CN107134811A - Network load regulation spare capacity appraisal procedure based on frequency shift (FS) probability distribution - Google Patents

Abstract

The system-based adjustment reserve capacity of the present invention deals with power deviation caused by load fluctuations, and proposes an evaluation method for adjustment reserve capacity based on frequency offset probability distribution to evaluate the load reserve capacity for balancing load fluctuations. The invention comprises the following steps: the active power deviation caused by unit output and load fluctuation causes the system frequency to deviate from the rated value, and constructs and adjusts the reserve capacity evaluation method based on the frequency deviation probability distribution; the load fluctuation generates the system frequency deviation value, and according to the power system Based on the frequency characteristics, the deviation value of the active power of the system is obtained.

Description

Evaluation method of power grid load regulation reserve capacity based on frequency offset probability distribution

technical field

The invention relates to the field of power grid reserve capacity, in particular to a large power grid load regulation reserve capacity evaluation method based on frequency offset probability distribution.

Background technique

With the continuous development of the power grid and the improvement of power technology, the traditional method of calculating load reserve capacity based on the percentage of power generation load can no longer meet the needs of power system analysis. Uncertain real-time load, resulting in load fluctuations, has a greater impact on the selection of power system load reserve capacity.

In actual operation, the load of the power system fluctuates rapidly in real time, but it takes a certain amount of time to change the output of the generator set, and the generator set cannot balance the load in real time, which causes an active power deviation between the load and the output of the unit, resulting in system failure. Frequency offset nominal 50Hz. Therefore, the system frequency offset reflects the system active power deviation, and the active power deviation reflects the magnitude of the load fluctuation. The invention proposes a new evaluation method for load regulation reserve capacity based on system frequency offset, which has reference value for perfecting power system planning and operation standards.

Contents of the invention

The adjustment reserve capacity of the system deals with the power deviation caused by load fluctuations. From this point of view, the present invention proposes an evaluation method for adjustment reserve capacity based on frequency offset probability distribution to evaluate the load reserve capacity for balancing load fluctuations.

In order to achieve the above object, the present invention adopts the following technical solution: a large power grid load regulation backup capacity evaluation method based on frequency offset probability distribution, including the following steps:

Step S1: The deviation of the active power between the output of the unit and the load causes the system frequency to deviate from the rated value, and an evaluation method for regulating the reserve capacity is constructed based on the probability distribution of the frequency deviation;

Step S2: The system frequency offset value Δf generated by load fluctuation, according to the comprehensive frequency characteristics of the power system, the system active power deviation value can be obtained as:

ΔP=β×Δf(1), which is to adjust the reserve capacity,

Among them: β is the power system frequency response characteristic coefficient, the unit is MW/0.1Hz.

Further, in the step S1, the power system is adjusted once, resulting in a system frequency shift, and the specific system change process is as follows:

When the load of system A suddenly increases at a certain moment, the generator output is smaller than the load, and a negative active power deviation ΔP appears. At this time, the frequency drops rapidly, and the power system adjustment takes effect quickly. After a certain period of time, the maximum frequency deviation is reached at time X. Shift, at a certain time B after the event occurs, the first adjustment ends, and then the second frequency adjustment begins at time B, AGC controls the unit to increase output, and at time C after the event occurs, the system frequency begins to slowly increase to 50Hz recover.

Further, the algorithm of the system frequency offset value Δf in the step S2 is as follows:

In the actual operation of the power system, after the system frequency interference signal is filtered by the SCADA system in real time, sampling is performed every second. In order to satisfy the Nyquist sampling theorem, when the sampling frequency f _s.max is greater than or equal to the highest frequency f in the signal When it is 2 times of _max (f _{s.max ≥} 2f _max ), use one frequency sampling point per minute to obtain a frequency value, and use a large number of frequency offset recording data to obtain the probability distribution of active power deviation ΔP.

Further, the frequency response characteristic coefficient β is time-varying and non-linear, and the β algorithm in the step S2 is as follows:

Method 1, the frequency characteristic response coefficient is taken as a certain percentage of the annual maximum load:

In the existing research results, most power systems take the frequency characteristic response characteristic coefficient as a certain percentage of the annual maximum load, that is, the peak load percentage, and the frequency characteristic response coefficient of most control areas is 1% of the annual maximum expected load ~1.5%;

Method 2, the frequency characteristic response coefficient is taken as a certain percentage of the actual load:

Considering the time-varying characteristics of the frequency characteristic response coefficient β, it is obtained by multiplying the actual load by a certain percentage;

Method 3, three-stage frequency characteristic response coefficient method:

Considering that thermal power units and hydroelectric units usually set different primary frequency modulation dead zones in the power system, referring to relevant literature, the β coefficient can be set in three sections according to the frequency modulation dead zones of thermal power units and hydroelectric units. The dead zones are respectively ±f _fire , ±f _water , and the setting method of the three-stage frequency characteristic response coefficient β is as follows:

1) When the frequency deviation is less than ±f _fire , according to the system load and load frequency characteristic coefficient at the time of disturbance, calculate the natural frequency coefficient related to the load, and obtain the β value of the first section:

Among them: β _L* is the active power change caused by 1% frequency change, which is determined according to the system load level and composition, and generally takes 1% to 3%; P _Le and f _e are the rated load and system rated frequency respectively;

2) When the frequency deviation is between ±f _fire and ±f _water , according to the installed ratio of thermal power and hydropower, the second β value is obtained approximately:

β ₂ ≈K _G n _gh +K _L ≈(β-K _L )n _gh +K _L (3)

Among them: K _G , K _L are frequency characteristic coefficients of generator and load respectively; n _gh is the ratio of thermal power installed capacity to total installed capacity;

3) When the frequency deviation exceeds ±f _water , use the "power grid frequency response and natural frequency calculation method" recommended by NERC to calculate the third β value:

Among them: ΔP _A , Δf _A are the power deviation value and frequency deviation value before the system disturbance respectively; ΔP _B , Δf _B are respectively the power deviation before the AGC action after the system disturbance followed by the action of the governor to stabilize the frequency value and frequency deviation value;

Further, the calculation method for adjusting the reserve capacity in the step S2 is as follows:

Method 1: Calculation method of adjusted reserve capacity based on the annual maximum load percentage β value,

The frequency characteristic response coefficient β value is obtained by multiplying the maximum load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of active power deviation ΔP is obtained by using the formula ΔP=β×Δf, and the adjustment reserve is obtained by R=-ΔP Capacity probability distribution, so as to obtain the adjusted reserve capacity under a certain cumulative probability;

Method 2: Calculation method of adjusted reserve capacity based on the annual actual load percentage β value,

The value of the frequency response coefficient β is obtained by multiplying the actual load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of the active power deviation ΔP is obtained by using the formula ΔP=β×Δf, so as to obtain the probability distribution of the active power deviation ΔP under a certain cumulative probability regulation reserve capacity;

Method 3: Based on the three-stage adjustment reserve capacity calculation method under the annual maximum load percentage β value,

The maximum load of the year is multiplied by a certain percentage to obtain the frequency characteristic response coefficients β ₁ , β ₂ , and β ₃ of each section. According to the dead zone of primary frequency modulation of different units, different frequency characteristic response coefficients are used to calculate the active power by formula (5). Power deviation ΔP probability distribution;

Method 4: Based on the three-stage adjustment reserve capacity calculation method based on the annual actual load percentage β value,

Multiply the actual load of the year by a certain percentage to obtain the frequency characteristic response coefficients β _1* , β ₂ *, and β ₃ * of each segment. According to the dead zone of primary frequency modulation of different units, different frequency characteristic response coefficients are used, and the formula (5 ) Calculate the active power deviation ΔP probability distribution.

Method 5: Calculation method of hybrid three-stage adjustment reserve capacity,

Multiply the actual year by a certain percentage to get the first-stage frequency characteristic response coefficient β ₁ *, multiply the annual maximum load by a certain percentage to obtain the second and third-stage frequency characteristic response coefficients β ₂ and β ₃ , according to the primary frequency adjustment of different units The dead zone is the limit, and different frequency characteristic response coefficients are used to calculate the probability distribution of active power deviation ΔP by using formula (7).

The above five methods obtain the probability distribution of active power deviation, and combine the calculation results under different conditions and the 3σ principle in probability theory to obtain the regulation reserve capacity under a certain cumulative probability.

By adopting the adjustment reserve capacity evaluation method based on the frequency offset proposed by the present invention, it can effectively guide the planning of the power system and the selection of the operation adjustment reserve capacity. The invention has universal applicability and practicability for adapting to the situation of new electricity reform and the development of new energy sources, meeting the needs of the system and the future development of the power grid.

Description of drawings

Fig. 1 is a flow chart of the present invention.

Figure 2 is a typical curve of frequency fluctuation after a generator set failure.

Fig. 3 is a distribution diagram of the frequency offset probability of a large power grid.

Fig. 4 is the cumulative probability curve of large power grid frequency deviation.

detailed description

The accompanying drawings are for illustrative purposes only, and should not be construed as limitations on this patent; in order to better illustrate this embodiment, certain components in the accompanying drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art It is understandable that some well-known structures and descriptions thereof may be omitted in the drawings. The positional relationship described in the drawings is for illustrative purposes only, and should not be construed as a limitation on this patent.

As shown in Figure 1, a large power grid load backup adjustment backup capacity evaluation method based on frequency offset probability distribution includes the following steps:

Step S1: In the actual power grid operation, the unit output and load cannot be equal at all times, and there will always be active power deviation between the two, which will cause the system frequency to deviate from the rated value. Adjustment reserve capacity assessment method for frequency offset probability distribution;

Step S2: The system frequency deviation value caused by load fluctuation is Δf. According to the comprehensive frequency characteristics of the power system, the system active power deviation value can be obtained as:

ΔP=β×Δf (1), which is to adjust the reserve capacity,

Where: β is the power system frequency response characteristic coefficient, the unit is MW/0.1Hz;

Among them, the first adjustment of the power system in step S1 causes the system frequency to shift, and the specific system change process is as follows:

As shown in Fig. 2, Fig. 2 is a typical curve of power system frequency fluctuation after a generator unit fails. Considering that the increase of load is approximately equivalent to the decrease of generator output, it can describe the system frequency fluctuation after a sudden increase of load. When the system load suddenly increases at a certain moment (point A in the figure), the output of the generator is smaller than the load, and a negative active power deviation ΔP appears. At this time, the frequency drops rapidly, and the primary adjustment of the power system takes effect quickly. After 10 seconds (point X in the figure), the maximum frequency offset is reached, and 30 seconds after the event occurs (point B in the figure), an adjustment ends. Then the frequency is adjusted twice from point B, and the AGC controls the unit to increase the output. After 60s after the incident (point C in the figure), the system frequency begins to slowly recover to 50Hz;

Wherein, for the calculation method of the system frequency offset value Δf, the algorithm of the system frequency offset value in step S2 is as follows:

In the actual operation of the power system, after filtering the system frequency interference signal in real time through the SCADA system, sampling is performed every second. In order to satisfy the Nyquist sampling theorem (when the sampling frequency f _s.max is greater than the highest frequency f _max in the signal (f _{s.max ≥} 2f _max ), the digital signal after sampling completely retains the information in the original signal.), this study uses one frequency sampling point per minute to obtain a frequency value, and uses a large number of frequency offsets By shifting the recorded data, the probability distribution of the active power deviation ΔP can be obtained;

Among them, for the method of calculating the frequency response characteristic coefficient of the power system, the frequency response characteristic coefficient β is time-varying and non-linear, and the β algorithm in step S2 is as follows:

Method 1, the frequency characteristic response coefficient is taken as a certain percentage of the annual maximum load:

In the existing research results, most power systems take the frequency characteristic response characteristic coefficient as a certain percentage of the maximum load of the year, that is, the peak load % (MW/0.1Hz). This method generally obtains the frequency characteristic response coefficient β according to the frequency change curve through typical frequency fluctuation events (such as sudden failure of generator sets, large disturbance test). The frequency characteristic response coefficient of most control areas is between 1% and 1.5% (MW/0.1Hz) of the annual maximum expected load;

Method 2, the frequency characteristic response coefficient is taken as a certain percentage of the actual load:

Considering the time-varying characteristics of the frequency characteristic response coefficient β, it is obtained by multiplying the actual load by a certain percentage;

Method 3, three-stage frequency characteristic response coefficient method

Considering that thermal power units and hydroelectric units usually set different primary frequency modulation dead zones in the power system, referring to relevant literature, the β coefficient can be set in three sections according to the frequency modulation dead zones of thermal power units and hydroelectric units as boundaries. The dead zones of the primary frequency modulation of thermal power and hydroelectric units are ±f _fire and ±f _water respectively. The setting method of the three-stage frequency characteristic response coefficient β is as follows:

1) When the frequency deviation is less than ±f _fire , according to the system load and load frequency characteristic coefficient at the time of disturbance, calculate the natural frequency coefficient related to the load, and obtain the β value of the first section:

Among them: β _L* is the active power change caused by 1% frequency change, which is determined according to the system load level and composition, and generally takes 1% to 3%; P _Le and f _e are the rated load and system rated frequency respectively;

2) When the frequency deviation is between ±f _fire and ±f _water , according to the installed ratio of thermal power and hydropower, the second β value is obtained approximately:

β ₂ ≈K _G n _gh +K _L ≈(β-K _L )n _gh +K _L (3)

Among them: K _G , K _L are frequency characteristic coefficients of generator and load respectively; n _gh is the ratio of thermal power installed capacity to total installed capacity (thermal power and hydropower).

3) When the frequency deviation exceeds ±f _water , use the "power grid frequency response and natural frequency calculation method" recommended by NERC to calculate the third β value:

Among them: ΔP _A , Δf _A are the power deviation value and frequency deviation value before the system disturbance respectively; ΔP _B , Δf _B are respectively the power deviation before the AGC action after the system disturbance followed by the action of the governor to stabilize the frequency value and frequency deviation value;

5. The adjusting reserve capacity according to claim 1 and the method for obtaining the power system frequency response characteristic coefficient according to claim 4, characterized in that: the calculation method of adjusting reserve capacity in the step S2 is as follows:

Method 1: Calculation method of adjusted reserve capacity based on the annual maximum load percentage β value

The frequency characteristic response coefficient β value is obtained by multiplying the maximum load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of active power deviation ΔP is obtained by using the formula ΔP=β×Δf, and the adjustment reserve is obtained by R=-ΔP Capacity probability distribution, so as to obtain the adjusted reserve capacity under a certain cumulative probability;

Method 2: Calculation method for adjusting reserve capacity based on the annual actual load percentage β value

The value of the frequency response coefficient β is obtained by multiplying the actual load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of the active power deviation ΔP is obtained by using the formula ΔP=β×Δf, so as to obtain the probability distribution of the active power deviation ΔP under a certain cumulative probability regulation reserve capacity;

Method 3: Calculation method of three-stage regulation reserve capacity based on the annual maximum load percentage β value

Multiply the annual maximum load by a certain percentage to obtain the response coefficients β ₁ , β ₂ , and β ₃ of each frequency characteristic. According to the primary frequency regulation dead zone of different units as the boundary, different frequency characteristic response coefficients are used, and the probability distribution of active power deviation ΔP is calculated by formula (5);

Method 4: Calculation method of three-stage regulation reserve capacity based on the annual actual load percentage β value

Multiply the actual load of the year by a certain percentage to obtain the response coefficients β ₁ *, β ₂ *, and β ₃ * of each frequency characteristic. According to the primary frequency regulation dead zone of different units as the boundary, different frequency characteristic response coefficients are used to calculate the probability distribution of active power deviation ΔP by using formula (5).

Method 5: Calculation method of hybrid three-stage adjustment reserve capacity

Multiply the actual load of the year by a certain percentage to obtain the first-stage frequency characteristic response coefficient β ₁ *, and multiply the annual maximum load by a certain percentage to obtain the second and third-stage frequency characteristic response coefficients β ₂ and β ₃ . According to the dead zone of primary frequency modulation of different units as the boundary, different frequency characteristic response coefficients are used, and the probability distribution of active power deviation ΔP is calculated by formula (7).

The above five methods obtain the probability distribution of active power deviation, and combine the calculation results under different conditions and the 3σ principle in probability theory to obtain the regulation reserve capacity under a certain cumulative probability.

Taking a large power grid as an example, the evaluation method of regulating reserve capacity based on frequency offset includes the following steps:

(1) Frequency offset cumulative probability distribution.

According to the minute-by-minute frequency operation records of the large power grid, the probability distribution of the frequency deviation of the large power grid in a certain year is shown in Figure 3.

The cumulative probability distribution diagram of large power grid frequency obtained from the frequency offset probability distribution is shown in Figure 4: when the cumulative probability is 0.90, the frequency offset value Δf = 0.034Hz; when the cumulative probability is 0.95, the frequency offset value Δf = 0.037Hz; when the cumulative frequency is 0.99, the frequency offset value Δf=0.045Hz; when the cumulative frequency is 0.9999, the frequency offset value Δf=0.067Hz.

(2) Find the parameter β.

1) It is known that a typical frequency fluctuation event occurs in the power grid, a DC bipolar trip, and load shedding is 1800MW; the interval between points A and B is 18 seconds, ΔP=-1800MW, Δf=0.12Hz, and the whole network β=1500MW/0.1Hz; The load of the whole network at the time of tripping is 72791MW, and the percentage of β value in load can be calculated as 1500/72791×100%=2% (MW/0.1Hz);

2) Considering its time-varying nature, the actual grid frequency response coefficient β is 20% of the load per minute, so the load data per minute is multiplied by 20%;

3) Set in three stages

β ₁ : In case of an accident, the static frequency characteristic coefficient of the load accounts for 3.29% of the load, then: β ₁ ≈0.329%×Load(MW/0.1Hz);

β ₂ : Thermal power accounts for 67% of the total installed capacity, that is, n _gh = 67%. It is obtained: β ₂ ≈1.4456%×Load(MW/0.1Hz);

β ₃ : β ₃ ≈2%×Load(MW/0.1Hz);

2) The maximum grid load Load=119445MW, therefore, β ₁ ≈393MW/0.1Hz, β ₂ ≈1728MW/0.1Hz, β ₃ ≈2389MW/0.1Hz.

(3) Evaluation of grid load regulation reserve capacity.

1) The peak load of the local power grid is 80050MW, which accounts for 67.02% of the peak load of the large power grid. From the perspective of system scale and frequency adjustment responsibility, the adjustment reserve capacity of the local power grid should be 67.02% of the adjustment reserve capacity of the large power grid;

2) By adjusting the reserve capacity evaluation method based on frequency offset probability distribution:

Method 1: Calculation of the adjusted reserve capacity based on the annual maximum load percentage β value

The value of β is: β＝119445×2%MW/0.1Hz＝2389MW/0.1Hz. Under a certain cumulative probability, the value of the grid system adjustment reserve capacity is shown in Table 1:

Method 2: Calculation of the adjusted reserve capacity based on the β value of the actual load percentage per minute

The value of β is: 20% of the load per minute. Under a certain cumulative probability, the adjustment reserve capacity of the power grid system is shown in Table 2:

Method 3-5: Calculation of the adjusted reserve capacity under the three-stage β value, as shown in Table 3:

Combining the calculation results of the five methods, the value of the adjustment reserve capacity for load fluctuations is taken. The calculation results are summarized in Table 4:

(4) Recommended value of load regulation reserve capacity

Combining the calculation results under different conditions and the 3σ principle in probability theory, the load fluctuation value of the local power system can be taken as 1.2% of the maximum dispatching and maximum load of the year.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, on the basis of the above description, other changes or changes in different forms can also be made. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (5)

1. A large power grid load regulation reserve capacity evaluation method based on frequency deviation probability distribution, is characterized in that, comprises the following steps: Step S1: The deviation of the active power between the output of the unit and the load causes the system frequency to deviate from the rated value, and an evaluation method for regulating the reserve capacity is constructed based on the probability distribution of the frequency deviation; Step S2: The system frequency offset value Δf generated by load fluctuation, according to the comprehensive frequency characteristics of the power system, the system active power deviation value can be obtained as: ΔP=β×Δf (1), which is to adjust the reserve capacity, Among them: β is the power system frequency response characteristic coefficient, the unit is MW/0.1Hz. 2. The frequency offset-based adjustment reserve capacity evaluation method according to claim 1, characterized in that: in the step S1, the power system is adjusted once, resulting in a system frequency offset, and the specific system change process is as follows: When the load of system A suddenly increases at a certain moment, the generator output is smaller than the load, and a negative active power deviation ΔP appears. At this time, the frequency drops rapidly, and the power system adjustment takes effect quickly. After a certain period of time, the maximum frequency deviation is reached at time X. Shift, at a certain time B after the event occurs, the first adjustment ends, and then the second frequency adjustment begins at time B, AGC controls the unit to increase output, and at time C after the event occurs, the system frequency begins to slowly increase to 50Hz recover. 3. The frequency offset-based adjustment reserve capacity evaluation method according to claim 1, characterized in that: the algorithm of the system frequency offset value Δf in the step S2 is as follows: In the actual operation of the power system, after the system frequency interference signal is filtered by the SCADA system in real time, sampling is performed every second. In order to satisfy the Nyquist sampling theorem, when the sampling frequency f _s.max is greater than or equal to the highest frequency f in the signal When it is 2 times of _max , one frequency sampling point per minute is used to obtain a frequency value, and a large number of frequency offset recording data can be used to obtain the probability distribution of the active power deviation ΔP. 4. The adjustment reserve capacity evaluation method based on frequency offset according to claim 3, characterized in that: the frequency response characteristic coefficient β is time-varying and non-linear, and the β algorithm in the step S2 is as follows: Method 1, the frequency characteristic response coefficient is taken as a certain percentage of the annual maximum load: In the existing research results, most power systems take the frequency characteristic response characteristic coefficient as a certain percentage of the annual maximum load, that is, the peak load percentage, and the frequency characteristic response coefficient of most control areas is 1% of the annual maximum expected load ~1.5%; Method 2, the frequency characteristic response coefficient is taken as a certain percentage of the actual load: Considering the time-varying characteristics of the frequency characteristic response coefficient β, it is obtained by multiplying the actual load by a certain percentage; Method 3, three-stage frequency characteristic response coefficient method: Considering that thermal power units and hydroelectric units usually set different primary frequency modulation dead zones in the power system, referring to relevant literature, the β coefficient can be set in three sections according to the frequency modulation dead zones of thermal power units and hydroelectric units. The dead zones are respectively ±f _fire , ±f _water , and the setting method of the three-stage frequency characteristic response coefficient β is as follows: 1) When the frequency deviation is less than ±f _fire , according to the system load and load frequency characteristic coefficient at the time of disturbance, calculate the natural frequency coefficient related to the load, and obtain the β value of the first section: Among them: β _L* is the active power change caused by 1% frequency change, which is determined according to the system load level and composition, and generally takes 1% to 3%; P _Le and f _e are the rated load and system rated frequency respectively; 2) When the frequency deviation is between ±f _fire and ±f _water , according to the installed ratio of thermal power and hydropower, the second β value is obtained approximately: β ₂ ≈K _G n _gh +K _L ≈(β-K _L )n _gh +K _L (3) Among them: K _G , K _L are frequency characteristic coefficients of generator and load respectively; n _gh is the ratio of thermal power installed capacity to total installed capacity; 3) When the frequency deviation exceeds ±f _water , use the "power grid frequency response and natural frequency calculation method" recommended by NERC to calculate the third β value: Among them: ΔP _A , Δf _A are the power deviation value and frequency deviation value before the system disturbance respectively; ΔP _B , Δf _B are respectively the power deviation before the AGC action after the system disturbance followed by the action of the governor to stabilize the frequency value and frequency deviation value. 5. The frequency offset-based adjustment reserve capacity evaluation method according to claim 4, characterized in that, the calculation method of the adjustment reserve capacity in the step S2 is as follows: Method 1: Calculation method of adjusted reserve capacity based on the annual maximum load percentage β value, The frequency characteristic response coefficient β value is obtained by multiplying the maximum load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of active power deviation ΔP is obtained by using the formula ΔP=β×Δf, and the adjustment reserve is obtained by R=-ΔP Capacity probability distribution, so as to obtain the adjusted reserve capacity under a certain cumulative probability; Method 2: Calculation method of adjusted reserve capacity based on the annual actual load percentage β value, The value of the frequency response coefficient β is obtained by multiplying the actual load of the year by a certain percentage. According to the annual frequency deviation data per minute, the probability distribution of the active power deviation ΔP is obtained by using the formula ΔP=β×Δf, so as to obtain the probability distribution of the active power deviation ΔP under a certain cumulative probability regulation reserve capacity; Method 3: Based on the three-stage adjustment reserve capacity calculation method under the annual maximum load percentage β value, The maximum load of the year is multiplied by a certain percentage to obtain the frequency characteristic response coefficients β ₁ , β ₂ , and β ₃ of each section. According to the dead zone of primary frequency modulation of different units, different frequency characteristic response coefficients are used to calculate the active power by formula (5). Power deviation ΔP probability distribution; Method 4: Based on the three-stage adjustment reserve capacity calculation method based on the annual actual load percentage β value, The frequency characteristic response coefficients β _1* , β _2* , and β _3* of each section are obtained by multiplying the actual load of the year by a certain percentage, and different frequency characteristic response coefficients are used according to the dead zone of primary frequency modulation of different units, and the formula (5 ) Calculate the active power deviation ΔP probability distribution. Method 5: Calculation method of hybrid three-stage adjustment reserve capacity, Multiply the actual annual value by a certain percentage to get the first-stage frequency characteristic response coefficient β _1* , multiply the annual maximum load by a certain percentage to obtain the second and third-stage frequency characteristic response coefficients β ₂ and β ₃ , according to the primary frequency adjustment of different units The dead zone is the limit, and different frequency characteristic response coefficients are used to calculate the probability distribution of active power deviation ΔP by using formula (7). The above five methods obtain the probability distribution of active power deviation, and combine the calculation results under different conditions and the 3σ principle in probability theory to obtain the regulation reserve capacity under a certain cumulative probability.