A method and device for combined frequency modulation of a thermal power unit and a thermal storage unit considering response characteristics of the thermal power unit

Abstract

The application discloses a kind of fire storage combined frequency modulation method and device considering the response characteristics of thermal power generating unit, first, according to the rated power of thermal power generating unit, reheater time constant, the proportion of power generated by high-pressure turbine and the adjustment coefficient of thermal power generating unit, the dynamic response characteristics of thermal power generating unit in the process of participating in primary frequency modulation are obtained;Then, according to the dynamic response characteristics, the condition that the maximum frequency deviation after load disturbance is equal to the steady-state frequency deviation is derived;Through energy storage system compensation, the thermal storage combined system shows equivalent to meet the frequency modulation characteristics that the maximum frequency deviation is equal to the steady-state frequency deviation, and the power of energy storage system that should be compensated when thermal power generating unit participates in primary frequency modulation is calculated.The above-mentioned method and device solve the problem of deterioration of primary frequency modulation capability of thermal power generating unit and unclear frequency control target, and effectively improve the primary frequency modulation capability of thermal storage combined system.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method and apparatus for combined thermal power and energy storage frequency regulation that takes into account the response characteristics of thermal power units. Background Technology

[0002] With the increasing penetration rate of new energy sources such as wind and solar power, the rotational inertia and primary frequency regulation capability of the power system are showing a continuous downward trend. Thermal power, with its stable primary energy source and mature technology system, remains the main resource for frequency regulation. However, against the backdrop of increasing new energy penetration, in order to provide absorption space for new energy sources whose power output varies over time, thermal power units need to undergo deep peak shaving. However, deep peak shaving retrofits reduce the primary frequency regulation capability of thermal power units. Frequent system frequency exceedances force the governors of thermal power units to repeatedly operate, resulting in insufficient time for the thermal energy storage of the units to recover, further reducing the primary frequency regulation capability. Given the declining frequency regulation capability of thermal power units and their inability to meet the requirements for system frequency stability, configuring a certain amount of energy storage can improve the problem of insufficient frequency regulation capability of thermal power units.

[0003] The frequency dynamics indicators of a power system include three aspects: the rate of change of frequency (ROCOF), the maximum frequency deviation, and the steady-state frequency deviation. The steady-state frequency deviation is related to the system's frequency regulation reserve capacity and the primary frequency regulation coefficient. ROCOF and the maximum frequency deviation are closely related to frequency regulation dynamic performance. The maximum frequency deviation is often used as the trigger signal for low-frequency and high-frequency protection and receives more attention. Assuming sufficient system reserve capacity, if the maximum frequency deviation during the frequency dynamic process can be made equal to the steady-state frequency deviation, then the maximum frequency deviation after disturbances can be kept at a low level, which is of great significance for maintaining system frequency stability.

[0004] When existing grid-connected power sources such as energy storage and wind / solar inverters participate in frequency regulation, they mainly refer to the frequency regulation methods of thermal power units. Their control parameter settings also reference the regulation range of thermal power units, resulting in unclear frequency control objectives and limiting their high flexibility to some extent. Therefore, fully leveraging the stable and reliable frequency regulation capabilities of thermal power and the flexible control strategies of energy storage, and developing more flexible frequency control strategies to meet the frequency regulation needs of high-voltage and high-efficiency power systems, is crucial to ensuring the safe and stable frequency of the power system. Summary of the Invention

[0005] The purpose of this invention is to provide a thermal power unit combined frequency regulation method and apparatus that takes into account the response characteristics of thermal power units, which solves the problems of deterioration of primary frequency regulation capability of thermal power units and unclear frequency control target, and effectively improves the primary frequency regulation capability of thermal power unit combined system.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A combined thermal power and energy storage frequency regulation method considering the response characteristics of thermal power units, the method comprising:

[0008] Step 1: Obtain the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit.

[0009] Step 2: Based on the dynamic response characteristics, derive the condition that the maximum frequency deviation after a load disturbance is equal to the steady-state frequency deviation;

[0010] Step 3: By compensating through the energy storage system, the combined thermal power and energy storage system exhibits the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation, and the power that the energy storage system should compensate for when the thermal power unit participates in primary frequency regulation is calculated.

[0011] A combined thermal power and energy storage frequency regulation device that takes into account the response characteristics of thermal power units, the device comprising:

[0012] The dynamic response characteristics acquisition module is used to acquire the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit.

[0013] The condition acquisition module is used to deduce the condition that the maximum frequency deviation after a load disturbance equals the steady-state frequency deviation based on the dynamic response characteristics.

[0014] The compensation power acquisition module is used to compensate the combined thermal power and energy storage system to make it exhibit the equivalent frequency regulation characteristics that satisfy the maximum frequency deviation equal to the steady-state frequency deviation, and to calculate the power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation.

[0015] As can be seen from the technical solutions provided by the present invention, the above-mentioned methods and devices solve the problems of deterioration of primary frequency regulation capability of thermal power units and unclear frequency control targets. By utilizing the known parameters of thermal power units and through the close cooperation between the energy storage system and the primary frequency regulation response characteristics of thermal power units, the primary frequency regulation capability of the thermal power-storage combined system is effectively improved, thereby improving the system frequency response, reducing the difficulty of frequency control and the risk of low-frequency load shedding. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of a combined thermal power and energy storage frequency regulation method that takes into account the response characteristics of thermal power units, provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the device described in an embodiment of the present invention;

[0019] Figure 3 The frequency curves for the two modes of frequency regulation with and without energy storage are shown in the examples of this invention.

[0020] Figure 4 This is a diagram showing the total frequency regulation power in two modes: with and without energy storage participating in frequency regulation, as illustrated in the examples of this invention.

[0021] Figure 5 This is a frequency regulation power curve of the energy storage system exemplified in this invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments, and do not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0023] like Figure 1 The diagram shown is a schematic flowchart of a combined thermal power and energy storage frequency regulation method considering the response characteristics of thermal power units, provided by an embodiment of the present invention. The method includes:

[0024] Step 1: Obtain the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit.

[0025] In this step, the acquired dynamic response characteristics are expressed as follows:

[0026] (1);

[0027] (2);

[0028] In the formula, s The Laplace operator is used to transform differential equations in the time domain t into algebraic equations in the complex frequency domain s via the Laplace transform; Δ P ( s ) represents the primary frequency regulation power of the thermal power unit in the s-domain; Δ f ( s () represents the frequency deviation of the s-domain system bounded by the dead zone; This refers to the droop coefficient of thermal power units;F HP The percentage of power generated by the high-pressure turbine; T RH This is the time constant of the reheater in a thermal power unit. P N Rated power of thermal power unit; f For grid connection frequency, f N Nominal frequency; f dead This is the dead zone frequency for primary frequency modulation control.

[0029] Step 2: Based on the dynamic response characteristics, derive the condition that the maximum frequency deviation after a load disturbance is equal to the steady-state frequency deviation;

[0030] In this step, when the system experiences an event of magnitude Δ P L When the power is disturbed, the system frequency dynamic s-domain equation is expressed as:

[0031] (3);

[0032] in, H Let be the inertia constant of the thermal power unit; D This represents the damping coefficient of the thermal power unit. K Let be the primary frequency regulation coefficient of the thermal power unit. Simplifying equation (3), we get:

[0033] (4);

[0034] (5);

[0035] (6);

[0036] Where, Δ f ( s () represents the frequency deviation of the s-domain system bounded by the dead zone. and These are the system's natural frequency and damping ratio, respectively; according to damping ratio Performing an inverse Laplace transform on equation (4), when When, the corresponding frequency analytical expression of the system in the time domain t Represented as:

[0037] (7);

[0038] (8);

[0039] (9);

[0040] (10);

[0041] Where t is time, Δ f ( t () represents the system frequency deviation in the time domain t, bounded by the dead zone. A proportionality coefficient is introduced to simplify the formula expression. ω r The oscillation frequency is... This is the initial phase. 、 The maximum frequency deviation of the system over the dead zone is an intermediate variable used to calculate the initial phase. Δf nadir and the time to reach the maximum frequency deviation t nadir for:

[0042] (11);

[0043] (12);

[0044] The magnitude of the power disturbance occurring in the system;

[0045] Assuming the system approaches steady state at its lowest frequency, meaning the maximum frequency deviation equals the steady-state frequency deviation, then:

[0046] (13);

[0047] Assuming a maximum frequency deviation exists, since both the constant and exponential terms are non-negative, the value of the sine function at the point of maximum frequency deviation must be non-zero. Substituting formula 8 into equation (13), we get:

[0048] (14);

[0049] Will and Substituting into formula 14 and simplifying, we get:

[0050] (15);

[0051] Solution T RH =0 or D=K=0 or F HP =1, the system damping is not under human control, and setting the primary frequency regulation coefficient to 0 will increase the steady-state frequency deviation. Therefore, the condition D=K=0 cannot meet the frequency regulation requirements.

[0052] When T RH =0 or F HPWhen the damping ratio is 1, the damping ratio of the system is infinite or greater than or equal to 1, which does not meet the prerequisite of an underdamped system. Therefore, the underdamped system cannot achieve the expected frequency modulation effect.

[0053] when When, the corresponding frequency analytical expression of the system in the time domain t for:

[0054] (16);

[0055] If the maximum frequency deviation of the system after load disturbance is equal to the steady-state frequency deviation, that is, the frequency continues to decrease, then Δf'(t)≤0. Therefore, differentiating equation (16), we have:

[0056] (17);

[0057] Let equation (17) be less than or equal to zero, then we get:

[0058] (18);

[0059] Because of T RH For positive finite values, in If we want equation (18) to be always equal to 0, then it must satisfy the following condition: ;

[0060] Will Substituting into equation (18), we get:

[0061] (19);

[0062] And because

[0063] ;

[0064] Solving

[0065] (20);

[0066] If and only if (D+K)T RH When =2H, the equality of formula (20) holds.

[0067] when When, the corresponding frequency analytical expression of the system in the time domain t for:

[0068] (twenty one);

[0069] If the maximum frequency deviation of the system after load disturbance is equal to the steady-state frequency deviation, i.e., the frequency continues to decrease, then Δf'(t) ≤ 0, and Δf'(t) is... Taking the derivative of equation (21), we have:

[0070] (twenty two);

[0071] Solving

[0072] (twenty three);

[0073] (twenty four);

[0074] (25);

[0075] for and In this case, since the hyperbolic tangent function is monotonically increasing on (0,+∞) and tends towards 1, the following condition must be satisfied:

[0076] (26);

[0077] At this point:

[0078] ;

[0079] or

[0080] ;

[0081] for In the following cases:

[0082] .

[0083] The following is about , and These three scenarios will be discussed:

[0084] 1) and Substitute the expressions into In the case of this, we have:

[0085] (27);

[0086] (28);

[0087] Differentiating the left side of equation (28), we have:

[0088] (29);

[0089] When F HP As F increases, equation (29) monotonically increases, therefore the left half of equation (28) is determined to be in F.HP Monotonically increasing on (1,+∞); when F HP When F = 1, equation (28) holds, therefore F HP ≥1 is Solution for the following situation;

[0090] 2) and Substitute the expressions into In the case of this, we have:

[0091] (30);

[0092] (31);

[0093] Differentiating the left side of equation (31), we have:

[0094] (32);

[0095] When F HP As F increases, equation (32) monotonically increases, therefore the left half of equation (31) is determined to be within F. HP Monotonically increasing on (1,+∞); when F HP When F = 1, equation (31) holds, therefore F HP ≥1 is Solution for the following situation;

[0096] 3) and Substitute the expressions into In the case of this, we have:

[0097] (33);

[0098] Substitute equation (33) back From the expression, we get:

[0099] (34);

[0100] Solving for F HP >1, only when T RH (D+KF HP ) = 2H and require Only when the expression (34) is satisfied; otherwise, it is not required. So in F HP When the value is 1, the system degenerates into a critically damped form, which also makes the system frequency satisfy the condition that the maximum frequency deviation is equal to the steady-state frequency deviation.

[0101] Therefore, the system frequency satisfies the condition that the maximum frequency deviation equals the steady-state frequency deviation as F HP ≥1.

[0102] Step 3: By compensating through the energy storage system, the combined thermal power and energy storage system exhibits the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation, and the power that the energy storage system should compensate for when the thermal power unit participates in primary frequency regulation is calculated.

[0103] In this step, the combined thermal power and energy storage system is compensated by the energy storage system to exhibit the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation. The formula for calculating the s-domain power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation is as follows:

[0104] (35);

[0105] In the formula Δ P st ( s ) represents the power that the energy storage system should compensate for in the s-domain; This refers to the droop coefficient of thermal power units; F HP The percentage of power generated by the high-pressure turbine; T RH This is the time constant of the reheater in a thermal power unit. P N The rated power of the thermal power unit; Δ f ( s ) represents the frequency deviation of the s-domain system bounded by the dead zone.

[0106] It is worth noting that the contents not described in detail in the embodiments of the present invention belong to the prior art known to those skilled in the art.

[0107] Based on the above method embodiments, this invention also provides a combined thermal power and energy storage frequency regulation device that takes into account the response characteristics of thermal power units, such as... Figure 2 The diagram shown is a structural schematic of the device according to an embodiment of the present invention. The device includes:

[0108] The dynamic response characteristics acquisition module is used to acquire the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit.

[0109] The condition acquisition module is used to deduce the condition that the maximum frequency deviation after a load disturbance equals the steady-state frequency deviation based on the dynamic response characteristics.

[0110] The compensation power acquisition module is used to compensate the combined thermal power and energy storage system to make it exhibit the equivalent frequency regulation characteristics that satisfy the maximum frequency deviation equal to the steady-state frequency deviation, and to calculate the power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation.

[0111] The specific implementation process of each module in the above device embodiment is described in the method embodiment.

[0112] This invention also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the method.

[0113] This invention also provides a computer storage medium storing a plurality of instructions adapted for loading and executing the method by a processor.

[0114] The method described in this invention is explained in detail below using simulation data of thermal power units, energy storage systems, and loads. The overall process for calculating the required power output of the energy storage system using the rated power of the thermal power unit, the reheater time constant, the power output ratio of the high-pressure turbine, and the thermal power unit droop coefficient is as follows:

[0115] 1. The dynamic response characteristics of thermal power units participating in primary frequency regulation are obtained based on the rated power of thermal power units, reheater time constant, power generation ratio of high-pressure turbines, and thermal power unit droop coefficient.

[0116] 2. Based on the dynamic response characteristics, derive the condition that the maximum frequency deviation after a load disturbance equals the steady-state frequency deviation;

[0117] 3. By compensating through the energy storage system, the combined thermal power and energy storage system exhibits the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation. Calculate the power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation.

[0118] like Figure 3 The diagram shows the frequency curves under two modes of frequency regulation with and without energy storage, as illustrated in this invention. At 50 seconds, due to a sudden load increase of 10MW, the frequency at the grid connection point of the thermal power unit begins to drop. In the single thermal power unit frequency regulation mode, the lowest frequency point drops to 49.45Hz around 53.5 seconds, and finally the frequency slowly recovers to 49.72Hz. In the combined thermal and energy storage frequency regulation mode, the lowest frequency point drops to 49.72Hz at 52.1 seconds, and the frequency does not fluctuate significantly thereafter. It can be seen that the method proposed in this invention can effectively suppress frequency fluctuations after system disturbance, ensuring that the maximum frequency deviation of the system is no greater than the steady-state frequency deviation.

[0119] like Figure 4The diagram shows the total frequency regulation power in two modes: with and without energy storage, as illustrated in the examples of this invention. The black dashed line represents the power generated by a single thermal power unit during the first frequency regulation period, reaching a peak of 72.3MW at 55.8s, and then slowly decreasing to 70MW. The black solid line represents the power generated by the combined thermal and energy storage system during the first frequency regulation period; after the disturbance occurs, the total power rises rapidly, reaching 70MW at 53.5s, and then remains unchanged. Figure 4 It can be seen that the method proposed in this invention can quickly replenish the frequency regulation power that thermal power units fail to generate due to the hysteresis effect and improve the primary frequency regulation capability of the thermal power-storage combined system.

[0120] like Figure 5 The figure shows the frequency regulation power curve of the energy storage system in the example of this invention. The solid black line represents the power generated by the energy storage system when participating in frequency regulation. After the disturbance occurs, the power of the energy storage system rises rapidly; at 52s, the energy storage system reaches a peak power of 5.5MW, and then slowly decreases to 0. The frequency regulation power is all borne by the thermal power unit. Figure 5 It can be seen that by using the method proposed in this invention, the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the thermal power unit droop coefficient can be used to calculate the power output of the energy storage system and achieve the control objective that the maximum frequency deviation is equal to the steady-state frequency deviation.

[0121] In summary, the method and apparatus described in the embodiments of the present invention have the following advantages:

[0122] (1) Based on the problem that the frequency regulation of thermal power units has a hysteresis effect and the maximum frequency deviation after disturbance is often greater than the steady-state frequency deviation, this invention, combined with the obtained key parameters, derives the condition that the maximum frequency deviation after disturbance is equal to the steady-state frequency deviation, and designs a corresponding energy storage system control strategy, which achieves the effect that the maximum frequency deviation after disturbance is equal to the steady-state frequency deviation, and can effectively reduce the difficulty of frequency control and the risk of low-frequency load reduction.

[0123] (2) This invention fully considers the problems of unclear coordination principles and unclear frequency control objectives of existing grid-connected power sources such as energy storage and wind power photovoltaic inverters. The proposed control strategy takes maximizing the maximum frequency deviation as the control objective, and makes full use of the advantages of stable and reliable frequency regulation capability of thermal power and flexible control strategy of energy storage, providing a new idea for flexible frequency control of new power systems.

[0124] (3) The present invention takes into account the problem that the frequency regulation capability often decreases after the flexible modification of thermal power units. The proposed thermal power and storage combined frequency regulation control strategy can improve the overall frequency regulation capability of the system, while reducing the reciprocating action of the speed governor and the heat storage consumption of the boiler during the primary frequency regulation of the thermal power unit, and enhancing the continuous primary frequency regulation capability of the thermal power unit.

[0125] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims. The information disclosed in the background section is intended only to enhance the understanding of the overall background technology of the present invention and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art.

Claims

1. A combined thermal power and energy storage frequency regulation method considering the response characteristics of thermal power units, characterized in that, The method includes: Step 1: Obtain the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit. Step 2: Based on the dynamic response characteristics, derive the condition that the maximum frequency deviation after a load disturbance is equal to the steady-state frequency deviation; Step 3: By compensating through the energy storage system, the combined thermal power and energy storage system exhibits the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation, and the power that the energy storage system should compensate for when the thermal power unit participates in primary frequency regulation is calculated.

2. The thermal power unit-storage combined frequency regulation method considering the response characteristics of thermal power units according to claim 1, characterized in that, In step 1, the obtained dynamic response characteristics are expressed as follows: （1）； （2）； In the formula, s is the Laplace operator, used to transform differential equations in the time domain t into algebraic equations in the complex frequency domain s through the Laplace transform; Δ P ( s () represents the primary frequency regulation power of the thermal power unit in the s-domain; Δ f ( s () represents the frequency deviation of the s-domain system bounded by the dead zone; This refers to the droop coefficient of thermal power units; F HP The percentage of power generated by the high-pressure turbine; T RH This is the time constant of the reheater in a thermal power unit. P N Rated power of thermal power unit; f For grid connection frequency, f N Nominal frequency; f dead This is the dead zone frequency for primary frequency modulation control.

3. The combined thermal power and energy storage frequency regulation method considering the response characteristics of thermal power units according to claim 2, characterized in that, In step 2, when the system experiences an event of magnitude Δ P L When the power is disturbed, the system frequency dynamic s-domain equation is expressed as: （3）； in, H Let be the inertia constant of the thermal power unit; D This represents the damping coefficient of the thermal power unit. K Let be the primary frequency regulation coefficient of the thermal power unit. Simplifying equation (3), we get: （4）； （5）； （6）； Where, Δ f ( s () represents the frequency deviation of the s-domain system bounded by the dead zone. and These are the system's natural frequency and damping ratio, respectively; according to damping ratio Performing an inverse Laplace transform on equation (4), when When, the corresponding frequency analytical expression of the system in the time domain t Represented as: （7）； （8）； （9）； （10）； Where t is time, Δ f ( t () represents the system frequency deviation in the time domain t, bounded by the dead zone. A proportionality coefficient is introduced to simplify the formula expression. ω r The oscillation frequency is... This is the initial phase. 、 The maximum frequency deviation of the system over the dead zone is an intermediate variable used to calculate the initial phase. Δf nadir and the time to reach the maximum frequency deviation t nadir for: （11）； （12）； The magnitude of the power disturbance occurring in the system; Assuming the system approaches steady state at its lowest frequency, meaning the maximum frequency deviation equals the steady-state frequency deviation, then: （13）； Assuming a maximum frequency deviation exists, since both the constant and exponential terms are non-negative, the value of the sine function at the point of maximum frequency deviation must be non-zero. Substituting formula 8 into equation (13), we get: （14）； Will and Substituting into formula 14 and simplifying, we get: （15）； Solution T RH =0 or D=K=0 or F HP =1, the system damping is not under human control, and setting the primary frequency regulation coefficient to 0 will increase the steady-state frequency deviation. Therefore, the condition D=K=0 cannot meet the frequency regulation requirements. When T RH =0 or F HP When the damping ratio is 1, the damping ratio of the system is infinite or greater than or equal to 1, which does not meet the prerequisite of an underdamped system. Therefore, the underdamped system cannot achieve the expected frequency modulation effect.

4. The thermal power unit-storage combined frequency regulation method considering the response characteristics of thermal power units according to claim 3, characterized in that, when When, the corresponding frequency analytical expression of the system in the time domain t for: （16）； If the maximum frequency deviation of the system after load disturbance is equal to the steady-state frequency deviation, that is, the frequency continues to decrease, then Δf'(t)≤0. Therefore, differentiating equation (16), we have: （17）； Let equation (17) be less than or equal to zero, then we get: （18）； Because of T RH For positive finite values, in If we want equation (18) to be always equal to 0, then it must satisfy the following condition: ; Will Substituting into equation (18), we get: （19）； And because ； Solving （20）； If and only if (D+K)T RH When =2H, the equality of formula (20) holds.

5. The thermal power unit-storage combined frequency regulation method considering the response characteristics of thermal power units according to claim 4, characterized in that, when When, the corresponding frequency analytical expression of the system in the time domain t for: （21）； If the maximum frequency deviation of the system after load disturbance is equal to the steady-state frequency deviation, i.e., the frequency continues to decrease, then Δf'(t) ≤ 0, and Δf'(t) is... Taking the derivative of equation (21), we have: （22）； Solving （23）； （24）； （25）； for and In this case, since the hyperbolic tangent function is monotonically increasing on (0,+∞) and tends towards 1, the following condition must be satisfied: （26）； At this point: ； or ； for In the following cases: 。 6. The thermal power unit-storage combined frequency regulation method considering the response characteristics of thermal power units according to claim 5, characterized in that, against , and These three scenarios will be discussed: 1) and Substitute the expressions into In the case of this, we have: （27）； （28）； Differentiating the left side of equation (28), we have: （29）； When F HP As F increases, equation (29) monotonically increases, therefore the left half of equation (28) is determined to be in F. HP Monotonically increasing on (1,+∞); when F HP When F = 1, equation (28) holds, therefore F HP ≥1 is Solution for the following situation; 2) and Substitute the expressions into In the case of this, we have: （30）； （31）； Differentiating the left side of equation (31), we have: （32）； When F HP As F increases, equation (32) monotonically increases, therefore the left half of equation (31) is determined to be within F. HP Monotonically increasing on (1,+∞); when F HP When F = 1, equation (31) holds, therefore F HP ≥1 is Solution for the following situation; 3) and Substitute the expressions into In the case of this, we have: （33）； Substitute equation (33) back From the expression, we get: （34）； Solving for F HP >1, only when T RH (D+KF HP ) = 2H and require Only when the expression (34) is satisfied; otherwise, it is not required. So in F HP When the value is 1, the system degenerates into a critically damped form, which also makes the system frequency satisfy the condition that the maximum frequency deviation is equal to the steady-state frequency deviation. Therefore, the system frequency satisfies the condition that the maximum frequency deviation equals the steady-state frequency deviation as F HP ≥1.

7. The thermal power unit-storage combined frequency regulation method considering the response characteristics of thermal power units according to claim 2, characterized in that, In step 3, the combined thermal power and energy storage system is compensated by the energy storage system to exhibit the equivalent frequency regulation characteristic that satisfies the maximum frequency deviation equal to the steady-state frequency deviation. The formula for calculating the s-domain power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation is as follows: （35）； In the formula Δ P st ( s ) represents the power that the energy storage system should compensate for in the s-domain; This refers to the droop coefficient of thermal power units; F HP The percentage of power generated by the high-pressure turbine; T RH This is the time constant for the reheater of a thermal power unit. P N Rated power of thermal power units; Δ f ( s ) represents the frequency deviation of the s-domain system bounded by the dead zone.

8. A combined thermal power and energy storage frequency regulation device considering the response characteristics of thermal power units, characterized in that, The device includes: The dynamic response characteristics acquisition module is used to acquire the dynamic response characteristics of the thermal power unit participating in the primary frequency regulation process based on the rated power of the thermal power unit, the reheater time constant, the power generation ratio of the high-pressure turbine, and the droop coefficient of the thermal power unit. The condition acquisition module is used to deduce the condition that the maximum frequency deviation after a load disturbance equals the steady-state frequency deviation based on the dynamic response characteristics. The compensation power acquisition module is used to compensate the combined thermal power and energy storage system to make it exhibit the equivalent frequency regulation characteristics that satisfy the maximum frequency deviation equal to the steady-state frequency deviation, and to calculate the power that the energy storage system should compensate when the thermal power unit participates in primary frequency regulation.

9. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the method according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that, The computer storage medium stores a plurality of instructions adapted for loading by a processor and executing the method of any one of claims 1 to 7.

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