New energy distribution and storage multi-stage operation method for power contract time-sharing assessment

Abstract

The invention discloses a power contract time-sharing assessment-oriented new energy distribution and storage multi-stage operation method, and belongs to the technical field of novel power system scheduling and operation, and the method comprises the steps: building an RES income settlement model which faces daily power contract time-varying default assessment and considers the relation between daily power contract performance capability and power market clearing electricity price; an RES daily power contract day-ahead optimization declaration method considering self-built BESS auxiliary adjustment capability under a daily power contract time-sharing default assessment mode is provided; in a daily power contract time-sharing default assessment mode, the RES daily power contract intra-day rolling execution method with the help of self-established BESS auxiliary adjustment is established. Compared with a traditional RES power generation curve declaration and execution method, the method has the advantage that the net income can be stably and obviously improved in the 30-day operation period.

Description

Technical Field

[0001] The present invention belongs to the technical field of new power system dispatching and operation, and specifically relates to a multi-stage operation method for distributing and storing new energy for time-sharing assessment of power contracts. Background Art

[0002] Unlike conventional thermal power units, new energy stations (RES) cannot effectively track the electricity demand of power users without other auxiliary adjustment means due to their inherent randomness and volatility. Therefore, the power grid must change the planned output of conventional thermal power units to accurately track the real-time power consumption curve of the load. At this time, if the thermal power unit is in a deep peak regulation or peak output state, changing the power generation plan formulated a few days ago will incur additional adjustment costs. Following the current "who uses, who pays" principle of sharing the power auxiliary service costs of the power grid, this part of the cost caused by the breach of the RES daily time scale power contract needs to be borne by the user and RES. For the real-time operating income of RES, bearing this part of the cost will significantly reduce its net profit. For the long-term operating income of RES, if it cannot perform the daily power contract well, resulting in users being forced to pay a large amount of assessment fees, then the competitiveness of RES in the power market will be significantly reduced, and its transaction price will be greatly discounted.

[0003] Affected by the policy of mandatory configuration of battery energy storage system (BESS) for RES, RES has a certain degree of autonomous regulation capability at the hardware level. With the help of BESS and reasonable modification of power contracts, the contract performance capability of RES can be greatly improved. At present, BESS is still widely used for peak shaving and valley filling, and it is often not able to effectively charge and discharge once a day, so its rate of return is very low. In addition, the use of BESS for power contract performance can effectively reduce the idle rate of BESS. Due to the extremely uneven distribution of RES output within the daily time scale, the pressure caused by its randomness and volatility on grid operation is also intermittent. During the period when some RES output is low or / and the grid flexibility regulation resources are relatively abundant, the grid has a low assessment of the performance of RES daily power contracts. In the period when other RES output is high or / and the grid flexibility regulation resources are relatively scarce, the grid has a high assessment of the performance of RES daily power contracts. In the face of complex and time-varying daily power contract execution pressure, a multi-stage operation method of new energy storage for time-sharing assessment of power contracts is needed to solve how RES can make good use of its own BESS to reasonably formulate and perform daily power contracts. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a multi-stage operation method for storing new energy for time-sharing assessment of power contracts, thereby solving the problems in the above-mentioned background technology.

[0005] The purpose of the present invention is achieved as follows: a multi-stage operation method for distributing and storing new energy for time-sharing assessment of power contracts, which includes: S1, establishing a RES income settlement model for time-varying default assessment of daily power contracts, considering the relationship between daily power contract performance capacity and power market clearing electricity price; S2, proposing a RES daily power contract day-ahead optimization declaration method considering the auxiliary regulation capacity of self-built BESS under the daily power contract time-sharing default assessment mode; S3, establishing a RES daily power contract intraday rolling execution method with the help of self-built BESS auxiliary regulation under the daily power contract time-sharing default assessment mode.

[0006] Furthermore, the RES revenue settlement model includes how much default assessment fees are generated in the process of fulfilling the daily power contract and how high the electricity price can be cleared in the power market under the current contract fulfillment capacity;

[0007] The mathematical model of RES income settlement model is:

[0008]

[0009] Where: C R is the total income of RES, yuan; c e is the transaction price of RES in the power market, RMB / MWh; t represents the dispatching period; N T is the number of scheduling periods in a day, which is 96; Δt is the duration of the scheduling period, h, which is Δt=0.25h; P t is the actual grid-connected power of RES during period t, MW; C fee The default assessment fee that RES needs to pay is RMB.

[0010] Furthermore, the calculation model of the comprehensive default index of RES daily power contract is:

[0011]

[0012] Where: R is the daily power contract comprehensive default index of RES; P t dev is the default power of RES in period t, MW; α t is the default ratio allowed in period t; r t is the default weight coefficient for period t, which is about P t dev / P t The function of P t dev / P t The bigger the t The larger the P t dev / P t With r tThere are also differences in the relationship between t dev-r (.) indicates r t With P t dev / P t The functional relationship between t sch is the daily power contract planned power of RES in period t, MW;

[0013] After calculating the daily power contract comprehensive default index R, establish c e and C fee The calculation model is:

[0014] c e =f price-R (R) (5)

[0015]

[0016] Where: f price-R (.) is c e The functional relationship between and R, the specific form of which is determined by the result of electricity market clearing; c R is the price coefficient for default assessment, RMB / MWh; R min It is the default assessment threshold. When R is lower than this value, no assessment will be conducted.

[0017] Furthermore, the day-ahead optimization declaration method of the daily power contract includes expected electricity fee income, expected default assessment fee and self-built BESS use cost; the optimization target of the daily power contract in each period is:

[0018]

[0019] Where: is the total expected net benefit, yuan; is the total expected revenue from electricity sales, yuan; is the total expected assessment cost, yuan; is the total expected cost of BESS, RMB;

[0020] calculate Using the actual grid power and market transaction price of RES at each time period, The calculation method is,

[0021]

[0022] Where: is the expected transaction price of RES, RMB / MWh; P t,f is the expected on-grid power of RES in period t, MW;

[0023] P t,fThe calculation method is,

[0024]

[0025] Where: P t org is the original predicted power of RES in period t, MW; is the expected charging and discharging power of the self-built BESS during period t, MW; η ch , η dch The charge and discharge loss rate of BESS;

[0026] The calculation method is,

[0027]

[0028] Where: R f is the expected value of the comprehensive default index of RES’ daily electricity contract; is the expected deviation power of RES in period t, MW; is the expected positive and negative deviation power of RES in period t, MW; P G is the installed capacity of RES, MW; f t (P) is the probability density distribution function of the RES day-ahead power forecast for period t.

[0029] Further, The value range of is constrained to be,

[0030]

[0031] Where: is the installed capacity of BESS, MWh; μ is the statistical value of the daily equivalent charge and discharge cycles of BESS; δ ch , δ dch is the maximum charge and discharge rate of BESS; T is the calculated δ ch , δ dch The time period is h, and T = 1.0h;

[0032] The specific calculation formula is:

[0033]

[0034] The calculation method is,

[0035]

[0036] Where: c BESS It is the lifetime consumption cost of BESS per unit charge and discharge, RMB / MWh.

[0037] Furthermore, the intraday rolling execution method of the daily power contract includes making corrections based on the latest power forecast data and the actual state of charge of the BESS; the optimization goal of correcting the actual charging and discharging action of the BESS is to maximize the total net profit of the RES within the intraday forecast window, and the optimization goal is,

[0038]

[0039] Where: is the net profit of RES in the short-term window starting from time period t, RMB; N s N is the number of scheduling periods contained in the short-term window within the day. s =8; is the electricity sales revenue of RES during period t, yuan; is the assessment fee of RES in period t, yuan; is the cost of using BESS in period t, yuan;

[0040] Since the daily power contract has not been fully executed, the value of the comprehensive default index R of the daily power contract is unknown, so the electricity price c e It is also unknown. According to the preliminary calculation of the default situation of power contracts that have been executed and will be executed in the short term, The calculation method is,

[0041]

[0042] c e,t =f price-R (R t ) (twenty one)

[0043]

[0044] Where: c e,t is the transaction price of RES up to the end of period t, RMB / MWh; R t is the calculated value of the comprehensive default index of the daily power contract up to the period t; since the daily power contract has not been fully executed, the value of the comprehensive default index R of the daily power contract is unknown, and the incremental assessment fee that RES needs to pay in period t is The calculation method is,

[0045]

[0046] Due to the cost of using BESS It is clearly linearly related to the charging and discharging power of BESS, so it can be directly calculated. The specific formula is:

[0047]

[0048] In the day-ahead stage, since it is still far from the actual power generation stage, the constraints of the BESS charge state on the charging and discharging power of the BESS are not considered. In the intraday stage, the RES is about to call the BESS to actually perform charging and discharging operations, and the current SOC of the BESS is known. t ch , P t dch To satisfy the following constraints,

[0049]

[0050] SOC min SOC t SOC max (26)

[0051] Where: SOC t is the SOC of BESS during period t; SOC min , SOC max It is the upper and lower limit of SOC of BESS.

[0052] Beneficial effects of the present invention: Compared with the traditional RES power generation curve declaration and execution method, the RES created by the present invention can stably and significantly improve its net income in a 30-day operation cycle. Specifically, the net income of the RES created by the present invention has increased from the original 75.63957 million yuan to the current 83.80266 million yuan, an increase of 10.792%. This shows that when facing the new scenario of daily time-scale power contract time-sharing default assessment, the RES-BESS multi-stage joint operation method proposed by the present invention can better improve the net income of the RES-BESS consortium compared with the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the time-sharing characteristics of the power grid of the present invention for the assessment of the RES daily power contract;

[0054] Figure 2 is the default weight coefficient r of the present invention t and default power ratio P t dev / P t Schematic diagram of the relationship between them;

[0055] Figure 3 It is a schematic diagram of the original power curve of the RES of the present invention within 30 days;

[0056] Figure 4 is the RES clearing electricity price c of the present invention e Diagram of the relationship between the comprehensive default index R of the daily power contract;

[0057] Figure 5It is a schematic diagram comparing the cumulative net income curves of RES of method 1 and method 2 of the present invention;

[0058] Figure 6 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0059] The present invention is further described in detail below in conjunction with the accompanying drawings, just to more clearly illustrate and explain the present invention.

[0060] like Figure 1-6 As shown, this embodiment discloses a multi-stage operation method for storing new energy for power contract time-sharing assessment, and the steps are as follows:

[0061] Step 1: Establish a RES revenue settlement model for the time-varying default assessment of daily electricity contracts, taking into account the relationship between the daily electricity contract performance capacity and the electricity market clearing price.

[0062] Two factors need to be considered in the RES revenue settlement model: one is how much default assessment fees RES has generated in the process of fulfilling the daily electricity contract; the other is how high an electricity price RES can clear in the electricity market under its current contract fulfillment capacity.

[0063] The mathematical model of RES income settlement model is as follows:

[0064]

[0065] Where: C R is the total income of RES, yuan; c e is the transaction price of RES in the power market, RMB / MWh; t represents the dispatching period; N T is the number of scheduling periods in a day, which is 96 in this paper; Δt is the duration of the scheduling period, h, which is 0.25h in this paper; P t is the actual grid-connected power of RES during period t, MW; C fee The default assessment fee that RES needs to pay is RMB.

[0066] In formula (1), c e and C fee All of them must be determined based on the comprehensive breach of the daily power contract, so it is necessary to calculate C R First, we need to establish a RES contract fulfillment rate model.

[0067] Not all RES defaults will be assessed. During periods when grid regulation resources are more abundant, some minor RES defaults can be corrected by using free regulation resources, and RES will be exempt from assessment. Figure 1As shown in Figure 1, the price of grid flexibility regulation resources is not constant in the same period. The greater the default of RES, that is, the more regulation resources are consumed, the higher the unit price of regulation resources. Therefore, the intensity of default assessment received by RES will increase with the severity of default.

[0068] The calculation model of the comprehensive default index of RES daily electricity contract is as follows:

[0069]

[0070] Where: R is the daily power contract comprehensive default index of RES; P t dev is the default power of RES in period t, MW; α t is the default ratio allowed in period t; r t is the default weight coefficient for period t, which is about P t dev / P t Functions such as Figure 2 As shown, P t dev / P t The bigger the t The larger the P t dev / P t With r t There are also differences in the relationship between t dev-r (.) indicates r t With P t dev / P t The functional relationship between t sch is the daily power contract planned power of RES in period t, MW.

[0071] After calculating the daily power contract comprehensive default index R, we can continue to establish c e and C fee The calculation model is:

[0072] c e =f price-R (R) (5)

[0073]

[0074] Where: f price-R (.) is c e The functional relationship between and R, the specific form of which is determined by the result of electricity market clearing; c R is the price coefficient for default assessment, RMB / MWh; R min It is the default assessment threshold. When R is lower than this value, no assessment will be conducted.

[0075] Afterwards, the RES-BESS joint operation method can be designed based on the above-mentioned revenue settlement model. The RES-BESS joint operation is specifically divided into two stages, the day-ahead stage and the intraday stage. In the day-ahead stage, RES needs to report the daily power contract curve to the power grid based on the long-term power forecast information with low prediction accuracy and the time domain distribution of the BESS operating conditions with high uncertainty. In the intraday stage, RES uses the real-time power forecast information with high prediction accuracy and rolling updates, as well as the determined BESS operating conditions, to specifically call BESS to correct the power contract deviation. In this stage, RES needs to consider different issues and complete different tasks, so it is necessary to design an optimized operation method in stages.

[0076] Step 2: Propose a method for optimizing the declaration of RES daily power contracts in the daily power contract time-sharing default assessment mode, taking into account the auxiliary regulation capability of self-built BESS.

[0077] The optimization goal of RES when reporting daily power contracts to the power grid is to maximize the expected daily benefits. The three specific factors to be considered include: ① expected electricity bill benefits; ② expected default assessment costs; ③ self-built BESS usage costs. The optimization goal is to maximize the expected daily benefits.

[0078] The optimization objectives of the daily electricity contracts for each period are as follows:

[0079]

[0080] Where: is the total expected net benefit, yuan; is the total expected revenue from electricity sales, yuan; is the total expected assessment cost, yuan; is the total expected cost of BESS, yuan.

[0081] calculate The actual grid-connected power and market transaction price of RES in each period are required. The calculation method is as follows:

[0082]

[0083] Where: is the expected transaction price of RES, RMB / MWh; P t,f is the expected grid-connected power of RES in period t, MW.

[0084] Since RES will call on its own BESS to assist in correcting the contract deviation, and BESS will generate certain energy losses during the charging and discharging process, the expected grid-connected power of RES is equal to the original power minus the charging and discharging loss of BESS.t,f The calculation method is as follows:

[0085]

[0086] Where: P t org is the original predicted power of RES in period t, MW; is the expected charging and discharging power of the self-built BESS during period t, MW; η ch , η dch is the charge and discharge loss rate of BESS.

[0087] calculate It is necessary to know the expected value of the comprehensive default index R of the RES daily power contract. Specifically, it is necessary to know the expected deviation, default weight coefficient and default allowance ratio of each time period. The default weight coefficient and default allowance ratio are issued to RES after the power grid comprehensively judges the resource abundance of the entire network flexibility regulation, while the expected deviation of each time period is jointly determined by the daily power contract plan of RES and the regulation capability of BESS.

[0088] The calculation method is as follows:

[0089]

[0090]

[0091] Where: R f is the expected value of the comprehensive default index of RES’ daily electricity contract; is the expected deviation power of RES in period t, MW; is the expected positive and negative deviation power of RES in period t, MW; P G is the installed capacity of RES, MW; f t (P) is the probability density distribution function of the RES day-ahead power forecast for period t.

[0092] As shown in equations (10)-(14), in addition to the daily power contract plan value P t sch outside, It is a decision important variables. If it can be freely taken, then It can definitely drop to 0, but the adjustment capability of the upper BESS is effective. The value of needs to meet certain constraints. Specifically, the total charge and discharge amount of BESS in one day can be estimated based on the statistical value of the daily equivalent charge and discharge cycle number of BESS, and the average value of a certain period can be calculated after averaging it in each period. In addition, affected by technical conditions, BESS has a maximum charge and discharge rate. Likewise, technical limitations cannot be exceeded.

[0093] The value range constraints are as follows:

[0094]

[0095] Where: is the installed capacity of BESS, MWh; μ is the statistical value of the daily equivalent charge and discharge cycles of BESS; δ ch , δ dch is the maximum charge and discharge rate of BESS; T is the calculated δ ch , δ dch The time period is h, and the present invention takes T=1.0h.

[0096] So far, we can calculate Continue Introduction The calculation method of . Mainly affected by R f Influence, R has been introduced in the above model f The calculation method of The specific calculation formula is as follows:

[0097]

[0098] Finally, the introduction The unit charge and discharge life loss cost of BESS can be provided by the manufacturer, so as long as the expected charge and discharge power of BESS in each period is known, You can calculate

[0099] The calculation method is as follows:

[0100]

[0101] Where: c BESS It is the lifetime consumption cost of BESS per unit charge and discharge, RMB / MWh.

[0102] Step 3: Establish a daily rolling execution method for RES daily power contracts under the time-sharing default assessment mode of daily power contracts, with the assistance of self-built BESS for adjustment.

[0103] After RES completes the declaration of the daily power contract plan curve in the day-ahead stage, it will enter the actual contract execution stage. At this time, the power forecast data of RES will be updated, and the forecast accuracy will be greatly improved. At this time, the expected BESS charging and discharging power of the day-ahead may be different from the actual situation, and it needs to be corrected according to the latest power forecast data and the actual state of charge (SOC) of BESS.

[0104] The optimization goal of correcting the actual charging and discharging action of BESS is still to maximize the total net profit of RES within the intraday forecast window. The optimization goals are as follows:

[0105]

[0106] Where: is the net profit of RES in the short-term window starting from time period t, RMB; N s is the number of scheduling periods contained in the short-term window within the day. In this paper, N is taken s =8; is the electricity sales revenue of RES in period t, yuan; is the assessment fee of RES in period t, yuan; is the cost of using BESS in period t, yuan.

[0107] Since the daily power contract has not been fully executed, the value of the comprehensive default index R of the daily power contract is still unknown, so the electricity price c e It is also unknown and requires preliminary estimation based on the defaults of electricity contracts that have been executed so far and will be executed within a short window.

[0108] The calculation method is as follows:

[0109]

[0110] c e,t =f price-R (R t ) (twenty one)

[0111]

[0112] Where: c e,t is the transaction price of RES up to the end of period t, RMB / MWh; R t It is the calculated value of the comprehensive default index of the daily electricity contract up to the period t.

[0113] Similarly, since the daily power contract has not been fully executed, the value of the daily power contract comprehensive default index R is still unknown, so the incremental assessment fee that RES needs to pay in period t is It can only be known through measurement.

[0114] The calculation method is as follows:

[0115]

[0116] Due to the cost of using BESS It has a clear linear correlation with the charging and discharging power of BESS, so it can be directly calculated. The specific formula is as follows:

[0117]

[0118] In the day-ahead stage, since it is still far from the actual power generation stage, the constraints of the BESS state of charge (SOC) on the charging and discharging power of the BESS are not considered. However, in the intraday stage, the RES will call the BESS to actually perform charging and discharging operations, and the current SOC of the BESS is known, so P t ch , P t dch In addition to satisfying the constraints shown in formula (16), the following constraints must also be satisfied:

[0119]

[0120] SOC min SOC t SOC max (26)

[0121] Where: SOC t is the SOC of BESS during period t; SOC min , SOC max It is the upper and lower limit of SOC of BESS.

[0122] A set of examples are used to verify the effectiveness of the operating method proposed in the present invention.

[0123] Scenario setting: The measured data of the original power curve of a RES within 30 days is as follows: Figure 3 The technical parameters of self-built BESS and RES are shown in Table 1. The relevant parameters of the grid's assessment requirements for RES daily power contracts are shown in Table 2. The relationship between RES clearing electricity price and the comprehensive default index R of daily power contracts is shown in Table 2. Figure 4 As shown in Figure 2, the probability density distribution function of the day-ahead power forecast deviation ratio of RES satisfies a normal distribution with a mean of 0 and a standard deviation of 0.3.

[0124] Table 1 Technical parameters of self-built BESS and RES

[0125]

[0126] Table 2 RES daily power contract default assessment related parameters

[0127]

[0128]

[0129] It is assumed that RES uses two methods to deal with the daily power contract time-sharing default assessment implemented by the power grid: Method 1 is the RES-BESS joint operation method proposed in the present invention, and Method 2 is to directly declare the original power curve as the daily power contract plan curve and call the self-built BESS only according to the power deviation correction demand of the current period during the intraday stage.

[0130] The cumulative net benefit curves of RES when the above two methods are used are simulated, and the results are as follows: Figure 5 As shown. Figure 5 It can be seen that when the joint operation method (method 1) proposed in this paper is adopted, compared with the traditional RES power generation curve declaration and execution method (method 2), RES can stably and significantly improve its net income in the 30-day operation cycle. Specifically, the net income of RES increased from 75.63957 million yuan in method 2 to 83.80266 million yuan in method 1, an increase of 10.792%. This shows that when facing the new scenario of daily time-scale power contract time-sharing default assessment, the RES-BESS multi-stage joint operation method proposed in this paper can better improve the net income of the RES-BESS consortium compared with the traditional method.

[0131] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-stage operation method for storing new energy for power contract time-sharing assessment, characterized in that: include: S1. Establish a RES revenue settlement model for the time-varying default assessment of daily power contracts, taking into account the relationship between the performance capacity of daily power contracts and the clearing price of the power market; S2. Propose a method for optimizing the declaration of RES daily power contracts in the day-ahead mode of daily power contract time-sharing default assessment, taking into account the auxiliary regulation capability of self-built BESS; S3. Establish a method for the intraday rolling execution of RES daily power contracts under the time-sharing default assessment mode of daily power contracts, with the assistance of self-built BESS for adjustment.

2. The multi-stage operation method for storing new energy for time-sharing assessment of power contracts according to claim 1 is characterized by: The RES revenue settlement model includes how much default assessment fees are generated in the process of fulfilling the daily power contract and how high the electricity price can be cleared in the power market under the current contract fulfillment capacity; The mathematical model of RES income settlement model is: Where: C R is the total income of RES, yuan; c e is the transaction price of RES in the power market, RMB / MWh; t represents the dispatching period; N T is the number of scheduling periods in a day, which is 96; Δt is the duration of the scheduling period, h, which is Δt=0.25h; P t is the actual grid-connected power of RES during period t, MW; C fee The default assessment fee that RES needs to pay is RMB.

3. The multi-stage operation method for storing new energy for time-sharing assessment of power contracts according to claim 2 is characterized by: The calculation model of the comprehensive default index of RES daily electricity contract is: Where: R is the daily power contract comprehensive default index of RES; P t dev is the default power of RES in period t, MW; α t is the default ratio allowed in period t; r t is the default weight coefficient for period t, which is about P t dev / P t The function of P t dev / P t The bigger the t The larger the P t dev / P t With r t There are also differences in the relationship between t dev-r (.) indicates r t With P t dev / P t The functional relationship between t sch is the daily power contract planned power of RES in period t, MW; After calculating the daily power contract comprehensive default index R, establish c e and C fee The calculation model is: c e =f price-R (R)(5) Where: f price-R (.) is c e The functional relationship between and R, the specific form of which is determined by the result of electricity market clearing; c R is the price coefficient for default assessment, RMB / MWh; R min It is the default assessment threshold. When R is lower than this value, no assessment will be conducted.

4. The multi-stage operation method for storing new energy for time-sharing assessment of power contracts according to claim 1 is characterized by: The day-ahead optimization declaration method for the daily power contract includes expected electricity revenue, expected default assessment costs, and the cost of using the self-built BESS; the optimization objectives of the daily power contract for each period are: Where: is the total expected net benefit, yuan; is the total expected electricity sales revenue, yuan; is the total expected assessment cost, yuan; is the total expected cost of BESS, RMB; calculate Using the actual grid power and market transaction price of RES at each time period, The calculation method is, Where: is the expected transaction price of RES, RMB / MWh; P t,f is the expected grid-connected power of RES in period t, MW; P t,f The calculation method is, Where: P t org is the original predicted power of RES in period t, MW; is the expected charging and discharging power of the self-built BESS during period t, MW; η ch , η dch The charge and discharge loss rate of BESS; The calculation method is, Where: R f is the expected value of the comprehensive default index of RES’ daily electricity contract; is the expected deviation power of RES in period t, MW; is the expected positive and negative deviation power of RES in period t, MW; P G is the installed capacity of RES, MW; f t (P) is the probability density distribution function of the RES day-ahead power forecast for period t.

5. The multi-stage operation method for storing new energy for time-sharing assessment of power contracts according to claim 4 is characterized by: The value range of is constrained to be, Where: is the installed capacity of BESS, MWh; μ is the statistical value of the daily equivalent charge and discharge cycles of BESS; δ ch ,δ dch is the maximum charge and discharge rate of BESS; T is the calculated δ ch ,δ dch The time period is h, and T = 1.0h; The specific calculation formula is: The calculation method is, Where: c BESS It is the lifetime consumption cost of BESS per unit charge and discharge, RMB / MWh.

6. The multi-stage operation method for storing new energy for time-sharing assessment of power contracts according to claim 1 is characterized by: The intraday rolling execution method of the daily power contract includes making corrections based on the latest power forecast data and the actual state of charge of the BESS; the optimization goal of correcting the actual charging and discharging action of the BESS is to maximize the total net profit of the RES within the intraday forecast window, and the optimization goal is, Where: is the net profit of RES in the short-term window starting from time period t, RMB; N s N is the number of scheduling periods contained in the short-term window within the day. s =8; is the electricity sales revenue of RES in period t, yuan; is the assessment fee of RES in period t, yuan; is the cost of using BESS in period t, yuan; Since the daily power contract has not been fully executed, the value of the comprehensive default index R of the daily power contract is unknown, so the electricity price c e It is also unknown. According to the preliminary calculation of the default situation of power contracts that have been executed and will be executed in the short term, The calculation method is, c e,t =f price-R (R t )(21) Where: c e,t is the transaction price of RES up to the end of period t, RMB / MWh; R t is the calculated value of the comprehensive default index of the daily power contract up to the period t; since the daily power contract has not been fully executed, the value of the comprehensive default index R of the daily power contract is unknown, and the incremental assessment fee that RES needs to pay in period t is The calculation method is, Due to the cost of using BESS It is clearly linearly related to the charging and discharging power of BESS, so it can be directly calculated. The specific formula is: In the day-ahead stage, since it is still far from the actual power generation stage, the constraints of the BESS charge state on the charging and discharging power of the BESS are not considered. In the intraday stage, the RES is about to call the BESS to actually perform charging and discharging operations, and the current SOC of the BESS is known. t ch , P t dch To satisfy the following constraints, SOC min ≤SOC t ≤SOC max (26) Where: SOC t is the SOC of BESS during period t; SOC min , SOC max It is the upper and lower limit of SOC of BESS.

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