Capacity demand curve making method considering power supply investment

Abstract

The invention belongs to the technical field of capacity demand in an electric power system, and relates to a capacity demand curve making method considering power supply investment, which comprises the following steps of: 1, acquiring system basic technical data from an electric power system planning department; 2, setting an iteration initial value; step 3, formulating a capacity demand curve; 4, solving the equalization problem of the power generation company, and obtaining the new capacity of the power generation company and the clearing result of each market; step 5, repeating the step 3 to the step 4 until the two capacity demand curves are the same in shape, namely the capacity demand curve considering the power generation investment and considering the flexibility and the elastic demand; according to the method, the flexibility and elasticity demands are brought into the capacity demand, the influence of power generation investment planning on the capacity demand is considered, and the flexibility and elasticity of the power system are ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of capacity demand in power systems and relates to a method for formulating a capacity demand curve taking power source investment into consideration. Background Art

[0002] In order to accelerate the transformation of energy structure and promote the low-carbon transformation of power system, it has become a consensus among countries to vigorously develop new energy and accelerate the construction of new power system. However, as the proportion of new energy increases rapidly, the power system will face a series of flexibility and stability problems. How to improve the adequacy of power generation capacity under the new power system and provide sufficient frequency regulation, ramp climbing, inertia and other capabilities has become a problem that needs to be solved urgently.

[0003] As an effective market mechanism to stimulate investment in power generation units and ensure sufficient power generation capacity, the capacity market has been practiced in many countries. In order to effectively stimulate power generation investment, the power generation investment behavior of different power generation companies needs to be considered when formulating the capacity market demand curve. Power generation investment models have been established in the prior art, some of which consider the power generation investment models of power generation companies under the forward capacity market, annual clearing capacity market and pure energy market. Some studies have also proposed power generation investment models for power generation companies in capacity markets specifically for new investments, and compared them with existing and newly entered capacity markets. It was found that the former led to more power generation investment. Power generation investment among multiple power generation companies creates a balance problem, which is usually solved using game theory methods.

[0004] However, although the prior art has studied the balance of power generation investment under a given power generation capacity, little attention has been paid to how to formulate the power generation demand curve by considering its guidance on the balance of power generation investment. In order to optimize the power generation mix to enhance flexibility and resilience, power generation investment and its balance should be considered when formulating the capacity demand curve. Formulating such a capacity demand curve by considering the guidance of power generation investment balance will be more complicated than simply solving the power generation investment balance with predefined power generation capacity, because this may lead to a balance adjustment problem rather than just a balance solution. In addition, in countries or regions with multi-regional coupled power markets, the design of the capacity market should also consider its guidance on power generation investment in each region, because inappropriate capacity market mechanisms in multi-regional coupled power markets may have a negative impact on producers' profits and reduce capacity adequacy, causing the power generation mix in each region to be mutually affected.

[0005] Therefore, a method is needed to solve the above technical problems by formulating a capacity demand curve and effectively stimulating power generation investment. Summary of the invention

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for formulating a capacity demand curve considering power source investment, including: specifying flexible and elastic requirements as climbing capacity, inertia and recovery capacity, and on this basis, proposing a capacity demand curve formulation model considering the balance of power generation investment among power generation companies; using the KKT condition of the model to solve the balance problem among power generation companies; based on the investment and provision strategy of the power generation company, obtaining the capacity demand curve of power generation capacity, climbing capacity, inertia and recovery capacity through an iterative algorithm; specifically including the following steps:

[0007] Step 1: Obtain basic technical data of the system from the power system planning department;

[0008] Step 2: Set the initial value of iteration;

[0009] Step 3: Develop the capacity demand curve;

[0010] Step 4: Solve the equilibrium problem of the power generation company and obtain the new capacity of the power generation company and the clearing results of each market;

[0011] Step 5: Repeat steps 3 to 4 until the shapes of the two capacity demand curves are the same. This is the capacity demand curve that takes into account power generation investment and flexibility and elasticity requirements.

[0012] Preferably, in step 1, the basic technical data of the system include: technical parameters of various types of power sources in the power system, existing transmission grid and network parameters, load demand and forecast data of new energy power generation;

[0013] In step 2, the initial values ​​of the iteration include the new capacity of the unit, the market quotations, and the line capacity;

[0014] In step 3, the capacity demand curve is formulated for all regions based on the new capacity of the units, market quotations, and line capacity. The capacity demand includes power generation capacity demand, flexibility, and elastic demand capacity.

[0015] Preferably, in step 3, a capacity demand curve formulation model is established which comprehensively considers power generation investment and flexibility and elasticity requirements; two capacity demand curves are given in step 3, one capacity demand curve is used for power generation capacity, and the other capacity demand curve is used for three ancillary service products, also known as flexibility and elasticity demand curves. The reason why three ancillary service products can use one demand curve is that various types of ancillary services have certain substitutability.

[0016] Preferably, in step 3, the objective function of the capacity demand curve includes:

[0017] (1)

[0018] (2)

[0019] (3)

[0020] (4)

[0021] (5)

[0022] In formula (1) to formula (5), Respectively represent the index of time and scene; , , , They represent the cost of generation capacity, the cost of flexibility and elasticity capacity, the economic losses caused by insufficient generation capacity, and the economic losses caused by insufficient flexibility and elasticity capacity, respectively; , , They represent the unit generation capacity quotation, unit flexibility and elastic capacity quotation, line generation capacity quotation, line flexibility and elastic capacity quotation respectively; represents the set of units in area i; represents the set of regions connected to region i; , , , They represent the generating capacity of the unit, the flexibility and elasticity of the unit, the generating capacity of the line, the flexibility and elasticity of the line respectively; They represent the penalty factors for insufficient power generation capacity / ramp climbing / inertia / accident recovery capability respectively; , , , They respectively represent the shortfall in power generation capacity, ramp rate, inertia, and accident recovery capability.

[0023] Preferably, the step 4 specifically includes the following sub-steps:

[0024] Step 4.1: With the goal of maximizing the revenue of the power generation company, establish a power generation investment planning model for each power generation company, taking into account the revenue, power generation cost and investment and construction cost of the power generation company in the capacity market and the electric energy market;

[0025] Step 4.2: Establish the clearing model of the capacity market and the clearing model of the electric energy market respectively. In addition to the basic unit capacity, the trading products in the capacity market also include three trading products that support flexibility and elasticity demand: ramping capability, inertia, and accident recovery capability. The impact of charging and discharging of energy storage systems is considered in the electric energy market.

[0026] Step 4.3: Model transformation; solve the KKT conditions of the power generation investment planning model, capacity market clearing model and electric energy market clearing model of each power generation company respectively to obtain the optimality conditions of the entire problem; combine the optimality conditions of all models to solve the investment strategies, bidding strategies and clearing results of the capacity market and electric energy market of all power generation companies.

[0027] Preferably, in step 4.1, the objective function of the power generation investment planning model includes:

[0028] (20)

[0029] In formula (20), It represents the unit investment cost of new generating units; Indicates the newly built capacity of the unit; Indicates the unit Costs; , , Respectively represent the unit The number of successful bids in the energy market, the number of successful bids in the capacity market for capacity support, and the number of successful bids in the capacity market for flexibility and elasticity support; , , , , Respectively Time zone The clearing price of the electricity energy market, the clearing price of the capacity market, the clearing price of the capacity market ramping capacity, the clearing price of the capacity market inertia, and the clearing price of the capacity market accident recovery capacity; , Respectively represent the unit number and the power generation company The collection of units; , Respectively represent the index and total number of time; ω, They represent the scene number and the probability of occurrence respectively.

[0030] Preferably, in step 4.2, the objective function of the capacity market clearing model includes:

[0031] (twenty three)

[0032] In formula (23), , Respectively represent the load curve segment index and total number; Respectively represent the region index and total number; Respectively represent the unit number index and total number; , , , Respectively represent the load curve Segment quotations in capacity market, ramping, inertia, and accident recovery; , , , Respectively represent the load curve Segment needs; denote the bids of the units in the capacity market and the flexibility and elasticity market respectively; Represent the winning capacity of the unit in the capacity market and the flexibility and elasticity market respectively.

[0033] Preferably, in step 4.2, the objective function of the electric energy market clearing model includes:

[0034] (34)

[0035] In formula (34), Indicates the time index and total number; Indicates the energy storage index and total number; represents the probability of the scenario; Indicates the market quotation of electric energy; Indicates the energy storage charging price; , Respectively represent the unit Winning bid power and energy storage charging power.

[0036] The beneficial effects of the present invention are:

[0037] 1. The present invention is used to determine the capacity demand curve of the power system in the power market environment. While incorporating flexibility and elasticity requirements into the capacity demand, it also considers the impact of power generation investment planning on the capacity demand, thereby ensuring sufficient flexibility and elasticity of the power system.

[0038] 2. The present invention can realize the formulation of capacity demand curves and effectively stimulate power generation investment. Compared with the traditional capacity demand curve formulation method, the present invention takes into account the impact of power generation investment on capacity demand, and incorporates flexibility and elasticity into the capacity market. By solving the equilibrium relationship between the power generation company in the capacity market and the electric energy market, the new capacity and market quotation strategy of the power generation company are calculated, and the capacity demand curve is calculated iteratively. The present invention provides two capacity curves, one for power generation capacity and the other for three ancillary service products. The present invention can effectively consider the impact of power generation investment on capacity demand, incorporate the impact of power generation investment into the demand curve formulation model by iteratively solving the capacity demand curve and market equilibrium, and consider the flexibility and elasticity requirements of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1It is a schematic diagram of the relationship between the various parts of an investment planning method of a method for formulating a capacity demand curve taking into account power source investment in the present invention;

[0040] Figure 2 is a schematic diagram of the capacity demand curve of region 1 of the present invention;

[0041] Figure 3 is a schematic diagram of the capacity demand curve for region 2 of the present invention;

[0042] Figure 4 It is a schematic flow chart of the method of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technologies in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] refer to Figures 1 to 4 The method for formulating a capacity demand curve taking into account power source investment in this embodiment is used to determine the capacity demand of the power system in a power market environment. While incorporating flexibility and elasticity demands into the capacity demand, it also considers the impact of power generation investment planning on the capacity demand to ensure sufficient flexibility and elasticity of the power system.

[0045] In order to achieve the above objectives, this implementation method specifies flexible and elastic demand as three trading products: ramping capacity, inertia, and recovery capacity, and studies the capacity demand quantification model. On this basis, a capacity demand curve formulation model considering the balance of power generation investment among power generation companies is proposed. The KKT condition of the constructed model is used to solve the equilibrium problem among power generation companies. Based on the investment and provision strategies of power generation companies, the capacity demand curves of power generation capacity, ramping capacity, inertia, and recovery capacity are obtained through an iterative algorithm.

[0046] The specific steps include:

[0047] Step 1: Obtain basic system technical data from the power system planning department.

[0048] The basic technical data of the system include: technical parameters of various types of power sources in the power system, existing transmission grid and network parameters, load demand and forecast data of new energy power generation.

[0049] Step 2: Set the initial values ​​for iteration, including new capacity of units, market quotations, line capacity, etc.

[0050] Step 3: Develop capacity demand curves; Based on the new capacity of units, market quotations, and line capacity, develop capacity demand curves for all regions, including power generation capacity demand, flexibility, and elastic demand capacity.

[0051] Step 4: Solve the equilibrium problem of the power generation company and obtain the new capacity of the power generation company and the market clearing results, which includes the following steps:

[0052] Step 4.1: With the goal of maximizing the revenue of power generation companies, establish a power generation investment planning model for each power generation company, taking into account the revenue, power generation cost and investment and construction cost of the power generation company in the capacity market and the electric energy market.

[0053] Step 4.2: Establish clearing models for the capacity market and the electric energy market respectively. In addition to the basic unit capacity, the trading products in the capacity market also include three trading products that support flexibility and elasticity demand: ramping capability, inertia, and accident recovery capability. The impact of charging and discharging of energy storage systems is considered in the electric energy market.

[0054] Step 4.3: Model transformation. Solve the KKT conditions of the power generation investment planning model, capacity market clearing model and electric energy market clearing model of each power generation company respectively to obtain the optimality conditions of the whole problem. Combine the optimality conditions of all models to solve the investment strategies, bidding strategies and clearing results of capacity market and electric energy market of all power generation companies.

[0055] Step 5: Repeat steps 3-4 until the shapes of the two capacity demand curves are the same. This is the capacity demand curve that takes into account power generation investment and flexibility and elasticity requirements.

[0056] Furthermore, step 3 establishes a capacity demand curve formulation model that comprehensively considers power generation investment and flexibility and elasticity requirements, which is the core step of the present invention. In step 3, two capacity demand curves will be given, one for power generation capacity and the other for three ancillary service products, also known as flexibility and elasticity demand curves. The three ancillary service products can use one demand curve because various ancillary services have certain substitutability.

[0057] Furthermore, step 4 solves the equilibrium problem of power generation companies participating in different markets. The traditional capacity market only includes one transaction type, namely power generation capacity. The present invention incorporates the flexibility and elasticity of the power system into the capacity market, adds three trading products, namely ramping capacity, inertia and accident recovery capacity, in the capacity market, fully considers the system flexibility and elasticity requirements, and considers the relevant decisions and impacts of energy storage in the electric energy market. Based on the new capacity of different power generation companies in the market equilibrium results and the winning capacity of each market, a relevant capacity demand curve can be formulated for each transaction type, which effectively stimulates investment in power generation capacity and ensures that the system maintains a certain degree of abundance and elasticity.

[0058] The present invention is further described below in conjunction with the accompanying drawings, when the method of the present invention is applied:

[0059] Step 1: Get the required data from relevant departments. The input data for the calculation model obtained from relevant departments include the following data:

[0060] The basic technical data of the system include: technical parameters of various types of power sources in the power system, existing transmission grid and network parameters, load demand and new energy power generation forecast data.

[0061] After obtaining the above information from relevant departments, follow the steps below to carry out power generation investment planning that takes into account the coupling of capacity market and electricity energy market.

[0062] Step 2: Set the initial values ​​for iteration, including the new capacity of the unit, market quotations, line capacity, etc. The new capacity of the unit can be set to 0, and other data can be set to initial values ​​based on historical data.

[0063] Step 3: Capacity demand curve formulation. It should be noted that in the capacity demand curve formulation model, the subscript represents the inflection point on the capacity demand curve. By calculating the expected economic loss caused by insufficient supply capacity and the expected cost of purchasing capacity at a series of inflection points of the capacity demand curve, the price corresponding to each inflection point is obtained through the dual multipliers of constraints (6)-(9), and the capacity demand curve can be obtained. The objective function is shown in equations (1)-(5). Constraints (6)-(9) represent the load loss caused by insufficient power generation capacity, ramping capacity, inertia, and accident recovery capacity, respectively. (10)-(13) represent the constraints on the overall supply capacity of power generation capacity, ramping capacity, inertia, and recovery capacity, respectively. (14)-(16) provide capacity setting limits for units in the capacity market. Renewable energy can only provide power generation capacity products, while other types of units such as thermal power units and energy storage can provide power generation capacity, ramping capacity, inertia, and accident recovery capacity. (17)-(19) impose restrictions on inter-regional transmission capacity.

[0064] Objective function:

[0065] (1)

[0066] (2)

[0067] (3)

[0068] (4)

[0069] (5)

[0070] (6)

[0071] (7)

[0072] (8)

[0073] (9)

[0074] (10)

[0075] (11)

[0076] (12)

[0077] (13)

[0078] (14)

[0079] (15)

[0080] (16)

[0081] (17)

[0082] (18)

[0083] (19)

[0084] Where: ":" is followed by the dual variable corresponding to the constraint condition;

[0085] - Cost of generation capacity / cost of flexibility and elasticity / economic losses caused by insufficient generation capacity / economic losses caused by insufficient flexibility and elasticity;

[0086] , ——Power generation capacity quotation / flexibility and elastic capacity quotation / line power generation capacity quotation / line flexibility and elastic capacity quotation;

[0087] , , , ——Generation capacity of the unit / flexibility and elasticity of the unit / generation capacity of the line / flexibility and elasticity of the line;

[0088] ——penalty factor of the corresponding product;

[0089] , , , —— Shortage of power generation capacity / rampability / inertia / accident recovery capability;

[0090] ——

[0091] ——Load / wind power output / photovoltaic output / unit power generation;

[0092] ——Load change / wind power output change / photovoltaic output change / climbing ability;

[0093] ——Frequency / load loss / maximum frequency change rate / inertia;

[0094] ——Accident probability / power outage loss / power outage time / accident recovery capacity;

[0095] ——Climbing capacity factor / inertia capacity factor / accident recovery capacity factor;

[0096] ——New capacity / existing installed capacity;

[0097] ——credible capacity factor;

[0098] - Line capacity caps for generation capacity / Line capacity caps for flexibility and resiliency / Line transmission capacity;

[0099] Step 4: Solve the equilibrium problem of the power generation company and obtain the decision result of the power generation company based on market clearing.

[0100] Specifically, 4.1: Establish a power generation investment planning model for power generation companies, and consider the bidding decisions of power generation companies in the capacity market and the electric energy market. The decision variables of this model include the newly installed capacity of the power generation company and the quotations in each market. For a certain power generation company, the strategic bidding is carried out with the goal of maximizing its own profit, including the income, investment cost and power generation cost in the electric energy market and the capacity market. The objective function is formula (20), and the constraints include the newly added capacity constraint formula (21) of the power generation unit and the market quotation constraint formula (22) of the unit.

[0101] Objective function:

[0102] (20)

[0103] st

[0104] (twenty one)

[0105] (twenty two)

[0106] Where: ":" is followed by the dual variable corresponding to the constraint condition;

[0107] ——Unit investment cost of new units;

[0108] ——New capacity of the unit;

[0109] ——Unit number / Generator The collection of units;

[0110] - Index and total number of times;

[0111] ——Scenario number and probability of occurrence;

[0112] --unit Costs;

[0113] --unit The amount of winning bids in the electric energy market / the amount of winning bids in the capacity market for capacity support / the amount of winning bids in the capacity market for flexibility and elasticity support;

[0114] - area number;

[0115] —— Time zone The clearing price of the electricity energy market / the clearing price of the capacity market / the clearing price of the capacity market ramping capacity / the clearing price of the capacity market inertia / the clearing price of the capacity market accident recovery capacity;

[0116] --unit Maximum new capacity / existing installed capacity;

[0117] ——Power generation company Maximum new construction capacity factor;

[0118] ——Flexible capacity, electricity market quotation and its upper limit of capacity / support flexibility in the capacity market.

[0119] 4.2.1: Establish a capacity market clearing model. The capacity market clearing model takes the maximum social welfare as the optimization goal, that is, the maximum total social surplus as the goal. Through the market clearing model, the system capacity clearing price and various auxiliary service clearing prices for flexibility and elasticity support can be calculated, and then used for power generation company decision-making. The constraints include (24)-(33), where (24)-(27) represent the supply and demand balance relationship of power generation capacity, ramping, inertia, and accident recovery capacity, respectively, and their dual multipliers are the clearing prices of the corresponding markets, (28)-(30) set restrictions on the configuration capacity of power generation capacity, flexibility and elasticity, (31) constrains the capacity of each segment of the capacity demand curve, (32) is the limit of inter-regional transmission capacity, and (33) is the balance of inter-regional transmission capacity.

[0120] Objective function:

[0121] (twenty three)

[0122] st

[0123] (twenty four)

[0124] (25)

[0125] (26)

[0126] (27)

[0127] (28)

[0128] (29)

[0129] (30)

[0130] (31)

[0131] (32)

[0132] (33)

[0133] Where: ":" is followed by the dual variable corresponding to the constraint condition;

[0134] ——Load curve segment index and total number;

[0135] ——Load curve Segment quotations in capacity market / ramp / inertia / accident recovery;

[0136] ——Load curve Segment needs;

[0137] --line Available capacity / ancillary service capacity;

[0138] --area The collection of units;

[0139] ——Photovoltaic / wind turbine assembly;

[0140] ——climbing / inertia / accident recovery capacity coefficient;

[0141] ——Capacity market upper limit coefficient for unit participation;

[0142] --line The maximum transmission capacity of

[0143] 4.2.2: Establish an electric energy market clearing model. The goal of electric energy market clearing is to maximize social welfare. Considering that users do not participate in bidding, the goal is to minimize the bidding revenue of the power generation company. At the same time, the impact of energy storage is considered, as shown in formula (34). The constraints include: unit bidding power constraint (35), energy storage charging constraint (36), power balance constraint (37), line transmission capacity constraint (38), energy storage state charging and discharging constraint (39)-(40).

[0144] Objective function:

[0145] (34)

[0146] st

[0147] (35)

[0148] (36)

[0149] (37)

[0150] (38)

[0151] (39)

[0152] (40)

[0153] Where: ":" is followed by the dual variable corresponding to the constraint condition;

[0154] ——Energy storage charging price;

[0155] ——Energy storage charging capacity;

[0156] ——Wind power generation / photovoltaic power generation / unit Winning bid power / line transmission power / load demand / energy storage charging power;

[0157] --line For Node The power transfer factor of

[0158] ——Minimum and maximum energy storage capacity.

[0159] 4.3.1: Model transformation, solving the KKT conditions of the above three models (power generation investment planning model, capacity market model, and electricity energy market model) to form the optimality conditions.

[0160] 4.3.2: Solve the equilibrium problem, obtain the bidding strategy, and build the capacity of the new unit.

[0161] Step 5: Repeat steps 3 and 4 until the load curves are the same.

[0162] Example

[0163] In order to verify the effectiveness of the method proposed in the present invention, two regional power systems are selected for calculation and analysis. The power load of the two regions is 200MW, and the regions are interconnected through a tie line. The power generation companies and installed capacities of the two regions are shown in Table 1.

[0164]

[0165] Design comparison example:

[0166] Example 1: The transmission capacity of the regional interconnection line is 50MW, that is, inter-regional transmission is not blocked;

[0167] Example 2: The transmission capacity of the regional interconnection line is 10MW, which means that inter-regional transmission is blocked.

[0168] Figure 2-Figure 3 The capacity demand curves of the two regions under Example 1 and Example 2 are given. In order to intuitively and quantitatively represent the flexibility and elasticity requirements, the capacity requirements of ramping capacity, inertia and recovery capacity are transformed into the corresponding capacity with average ramping performance, inertia constant and available time coefficient.

[0169] First, the maximum demands for the generation capacity of the two regions on the capacity demand curve are similar (145MW for region 1 and 154MW for region 2) because the total installed capacity and load demand of the two regions are very close. The ramping capacity and inertia, which are closely related to the installed capacity of renewable energy, are significantly higher in region 1 (107.5MW and 152MW) than in region 2 (53MW and 102MW) on the capacity demand curve because renewable energy is mainly installed in region 1. The differences in the capacity demand curves for ramping capacity and inertia indicate that the proposed method for formulating the capacity demand curve can effectively reflect the flexibility needs of each region. In terms of recovery capacity, the capacity demand curves of the two regions are also similar, and the demand for recovery capacity is relatively small.

[0170] In addition, if Figure 2 As shown in Figure 1, the change in inter-regional transmission capacity has a significant impact on the generation capacity and inertia capacity demand curve of region 1. Since region 1 has a large installed capacity of renewable energy, but low installed capacity of thermal power and energy storage, when the transmission capacity between the two regions is limited, the demand for flexibility and elasticity in region 2 is difficult to be supported by region 1. Therefore, it is necessary to increase the configuration capacity of ramping capacity, inertia and accident recovery capacity, while reducing the configuration demand of generation capacity. Figure 3 As shown in Figure 2, the change in inter-regional transmission capacity also has a significant impact on the capacity demand curve of ramping capacity and inertia in Region 2. Due to the large existing thermal power and energy storage capacity, there is excess ramping capacity and inertia in Region 2. When inter-regional transmission capacity is insufficient, excess ramping capacity can be provided in Region 2, and the price on the demand curve can be lower.

[0171] It can be seen that each region can formulate a capacity demand curve for power generation capacity, ramping capacity, inertia capacity and recovery capacity by adjusting the maximum demand and corresponding capacity price on the capacity demand curve to reflect the excess or shortage of these capacities. Such a capacity demand curve can help meet the needs of power generation capacity, flexibility and elasticity, and guide the reasonable investment of power generation companies.

[0172] In summary, the present invention incorporates flexibility and elasticity requirements into capacity requirements while taking into account the impact of power generation investment planning on capacity requirements, thereby ensuring sufficient flexibility and elasticity of the power system.

[0173] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for formulating a capacity demand curve considering power source investment, characterized in that: include: Flexible and elastic demands are designated as ramping capacity, inertia and recovery capacity. On this basis, a capacity demand curve formulation model considering the balance of power generation investment among power generation companies is proposed; the KKT condition of the model is used to solve the equilibrium problem among power generation companies; based on the investment and supply strategies of power generation companies, the capacity demand curve of power generation capacity, ramping capacity, inertia and recovery capacity is obtained through an iterative algorithm; the specific steps include: Step 1: Obtain basic technical data of the system from the power system planning department; Step 2: Set the initial value of the iteration; Step 3: Develop the capacity demand curve; Step 4: Solve the equilibrium problem of the power generation company and obtain the new capacity of the power generation company and the clearing results of each market; Step 5: Repeat steps 3 to 4 until the shapes of the two capacity demand curves are the same. This is the capacity demand curve that takes into account power generation investment and flexibility and elasticity requirements.

2. A method for formulating a capacity demand curve considering power source investment according to claim 1, characterized in that: In step 1, the basic technical data of the system include: technical parameters of various types of power sources in the power system, existing transmission grid and network parameters, load demand and forecast data of new energy power generation; In step 2, the initial values ​​of the iteration include the newly built capacity of the unit, the market quotations, and the line capacity; In step 3, the capacity demand curve is formulated for all regions based on the newly built capacity of the units, market quotations, and line capacity. The capacity demand includes power generation capacity demand, flexibility, and elastic demand capacity.

3. A method for formulating a capacity demand curve considering power source investment according to claim 1, characterized in that: In the step 3, a capacity demand curve formulation model is established that comprehensively considers power generation investment and flexibility and elasticity requirements; two capacity demand curves are given in the step 3, one capacity demand curve is used for power generation capacity, and the other capacity demand curve is used for three ancillary service products.

4. A method for formulating a capacity demand curve considering power source investment according to claim 1, characterized in that: In step 3, the objective function of the capacity demand curve includes: （1） （2） （3） （4） （5） In formula (1) to formula (5), Respectively represent the index of time and scene; , , , They represent the cost of generation capacity, the cost of flexibility and elasticity capacity, the economic losses caused by insufficient generation capacity, and the economic losses caused by insufficient flexibility and elasticity capacity, respectively; , , They represent the unit generation capacity quotation, unit flexibility and elastic capacity quotation, line generation capacity quotation, line flexibility and elastic capacity quotation respectively; represents the set of units in area i; represents the set of regions connected to region i; , , , They represent the generating capacity of the unit, the flexibility and elasticity of the unit, the generating capacity of the line, the flexibility and elasticity of the line respectively; They represent the penalty factors for insufficient power generation capacity / ramp climbing / inertia / accident recovery capability respectively; , , , They respectively represent the shortfall in power generation capacity, ramp rate, inertia, and accident recovery capability.

5. The method for formulating a capacity demand curve considering power source investment according to claim 1, characterized in that: The step 4 specifically includes the following sub-steps: Step 4.1: With the goal of maximizing the revenue of the power generation company, establish a power generation investment planning model for each power generation company, taking into account the revenue, power generation cost and investment and construction cost of the power generation company in the capacity market and the electric energy market; Step 4.2: Establish the clearing model of the capacity market and the clearing model of the electric energy market respectively. In addition to the basic unit capacity, the trading products in the capacity market also include three trading products that support flexibility and elasticity demand: ramping capability, inertia, and accident recovery capability. The impact of charging and discharging of energy storage systems is considered in the electric energy market. Step 4.3: Model transformation; solve the KKT conditions of the power generation investment planning model, capacity market clearing model and electric energy market clearing model of each power generation company respectively to obtain the optimality conditions of the entire problem; combine the optimality conditions of all models to solve the investment strategies, bidding strategies and clearing results of the capacity market and electric energy market of all power generation companies.

6. A method for formulating a capacity demand curve considering power source investment according to claim 5, characterized in that: In step 4.1, the objective function of the power generation investment planning model includes: （20） In formula (20), It represents the unit investment cost of new generating units; Indicates the newly built capacity of the unit; Indicates the unit Costs; , , Respectively represent the unit The number of successful bids in the energy market, the number of successful bids in the capacity market for capacity support, and the number of successful bids in the capacity market for flexibility and elasticity support; , , , , Respectively Time zone The clearing price of the electricity energy market, the clearing price of the capacity market, the clearing price of the capacity market ramping capacity, the clearing price of the capacity market inertia, and the clearing price of the capacity market accident recovery capacity; , Respectively represent the unit number and the power generation company The collection of units; , Respectively represent the index and total number of time; ω, They represent the scene number and the probability of occurrence respectively.

7. A method for formulating a capacity demand curve considering power source investment according to claim 5, characterized in that: In step 4.2, the objective function of the capacity market clearing model includes: （23） In formula (23), , Respectively represent the load curve segment index and total number; Respectively represent the region index and total number; Respectively represent the unit number index and total number; , , , Respectively represent the load curve Segment quotations in capacity market, ramping, inertia, and accident recovery; , , , Respectively represent the load curve Segment needs; denote the bids of the units in the capacity market and the flexibility and elasticity market respectively; Represent the winning capacity of the unit in the capacity market and the flexibility and elasticity market respectively.

8. The method for formulating a capacity demand curve considering power source investment according to claim 5, characterized in that: In step 4.2, the objective function of the clearing model of the electric energy market includes: （34） In formula (34), Indicates the time index and total number; Indicates the energy storage index and total number; represents the probability of the scenario; Indicates the market quotation of electric energy; Indicates the energy storage charging price; , Respectively represent the unit Winning bid power and energy storage charging power.

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