Photovoltaic / energy storage / combined cooling, heating and power hybrid intelligent microgrid control device and method

Abstract

A photovoltaic / energy storage / combined cooling, heating and power hybrid intelligent microgrid control device and a method for using same. The photovoltaic / energy storage / combined cooling, heating and power hybrid intelligent microgrid control device comprises a microgrid system; the microgrid system comprises a distributed power supply (1); the distributed power supply (1) is electrically connected to a battery energy storage structure (2); the battery energy storage structure (2) is electrically connected to a flywheel energy storage structure (3) and a grid-connected flywheel structure (6); the flywheel energy storage structure (3) is electrically connected to a secondary energy storage structure (4); the secondary energy storage structure (4) is electrically connected to a load device (5); the grid-connected flywheel structure (6) is electrically connected to a grid-connected inverter (7); and the grid-connected inverter (7) is electrically connected to an external grid.

Description

Photovoltaic energy storage trigeneration hybrid intelligent microgrid control device and method

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 28, 2023, with application number 202311087165.2. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of microgrid technology, and for example relates to a photovoltaic energy storage trigeneration hybrid intelligent microgrid control device and method. Background Art

[0003] A microgrid refers to a small power generation and distribution system composed of distributed energy, energy storage devices, energy conversion devices, related loads and monitoring. It can operate in isolation or in conjunction with the grid. Due to the low inertia of the microgrid, when the grid is disturbed, the microgrid is prone to instability and disconnection from the grid. The instability problem can be divided into device-level instability and system-level instability, and the two stimulate each other.

[0004] Microgrid control devices and systems can rationally plan and distribute power to each level of equipment in a microgrid, improving the efficiency of microgrid operation. For example, the operation control method, device, control device, and system for a microgrid system disclosed in Chinese Patent Publication No. CN115912500A apply a software system, but the microgrid is still affected by grid disturbances.

[0005] Summary of the Invention

[0006] The present application provides a photovoltaic energy storage trigeneration hybrid smart microgrid control device and method, which controls the operation of the microgrid by setting hardware devices and reduces the disturbance of the power grid to the microgrid.

[0007] The present application provides a photovoltaic energy storage trigeneration hybrid intelligent microgrid control device, comprising: a microgrid system, the microgrid system including a distributed power source; the distributed power source is electrically connected to a battery energy storage structure, the battery energy storage structure is electrically connected to a flywheel energy storage structure and a grid-connected flywheel structure, the flywheel energy storage structure is electrically connected to a secondary energy storage structure, the secondary energy storage structure is electrically connected to a load device, the grid-connected flywheel structure is electrically connected to a grid-connected inverter, and the grid-connected inverter is configured to be electrically connected to an external power grid; the microgrid system also includes a microgrid control structure, the microgrid control structure is connected to the distributed power source, the battery energy storage structure, the flywheel energy storage structure, the secondary energy storage structure, the load device, the grid-connected flywheel structure and the grid-connected inverter.

[0008] As an optional solution, distributed power sources include distributed photovoltaic power generation structure, wind power generation structure and trigeneration power generation structure.

[0009] As an optional solution, the battery energy storage structure and the secondary energy storage structure both adopt electrochemical energy storage methods, and both the battery energy storage structure and the secondary energy storage structure include multiple batteries.

[0010] As an optional solution, the flywheel energy storage structure includes two parallel flywheel units, and ordinary transfer switches are installed at the connection between the flywheel energy storage structure and the battery energy storage structure, as well as at the connection between the flywheel energy storage structure and the secondary energy storage structure.

[0011] As an optional solution, the grid-connected flywheel structure includes two parallel flywheel units, and high-speed transfer switches are installed at the connection between the grid-connected flywheel structure and the battery energy storage structure, as well as at the connection between the grid-connected flywheel structure and the grid-connected inverter.

[0012] As an optional solution, the flywheel unit contains multiple flywheel batteries, and the motors in the flywheel batteries are all three-phase synchronous motors.

[0013] As an optional solution, the grid-connected inverter is configured to have a high-speed static switch installed between the inverter and the external grid.

[0014] As an optional solution, the microgrid control structure includes a central control device and multiple data acquisition and monitoring devices. The multiple data acquisition and monitoring devices are electrically connected to the distributed power supply, battery energy storage structure, flywheel energy storage structure, secondary energy storage structure, load equipment, grid-connected flywheel structure and grid-connected inverter. The central control device includes at least a main control module, a data analysis module and a human-computer interaction module.

[0015] The present application also provides a method for using a photovoltaic energy storage trigeneration hybrid smart microgrid control device, comprising:

[0016] Distributed power sources generate electricity in a variety of ways and deliver it to battery storage structures;

[0017] The battery energy storage structure transmits electricity to one of the two parallel flywheel units of the flywheel energy storage structure for storage. After the energy storage is completed, the circuit is switched through a common transfer switch, so that the battery energy storage structure transmits electricity to the other flywheel unit of the flywheel energy storage structure. The flywheel unit after the energy storage is completed generates electricity and transmits the electricity to the secondary energy storage structure.

[0018] The secondary energy storage structure distributes the electricity to the load equipment;

[0019] When the distributed power generation has surplus electricity, the battery energy storage structure transmits the electricity to one of the two parallel flywheel units of the grid-connected flywheel structure for storage. After the energy storage is completed, the high-speed conversion switch switches the circuit, allowing the battery energy storage structure to transmit the electricity to the other flywheel unit of the grid-connected flywheel structure. The flywheel unit that has completed the energy storage will generate electricity and transmit the electricity to the external power grid through the grid-connected inverter.

[0020] Among them, during the power transmission process, the central control device in the microgrid control structure collects and monitors the voltage and current information of the distributed power source, battery energy storage structure, flywheel energy storage structure, secondary energy storage structure, load equipment, grid-connected flywheel structure and grid-connected inverter through the acquisition and monitoring equipment, and controls the operation of the microgrid system according to the voltage information and current information. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic diagram of the structure of a photovoltaic energy storage trigeneration hybrid smart microgrid control device provided in an embodiment of the present application.

[0022] FIG2 is a structural block diagram of a central control device provided in an embodiment of the present application.

[0023] FIG3 is a flow chart of a method for using a photovoltaic energy storage trigeneration hybrid smart microgrid control device according to an embodiment of the present application.

[0024] In the figure: 1. Distributed power source; 101. Distributed photovoltaic power generation structure; 102. Wind power generation structure; 103. Combined cooling, heating and electrical power generation structure; 2. Battery energy storage structure; 3. Flywheel energy storage structure; 4. Secondary energy storage structure; 5. Load equipment; 6. Grid-connected flywheel structure; 7. Grid-connected inverter; 701. High-speed static switch; 8. Microgrid control structure; 801. Central control equipment; 8011. Main control module; 8012. Data analysis module; 8013. Human-computer interaction module; 802. Acquisition and monitoring equipment; 9. Flywheel unit; 10. Ordinary transfer switch; 11. High-speed transfer switch. DETAILED DESCRIPTION

[0025] The technical solution of this application will be described below with reference to embodiments.

[0026] Example 1

[0027] A photovoltaic energy storage trigeneration hybrid intelligent microgrid control device, as shown in Figure 1, includes: a microgrid system, the microgrid system includes a distributed power supply 1, the distributed power supply 1 is electrically connected to a battery energy storage structure 2, the battery energy storage structure 2 is electrically connected to a flywheel energy storage structure 3, the flywheel energy storage structure 3 is electrically connected to a secondary energy storage structure 4, the secondary energy storage structure 4 is electrically connected to a load device 5, the battery energy storage structure 2 is also electrically connected to a grid-connected flywheel structure 6, the grid-connected flywheel structure 6 is electrically connected to a grid-connected inverter 7, and the grid-connected inverter 7 is electrically connected to an external power grid. The microgrid system also includes a microgrid control structure 8, which is connected to the distributed power supply 1, the battery energy storage structure 2, the flywheel energy storage structure 3, the secondary energy storage structure 4, the load device 5, the grid-connected flywheel structure 6 and the grid-connected inverter 7.

[0028] The present application adds a flywheel energy storage structure 3 and a grid-connected flywheel structure 6 to the microgrid system, and utilizes the physical energy storage structure to form a certain degree of physical isolation between the power supply part and the load part of the microgrid system, and between the power supply part of the microgrid system and the external power grid. That is, the power supply part, the load part and the external power grid of the microgrid system are relatively independent. Therefore, when the external power grid is disturbed, it is difficult to affect most of the equipment in the microgrid system, so that the microgrid system can also operate smoothly when the external power grid is disturbed.

[0029] 1 , the distributed power source 1 includes a distributed photovoltaic power generation structure 101 , a wind power generation structure 102 and a combined cooling, heating and electrical power generation structure 103 , and uses a variety of methods to generate electricity to ensure the power generation of the microgrid system.

[0030] Referring to 1 , the battery energy storage structure 2 and the secondary energy storage structure 4 both adopt electrochemical energy storage methods, and both the battery energy storage structure 2 and the secondary energy storage structure 4 include multiple batteries.

[0031] 1 , the flywheel energy storage structure 3 includes two parallel flywheel units 9 , and common transfer switches 10 are installed at the connection between the flywheel energy storage structure 3 and the battery energy storage structure 2 and at the connection between the flywheel energy storage structure 3 and the secondary energy storage structure 4 .

[0032] 1 , the grid-connected flywheel structure 6 includes two parallel flywheel units 9 , and high-speed transfer switches 11 are installed at the connection between the grid-connected flywheel structure 6 and the battery energy storage structure 2 and at the connection between the grid-connected flywheel structure 6 and the grid-connected inverter 7 .

[0033] 1 , the flywheel unit 9 includes multiple flywheel batteries. The motors in the flywheel batteries are all three-phase synchronous motors. Synchronous motors are less affected by voltage than asynchronous motors and are more stable during grid disturbances.

[0034] 1 , a high-speed static switch 701 is installed between the grid-connected inverter 7 and the external grid. When the disturbance is too large, the high-speed static switch 701 can disconnect the microgrid system from the external grid and switch to island mode.

[0035] 1 and 2 , the microgrid control structure 8 includes at least a central control device 801 and multiple acquisition and monitoring devices 802 . The multiple acquisition and monitoring devices 802 are electrically connected to the distributed power source 1, the battery energy storage structure 2, the flywheel energy storage structure 3, the secondary energy storage structure 4, the load device 5, the grid-connected flywheel structure 6, and the grid-connected inverter 7. The central control device 801 includes at least a main control module 8011, a data analysis module 8012, and a human-computer interaction module 8013.

[0036] 3 , a method for using a photovoltaic energy storage trigeneration hybrid smart microgrid control device includes the following steps:

[0037] S1: Distributed power generation 1 generates electricity through various means and transmits the electricity to battery energy storage structure 2;

[0038] S2: The battery energy storage structure 2 transmits electricity to one of the flywheel units 9 of the flywheel energy storage structure 3 for storage, causing the flywheel unit 9 to store energy. After the energy storage is completed, the circuit is switched by the common transfer switch 10, causing the battery energy storage structure 2 to transmit electricity to another flywheel unit 9 of the flywheel energy storage structure 3. The flywheel unit 9 that has completed energy storage generates electricity and transmits the electricity to the secondary energy storage structure 4.

[0039] S3: The secondary energy storage structure 4 distributes the electricity to the load device 5;

[0040] S4: When the distributed power source 1 generates surplus power, the battery energy storage structure 2 transmits the power to one of the flywheel units 9 of the grid-connected flywheel structure 6 for storage, causing the flywheel unit 9 to store energy. After the energy storage is completed, the high-speed transfer switch 11 switches the circuit, causing the battery energy storage structure 2 to transmit the power to another flywheel unit 9 of the grid-connected flywheel structure 6. The flywheel unit 9 that has completed energy storage generates electricity and transmits the electricity to the external power grid through the grid-connected inverter 7.

[0041] S5: During the process from S1 to S4, the central control device 801 in the microgrid control structure 8 collects and monitors the voltage and current information of the distributed power source 1, the battery energy storage structure 2, the flywheel energy storage structure 3, the secondary energy storage structure 4, the load device 5, the grid-connected flywheel structure 6 and the grid-connected inverter 7 through the acquisition and monitoring device 802, and controls the operation of the microgrid system according to the voltage and current information.

[0042] Exemplarily, the acquisition monitoring device 802 monitors and collects the voltage information and current information of the distributed power source 1, the battery energy storage structure 2, the flywheel energy storage structure 3, the secondary energy storage structure 4, the load device 5, the grid-connected flywheel structure 6 and the grid-connected inverter 7, and sends the above voltage information and current information to the central control device 801. The central control device 801 controls the operation of the microgrid system according to the above voltage information and current information.

[0043] In the intelligent microgrid control device, the flywheel energy storage structure 3 and the grid-connected flywheel structure 6 are physical energy storage structures, which can convert electrical energy into kinetic energy for storage, and convert kinetic energy into electrical energy when needed; and both the flywheel energy storage structure 3 and the grid-connected flywheel structure 6 use two flywheel units 9, so the process of the battery energy storage structure 2 storing energy in the flywheel energy storage structure 3 and the grid-connected flywheel structure 6, the flywheel energy storage structure 3 releasing energy into the secondary energy storage structure 4, and the grid-connected flywheel structure 6 releasing energy into the external power grid are relatively independent, so when the external power grid is disturbed, it is difficult to interfere with the power supply part of the microgrid system where the battery energy storage structure 2 is located, and the load part where the flywheel energy storage structure 3 is located.

[0044] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them.

Claims

1. A photovoltaic energy storage trigeneration hybrid intelligent microgrid control device, comprising: A microgrid system, the microgrid system comprising a distributed power source (1); the distributed power source (1) is electrically connected to a battery energy storage structure (2), the battery energy storage structure (2) is electrically connected to a flywheel energy storage structure (3) and a grid-connected flywheel structure (6), the flywheel energy storage structure (3) is electrically connected to a secondary energy storage structure (4), the secondary energy storage structure (4) is electrically connected to a load device (5), the grid-connected flywheel structure (6) is electrically connected to a grid-connected inverter (7), and the grid-connected inverter (7) is configured to be electrically connected to an external power grid; The microgrid system further comprises a microgrid control structure (8), wherein the microgrid control structure (8) is connected to the distributed power source (1), the battery energy storage structure (2), the flywheel energy storage structure (3), the secondary energy storage structure (4), the load device (5), the grid-connected flywheel structure (6) and the grid-connected inverter (7).

2. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 1, wherein: The distributed power source (1) comprises a distributed photovoltaic power generation structure (101), a wind power generation structure (102) and a combined cooling, heating and electrical power generation structure (103).

3. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 2, wherein: The battery energy storage structure (2) and the secondary energy storage structure (4) both adopt an electrochemical energy storage method, and the battery energy storage structure (2) and the secondary energy storage structure (4) both include a plurality of storage batteries.

4. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 2, wherein: The flywheel energy storage structure (3) comprises two parallel flywheel units (9), and common conversion switches (10) are installed at the connection between the flywheel energy storage structure (3) and the battery energy storage structure (2) and at the connection between the flywheel energy storage structure (3) and the secondary energy storage structure (4).

5. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 4, wherein: The grid-connected flywheel structure (6) comprises two parallel flywheel units (9), and a high-speed conversion switch (11) is installed at the connection between the grid-connected flywheel structure (6) and the battery energy storage structure (2) and at the connection between the grid-connected flywheel structure (6) and the grid-connected inverter (7).

6. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 4 or 5, wherein: The flywheel unit (9) contains a plurality of flywheel batteries, and the motors in the flywheel batteries are all three-phase synchronous motors.

7. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to any one of claims 1 to 5, wherein: The grid-connected inverter (7) is configured to have a high-speed static switch (701) installed between the inverter and the external power grid.

8. The photovoltaic energy storage trigeneration hybrid intelligent microgrid control device according to claim 7, wherein: The microgrid control structure (8) comprises a central control device (801) and a plurality of data acquisition and monitoring devices (802), wherein the plurality of data acquisition and monitoring devices (802) are electrically connected to the distributed power source (1), the battery energy storage structure (2), the flywheel energy storage structure (3), the secondary energy storage structure (4), the load device (5), the grid-connected flywheel structure (6) and the grid-connected inverter (7), and the central control device (801) comprises at least a main control module (8011), a data analysis module (8012) and a human-computer interaction module (8013).

9. A method for using a photovoltaic energy storage trigeneration hybrid intelligent microgrid control device, applied to the photovoltaic energy storage trigeneration hybrid intelligent microgrid control device of claim 8, the method comprising: Distributed power sources (1) generate electricity in a variety of ways and transmit the electricity to the battery energy storage structure (2); The battery energy storage structure (2) transmits electric power to one of the two parallel flywheel units (9) of the flywheel energy storage structure (3) for storage. After energy storage is completed, the circuit is switched by a common conversion switch (10) so that the battery energy storage structure (2) transmits electric power to the other flywheel unit (9) of the flywheel energy storage structure (3). The flywheel unit (9) after energy storage is completed generates electricity and transmits electric power to the secondary energy storage structure (4). The secondary energy storage structure (4) distributes the electricity to the load device (5); When the distributed power source (1) generates surplus power, the battery energy storage structure (2) transmits the power to one of the two parallel flywheel units (9) of the grid-connected flywheel structure (6) for storage. After the energy storage is completed, the circuit is switched by the high-speed conversion switch (11), so that the battery energy storage structure (2) transmits the power to the other flywheel unit (9) of the grid-connected flywheel structure (6). The flywheel unit (9) after the energy storage is completed generates power and transmits the power to the external power grid through the grid-connected inverter (7); In the process of power transmission, the central control device (801) in the microgrid control structure (8) collects and monitors the voltage information and current information of the distributed power source (1), the battery energy storage structure (2), the flywheel energy storage structure (3), the secondary energy storage structure (4), the load device (5), the grid-connected flywheel structure (6) and the grid-connected inverter (7) through the collection and monitoring device (802), and controls the operation of the microgrid system according to the voltage information and current information.

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