A method and system for analyzing the active power deficit in the power balance of an interconnected power grid

Abstract

The present invention discloses a method and system for analyzing the active power deficit in the power balance of an interconnected power grid. The method includes: determining the basic parameters of the operation of the target regional power grid; calculating the 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP of the dynamic difference on the maximum load day, based on the basic parameters and the actual output curves of wind and light limit ; when the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal, determining the conventional unit spinning reserve coefficient λ and the demand-side response factor η of the target regional power grid; determining the optimal conventional unit on-line capacity P G and the spinning reserve capacity P spin‑res . The active power deficit analysis method for interconnected provincial power balance based on the actual output curves of wind and light in the present invention is used to determine the optimal conventional unit on-line and spinning reserve capacities, so as to improve the economic operation level of the power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more specifically, to a method and system for analyzing the active power deficit of interconnected power grids for power balance. Background Art

[0002] With the increasing frequency of power trading and exchange between power grids, on the premise that the ceiling of thermal power and the scale of external power are basically determined, as the power grid continuously reduces the output of conventional units and the penetration rate of new energy continues to increase, how to balance the load and achieve power balance is an urgent problem for the current power grid. For the current situation and long-term goals of provincial power grids, based on the actual output curves of wind and light, combined with demand-side response, how to determine the optimal starting capacity and spinning reserve capacity of conventional units. In addition to considering power balance, it is also necessary to consider whether the constraints such as transient stability and static stability of the system meet the actual power grid safety and stability operation threshold.

[0003] Therefore, the method for analyzing the active power deficit of interconnected provincial power balance has increasingly become a research hotspot. Summary of the Invention

[0004] The technical solution of the present invention provides a method and system for analyzing the active power deficit of interconnected power grids for power balance, so as to solve the problem of how to analyze the active power deficit of interconnected provincial power balance.

[0005] To solve the above problems, the present invention provides a method for analyzing the active power deficit of interconnected power grids for power balance, the method comprising:

[0006] Determining the basic parameters of the target regional power grid operation;

[0007] Based on the basic parameters and the actual output curves of wind and light, calculating the 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP of the dynamic difference on the maximum load day limit ;

[0008] When the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal, determining the spinning reserve coefficient λ of the conventional unit and the demand-side response factor η of the target regional power grid;

[0009] Based on the spinning reserve coefficient λ of the conventional unit and the demand-side response factor η, determining the optimal starting capacity P G of the conventional unit and the spinning reserve capacity P spin-res .

[0010] Preferably, the determining the basic parameters of the target regional power grid operation includes:

[0011] S1. Determine the 24-hour load levels on the day with the maximum load of the target area power grid, i.e., the active power demand P load(t)-max ;

[0012] S2. Determine the operating installed capacity P of the conventional units within the target area on the day with the maximum load G ;

[0013] S3. Determine the spinning reserve rate λ of the conventional units within the target area and the spinning reserve capacity P spin-res ,

[0014] P spin-res = λP G ;

[0015] S4. Determine the output levels of the wind turbines within the target area over 24 hours on the day with the maximum load, i.e., the active power output P of the wind turbines G(t)-WIND ;

[0016] S5. Determine the output levels of the photovoltaic units within the target area over 24 hours on the day with the maximum load, i.e., the active power output P of the photovoltaic units G(t)-PV ;

[0017] S6. Determine the output levels of the new energy units within the target area over 24 hours on the day with the maximum load, i.e., the active power output P of the new energy units G(t)-new ,

[0018] P G(t)-new = P G(t)-WINDG + P G(t)-PV ;

[0019] S7. Determine the output levels of the centrally dispatched units within the target area over 24 hours on the day with the maximum load, i.e., the active power output P of the centrally dispatched units G(t)-int ,

[0020] P G(t)-int =(1 - λ)P G + P G(t)-new ;

[0021] S8. Determine the reserve capacity P required by the centrally dispatched units in the target area G-spare ;

[0022] S9. Determine the transmission capacity of each interconnected AC channel between the target area and the outside on the day with the maximum load, i.e., the active power P fed in through AC AC-ext ;

[0023] S10. Determine the transmission capacity of each interconnected DC channel between the target area and the outside on the day with the maximum load, i.e., the active power P fed in through DC DC-ext ;

[0024] S11. Determine the transmission capacity of the target area and each external interconnected AC and DC channels on the maximum load day, i.e., the active power of AC feed-in and DC feed-in, and \(P_{ac}\) G-ext ,

[0025] \(P_{ac}\) G-ext = \(P_{ac}\) AC-ext +\(P_{dc}\) DC-ext ;

[0026] S12. Determine the maximum load level of the whole society that can participate in demand response, i.e., the total active power \(P_{total}\) Total load-max ;

[0027] S13. Determine the demand response factor \(\eta\) of the power grid; at the maximum load level of the whole society in S12, the active power of demand response is \(P_{dr}\) Response load , \(P_{dr}\) Response load =\(\eta P_{total}\) Total load-max .

[0028] Preferably, based on the basic parameters and the actual output curves of wind and light, calculate the 24-hour dynamic difference \(\Delta P\) between the load and the output on the maximum load day, and the highest peak value \(\Delta P_{max}\) of the dynamic difference on the maximum load day limit , and the calculation formula for the 24-hour dynamic difference \(\Delta P\) is:

[0029] \(\Delta P = P_{total}\) load(t)-max - (\(P_{ac}\) G(t)-int - \(P_{wind}\) G-spare ) - \(P_{solar}\) G-ext - \(P_{other}\) Response load

[0030] That is:

[0031]

[0032] Preferably, determine the optimal starting capacity \(P_{unit}\) and spinning reserve capacity \(P_{reserve}\) of the conventional units based on the conventional unit spinning reserve coefficient \(\lambda\) and the demand response factor \(\eta\) G and the spinning reserve capacity \(P_{reserve}\) spin-res , including:

[0033] Calculate the peak value \(\Delta P_{max}\) of a dynamic difference through the 24-hour dynamic difference \(\Delta P\) calculation formula limit , so that the duration of the maximum load day dynamic difference \(\Delta P\) in the range of 0 to \(\Delta P_{max}\) limit is the artificially set duration, and then obtain \(P_{unit}\) through the transformation of the 24-hour dynamic difference \(\Delta P\) calculation formula G :

[0034]

[0035] where \(\Delta P\in(0,\Delta P_{max}\) limit ,

[0036] Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV )+P G-spare -(P AC-ext +P DC-ext ) be equal to the constant C, and ΔP = ΔP limit , then the above formula becomes:

[0037]

[0038] Extend the results of the typical load day to the whole year:

[0039]

[0040] where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient on the nth day of the whole year.

[0041] Based on another aspect of the present invention, the present invention provides a system for analyzing the active power deficit of the interconnected power grid power balance, and the system includes:

[0042] An initial unit for determining the basic parameters of the target area power grid operation;

[0043] A calculation unit for calculating the 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP limit of the dynamic difference on the maximum load day based on the basic parameters and the actual output curves of wind and light;

[0044] A determination unit for determining the spinning reserve coefficient λ of the conventional unit and the demand-side response factor η of the target area power grid when the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal; determining the optimal on-grid capacity P G of the conventional unit and the spinning reserve capacity P spin-res based on the spinning reserve coefficient λ of the conventional unit and the demand-side response factor η.

[0045] Preferably, the initial unit for determining the basic parameters of the target area power grid operation includes:

[0046] S1. Determine the 24-hour load level on the maximum load day of the target area power grid, that is, the active power demand P load(t)-max ;

[0047] S2. Determine the on-grid capacity P G of the internal conventional units in the target area on the maximum load day;

[0048] S3. Determine the spinning reserve rate λ of the internal conventional units in the target area, the spinning reserve capacity P spin-res ,

[0049] P spin-res = λP G ;

[0050] S4. Determine the output level of the wind turbines within the target area over 24 hours on the maximum load day, i.e., the active power output P of the wind turbines G(t)-WIND ;

[0051] S5. Determine the output level of the photovoltaic units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the photovoltaic units G(t)-PV ;

[0052] S6. Determine the output level of the new energy units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the new energy units G(t)-new ,

[0053] P G(t)-new = P G(t)-WINDG + P G(t)-PV ;

[0054] S7. Determine the output level of the grid-connected units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the grid-connected units G(t)-int ,

[0055] P G(t)-int = (1 - λ)P G + P G(t)-new ;

[0056] S8. Determine the reserve capacity P required for the grid-connected units in the target area G-spare ;

[0057] S9. Determine the transmission capacity of each interconnected AC channel between the target area and the outside on the maximum load day, i.e., the active power P fed in through AC AC-ext ;

[0058] S10. Determine the transmission capacity of each interconnected DC channel between the target area and the outside on the maximum load day, i.e., the active power P fed in through DC DC-ext ;

[0059] S11. Determine the transmission capacity of each interconnected AC and DC channel between the target area and the outside on the maximum load day, i.e., the sum of the active power fed in through AC and DC, P G-ext ,

[0060] P G-ext = P AC-ext + P DC-ext ;

[0061] S12. Determine the maximum load level of the whole society that can participate in demand-side response, i.e., the total active power P Total load-max ;

[0062] S13, determine the demand side response factor η of the power grid; at the maximum social load level in S12, the active power of the demand side response is P Response load , P Response load =ηP Total load-max .

[0063] Preferably, the calculation unit is used to calculate the 24-hour dynamic difference ΔP between load and output on the maximum load day and the highest peak value ΔP of the dynamic difference on the maximum load day based on the basic parameters and the actual wind and solar output curve. limit , the calculation formula of 24-hour dynamic difference ΔP is:

[0064] ΔP=P load(t)-max -(P G(t)-int -P G-spare )-P G-ext -P Response load

[0065] Right now:

[0066]

[0067] Preferably, the determining unit is used to determine the optimal conventional unit startup capacity P based on the conventional unit spinning reserve coefficient λ and the demand side response factor η. G and spinning reserve capacity P spin-res ,include:

[0068] Calculate the peak value ΔP of a dynamic difference by using the 24-hour dynamic difference ΔP calculation formula limit , so that the maximum load daily dynamic difference ΔP is between 0 and ΔP limit The duration of the interval is the duration set manually, and then P is obtained by transforming the 24-hour dynamic difference ΔP calculation formula. G :

[0069]

[0070] Among them, ΔP∈(0,ΔP limit ],

[0071] Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV )+P G-spare -(P AC-ext +P DC-ext ) is equal to the constant C, ΔP=ΔP limit , then the above formula is:

[0072]

[0073] Extend the results of a typical load day to the whole year:

[0074]

[0075] where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient for the nth day of the whole year.

[0076] The technical solution of the present invention provides a method and system for analyzing the active power deficit in the power balance of an interconnected power grid. The method includes: determining the basic parameters of the operation of the target regional power grid; calculating the 24-hour dynamic difference ΔP between the load and the output, and the highest peak value ΔP of the dynamic difference on the maximum load day, based on the basic parameters and the actual output curves of wind and light limit ; when the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal, determining the spinning reserve coefficient λ of the conventional units and the demand response factor η of the target regional power grid; determining the optimal starting capacity P G of the conventional units and the spinning reserve capacity P spin-res . The technical solution of the present invention provides a method for analyzing the active power deficit in the power balance of an interconnected provincial power grid based on the actual output curves of wind and light considering demand response, proposes several concepts of multi-level AC and DC power inputs from outside and inside the region, counts the transmission power data of the interconnected AC channels between the provincial power grid and the external and internal sub-regional power grids of the provincial power grid, considers the demand response coefficient, and based on the actual output curves of wind and light, obtains the 24-hour dynamic difference (active power deficit) between the load and the output on the maximum load day. By analyzing the peak value (maximum active power deficit capacity) and the duration of the dynamic difference on the maximum load day in summer, the starting and spinning reserve capacities of the conventional units are allocated, and a method for analyzing the active power deficit in the power balance of an interconnected provincial power grid based on the actual output curves of wind and light considering demand response is constructed, so as to determine the optimal starting and spinning reserve capacities of the conventional units. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] By referring to the following drawings, the exemplary embodiments of the present invention can be more fully understood:

[0078] Figure 1 is a flowchart of a method for analyzing the active power deficit in the power balance of an interconnected power grid according to a preferred embodiment of the present invention;

[0079] Figure 2 is a flowchart of a program for analyzing the active power deficit of a provincial power grid according to a preferred embodiment of the present invention;

[0080] Figure 3 is a schematic diagram of the summer output curve of wind according to a preferred embodiment of the present invention;

[0081] Figure 4 Schematic diagram of wind power output curve according to a preferred embodiment of the present invention;

[0082] Figure 5 Schematic diagram of photovoltaic power output curve according to a preferred embodiment of the present invention;

[0083] Figure 6 Schematic diagram of dynamic difference curve of active power deficit in 24 hours on the maximum load day according to a preferred embodiment of the present invention;

[0084] Figure 7 System structure diagram for analyzing active power deficit in interconnected power grid power balance according to a preferred embodiment of the present invention. Specific embodiments

[0085] Now, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not limitations on the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0086] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields, and should not be understood as idealized or overly formal meanings.

[0087] Figure 1 Flowchart of a method for analyzing active power deficit in interconnected power grid power balance according to a preferred embodiment of the present invention. The present invention provides a method for analyzing active power deficit in interconnected provincial power balance based on the actual output curves of wind and light, taking into account the demand-side response coefficient, and based on the actual output curves of wind and light, obtaining the 24-hour dynamic difference (active power deficit) between the load and the output on the maximum load day. By analyzing the peak value (maximum active power deficit capacity) and the duration of the dynamic difference on the maximum load day in summer, the startup of conventional units and the spinning reserve capacity are allocated, and a method for analyzing active power deficit in interconnected provincial power balance based on the actual output curves of wind and light considering the demand-side response is constructed, so as to determine the optimal startup of conventional units and the spinning reserve capacity.

[0088] As Figure 1 shown, the present invention provides a method for analyzing active power deficit in interconnected power grid power balance, and the method includes:

[0089] Step 101: Determine the basic parameters of the target regional power grid operation;

[0090] Preferably, determine the basic parameters of the target area power grid operation, including:

[0091] S1. Determine the 24-hour load level of the maximum load day of the target area power grid, that is, the active power demand P load(t)-max ;

[0092] S2. Determine the operating installed capacity P of the conventional units within the target area on the maximum load day G ;

[0093] S3. Determine the spinning reserve rate λ of the conventional units within the target area, and the spinning reserve capacity P spin-res ,

[0094] P spin-res = λP G ;

[0095] S4. Determine the output level of the wind turbines within the target area in 24 hours on the maximum load day, that is, the active power output P of the wind turbines G(t)-WIND ;

[0096] S5. Determine the output level of the photovoltaic units within the target area in 24 hours on the maximum load day, that is, the active power output P of the photovoltaic units G(t)-PV ;

[0097] S6. Determine the output level of the new energy units within the target area in 24 hours on the maximum load day, that is, the active power output P of the new energy units G(t)-new ,

[0098] P G(t)-new = P G(t)-WINDG + P G(t)-PV ;

[0099] S7. Determine the output level of the centrally dispatched units within the target area in 24 hours on the maximum load day, that is, the active power output P of the centrally dispatched units G(t)-int ,

[0100] P G(t)-int = (1 - λ)P G + P G(t)-new ;

[0101] S8. Determine the reserve capacity P required by the centrally dispatched units in the target area G-spare ;

[0102] S9. Determine the transmission capacity of each interconnected AC channel between the target area and the outside on the maximum load day, that is, the active power P fed in by AC AC-ext ;

[0103] S10. Determine the transmission capacity of the target area and each external interconnected DC channel on the maximum load day, i.e., the active power P fed by the DC DC-ext ;

[0104] S11. Determine the transmission capacity of the target area and each external interconnected AC and DC channels on the maximum load day, i.e., the sum P of the active power fed by the AC and the active power fed by the DC G-ext ,

[0105] P G-ext = P AC-ext + P DC-ext ;

[0106] S12. Determine the maximum load level of the whole society that can participate in demand-side response, i.e., the total active power P Totalload-max ;

[0107] S13. Determine the demand-side response factor η of the power grid; at the maximum load level of the whole society in S12, the active power of the demand-side response is P Response load , P Response load = ηP Total load-max .

[0108] Step 102: Based on the basic parameters and the actual output curves of wind and light, calculate the 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP of the dynamic difference on the maximum load day limit ;

[0109] Preferably, based on the basic parameters and the actual output curves of wind and light, calculate the 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP of the dynamic difference on the maximum load day limit , and the calculation formula for the 24-hour dynamic difference ΔP is:

[0110] ΔP = P load(t)-max -(P G(t)-int - P G-spare )- P G-ext - P Response load

[0111] That is:

[0112]

[0113] Step 103: When the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal, determine the conventional unit spinning reserve coefficient λ and the demand-side response factor η of the target area power grid;

[0114] Step 104: Determine the optimal conventional unit on-line capacity P G and the spinning reserve capacity Pspin-res 。

[0115] Preferably, the optimal starting capacity P of the conventional unit and the spinning reserve capacity P are determined based on the conventional unit spinning reserve coefficient λ and the demand-side response factor η G and the spinning reserve capacity P spin-res , including:

[0116] Calculating the peak value ΔP of a dynamic difference through the 24-hour dynamic difference ΔP calculation formula limit such that the duration of the dynamic difference ΔP on the maximum load day within the range of 0 to ΔP limit is the artificially set duration, and then obtaining P through transformation of the 24-hour dynamic difference ΔP calculation formula G :

[0117]

[0118] where ΔP ∈ (0, ΔP limit ,

[0119] Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV ) + P G-spare -(P AC-ext +P DC-ext ) be equal to the constant C, and ΔP = ΔP limit , then the above formula is:

[0120]

[0121] Extending the results of the typical load day to the whole year:

[0122]

[0123] where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient on the nth day of the whole year.

[0124] The following is an example of the implementation manner of the present invention. As Figure 2 shown, the present invention provides a method flow for analyzing the active power deficit of the interconnected provincial power balance based on the actual output curve of wind and light considering the demand-side response. The method includes the following steps:

[0125] (1) Determining the 24-hour load level of the provincial power grid on the maximum load day, that is, the active power demand P load(t)-max ;

[0126] (2) Determining the operating installed capacity P of the conventional units within the provincial power grid on the maximum load day G ;

[0127] (3) Determine the spinning reserve rate λ of conventional units within the provincial power grid and the spinning reserve capacity P spin-res ;

[0128] P spin-res = λP G (1)

[0129] (4) Determine the output level of wind turbines within the provincial power grid over 24 hours on the peak load day, i.e., the active power output P of the wind turbines G(t)-WIND ;

[0130] (5) Determine the output level of photovoltaic units within the provincial power grid over 24 hours on the peak load day, i.e., the active power output P of the photovoltaic units G(t)-PV ;

[0131] (6) Determine the output level of new energy units within the provincial power grid over 24 hours on the peak load day, i.e., the active power output P of the new energy units G(t)-new ;

[0132] P G(t)-new = P G(t)-WINDG + P G(t)-PV (2)

[0133] (7) Determine the output level of the grid-connected units within the provincial power grid over 24 hours on the peak load day, i.e., the active power output P of the grid-connected units G(t)-int ;

[0134] P G(t)-int =(1 - λ)P G + P G(t)-new (3)

[0135] (8) Determine the reserve capacity P required for the grid-connected units of the provincial power grid G-spare ;

[0136] (9) Determine the transmission capacity of each interconnected AC channel between the provincial power grid and the outside on the peak load day, i.e., the active power P fed in through AC AC-ext ;

[0137] (10) Determine the transmission capacity of each interconnected DC channel between the provincial power grid and the outside on the peak load day, i.e., the active power P fed in through DC DC-ext ;

[0138] (11) Determine the transmission capacity of each interconnected AC and DC channel between the provincial power grid and the outside on the peak load day, i.e., the sum of the active powers P fed in through AC and DC G-ext ;

[0139] P G-ext = P AC-ext + P DC-ext (4)

[0140] (12) Determine the maximum load level of the whole society that can participate in demand-side response, that is, the total active power P Total load-max ;

[0141] (13) Determine the demand-side response factor η of the power grid; under the maximum load level of the whole society analyzed in step 12, the active power of demand-side response is P Response load ;

[0142] P Response load = ηP Total load-max (5)

[0143] (14) After determining the above steps, based on the actual output curves of wind and light, such as Figure 3 、 Figure 4 、 Figure 5 , obtain the 24-hour dynamic difference ΔP between the load and the output on the maximum load day;

[0144] ΔP = P load(t)-max -(P G(t)-int -P G-spare )-P G-ext -P Response load (6)

[0145] That is:

[0146]

[0147] After determining the basic parameters of the above steps, according to the 24-hour dynamic difference (active power deficit) between the load and the output on the maximum load day obtained in step (14), by analyzing the peak value (maximum active power deficit capacity) ΔP of the dynamic difference on the maximum load day in summer limit and the optimal duration of ΔP in the range of 0 to ΔP limit interval, go to step (3) and step (13), and repeatedly adjust and allocate the start-up of conventional units and the spinning reserve coefficient λ, the demand-side response factor η, and accordingly determine the optimal start-up capacity P G of conventional units and the spinning reserve capacity P spin-res .

[0148] Among them:

[0149] First, calculate the peak value ΔP of a dynamic difference through equation (7) limit , so that the duration of the dynamic difference ΔP on the maximum load day in the range of 0 to ΔP limit interval is the artificially set duration, such as Figure 6 (the artificially set duration is about 2 hours) shown. Then, obtain P G by transforming formula (7) as follows:

[0150]

[0151] where, ΔP ∈ (0, ΔP limit .

[0152] Let P load(t)-max -(P G(t)-WINDG + P G(t)-PV ) + P G-spare -(P AC-ext + P DC-ext ) be equal to the constant C, and ΔP = ΔP limit , then the above formula becomes:

[0153]

[0154] After obtaining the results of a typical load day selected by the present invention, it can also be extended to 365 days of a year to form a generalizable regular summary. The formula is as follows:

[0155]

[0156] Based on this, determine the optimal on - line capacity P G of the conventional units and the spinning reserve coefficient λ.

[0157] Through the present invention, an interconnected provincial power grid active power deficit analysis method based on the actual output curves of wind and light by considering the impact of demand - side response can be used to determine the optimal on - line and spinning reserve capacities of conventional units, and improve the economic operation level of the power grid.

[0158] The present invention takes the power grid of Province A in the year 2025 as the research object. Through an interconnected provincial power grid active power deficit analysis method based on the actual output curves of wind and light by considering the impact of demand - side response, the optimal on - line and spinning reserve capacities of conventional units are determined. The basic parameters and result statistics of this example are shown in Table 1, Table 2, Figure 6 as shown below.

[0159] Table 1 Power balance table inside and outside the provincial power grid Unit: MW

[0160]

[0161] Table 2 Dynamic difference table of active power deficit in 24 hours on the maximum load day

[0162]

[0163] The analysis steps are as follows:

[0164] (1) The 24 - hour load level of the maximum load day in summer 2025 of the power grid of Province A, that is, the active power demand P load(t)-max , as shown in Table 2;

[0165] (2) The operating installed capacity P of the conventional units in the power grid of Province A on the maximum load day in 2025G = 70640 + 5320 = 75960 MW, as shown in Table 2;

[0166] (3) In 2025, the spinning reserve rate λ of the conventional units within the power grid of Province A is 13.5%, and the spinning reserve capacity P spin-res ;

[0167] P spin-res = λP G = 13.5% × 75960 = 10254.6 MW (1)

[0168] (4) The output level of the wind turbines within the power grid of Province A in 24 hours on the maximum load day in 2025, that is, the active power output P of the wind turbines G(t)-WIND , which is obtained by multiplying the total regulated wind power output in 2025 by the wind power summer output coefficient. The results are shown in Table 2;

[0169] (5) The output level of the photovoltaic units within the power grid of Province A in 24 hours on the maximum load day in 2025, that is, the active power output P of the photovoltaic units G(t)-PV , which is obtained by multiplying the total regulated photovoltaic output in 2025 by the photovoltaic output coefficient. The results are shown in Table 2;

[0170] (6) The output level of the new energy units within the power grid of Province A in 24 hours on the maximum load day in 2025, that is, the active power output P of the new energy units G(t)-new ;

[0171] P G(t)-new = P G(t)-WINDG + P G(t)-PV (2)

[0172] (7) The output level of the total regulated units within the power grid of Province A in 24 hours on the maximum load day in 2025, that is, the active power output P of the total regulated units G(t)-int , as shown in Table 2;

[0173] P G(t)-int = (1 - λ)P G + P G(t)-new (3)

[0174] (8) The standby capacity P required for the total regulated units of the power grid of Province A in 2025 G-spare = 12000 MW, as shown in Table 1;

[0175] (9) The transmission capacity of each interconnected AC channel between the power grid of Province A and the outside in 24 hours on the maximum load day in 2025, that is, the active power P fed in by AC AC-ext , as shown in Table 1;

[0176] P AC-ext = 4640 MW (4)

[0177] (10) Transmission capacity of the power grid in Province A and each external interconnected DC channel on the maximum load day in 2025, that is, the active power P fed by DC DC-ext , as shown in Table 1;

[0178] P DC-ext = 2000 + 7400 + 7400 + 490 = 17290 MW (5)

[0179] (11) Transmission capacity of the power grid in Province A and each external interconnected AC and DC channels on the maximum load day in 2025, that is, the sum of the active power fed by AC and DC P G-ext , as shown in Table 2;

[0180] P G-ext = P AC-ext + P DC-ext = 4640 + 17290 = 21930 MW (6)

[0181] (12) The maximum load level of the whole society that can participate in demand-side response in 2025, that is, the total active power P Total load-max = 98000 MW, as shown in Table 2;

[0182] (13) The demand-side response factor η of Province A in 2025; under the maximum load level of the whole society in analysis step 12, the active power of demand-side response is P Response load , as shown in Table 2;

[0183] P Response load = ηP Total load-max = 5% × 98000 = 4900 MW (7)

[0184] (14) After determining the foregoing steps, based on the actual output curves of wind and light, such as Figure 3 , Figure 4 , Figure 5 , the 24-hour dynamic difference ΔP between the load and output on the maximum load day is obtained, as shown in Table 2;

[0185] ΔP = P load(t)-max - (P G(t)-int - P G-spare ) - P G-ext - P Response load (8)

[0186] (15) After determining the basic parameters of the foregoing steps, based on the 24-hour dynamic difference (active power deficit) between the load and output on the maximum load day obtained in step 14, by analyzing the peak value of the dynamic difference on the maximum load day in summer (maximum active power deficit capacity) ΔP limit is 2754.29 MW, ΔP is within 0 to ΔP limitThe optimal duration of the interval is about 2 hours. At this time, the spinning reserve coefficient λ is 13.5%, and the demand-side response factor η is 5%. Based on this, the optimal installed capacity P of the conventional units is determined. G is 75,960 MW, and the spinning reserve capacity P spin-res is 10,254.6 MW.

[0187] Figure 7 is the system structure diagram for analyzing the active power deficit in the interconnected power grid power balance according to the preferred embodiment of the present invention. As Figure 7 shown, the present invention provides a system for analyzing the active power deficit in the interconnected power grid power balance. The system includes:

[0188] An initial unit 701 for determining the basic parameters of the target area power grid operation;

[0189] Preferably, the initial unit 701 is used to determine the basic parameters of the target area power grid operation, including:

[0190] S1. Determine the 24-hour load level on the maximum load day of the target area power grid, that is, the active power demand P load(t)-max ;

[0191] S2. Determine the installed capacity P of the conventional units within the target area on the maximum load day G ;

[0192] S3. Determine the spinning reserve rate λ of the conventional units within the target area, the spinning reserve capacity P spin-res ,

[0193] P spin-res = λP G ;

[0194] S4. Determine the output level of the wind turbines within the target area on the 24 hours of the maximum load day, that is, the active power output P of the wind turbines G(t)-WIND ;

[0195] S5. Determine the output level of the photovoltaic units within the target area on the 24 hours of the maximum load day, that is, the active power output P of the photovoltaic units G(t)-PV ;

[0196] S6. Determine the output level of the new energy units within the target area on the 24 hours of the maximum load day, that is, the active power output P of the new energy units G(t)-new ,

[0197] P G(t)-new = P G(t)-WINDG + P G(t)-PV ;

[0198] S7. Determine the output level of the grid-connected units within the target area for 24 hours on the maximum load day, i.e., the active power output P of the grid-connected units. G(t)-int ,

[0199] P G(t)-int = (1 - λ)P G + P G(t)-new ;

[0200] S8. Determine the reserve capacity P required by the grid-connected units in the target area. G-spare ;

[0201] S9. Determine the transmission capacity of each interconnected AC channel between the target area and the outside on the maximum load day, i.e., the active power P fed in by the AC. AC-ext ;

[0202] S10. Determine the transmission capacity of each interconnected DC channel between the target area and the outside on the maximum load day, i.e., the active power P fed in by the DC. DC-ext ;

[0203] S11. Determine the transmission capacity of each interconnected AC and DC channel between the target area and the outside on the maximum load day, i.e., the sum P of the active power fed in by the AC and the active power fed in by the DC. G-ext ,

[0204] P G-ext = P AC-ext + P DC-ext ;

[0205] S12. Determine the maximum load level of the whole society that can participate in demand-side response, i.e., the total active power P. Total load-max ;

[0206] S13. Determine the demand-side response factor η of the power grid; at the maximum load level of the whole society in S12, the active power of the demand-side response is P. Response load , P Response load = ηP Total load-max .

[0207] The calculation unit 702 is configured to calculate the 24-hour dynamic difference ΔP between the load and the output on the maximum load day and the highest peak value ΔP of the dynamic difference on the maximum load day based on the basic parameters and the actual output curve of the wind and light. limit ;

[0208] Preferably, the calculation unit 702 is configured to calculate the 24-hour dynamic difference ΔP between the load and the output on the maximum load day and the highest peak value ΔP of the dynamic difference on the maximum load day based on the basic parameters and the actual output curve of the wind and light. limit , and the calculation formula for the 24-hour dynamic difference ΔP is:

[0209] ΔP = P load(t)-max - (PG(t)-int -P G-spare )-P G-ext -P Response load

[0210] That is:

[0211]

[0212] Determination unit 703, configured to determine the demand response factor η of the target regional power grid for the conventional unit spinning reserve coefficient λ when the duration of the dynamic difference ΔP in the range of 0 to ΔP limit interval is optimal; determine the optimal conventional unit on-capacity P G and spinning reserve capacity P spin-res .

[0213] Preferably, the determination unit 703 is configured to determine the optimal conventional unit on-capacity P G and spinning reserve capacity P spin-res , including:

[0214] Calculate the peak value ΔP of a dynamic difference through the 24-hour dynamic difference ΔP calculation formula limit , so that the duration of the dynamic difference ΔP on the maximum load day in the range of 0 to ΔP limit interval is the artificially set duration, and then obtain P through the transformation of the 24-hour dynamic difference ΔP calculation formula G :

[0215]

[0216] where ΔP ∈ (0, ΔP limit ,

[0217] Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV )+P G-spare -(P AC-ext +P DC-ext ) be equal to the constant C, and ΔP = ΔP limit , then the above formula is:

[0218]

[0219] Extend the results of the typical load day to the whole year:

[0220]

[0221] where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient on the nth day of the whole year.

[0222] The present invention has been described by reference to a few embodiments. However, as is well known to those skilled in the art, other embodiments equivalent to those disclosed above of the present invention equally fall within the scope of the present invention as defined by the appended patent claims.

[0223] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless otherwise clearly defined therein. All references to "a / the [device, component, etc.]" are to be construed openly as at least one instance of the device, component, etc., unless otherwise explicitly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless explicitly stated.

Claims

1. A method for analyzing the active power deficit in the power balance of an interconnected power grid, the method comprising: Determine the basic parameters of the operation of the target regional power grid, including: S1. Determine the 24-hour load levels of the target regional grid on the day with the maximum load, i.e., the active power demand P load(t)-max ; S2, determine the operating installed capacity P of the conventional units within the target area on the maximum load day G ; S3. Determine the rotating reserve rate λ of the conventional units within the target area and the rotating reserve capacity P spin-res , P spin-res = λP G ; S4. Determine the output level of the wind turbines within the target area over 24 hours on the maximum load day, i.e., the active power output P of the wind turbines G(t)-WIND ; S5. Determine the output level of the photovoltaic units within the target area for 24 hours on the maximum load day, i.e., the active power output P of the photovoltaic units G(t)-PV ; S6. Determine the output level of the new energy units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the new energy units G(t)-new , P G(t)-new = P G(t)-WINDG + P G(t)-PV ; S7, determine the output level of the grid-connected units within the target area for 24 hours on the maximum load day, i.e., the active power output P of the grid-connected units G(t)-int , P G(t)-int = (1 - λ)P G + P G(t)-new ; S8, determine the reserve capacity P required for the unified adjustment unit in the target area G-spare ; S9, determine the transmission capacity of the target area and each external interconnected AC channel on the peak load day, i.e., the active power P of the AC feed-in AC-ext ; S10. Determine the transmission capacity of the target area and each external interconnected DC channel on the maximum load day, that is, the active power P fed by the DC DC-ext ; S11. Determine the transmission capacities of the target area and each external interconnected AC and DC channels on the peak load day, i.e., the active power sum P of AC feed-in and DC feed-in G-ext , P G-ext = P AC-ext + P DC-ext ; S12. Determine the maximum load level of the whole society that can participate in demand-side response, i.e., the total active power P Totalload-max ; S13. Determine the demand-side response factor η of the power grid; under the maximum load level of the whole society in S12, the active power of the demand-side response is P Response load , P Response load = ηP Total load-max ; Based on the above-mentioned basic parameters and the actual output curves of wind and light, calculate the 24-hour dynamic difference ΔP between the load and the output on the day of the maximum load, and the highest peak value ΔP of the dynamic difference on the day of the maximum load limit ; When the duration of the dynamic difference ΔP in the range of 0 to ΔP limit is optimal, determine the demand response factor η of the target area power grid for the spinning reserve coefficient λ of the conventional unit; Determine the optimal starting capacity \(P\) of the conventional unit and the spinning reserve capacity \(P\) based on the conventional unit spinning reserve coefficient \(\lambda\) and the demand-side response factor \(\eta\). G and the spinning reserve capacity \(P\) spin-res .

2. According to the method described in claim 1, based on the basic parameters and the actual output curves of wind and light, calculate the 24-hour dynamic difference ΔP between the load and the output on the day with the maximum load, and the highest peak value ΔP of the dynamic difference on the day with the maximum load limit , and the calculation formula for the 24-hour dynamic difference ΔP is as follows: ΔP = P load(t)-max -(P G(t)-int -P G-spare )-P G-ext -P Response load That is:

3. According to the method described in claim 2, determining the optimal on-grid capacity \(P\) of the conventional unit and the spinning reserve capacity \(P\) based on the spinning reserve coefficient \(\lambda\) of the conventional unit and the demand-side response factor \(\eta\) includes: G and the spinning reserve capacity \(P\) spin-res spin-res , including: Calculate the peak value ΔP of a dynamic difference through the 24-hour dynamic difference ΔP calculation formula limit such that the duration of the dynamic difference ΔP on the maximum load day within the range of 0 to ΔP limit is the artificially set duration, and then obtain P by transforming through the 24-hour dynamic difference ΔP calculation formula G : where ΔP ∈ (0, ΔP limit , Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV )+P G-spare -(P AC-ext +P DC-ext ) be equal to the constant C, and ΔP = ΔP limit , then the above equation becomes: Extend the results of a typical load day to the whole year: where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient on the nth day of the whole year.

4. A system for analyzing the active power deficit in the power balance of an interconnected power grid, the system comprising: An initial unit for determining the basic parameters of the operation of the target regional power grid, including: S1. Determine the 24-hour load levels of the target regional grid on the day with the maximum load, i.e., the active power demand P load(t)-max ; S2, determine the operating installed capacity P of the conventional units within the target area on the maximum load day G ; S3. Determine the rotation reserve rate λ of the conventional units within the target area and the rotation reserve capacity P spin-res , P spin-res = λP G ; S4. Determine the output level of the wind turbines within the target area over 24 hours on the maximum load day, i.e., the active power output P of the wind turbines G(t)-WIND ; S5. Determine the output level of the PV units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the PV units G(t)-PV ; S6. Determine the output level of the new energy units within the target area over 24 hours on the maximum load day, i.e., the active power output P of the new energy units G(t)-new , P G(t)-new = P G(t)-WINDG + P G(t)-PV ; S7, determine the output level of the grid-connected units within the target area for 24 hours on the maximum load day, i.e., the active power output P of the grid-connected units G(t)-int , P G(t)-int = (1 - λ)P G + P G(t)-new ; S8, determine the reserve capacity P required by the unified regulation unit for the target area G-spare ; S9. Determine the transmission capacity of the target area and each external interconnected AC channel on the peak load day, i.e., the active power P of the AC feed-in AC-ext ; S10. Determine the transmission capacity of the target area and each external interconnected DC channel on the maximum load day, that is, the active power P fed by the DC DC-ext ; S11, determine the transmission capacities of the target area and each external interconnected AC and DC channels on the peak load day, i.e., the active power sum P of AC feed-in and DC feed-in G-ext , P G-ext = P AC-ext + P DC-ext ; S12. Determine the maximum load level of the whole society that can participate in demand-side response, i.e., the total active power P Total load-max ; S13, determine the demand side response factor η of the power grid; at the maximum social load level in S12, the active power of the demand side response is P Response load , P Response load =ηP Total load-max ; A calculation unit, configured to calculate a 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and a highest peak value ΔP of the dynamic difference on the maximum load day, based on the basic parameters and the actual output curves of the wind and light limit ; A determining unit, configured to determine a demand-side response factor η of a target power grid of a conventional unit spinning reserve coefficient λ when a duration of the dynamic difference ΔP within an interval of 0 to ΔP limit is optimal; and determine an optimal on-grid capacity P of the conventional unit and a spinning reserve capacity P G based on the conventional unit spinning reserve coefficient λ and the demand-side response factor η spin-res .

5. The system according to claim 4, wherein the calculation unit is configured to calculate a 24-hour dynamic difference ΔP between the load and the output on the maximum load day, and the highest peak value ΔP of the dynamic difference on the maximum load day, based on the basic parameters and the actual output curves of the wind and light limit , and the calculation formula for the 24-hour dynamic difference ΔP is: ΔP = P load(t)-max -(P G(t)-int -P G-spare ) - P G-ext -P Response load That is:

6. The system according to claim 5, wherein the determining unit is configured to determine an optimal on - line capacity P of the conventional unit G and a spinning reserve capacity P spin-res , comprising: Calculate a peak value ΔP of the dynamic difference through the 24-hour dynamic difference ΔP calculation formula limit , so that the duration of the dynamic difference ΔP on the maximum load day in the range of 0 to ΔP limit is the artificially set duration, and then P is obtained through the transformation of the 24-hour dynamic difference ΔP calculation formula G : where ΔP ∈ (0, ΔP limit , Let P load(t)-max -(P G(t)-WINDG +P G(t)-PV )+P G-spare -(P AC-ext +P DC-ext ) be equal to the constant C, ΔP = ΔP limit , then the above equation becomes: Extend the results of a typical load day to the whole year: where n = 1, 2, 3... 365, and λ n is the spinning reserve coefficient for the nth day of the whole year.

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