Multi-target-based configuration method for network-forming type flow liquid energy storage system

Abstract

The invention provides a multi-target-based configuration method for a network-forming type flow liquid energy storage system. The configuration method for the network-forming type flow liquid energy storage system comprises the following steps: step (1), collecting working information of the energy storage system and working information of a related power grid; (2) judging whether the output electric energy of the energy storage system meets the requirements of a power grid or not, and if so, entering a step (4); if not, entering the step (3); (3) adding a discharge battery of the energy storage system, increasing the output electric energy of the energy storage system, and returning to the step (1); (4) calculating the working characteristic value of each battery pack of the energy storage system; and (5) performing work control configuration on the energy storage system according to the work characteristic values of the battery packs. The invention provides a multi-objective-based configuration method for a network-forming type flow liquid energy storage system, which can ensure that the energy storage system meets the demand of a power grid load and improve the working reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage configuration control, and in particular relates to a multi-objective-based grid-type liquid flow energy storage system configuration method. Background Art

[0002] Renewable energy power generation has entered a period of rapid development. A large number of distributed power sources are connected to the power system through converters, which not only have problems such as randomness, volatility and intermittency, but also due to the low inertia and no damping characteristics of power electronic equipment, the inertia level of the power system is reduced, and the system's anti-interference ability and stability are deteriorated. In order to smooth out the power fluctuations of new energy and promote the balance of power supply and load in the operation of the power system, the grid-type energy storage system is put into operation in the power grid. At the same time, in order to improve economic efficiency, a large number of liquid batteries are widely used, which have higher safety and service life.

[0003] The present invention proposes a multi-objective-based grid-type liquid flow energy storage system configuration method, which collects the working information of the energy storage system and the working information of the relevant power grid, calculates the output power forecast value of the renewable energy power generation, and judges whether the energy storage system meets the demand in combination with the demand of the power grid, and controls the output power at the same time; in addition, considering the impact during the operation of the liquid flow battery, the real-time rated capacity and charge and discharge depth of each battery group of the energy storage system are calculated, and the energy storage system is further configured and controlled to ensure that the energy storage system can meet the load demand of the power grid. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a multi-objective-based grid-type liquid flow energy storage system configuration method, which can ensure that the energy storage system meets the needs of the grid load and improves working reliability.

[0005] The present invention is specifically a multi-objective-based configuration method for a networked liquid energy storage system, and the networked liquid energy storage system configuration method comprises the following steps:

[0006] Step (1): collecting the working information of the energy storage system and the working information of the related power grid;

[0007] Step (2): Determine whether the power output of the energy storage system meets the power grid demand. If so, proceed to step (4); if not, proceed to step (3);

[0008] Step (3): adding a discharge battery to the energy storage system to increase the output power of the energy storage system, and returning to step (1);

[0009] Step (4): Calculating the operating characteristic value of each battery pack of the energy storage system;

[0010] Step (5): Performing operation control configuration on the energy storage system according to the operation characteristic values ​​of each battery pack.

[0011] Furthermore, the working information of the energy storage system collected in step (1) specifically includes output current, output voltage, and charge and discharge current of each battery pack;

[0012] The working information of the relevant power grid includes power grid load, new energy power generation working information, and traditional energy power generation working information.

[0013] Furthermore, in step (2), the specific method for determining whether the power output of the energy storage system meets the power grid demand is:

[0014] (21) Calculate the output power forecast value of renewable energy power generation;

[0015] (22) calculating the power difference between the grid load and the predicted value of the output power of the new energy power generation and the output power of the traditional energy power generation;

[0016] (23) Determine whether the electric energy difference is greater than the electric energy output by the energy storage system; if not, the grid demand is met; if so, the grid demand is not met.

[0017] Furthermore, the specific algorithm for calculating the output power prediction value of the renewable energy power generation in step (21) is:

[0018] Photovoltaic power generation output power forecast value:

[0019]

[0020] Among them, P PV,r is the rated value of photovoltaic power output, G(t) is the light intensity, G r is the reference value of light intensity, T(t) is the surface temperature of the solar panel, T r is the rated value of the solar panel surface temperature;

[0021] Wind power output power forecast value:

[0022]

[0023] Where P wind,r is the rated value of wind power output, v(t) is the wind speed, v r is the wind speed reference value, and θ is the angle between the wind direction and the wind blade.

[0024] Furthermore, the operating characteristic values ​​of each battery pack of the energy storage system calculated in step (4) include the real-time rated capacity and charge / discharge depth of each battery pack.

[0025] Furthermore, the specific method for calculating the real-time rated capacity of each battery pack is as follows:

[0026]

[0027] Where E r is the initial value of the rated capacity of each battery pack, k is the rated capacity correction factor, N is the total number of cycles, and L(n) is the life of each battery pack.

[0028] Furthermore, the specific algorithm for calculating the real-time charge and discharge depth is:

[0029]

[0030] where e star t is the initial value of the charge of each battery pack, e end is the final charge value of each battery pack, and Δt is the charge / discharge time of each battery pack.

[0031] Furthermore, in step (5), the specific method for configuring the operation control of the energy storage system according to the operation characteristic values ​​of each battery pack is:

[0032] (51) Determine whether the real-time rated capacity of each battery pack put into operation is greater than the electric energy difference. If so, proceed to step (52); if not, proceed to step (53);

[0033] (52) determining whether the real-time charge and discharge depth of each battery pack put into operation is greater than a real-time charge and discharge depth reference value; if not, proceeding to step (53);

[0034] (53) Control the backup battery pack to start working.

[0035] Furthermore, the initial values ​​of the rated capacities of the battery packs are configured identically, and are periodically switched as backup battery packs for ease of maintenance and replacement, and can ensure that the grid-type liquid flow energy storage system can meet grid demand.

[0036] Compared with the prior art, the beneficial effects are as follows: the grid-type liquid flow energy storage system configuration method collects the working information of the energy storage system and the working information of the relevant power grid, calculates the output power forecast value of the new energy power generation, and judges whether the energy storage system meets the demand in combination with the demand of the power grid, and controls the output power at the same time; in addition, the real-time rated capacity and charge and discharge depth of each battery group of the energy storage system are calculated, and the configuration control of the energy storage system is further carried out to ensure that the energy storage system can meet the load demand of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is a workflow diagram of a multi-objective-based method for configuring a grid-type liquid flow energy storage system. DETAILED DESCRIPTION

[0038] The specific implementation method of a multi-objective grid-type liquid flow energy storage system configuration method of the present invention is described in detail below in conjunction with the accompanying drawings.

[0039] like Figure 1 As shown, the configuration method of the networked liquid energy storage system of the present invention comprises the following steps:

[0040] Step (1): collecting the working information of the energy storage system and the working information of the related power grid;

[0041] Step (2): Determine whether the power output of the energy storage system meets the power grid demand. If so, proceed to step (4); if not, proceed to step (3);

[0042] Step (3): adding a discharge battery to the energy storage system to increase the output power of the energy storage system, and returning to step (1);

[0043] Step (4): Calculating the operating characteristic value of each battery pack of the energy storage system;

[0044] Step (5): Performing operation control configuration on the energy storage system according to the operation characteristic values ​​of each battery pack.

[0045] The working information of the energy storage system collected in step (1) specifically includes output current, output voltage, and charge and discharge current of each battery pack;

[0046] The working information of the relevant power grid includes power grid load, new energy power generation working information, and traditional energy power generation working information.

[0047] The specific method for determining whether the output power of the energy storage system meets the power grid demand in step (2) is:

[0048] (21) Calculate the output power forecast value of renewable energy power generation;

[0049] (22) calculating the power difference between the grid load and the predicted value of the output power of the new energy power generation and the output power of the traditional energy power generation;

[0050] (23) Determine whether the electric energy difference is greater than the electric energy output by the energy storage system; if not, the grid demand is met; if so, the grid demand is not met.

[0051] The specific algorithm for calculating the output power prediction value of renewable energy power generation in step (21) is:

[0052] Photovoltaic power generation output power forecast value:

[0053]

[0054] Among them, P PV,r is the rated value of photovoltaic power output, G(t) is the light intensity, G r is the reference value of light intensity, T(t) is the surface temperature of the solar panel, Tr is the rated value of the solar panel surface temperature;

[0055] Wind power output power forecast value:

[0056]

[0057] Where P wind,r is the rated value of wind power output, v(t) is the wind speed, v r is the wind speed reference value, and θ is the angle between the wind direction and the wind blade.

[0058] Taking into account the influencing factors such as the change in internal resistance and side reactions of the flow battery during operation, it is necessary to calculate the actual condition characteristic values ​​of each battery group. Therefore, the operating characteristic values ​​of each battery group of the energy storage system calculated in step (4) include the real-time rated capacity and charge and discharge depth of each battery group.

[0059] The specific method for calculating the real-time rated capacity of each battery pack is:

[0060]

[0061] Where E r is the initial value of the rated capacity of each battery pack, k is the rated capacity correction factor, N is the total number of cycles, and L(n) is the life of each battery pack.

[0062] The specific algorithm for calculating the real-time charge and discharge depth is:

[0063]

[0064] where e star t is the initial value of the charge of each battery pack, e end is the final charge value of each battery pack, and Δt is the charge / discharge time of each battery pack.

[0065] The specific method for configuring the operation control of the energy storage system according to the operation characteristic values ​​of each battery pack in step (5) is:

[0066] (51) Determine whether the real-time rated capacity of each battery pack put into operation is greater than the electric energy difference. If so, proceed to step (52); if not, proceed to step (53);

[0067] (52) determining whether the real-time charge and discharge depth of each battery pack put into operation is greater than a real-time charge and discharge depth reference value; if not, proceeding to step (53);

[0068] (53) Control the backup battery pack to start working.

[0069] The initial values ​​of the rated capacity of each battery pack are configured the same, and they are regularly switched as backup battery packs for maintenance and replacement, and can ensure that the grid-type liquid flow energy storage system can meet the needs of the power grid.

[0070] During initial configuration, the total rated capacity of the battery packs put into operation shall not be less than 80% of the grid load.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the present invention. A person skilled in the art should understand that the specific implementation of the present invention can be modified or replaced by equivalents, but these modifications or changes are within the scope of protection of the pending claims.

Claims

1. A multi-objective grid-type liquid energy storage system configuration method, characterized in that: The configuration method of the networked liquid flow energy storage system comprises the following steps: Step (1): collecting the working information of the energy storage system and the working information of the related power grid; Step (2): Determine whether the power output of the energy storage system meets the power grid demand. If so, proceed to step (4); if not, proceed to step (3); Step (3): adding a discharge battery to the energy storage system to increase the output power of the energy storage system, and returning to step (1); Step (4): Calculating the operating characteristic value of each battery pack of the energy storage system; Step (5): Performing operation control configuration on the energy storage system according to the operation characteristic values ​​of each battery pack.

2. A multi-objective grid-type liquid energy storage system configuration method according to claim 1, characterized in that: The working information of the energy storage system collected in step (1) specifically includes output current, output voltage, and charging and discharging current of each battery pack; the working information of the relevant power grid includes power grid load, new energy power generation working information, and traditional energy power generation working information.

3. A multi-objective grid-type liquid energy storage system configuration method according to claim 2, characterized in that: The specific method for determining whether the output power of the energy storage system meets the power grid demand in step (2) is: (21) Calculate the output power forecast value of renewable energy power generation; (22) calculating the power difference between the grid load and the predicted value of the output power of the new energy power generation and the output power of the traditional energy power generation; (23) Determine whether the electric energy difference is greater than the electric energy output by the energy storage system; if not, the grid demand is met; if so, the grid demand is not met.

4. A multi-objective grid-type liquid energy storage system configuration method according to claim 3, characterized in that: The specific algorithm for calculating the output power prediction value of renewable energy power generation in step (21) is: Photovoltaic power generation output power forecast value: Among them, P PV,r is the rated value of photovoltaic power output, G(t) is the light intensity, G r is the reference value of light intensity, T(t) is the surface temperature of the solar panel, T r is the surface temperature rating of the solar panel; Wind power output power forecast value: Where P wind,r is the rated value of wind power output, v(t) is the wind speed, v r is the wind speed reference value, and θ is the angle between the wind direction and the wind blade.

5. A multi-objective grid-type liquid energy storage system configuration method according to claim 4, characterized in that: The operating characteristic values ​​of each battery pack of the energy storage system calculated in step (4) include the real-time rated capacity and charge / discharge depth of each battery pack.

6. A multi-objective grid-type liquid energy storage system configuration method according to claim 5, characterized in that: The specific method for calculating the real-time rated capacity of each battery pack is: Where E r is the initial value of the rated capacity of each battery pack, k is the rated capacity correction factor, N is the total number of cycles, and L(n) is the life of each battery pack.

7. A multi-objective grid-type liquid energy storage system configuration method according to claim 6, characterized in that: The specific algorithm for calculating the real-time charge and discharge depth is: where e star t is the initial value of the charge of each battery pack, e end is the final charge value of each battery pack, and Δt is the charge / discharge time of each battery pack.

8. A multi-objective grid-type liquid energy storage system configuration method according to claim 7, characterized in that: The specific method for configuring the operation control of the energy storage system according to the operation characteristic values ​​of each battery pack in step (5) is: (51) Determine whether the real-time rated capacity of each battery pack put into operation is greater than the electric energy difference. If so, proceed to step (52); if not, proceed to step (53); (52) determining whether the real-time charge and discharge depth of each battery pack put into operation is greater than a real-time charge and discharge depth reference value; if not, proceeding to step (53); (53) Control the backup battery pack to start working.

9. A multi-objective grid-type liquid energy storage system configuration method according to claim 8, characterized in that: The initial values ​​of the rated capacities of the battery packs are configured identically, and are periodically switched to serve as the backup battery packs for ease of maintenance and replacement, and to ensure that the grid-type liquid flow energy storage system can meet grid demand.

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