A flywheel energy storage control method and device for auxiliary frequency modulation

Abstract

The invention discloses a flywheel energy storage control method and device for auxiliary frequency regulation, the method comprising: obtaining the historical data of the secondary frequency regulation instruction of the power grid dispatching and the historical data of the actual output of the thermal power plant; obtaining the energy storage auxiliary frequency regulation target value; processing the energy storage auxiliary frequency regulation target values ​​of multiple days to obtain the typical daily energy storage auxiliary frequency regulation target value; obtaining the full charge time of the flywheel energy storage battery configured in the thermal power plant; taking the full charge time of the flywheel energy storage battery as an interval, accumulating and counting the typical daily energy storage auxiliary frequency regulation target values ​​within the interval to obtain the long-term frequency regulation capacity value; when the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, pre-charging is performed; when the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, pre-discharging is performed; the advantage of the invention is that the system can meet the requirements of the secondary frequency regulation instruction for long-term unidirectional regulation, and avoid the frequency regulation failure or reverse regulation.

Description

Technical Field

[0001] The present invention relates to the technical field of power-level flywheel energy storage control strategies, and more specifically to a flywheel energy storage control method and device for auxiliary frequency modulation. Background Art

[0002] In new power systems, the demand for frequency regulation and peak regulation is increasing day by day, and the auxiliary frequency regulation market is becoming increasingly hot. Thermal energy storage combined frequency regulation has obvious advantages in the auxiliary frequency regulation market. Currently, energy storage auxiliary frequency regulation mainly uses lithium batteries, but flywheel energy storage has the advantages of high-rate charging, no loss in circulation, and high safety, making it possible for it to participate in the thermal energy storage frequency regulation system.

[0003] Chinese patent publication number CN113922391A discloses a control method for primary frequency regulation of a thermal power unit assisted by flywheel energy storage. The method utilizes the load characteristics of flywheel energy storage. When the grid frequency regulation requires frequency regulation and load reduction, the flywheel energy storage's fast charging function is utilized to use the motor in the flywheel energy storage system as a motor to accelerate the flywheel, converting electrical energy into mechanical energy, thereby reducing the unit load. When the grid frequency regulation requires load increase, the flywheel energy storage's fast discharge function is utilized to use the motor in the flywheel energy storage system as a generator to convert the flywheel's mechanical energy into electrical energy, supplying power to the outside, thereby increasing the unit load. However, this flywheel energy storage assisted frequency regulation method only performs corresponding flywheel energy storage charge and discharge control when frequency regulation is required to reduce load and increase load, and can only be applied to instantaneous regulation. When the flywheel battery is fully charged or empty, the control method fails. Therefore, it is only applicable to primary frequency regulation. In the face of secondary frequency regulation with longer instruction time, larger instructions, and long-term one-way instructions, this solution cannot be fully applied.

[0004] In addition, due to the small capacity of the flywheel energy storage battery, the flywheel may not be able to fully respond to long-term one-way secondary frequency modulation instructions, resulting in frequency modulation failure or even reverse frequency modulation. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the capacity of the flywheel energy storage battery in the prior art is relatively small, and the flywheel may not fully respond to a long-term unidirectional secondary frequency modulation instruction, resulting in frequency modulation failure or even reverse frequency modulation.

[0006] The present invention solves the above technical problems through the following technical means: a flywheel energy storage control method for auxiliary frequency modulation, comprising:

[0007] Step 1: Obtain the historical data of secondary frequency regulation instructions and actual output data of the thermal power plant;

[0008] Step 2: Obtain the target value of energy storage-assisted frequency regulation;

[0009] Step 3: Process the energy storage-assisted frequency regulation target values ​​for multiple days to obtain the energy storage-assisted frequency regulation target value for a typical day;

[0010] Step 4: Obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant;

[0011] Step 5: Taking the full charge time of the flywheel energy storage battery as an interval, the typical daily energy storage auxiliary frequency regulation target value within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value;

[0012] Step 6: When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant, and the long-term frequency regulation capacity value is screened and marked. It is pre-determined at what time the battery needs to continuously release electricity exceeding the first capacity, and the time for the flywheel energy storage battery to be fully charged is pushed forward at this time point to start charging, and at the same time, the corresponding load instruction is added to the unit;

[0013] Step 7: When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, it is necessary to charge the flywheel energy storage battery to reduce the actual output of the thermal power plant, select and mark the long-term frequency regulation capacity value, and pre-judge the time point at which the battery needs to continuously absorb electricity exceeding the second capacity. At this time point, push forward the full charge time of the flywheel energy storage battery to start discharging, and at the same time reduce the corresponding load instruction to the unit.

[0014] Beneficial effect: When facing a long-term unidirectional secondary frequency modulation instruction, the present invention pre-judges that the instruction will exceed the available capacity of the flywheel battery, and then charges or discharges the flywheel battery in advance, and applies a corresponding load instruction to the thermal power unit. Through this method, at the cost of increasing the number of charge and discharge times of the flywheel battery, the defect of insufficient capacity of the flywheel battery in the prior art is compensated, so that the system can meet the requirements of the secondary frequency modulation instruction of long-term unidirectional regulation, avoiding the situation of frequency modulation failure or reverse regulation.

[0015] Furthermore, the step 1 comprises:

[0016] Obtain the historical data A(i, j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i, j) of the actual output of the thermal power plant recorded in seconds on D days with similar characteristics to the thermal power plant, where i is the i-th day and j is the j-th second.

[0017] Furthermore, the step 2 includes:

[0018] The energy storage-assisted frequency regulation target value K(i,j) is obtained by subtracting the actual output historical data P(i,j) of the thermal power plant at the same moment from the secondary frequency regulation instruction historical data A(i,j), that is, K(i,j)=A(i,j)-P(i,j).

[0019] Furthermore, the step three includes:

[0020] The energy storage-assisted frequency regulation target values ​​for multiple days are processed to obtain the typical day energy storage-assisted frequency regulation target value Kd(j), which is calculated as follows:

[0021] Furthermore, the step 4 includes:

[0022] Get the power and capacity of the flywheel energy storage battery configured in the thermal power plant, where the battery power is Pc and the battery capacity is Cc. The time it takes to fully charge the flywheel energy storage battery is

[0023] Furthermore, the step five includes:

[0024] Taking the full charge time of the flywheel energy storage battery as the interval, the typical daily energy storage auxiliary frequency regulation target value Kd(j) within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value K dT (j), that is

[0025] Furthermore, the step six includes:

[0026] When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to discharge to make up for the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K is calculated. dT (j) is a positive value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) is greater than or equal to the first capacity, and K dT (j-1) is less than the first capacity, indicating that within T time after the jth second, the flywheel battery needs to continuously release electric energy exceeding the first capacity, and the first capacity is a positive value. To ensure that the flywheel battery has more than the first capacity at the jth second, a full charge instruction is given to the flywheel energy storage battery at the (jT)th second to achieve pre-charging, and the AGC instruction issued by the unit DCS from the (jT)th second to the (j-1)th second and at all time points when the long-term frequency modulation capacity value is greater than the first capacity increases the battery power Pc, thereby increasing the actual output of the thermal power plant and making up for the problem of insufficient overall output of the thermal storage system.

[0027] Furthermore, the step seven includes:

[0028] When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K dT (j) is a negative value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) is less than or equal to the second capacity, and K dT(j-1) is greater than the second capacity, and the second capacity is a negative value, indicating that within the T time after the jth second, the flywheel battery needs to continuously absorb electrical energy exceeding the absolute value of the second capacity. To ensure that the flywheel battery has the minimum power at the jth second, the minimum power is the full power minus the absolute value of the second capacity. At (jT) seconds, the flywheel energy storage battery is discharged to the minimum power instruction, and at (jT) seconds to (j-1) seconds and at all time points when the long-term frequency regulation capacity value is less than the second capacity, the AGC instruction issued to the unit DCS reduces the battery power Pc, reduces the actual output of the thermal power plant, and solves the problem that the overall output of the thermal storage system exceeds the secondary frequency regulation instruction.

[0029] The present invention also provides a flywheel energy storage control device for auxiliary frequency modulation, comprising:

[0030] The historical data acquisition module is used to obtain the historical data of the secondary frequency regulation instructions of the power grid dispatching and the historical data of the actual output of the thermal power plant;

[0031] A target value acquisition module is used to obtain the target value of energy storage auxiliary frequency regulation;

[0032] A daily target value acquisition module is used to process the energy storage-assisted frequency regulation target values ​​for multiple days to obtain a typical daily energy storage-assisted frequency regulation target value;

[0033] The charging time acquisition module is used to obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant;

[0034] The frequency regulation capacity acquisition module is used to accumulate and count the typical daily energy storage auxiliary frequency regulation target values ​​within the interval using the full charge time of the flywheel energy storage battery as an interval to obtain the long-term frequency regulation capacity value;

[0035] The pre-charging module is used when the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, and the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked, and the battery needs to be pre-determined at what time point it needs to continuously release electricity exceeding the first capacity. At this time point, the flywheel energy storage battery is pushed forward for a full charge time, and charging is started, and the corresponding load instruction is added to the unit at the same time;

[0036] The pre-discharge module is used when the secondary frequency regulation instruction is less than the actual output data of the thermal power plant. The flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked. It is pre-determined at what time the battery needs to continuously absorb electricity exceeding the second capacity. At this time point, the flywheel energy storage battery is fully charged for a period of time, and the discharge begins. At the same time, the corresponding load instruction is reduced for the unit.

[0037] Furthermore, the historical data acquisition module is also used for:

[0038] Obtain the historical data A(i, j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i, j) of the actual output of the thermal power plant recorded in seconds on D days with similar characteristics to the thermal power plant, where i is the i-th day and j is the j-th second.

[0039] Furthermore, the target value acquisition module is also used for:

[0040] The energy storage-assisted frequency regulation target value K(i,j) is obtained by subtracting the actual output historical data P(i,j) of the thermal power plant at the same moment from the secondary frequency regulation instruction historical data A(i,j), that is, K(i,j)=A(i,j)-P(i,j).

[0041] Furthermore, the daily target value acquisition module is also used for:

[0042] The energy storage-assisted frequency regulation target values ​​for multiple days are processed to obtain the typical day energy storage-assisted frequency regulation target value Kd(j), which is calculated as follows:

[0043] Furthermore, the charging duration acquisition module is also used for:

[0044] Get the power and capacity of the flywheel energy storage battery configured in the thermal power plant, where the battery power is Pc and the battery capacity is Cc. The time it takes to fully charge the flywheel energy storage battery is

[0045] Furthermore, the frequency modulation capacity acquisition module is also used for:

[0046] Taking the full charge time of the flywheel energy storage battery as the interval, the typical daily energy storage auxiliary frequency regulation target value Kd(j) within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value K dT (j), that is

[0047] Furthermore, the pre-charging module is also used for:

[0048] When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to discharge to make up for the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K is calculated. dT (j) is a positive value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) is greater than or equal to the first capacity, and K dT(j-1) is less than the first capacity, indicating that within T time after the jth second, the flywheel battery needs to continuously release electric energy exceeding the first capacity, and the first capacity is a positive value. To ensure that the flywheel battery has more than the first capacity at the jth second, a full charge instruction is given to the flywheel energy storage battery at the (jT)th second to achieve pre-charging, and the AGC instruction issued by the unit DCS from the (jT)th second to the (j-1)th second and at all time points when the long-term frequency modulation capacity value is greater than the first capacity increases the battery power Pc, thereby increasing the actual output of the thermal power plant and making up for the problem of insufficient overall output of the thermal storage system.

[0049] Furthermore, the pre-discharge module is also used for:

[0050] When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K dT (j) is a negative value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) is less than or equal to the second capacity, and K dT (j-1) is greater than the second capacity, and the second capacity is a negative value, indicating that within the T time after the jth second, the flywheel battery needs to continuously absorb electrical energy exceeding the absolute value of the second capacity. To ensure that the flywheel battery has the minimum power at the jth second, the minimum power is the full power minus the absolute value of the second capacity. At (jT) seconds, the flywheel energy storage battery is discharged to the minimum power instruction, and at (jT) seconds to (j-1) seconds and at all time points when the long-term frequency regulation capacity value is less than the second capacity, the AGC instruction issued to the unit DCS reduces the battery power Pc, reduces the actual output of the thermal power plant, and solves the problem that the overall output of the thermal storage system exceeds the secondary frequency regulation instruction.

[0051] The advantages of the present invention are:

[0052] (1) When facing a long-term unidirectional secondary frequency modulation instruction, the present invention pre-judges that the instruction will exceed the available capacity of the flywheel battery, and then charges or discharges the flywheel battery in advance, and applies a corresponding load instruction to the thermal power unit. Through this method, at the cost of increasing the number of charge and discharge times of the flywheel battery, the defect of insufficient capacity of the flywheel battery in the prior art is compensated, so that the system can meet the requirements of the secondary frequency modulation instruction of long-term unidirectional regulation, and avoid the situation of frequency modulation failure or reverse regulation.

[0053] (2) The present invention makes full use of the non-attenuation characteristic of the flywheel energy storage battery, and through the analysis of the frequency modulation curve data of a typical day, frequently charges and discharges in the form of pre-charging and pre-discharging to compensate for the small flywheel energy storage capacity and improve the overall frequency modulation level. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1This is a flow chart of a flywheel energy storage control method for auxiliary frequency modulation disclosed in Example 1 of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Example 1

[0057] like Figure 1 As shown, a flywheel energy storage control method for auxiliary frequency regulation includes:

[0058] S1: Obtain the historical data of the secondary frequency regulation instructions of the power grid dispatching and the historical data of the actual output of the thermal power plant; the specific process is:

[0059] Obtain the historical data A(i,j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i,j) of the actual output of the thermal power plant recorded in seconds on the D days with similar characteristics of the thermal power plant, in kW. Among them, i is the i-th day and j is the j-th second. The data of the days taken must have similar characteristics. If there are large differences in load characteristics, they cannot be selected. For example, data of the same working day or the same holiday or rest day can be selected.

[0060] S2: Obtain the target value of energy storage-assisted frequency regulation; the specific process is as follows:

[0061] The energy storage-assisted frequency regulation target value K(i,j) is obtained by subtracting the actual output historical data P(i,j) of the thermal power plant at the same moment from the secondary frequency regulation instruction historical data A(i,j), that is, K(i,j)=A(i,j)-P(i,j).

[0062] S3: Process the energy storage-assisted frequency regulation target values ​​for multiple days to obtain the energy storage-assisted frequency regulation target value for a typical day; the specific process is as follows:

[0063] The energy storage-assisted frequency regulation target values ​​for multiple days are processed to obtain the typical day energy storage-assisted frequency regulation target value Kd(j), which is calculated as follows:

[0064] S4: Obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant; the specific process is:

[0065] Get the power and capacity of the flywheel energy storage battery configured in the thermal power plant, where the battery power is Pc, in kW, and the battery capacity is Cc, in kWh. Then the flywheel energy storage battery is fully charged for

[0066] S5: Taking the full charge time of the flywheel energy storage battery as an interval, the typical daily energy storage auxiliary frequency regulation target value within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value; the specific process is:

[0067] Taking the full charge time of the flywheel energy storage battery as the interval, the typical daily energy storage auxiliary frequency regulation target value Kd(j) within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value K dT (j), that is

[0068] S6: When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant, the long-term frequency regulation capacity value is screened and marked, and the time point at which the battery needs to continuously release the power exceeding the first capacity is pre-determined. At this time point, the flywheel energy storage battery is fully charged for a period of time, and charging begins. At the same time, the corresponding load instruction is added to the unit. The specific process is as follows:

[0069] When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to discharge to make up for the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K is calculated. dT (j) is a positive value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) greater than or equal to 80% Cc, and K dT (j-1) is less than 80% Cc, indicating that the flywheel battery needs to continuously release more than 80% Cc of electrical energy within T time after the jth second. To ensure that the flywheel battery has more than 80% Cc of electricity at the jth second, a full charge instruction is given to the flywheel energy storage battery at the (jT)th second to achieve pre-charging, and the AGC instruction issued by the unit DCS from the (jT)th second to the (j-1)th second and at all time points when the long-term frequency modulation capacity value is greater than 80% Cc increases the battery power Pc, thereby increasing the actual output of the thermal power plant and compensating for the problem of insufficient overall output of the thermal storage system. It should be noted that the above 80% Cc is only a specific implementation method, and other values ​​can be used in actual applications, such as 70% Cc to 90% Cc.

[0070] S7: When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant, the long-term frequency regulation capacity value is screened and marked, and the time point at which the battery needs to continuously absorb electricity exceeding the second capacity is pre-determined. At this time point, the flywheel energy storage battery is fully charged for a period of time, and discharge begins. At the same time, the corresponding load instruction is reduced for the unit. The specific process is as follows:

[0071] When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K dT (j) is a negative value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) Less than or equal to -80% Cc, and K dT (j-1) is greater than -80% Cc, indicating that the flywheel battery needs to continuously absorb more than 80% Cc of electrical energy within T time after the jth second. To ensure that the flywheel battery has a power level below 20% Cc at the jth second, the flywheel energy storage battery is discharged to the minimum power command at the (jT)th second, and the AGC command issued to the unit DCS from the (jT)th second to the (j-1)th second and at all time points where the long-term frequency modulation capacity value is less than -80% Cc reduces the battery power Pc, reduces the actual output of the thermal power plant, and solves the problem that the overall output of the thermal storage system exceeds the secondary frequency modulation command. It should be noted that the above -80% Cc is only a specific implementation method, and other values ​​can be used in actual applications, such as -70% Cc to -90% Cc.

[0072] Through the above technical scheme, when the present invention faces a long-term unidirectional secondary frequency modulation instruction, it is pre-judged that the instruction will exceed the available capacity of the flywheel battery, and the flywheel battery is charged or discharged in advance, and the corresponding load instruction is applied to the thermal power unit. Through this method, at the cost of increasing the number of charge and discharge times of the flywheel battery, the defect of insufficient capacity of the flywheel battery in the prior art is compensated, so that the system can meet the requirements of the secondary frequency modulation instruction of long-term unidirectional regulation, and avoid the situation of frequency modulation failure or reverse regulation.

[0073] Example 2

[0074] Based on Example 1, Example 2 of the present invention further provides a flywheel energy storage control device for auxiliary frequency modulation, including:

[0075] The historical data acquisition module is used to obtain the historical data of the secondary frequency regulation instructions of the power grid dispatching and the historical data of the actual output of the thermal power plant;

[0076] A target value acquisition module is used to obtain the target value of energy storage auxiliary frequency regulation;

[0077] A daily target value acquisition module is used to process the energy storage-assisted frequency regulation target values ​​for multiple days to obtain a typical daily energy storage-assisted frequency regulation target value;

[0078] The charging time acquisition module is used to obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant;

[0079] The frequency regulation capacity acquisition module is used to accumulate and count the typical daily energy storage auxiliary frequency regulation target values ​​within the interval using the full charge time of the flywheel energy storage battery as an interval to obtain the long-term frequency regulation capacity value;

[0080] The pre-charging module is used when the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, and the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked, and the battery needs to be pre-determined at what time point it needs to continuously release electricity exceeding the first capacity. At this time point, the flywheel energy storage battery is pushed forward for a full charge time, and charging is started, and the corresponding load instruction is added to the unit at the same time;

[0081] The pre-discharge module is used when the secondary frequency regulation instruction is less than the actual output data of the thermal power plant. The flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked. It is pre-determined at what time the battery needs to continuously absorb electricity exceeding the second capacity. At this time point, the flywheel energy storage battery is fully charged for a period of time, and the discharge begins. At the same time, the corresponding load instruction is reduced for the unit.

[0082] Specifically, the historical data acquisition module is also used for:

[0083] Obtain the historical data A(i, j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i, j) of the actual output of the thermal power plant recorded in seconds on D days with similar characteristics to the thermal power plant, where i is the i-th day and j is the j-th second.

[0084] More specifically, the target value acquisition module is also used for:

[0085] The energy storage-assisted frequency regulation target value K(i,j) is obtained by subtracting the actual output historical data P(i,j) of the thermal power plant at the same moment from the secondary frequency regulation instruction historical data A(i,j), that is, K(i,j)=A(i,j)-P(i,j).

[0086] More specifically, the daily target value acquisition module is also used for:

[0087] The energy storage-assisted frequency regulation target values ​​for multiple days are processed to obtain the typical day energy storage-assisted frequency regulation target value Kd(j), which is calculated as follows:

[0088] More specifically, the charging time acquisition module is also used for:

[0089] Get the power and capacity of the flywheel energy storage battery configured in the thermal power plant, where the battery power is Pc and the battery capacity is Cc. The time it takes to fully charge the flywheel energy storage battery is

[0090] More specifically, the frequency modulation capacity acquisition module is further used for:

[0091] Taking the full charge time of the flywheel energy storage battery as the interval, the typical daily energy storage auxiliary frequency regulation target value Kd(j) within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value K dT (j), that is

[0092] More specifically, the pre-charging module is also used for:

[0093] When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to discharge to make up for the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K is calculated. dT (j) is a positive value, filter and mark the long-term frequency modulation capacity value K dT (j) If K dT (j) is greater than or equal to the first capacity, and K dT (j-1) is less than the first capacity, indicating that within T time after the jth second, the flywheel battery needs to continuously release electric energy exceeding the first capacity, and the first capacity is a positive value. To ensure that the flywheel battery has more than the first capacity at the jth second, a full charge instruction is given to the flywheel energy storage battery at the (jT)th second to achieve pre-charging, and the AGC instruction issued by the unit DCS from the (jT)th second to the (j-1)th second and at all time points when the long-term frequency modulation capacity value is greater than the first capacity increases the battery power Pc, thereby increasing the actual output of the thermal power plant and making up for the problem of insufficient overall output of the thermal storage system.

[0094] More specifically, the pre-discharge module is also used for:

[0095] When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. At this time, the long-term frequency regulation capacity value K dT (j) is a negative value, filter and mark the long-term frequency modulation capacity value K dT (j), if K dT (j) is less than or equal to the second capacity, and K dT (j-1) is greater than the second capacity, and the second capacity is a negative value, indicating that within the T time after the jth second, the flywheel battery needs to continuously absorb electrical energy exceeding the absolute value of the second capacity. To ensure that the flywheel battery has the minimum power at the jth second, the minimum power is the full power minus the absolute value of the second capacity. At (jT) seconds, the flywheel energy storage battery is discharged to the minimum power instruction, and at (jT) seconds to (j-1) seconds and at all time points when the long-term frequency regulation capacity value is less than the second capacity, the AGC instruction issued to the unit DCS reduces the battery power Pc, reduces the actual output of the thermal power plant, and solves the problem that the overall output of the thermal storage system exceeds the secondary frequency regulation instruction.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flywheel energy storage control method for auxiliary frequency modulation, characterized in that: include: Step 1: Obtain the historical data of secondary frequency regulation instructions and actual output data of the thermal power plant; Step 2: Subtract the actual output historical data from the secondary frequency regulation instruction historical data to obtain the energy storage auxiliary frequency regulation target value; Step 3: Calculate the average value of the energy storage-assisted frequency regulation target value for multiple days to obtain the energy storage-assisted frequency regulation target value for a typical day; Step 4: Obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant; Step 5: Taking the full charge time of the flywheel energy storage battery as an interval, the typical daily energy storage auxiliary frequency regulation target value within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value; Step 6: When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked, and the time point at which the battery needs to continuously release the power exceeding the first capacity is pre-determined. At this time point, the flywheel energy storage battery is fully charged for a period of time, and charging begins. At the same time, an AGC instruction is issued to the unit to increase the battery power. Step 7: When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, it is necessary to charge the flywheel energy storage battery to reduce the actual output of the thermal power plant, select and mark the long-term frequency regulation capacity value, and pre-judge the time point at which the battery needs to continuously absorb electricity exceeding the second capacity. At this time point, push forward the full charge time of the flywheel energy storage battery and start discharging. At the same time, issue an AGC instruction to the unit to reduce the battery power.

2. A flywheel energy storage control method for auxiliary frequency modulation according to claim 1, characterized in that: The step one comprises: Obtain the historical data A(i, j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i, j) of the actual output of the thermal power plant recorded in seconds on D days with similar characteristics to the thermal power plant, where i is the i-th day and j is the j-th second.

3. A flywheel energy storage control method for auxiliary frequency modulation according to claim 2, characterized in that: The second step comprises: The energy storage-assisted frequency regulation target value K(i,j) is obtained by subtracting the actual output historical data P(i,j) of the thermal power plant at the same moment from the secondary frequency regulation instruction historical data A(i,j), that is, K(i,j)=A(i,j)-P(i,j).

4. A flywheel energy storage control method for auxiliary frequency modulation according to claim 3, characterized in that: The step three comprises: The energy storage-assisted frequency regulation target values ​​for multiple days are processed to obtain the typical day energy storage-assisted frequency regulation target value Kd(j), which is calculated as follows:

5. A flywheel energy storage control method for auxiliary frequency modulation according to claim 4, characterized in that: The fourth step comprises: Get the power and capacity of the flywheel energy storage battery configured in the thermal power plant, where the battery power is Pc and the battery capacity is Cc. The time it takes to fully charge the flywheel energy storage battery is 6. A flywheel energy storage control method for auxiliary frequency modulation according to claim 5, characterized in that: The step five comprises: Taking the full charge time of the flywheel energy storage battery as the interval, the typical daily energy storage auxiliary frequency regulation target value Kd(j) within the interval is accumulated and counted to obtain the long-term frequency regulation capacity value K dT (j), that is 7. A flywheel energy storage control method for auxiliary frequency modulation according to claim 6, characterized in that: The step six comprises: When the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be discharged. At this time, the long-term frequency regulation capacity value K is calculated. dT (j) is a positive value, filter and mark the long-term frequency modulation capacity value K dT (j), if K dT (j) is greater than or equal to the first capacity, and K dT (j-1) is less than the first capacity, indicating that within the T time after the jth second, the flywheel battery needs to continuously release electrical energy exceeding the first capacity, and the first capacity is a positive value. To ensure that the flywheel battery has a power capacity greater than the first capacity at the jth second, a full charge instruction is given to the flywheel energy storage battery at the (jT)th second to achieve pre-charging, and the battery power Pc is increased for the AGC instruction issued by the unit DCS at the time points from the (jT)th second to the (j-1)th second and at all long-term frequency modulation capacity values ​​less than the first capacity.

8. A flywheel energy storage control method for auxiliary frequency modulation according to claim 7, characterized in that: The step seven comprises: When the secondary frequency regulation instruction is less than the actual output data of the thermal power plant, the flywheel energy storage battery needs to be charged. At this time, the long-term frequency regulation capacity value K dT (j) is a negative value, filter and mark the long-term frequency modulation capacity value K dT (j), if K dT (j) is less than or equal to the second capacity, and K dT (j-1) is greater than the second capacity, and the second capacity is a negative value, indicating that within the T time after the jth second, the flywheel battery needs to continuously absorb electrical energy exceeding the absolute value of the second capacity. To ensure that the flywheel battery has the minimum power at the jth second, the minimum power is the full power minus the absolute value of the second capacity. At (jT) seconds, the flywheel energy storage battery is discharged to the minimum power instruction, and the AGC instruction issued to the unit DCS from (jT) seconds to (j-1) seconds and at all time points when the long-term frequency modulation capacity value is greater than the second capacity reduces the battery power Pc.

9. A flywheel energy storage control device for auxiliary frequency modulation, characterized in that: include: The historical data acquisition module is used to obtain the historical data of the secondary frequency regulation instructions of the power grid dispatching and the historical data of the actual output of the thermal power plant; A target value acquisition module, used to subtract the actual output historical data from the secondary frequency regulation instruction historical data to obtain the energy storage auxiliary frequency regulation target value; A daily target value acquisition module is used to average the energy storage-assisted frequency regulation target values ​​over multiple days to obtain a typical daily energy storage-assisted frequency regulation target value; The charging time acquisition module is used to obtain the full charging time of the flywheel energy storage battery configured in the thermal power plant; The frequency regulation capacity acquisition module is used to accumulate and count the typical daily energy storage auxiliary frequency regulation target values ​​within the interval based on the time it takes for the flywheel energy storage battery to be fully charged, so as to obtain the long-term frequency regulation capacity value; The pre-charging module is used when the secondary frequency regulation instruction is greater than the actual output data of the thermal power plant, and the flywheel energy storage battery needs to be discharged to supplement the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked, and the battery needs to be discharged continuously to exceed the first capacity. At this time point, the flywheel energy storage battery is pushed forward to fully charge the time, and charging is started. At the same time, the AGC instruction is issued to the unit to increase the battery power; The pre-discharge module is used when the secondary frequency regulation instruction is less than the actual output data of the thermal power plant. The flywheel energy storage battery needs to be charged to reduce the actual output of the thermal power plant. The long-term frequency regulation capacity value is screened and marked. It is pre-determined at what time the battery needs to continuously absorb electricity exceeding the second capacity. At this time point, the flywheel energy storage battery is fully charged for a period of time, and the discharge begins. At the same time, the AGC instruction is issued to the unit to reduce the battery power.

10. A flywheel energy storage control device for auxiliary frequency modulation according to claim 9, characterized in that: The historical data acquisition module is also used for: Obtain the historical data A(i, j) of the secondary frequency regulation command of the power grid dispatching and the historical data P(i, j) of the actual output of the thermal power plant recorded in seconds on D days with similar characteristics to the thermal power plant, where i is the i-th day and j is the j-th second.

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