storage battery energy storage system is respectively connected with the super capacitor energy storage system and the direct current bus through a third DC / DC converter; and the controller is respectively connected with the direct current bus, the second DC / DC converter, the third DC / DC converter and the super capacitor energy storage system. According to the utility model, the advantages of the super capacitor energy storage system and the storage battery energy storage system are fully exerted, the service life of the whole energy storage system is prolonged, and the efficiency, stability and reliability of energy storage and output are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a novel hybrid energy storage system. Background Art

[0002] In recent years, the proportion of renewable energy power generation systems in the energy structure has continued to increase. However, renewable energy such as solar energy and wind energy are greatly affected by factors such as weather. The instability of their power generation makes it difficult to formulate accurate power generation plans, posing considerable challenges to the stable operation of the power grid.

[0003] In the prior art, batteries are usually used for energy storage. Batteries have a high energy density and convert electrical energy into chemical energy through chemical reactions for storage. When needed, the chemical energy is converted back into electrical energy for supply to circuits or devices. Batteries can store a large amount of electrical energy in a relatively small volume and weight, and are suitable for scenarios that require long-term energy storage. The application of batteries can alleviate the supply and demand imbalance between the production and use of new energy power generation systems, fill in peaks and valleys, and improve the flexibility and efficiency of the power system.

[0004] However, the current single battery energy storage system, which is provided by the battery for high-rate current discharge, will shorten its life. The battery energy storage system has problems such as slow response speed, short cycle life and inability to start at low temperatures, which limits the application of the battery energy storage system and also increases its construction cost and operating cost.

[0005] Therefore, there is an urgent need to develop a technology that can solve the above technical problems. Utility Model Content

[0006] The purpose of the utility model is to provide a new hybrid energy storage system in view of the technical defects in the prior art.

[0007] To this end, the utility model provides a novel hybrid energy storage system, including: a power generation system, a power grid, a DC bus, a controller, a second DC / DC converter, a third DC / DC converter, a supercapacitor energy storage system and a battery energy storage system;

[0008] A power generation system is connected to the DC bus through a first DC / DC converter;

[0009] A DC bus connected to a hybrid energy storage unit for energy storage and connected to a power grid via a DC / AC converter;

[0010] The hybrid energy storage unit comprises a supercapacitor energy storage system, a battery energy storage system and a controller;

[0011] Wherein, the supercapacitor energy storage system is connected to the DC bus through the second DC / DC converter;

[0012] The battery energy storage system is connected to the supercapacitor energy storage system and the DC bus through a third DC / DC converter;

[0013] The controller is respectively connected to the DC bus, the second DC / DC converter, the third DC / DC converter and the supercapacitor energy storage system.

[0014] It can be seen from the technical solution provided by the above utility model that, compared with the prior art, the utility model provides a new hybrid energy storage system with a scientific structural design. It not only has the characteristics of high power density, but also can maintain the characteristics of high energy density of the existing battery energy storage system, give full play to the advantages of supercapacitor energy storage system and battery energy storage system, which is conducive to extending the service life of the overall energy storage system, achieving normal startup at low temperature, and improving the efficiency, stability and reliability of energy storage and output. It is a high-performance energy storage solution with broad application prospects and has great production practice significance.

[0015] For the utility model, the supercapacitor used therein has the characteristics of high-rate current charging and discharging and good low-temperature characteristics because there is no electrochemical reaction during the charging and discharging process. By combining the supercapacitor with the battery, the number of cycles of the single energy storage system can be reduced, the service life of the entire energy storage system can be extended, the stability and reliability of the entire energy storage system can be improved, the system failure rate can be reduced, and the stable operation of the power system can be guaranteed.

[0016] For the utility model, the power type energy storage system and the energy type energy storage system are mixed as the energy storage system of the power generation system, which can not only meet the energy demand of the load, but also provide high power energy storage characteristics and energy recovery functions. Compared with single battery energy storage, the addition of supercapacitor energy storage system can effectively increase the service life of the battery, so that the energy storage system has both high power density and high energy density energy storage characteristics, significantly improving the overall performance of the energy storage system and effectively reducing the construction and operation costs of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A structural block diagram of a novel hybrid energy storage system provided by the utility model;

[0018] In the figure, 1 is a power generation system, 2 is a power grid, 3 is a DC bus, 4 is a controller, and 5 is a second DC / DC (i.e., DC-DC) converter;

[0019] 6 is a third DC / DC converter, 7 is a supercapacitor energy storage system, 8 is a battery energy storage system; 9 is a first DC / DC converter, and 10 is a DC / AC converter. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0023] See also Figure 1 , the utility model provides a novel hybrid energy storage system, comprising: a power generation system 1, a power grid 2, a DC bus 3, a controller 4, a second DC / DC converter 5, a third DC / DC converter 6, a supercapacitor energy storage system 7 and a battery energy storage system 8;

[0024] The power generation system 1 is connected to the DC bus 3 via a first DC / DC converter 9;

[0025] A DC bus 3 connected to a hybrid energy storage unit for energy storage, and connected to a power grid 2 via a DC / AC converter 10;

[0026] The hybrid energy storage unit comprises a supercapacitor energy storage system 7, a battery energy storage system 8 and a controller 4;

[0027] Wherein, the supercapacitor energy storage system 7 is connected to the DC bus 3 via the second DC / DC converter 5;

[0028] The battery energy storage system 8 is connected to the supercapacitor energy storage system 7 and the DC bus 3 respectively through the third DC / DC converter 6;

[0029] The controller 4 is respectively connected to the DC bus 3, the second DC / DC converter 5, the third DC / DC converter 6 and the supercapacitor energy storage system 7 (specifically at the terminal voltage, ie, the positive and negative electrodes).

[0030] It should be noted that the novel hybrid energy storage system provided by the present invention is a hybrid energy storage system including supercapacitors and batteries, and is a DC energy storage system.

[0031] In the present invention, the DC bus 3, as the main conductive channel in the DC power system, is used to transmit electrical energy from the power generation system to various load devices (such as the power grid) to ensure stable and reliable operation of the system.

[0032] In the present invention, in a specific implementation, the controller 4 is used to obtain the voltage values ​​of the DC bus 3, the second DC / DC converter 5 and the third DC / DC converter 6, and control the working states of the second DC / DC converter 5 and the third DC / DC converter 6.

[0033] It should be noted that, for the present invention, the controller 4 is used to control the energy exchange of the energy storage system according to the acquired voltage value; in specific implementation, the controller 4 completes the energy exchange with the DC bus 3 by controlling the second DC / DC converter 5 and the third DC / DC converter 6.

[0034] In a specific implementation, the controller 4 may be a programmable controller PLC, a central processing unit CPU, a digital signal processor DSP or a single-chip microcomputer MCU, for example, a microcontroller of the model GD32F305C.

[0035] It should be noted that the power generation system 1 is used to be connected to the DC bus 3 through the first DC / DC converter 9. When outputting electric energy to the outside, the DC bus 3 connected to the power generation system 1 needs to be connected to the power grid 2 through the DC / AC converter 10.

[0036] For the hybrid energy storage system provided by the utility model, the third DC / DC converter 6 is used to charge and discharge between the battery energy storage system 8 and the supercapacitor energy storage system 7; the second DC / DC converter 5 is used to charge and discharge the hybrid energy storage unit including the supercapacitor energy storage system 7 and the battery energy storage system 8;

[0037] For the present utility model, the controller 4 includes the following functions:

[0038] The controller 4 is used to determine the current working state of the hybrid energy storage unit by acquiring the voltage value on the DC bus 3;

[0039] The working state of the hybrid energy storage unit includes a power supply state of supplying power to the external power grid 2 and a charging state of being charged by the power generation system 1;

[0040] When the voltage value on the DC bus 3 is stable (for example, the voltage change value per unit time does not exceed a preset value, such as 10 V / s), it is determined that the hybrid energy storage unit is in a charging state. At this time, the controller 4 controls to turn on the second DC / DC converter 5, so that the hybrid energy storage unit is charged through the second DC / DC converter 5 and the DC bus 3;

[0041] Among them, when there is a large fluctuation in the voltage value on the power generation system 1 (for example, the voltage change value per unit time exceeds a preset value, which is, for example, 10V / s) or the output power is insufficient (for example, lower than a preset output power value, which is, for example, 10MW), it is judged that the hybrid energy storage unit is in a power supply state, and the controller 4 turns on the second DC / DC converter 5, so that the hybrid energy storage unit supplies power to the external power grid 2 through the second DC / DC converter 5 and the DC bus 3. Therefore, it can quickly respond to the needs of the external power grid 2 and realize the function of filling the peak and valley.

[0042] In terms of specific implementation, in the hybrid energy storage system, the principle of giving priority to charging and discharging the supercapacitor energy storage system 7 and using the battery energy storage system 8 as a backup power source should be followed.

[0043] The controller 4 is used to obtain the terminal voltage value of the supercapacitor energy storage system 7 (i.e., the voltage between the positive and negative poles of the system), determine its power state (i.e., whether there is excess power, i.e., excess energy), and then control the opening and closing (i.e., disconnection) of the third DC / DC converter 6; the specific description is as follows:

[0044] Among them, when the hybrid energy storage unit is in a charging state, the controller 4 preferentially turns on the second DC / DC converter 5, and charges the supercapacitor energy storage system 7 through the second DC / DC converter 5 and the DC bus 3; then, when the controller 4 detects that the terminal voltage of the supercapacitor energy storage system 7 is higher (that is, greater than a preset first voltage value, the preset first voltage value is, for example, 1500V), the controller 4 determines that the supercapacitor energy storage system 7 has excess energy, and the controller 4 controls the opening of the third DC / DC converter 6 to charge the battery energy storage system 8 (that is, the battery energy storage system 8 is charged through the second DC / DC converter 5 and the DC bus 3 and the third DC / DC converter 6), so as to recover the excess energy of the supercapacitor energy storage system 7;

[0045] Among them, when the hybrid energy storage unit is in the power supply (i.e., external discharge) state, the controller 4 preferentially turns on the second DC / DC converter 5, and enables the supercapacitor energy storage system 7 to supply power to the external power grid 2 (i.e., discharge to the outside) through the second DC / DC converter 5 and the DC bus 3; then, when it is detected that the terminal voltage of the supercapacitor energy storage system 7 is low (i.e., less than the preset second voltage value, the preset second voltage value is, for example, 1000V), the controller 4 determines that the supercapacitor energy storage system 7 does not have excess energy, and the controller 4 controls to turn on the third DC / DC converter 6, and uses the battery energy storage system 8 to discharge the supercapacitor energy storage system 7 (i.e., realize the function of charging the supercapacitor energy storage system 7), and at the same time discharges to the DC bus 3, and supplies power to the external power grid 2 (i.e., discharges to the outside) through the DC bus 3 and the second DC / DC converter 5.

[0046] In the present invention, in a specific implementation, the power generation system 1 is an existing power generation system, such as a solar power generation system or a wind power generation system with mature existing technology.

[0047] In the present utility model, in specific implementation, the supercapacitor energy storage system 7 includes a plurality of supercapacitor energy storage units connected in parallel;

[0048] In specific implementation, the supercapacitor energy storage unit is a supercapacitor monomer;

[0049] The supercapacitor monomer adopts a double-layer capacitor, for example, a double-layer capacitor with a rated voltage of 2.7V.

[0050] In the present utility model, in specific implementation, the battery energy storage system 8 includes a plurality of battery energy storage units connected in parallel;

[0051] The battery energy storage unit is a unit composed of lead-acid battery cells or lithium-ion battery cells, for example, a unit composed of lithium-ion battery cells with a rated voltage of 3.2V.

[0052] In the present invention, in a specific implementation, the power grid 2 is, for example, a household power grid with 220V AC power.

[0053] In the present invention, in specific implementation, a DC-DC (DC / DC) converter is a DC conversion device that converts a DC basic power supply into other voltage types, and is a well-known device with mature prior art. A DC-AC (AC / DC) converter is a conversion device that converts AC power into DC power, and is a well-known device with mature prior art.

[0054] It should be noted that matters not described in the present invention are applicable to the prior art.

[0055] Compared with the prior art, the new hybrid energy storage system provided by the utility model has the following beneficial effects:

[0056] 1. In the present utility model, the supercapacitor energy storage system 7 has the advantages of high-rate current charging and discharging and fast response, and is preferably used in the hybrid energy storage system, so that its high power density advantage can be fully utilized.

[0057] 2. In the present invention, the battery energy storage system 8 serves as a backup power source for the system and is the main energy storage device of the system, which can give full play to the advantages of its high energy density.

[0058] 3. In the present invention, the controller 4 can accurately control the working state of the hybrid energy storage unit in the entire hybrid energy storage system by acquiring the voltage values ​​of the DC bus 3, the second DC / DC converter 5 and the third DC / DC converter 6.

[0059] 4. The utility model has wide applicability: it is applicable to various types of new energy power generation systems to ensure the stability of power system operation.

[0060] In summary, the new hybrid energy storage system provided by the utility model is a supercapacitor and battery hybrid energy storage system, which has the energy storage characteristics of high power density and high energy density, significantly improves the overall performance of the energy storage system, and effectively reduces the construction and operation costs of the energy storage system.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A new hybrid energy storage system, characterized in that: include: A power generation system (1), a power grid (2), a DC bus (3), a controller (4), a second DC / DC converter (5), a third DC / DC converter (6), a supercapacitor energy storage system (7) and a battery energy storage system (8); The power generation system (1) is connected to the DC bus (3) via a first DC / DC converter (9); A DC bus (3) connected to a hybrid energy storage unit for storing energy, and connected to a power grid (2) via a DC / AC converter (10); The hybrid energy storage unit comprises a supercapacitor energy storage system (7), a battery energy storage system (8) and a controller (4); The supercapacitor energy storage system (7) is connected to the DC bus (3) via the second DC / DC converter (5); A battery energy storage system (8) is connected to the supercapacitor energy storage system (7) and the DC bus (3) respectively through a third DC / DC converter (6); The controller (4) is respectively connected to the DC bus (3), the second DC / DC converter (5), the third DC / DC converter (6) and the supercapacitor energy storage system (7).

2. The novel hybrid energy storage system according to claim 1, characterized in that: The controller (4) is a programmable controller PLC, a central processing unit CPU, a digital signal processor DSP or a single-chip microcomputer MCU.

3. The novel hybrid energy storage system according to claim 2, characterized in that: The controller (4) is a microcontroller of the GD32F305C model.

4. The novel hybrid energy storage system according to claim 1, characterized in that: The power generation system (1) is a solar power generation system or a wind power generation system.

5. The novel hybrid energy storage system according to claim 1, characterized in that: The supercapacitor energy storage system (7) comprises a plurality of supercapacitor energy storage units connected in parallel.

6. The novel hybrid energy storage system according to claim 5, characterized in that: The supercapacitor energy storage unit is a supercapacitor monomer; Supercapacitor monomer, using double layer capacitor.

7. The novel hybrid energy storage system according to claim 6, characterized in that: The EDLC is a double-layer capacitor with a rated voltage of 2.7V.

8. The novel hybrid energy storage system according to any one of claims 1 to 7, characterized in that: A battery energy storage system (8) comprises a plurality of battery energy storage units connected in parallel.

9. The novel hybrid energy storage system according to claim 8, characterized in that: The battery energy storage unit is a unit composed of lead-acid battery cells or lithium-ion battery cells.

10. The novel hybrid energy storage system according to claim 9, characterized in that: The battery energy storage unit is a unit composed of lithium-ion battery cells with a rated voltage of 3.2V.

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