Method and system for evaluating credible capacity of wind-solar-storage combined power generation system

Abstract

The invention provides a credible capacity evaluation method and system for a wind-solar-storage combined power generation system. The credible capacity evaluation method comprises the following steps: acquiring basic data required for calculating a net load curve; calculating a net load curve by using the basic data; establishing an objective function and an energy storage operation model of the method for evaluating the credible capacity of the wind-solar-energy-storage combined power generation system, and filtering the net load curve; and calculating the credible capacity of the wind-solar-storage combined power generation system according to the filtered net load curve. According to the invention, through the peak clipping and valley filling effect of energy storage, the large value and the small value in the net load curve are filtered out, so that the net load fluctuation reaches the minimum, and on the premise that the load per unit curve, the maximum load, the wind and light per unit curve, the wind and light installed capacity, the energy storage configuration capacity and the energy storage charge and discharge rate are given, the maximum load and the wind and light per unit curve are obtained. The credible capacity of the wind-solar-storage combined power generation system is evaluated and calculated.

Description

Technical Field

[0001] The present invention relates to the field of integrated energy systems, and in particular to a reliable capacity assessment method and system for a wind, solar and energy storage combined power generation system. Background Art

[0002] Credible capacity is a key indicator to measure the contribution of power generation equipment to the reliability of the power system. It is used to reflect the stable and reliable power output that the power generation equipment can provide when the system needs it. However, due to the volatility and uncertainty of renewable energy output, the evaluation of the credible capacity of renewable energy has become a new problem. At the same time, in order to smooth out the volatility and uncertainty of renewable energy, policies require that a certain proportion of energy storage be configured to make full use of the peak-shifting and valley-filling capabilities of energy storage, adjust the renewable energy output curve, and improve the capacity credibility of renewable energy. Under the premise of considering the volatility of wind and solar output, how to quantify the credible capacity of the wind, solar and storage combined power generation system is an urgent problem to be solved. Summary of the invention

[0003] In order to overcome the above-mentioned deficiencies of the prior art, the present invention discloses a reliable capacity assessment method and system for a wind-solar-storage combined power generation system.

[0004] The technical solution provided by the present invention is: a reliable capacity assessment method for a wind-solar-storage combined power generation system, comprising the following steps:

[0005] Obtain the basic data required for the net load curve;

[0006] Calculate the net load curve using basic data;

[0007] Establish the objective function of the reliable capacity assessment method of the wind-solar-storage combined power generation system and the energy storage operation model to filter the net load curve;

[0008] The reliable capacity of the wind-solar-storage combined power generation system is calculated based on the filtered net load curve.

[0009] Preferably, the basic data include: the original load per unit curve p load , wind power output per unit curve p wind , Photovoltaic output per unit curve p solar 、Maximum energy storage capacity S e 、Maximum charging power of energy storage P e,ch,max 、Maximum discharge power of energy storage P e,dis,max , Annual maximum load P load,max 、Wind power installed capacity C wind 、Photovoltaic installation C solar .

[0010] Further preferably, the net load curve is calculated The calculation formula is as follows:

[0011] P net =p load ·P load,max -p wind ·C wind -p solar ·C solar (1)

[0012] Among them, the original load per unit curve p load , Annual maximum load P load,max , wind power output per unit curve p wind 、Wind power installed capacity C wind , Photovoltaic output per unit curve p solar 、Photovoltaic installation C solar .

[0013] Further preferably, the net load curve is filtered, including establishing an objective function of a reliable capacity assessment method for a wind-solar-storage combined power generation system, and the objective function is as follows:

[0014]

[0015] In the formula, T represents the number of time periods in the optimization cycle, t represents the time period index within the cycle, and P t net represents the net load during period t; P t e,ch , P t e,dis Indicates the charging power and discharging power of energy storage during period t; It represents the average net load within the optimization period T, and the calculation formula is as follows:

[0016]

[0017] Further preferably, filtering the net load curve includes establishing an energy storage optimization model, and the energy storage optimization model is as follows:

[0018]

[0019] In the formula, dis represents discharge, ch represents charge, ΔT represents the time granularity, which is one hour; η e The charging and discharging efficiency of energy storage; is the amount of electricity stored in the energy storage system during period t, S 0 To optimize the storage capacity of the energy storage in the last period of the cycle, S e is the maximum storage capacity of the electric energy storage, P t e,ch , P t e,dis is the charging and discharging power of the energy storage in period t, P e,ch,max , P e,dis,maxThe maximum charging and discharging power of the electric energy storage; is the power generation state of the energy storage in period t, and a value of 1 represents the corresponding state.

[0020] Further preferably, the filtering of the net load curve is a rolling filtering, and the initial filtering cycle is 1 day. After the current cycle filtering is completed, check whether the energy storage capacity is fully utilized. If the energy storage capacity is not fully utilized, the optimization time span is extended from 24 hours to 48 hours until the energy storage is fully utilized. When the first optimization cycle is N days, the second round of optimization starts from the data of the N+1th day, and the above steps are repeated until the net load data of 365 days a year is covered.

[0021] Further optimization is performed to calculate the credible capacity of the wind-solar-storage combined power generation system by first using basic data to calculate the net load curve. The calculation formula is as follows:

[0022]

[0023] The maximum charging and discharging power of energy storage is a certain proportion of the installed capacity of new energy. e The calculation formula is as follows:

[0024] P e,ch,max =P e,dis,max =r e (C solar +C wind ) (11)

[0025] The net load curve P after filtering is obtained by rolling filtering using the established optimization model. Fnet , by arranging the above data from large to small, we can get the continuous load curve time series Continuous Net Load Curve Time Series and the filtered continuous net load curve time series

[0026] Further optimization is performed to calculate the credible capacity of the wind-solar-storage combined power generation system, and the allowable number of load loss hours h is set, and the average value of the continuous load curve in the first h hours and the continuous net load curve after filtering are taken and then subtracted to obtain the credible capacity of the wind-solar-storage combined power generation system. The calculation formula is as follows:

[0027]

[0028] Another aspect of the present invention further provides a reliable capacity assessment system for a wind-solar-storage combined power generation system, comprising: a basic data acquisition unit, for acquiring basic data required for a net load curve;

[0029] A net load curve calculation unit calculates a net load curve according to basic data;

[0030] Net load curve filtering unit, which performs rolling filtering on the net load curve;

[0031] The credible capacity calculation unit of the wind-solar-storage combined power generation system calculates the credible capacity of the wind-solar-storage combined power generation system based on the filtered net load curve.

[0032] Preferably, the net load curve filtering unit further comprises an optimization model establishing unit for performing rolling filtering on the net load curve according to the established optimization model.

[0033] The beneficial effects of the present invention are:

[0034] The net load curve is calculated by obtaining the basic data required for the net load curve, and then the peak-shaving and valley-filling capability of electrochemical energy storage is used to filter the net load curve. Under a given energy storage capacity and maximum charge and discharge power of energy storage, the peak-shaving and valley-filling effect of energy storage is used to filter out the larger and smaller values ​​in the net load curve, so that the net load fluctuation is minimized. Under the premise of a given original load curve, wind-solar unitary curve, wind-solar installed capacity, and configured energy storage capacity, the evaluation and calculation of the credible capacity of the wind-solar-storage combined power generation system can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0036] Figure 2 A rolling filter net load flow chart of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0037] Figure 3 A wind power per unit curve diagram of an embodiment of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0038] Figure 4 A photovoltaic per unit curve in an embodiment of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0039] Figure 5 The original load per unit curve of an embodiment of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0040] Figure 6 A net load curve of an embodiment of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0041] Figure 7 A filtered net load curve of an embodiment of a reliable capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention;

[0042] Figure 8 A schematic diagram of credible capacity calculation in an embodiment of a credible capacity assessment method for a wind-solar-storage combined power generation system provided by the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] The present invention provides a reliable capacity assessment method for a wind-solar-storage combined power generation system, referring to Figure 1 As shown, the following steps are included:

[0045] Obtain the basic data required for the net load curve;

[0046] Basic data include: original load per unit curve p load , wind power output per unit curve p wind , Photovoltaic output per unit curve p solar 、Maximum energy storage capacity S e 、Maximum charging power of energy storage P e,ch,max 、Maximum discharge power of energy storage P e,dis,max , Annual maximum load P load,max 、Wind power installed capacity C wind 、Photovoltaic installation C solar ;

[0047] Calculate the net load curve using basic data;

[0048] The calculated load curve is The calculation formula is as follows:

[0049] P net =p load ·P load,max -p wind ·C wind -p solar ·C solar (1)

[0050] Among them, the original load per unit curve p load , Annual maximum load P load,max , wind power output per unit curve p wind 、Wind power installed capacity C wind , Photovoltaic output per unit curve p solar 、Photovoltaic installation C solar ;

[0051] Establish the objective function and energy storage operation model of the reliable capacity assessment method of the wind-solar-storage combined power generation system, and filter the net load curve;

[0052] The overall optimization goal of the model is to filter out the larger and smaller values ​​in the net load curve through the peak-shaving and valley-filling effect of energy storage under a given energy storage capacity and maximum energy storage charge and discharge power, so that the net load fluctuation is minimized. Filtering the net load curve includes establishing the objective function of the reliable capacity assessment method of the wind-solar-storage combined power generation system. The objective function is as follows:

[0053]

[0054] In the formula, T represents the number of time periods in the optimization cycle, t represents the time period index within the cycle, and P t net represents the net load during period t; P t e,ch , P t e,dis Indicates the charging power and discharging power of energy storage during period t; It represents the average net load within the optimization period T, and the calculation formula is as follows:

[0055]

[0056] The objective function expressed in formula (2) explicitly incorporates the charging and discharging process of the energy storage system. By adjusting the charging and discharging power, the peak load is automatically shaving and valley filling is achieved. The model will give priority to compensating for extreme high loads (peak values) and low loads (valley values), making the utilization of energy storage resources more efficient. The objective function adjusts the net load based on the average value of the entire iteration cycle (24 hours, 48 ​​hours or longer), avoiding the model's over-reliance on a single adjustment period and being limited to short-term instantaneous demand, thus balancing the charging and discharging operations of the energy storage.

[0057] Filtering the net load curve includes establishing an energy storage optimization model, which is as follows:

[0058]

[0059] In the formula, dis represents discharge, ch represents charge, ΔT represents the time granularity, which is one hour; η e The charging and discharging efficiency of energy storage; is the amount of electricity stored in the energy storage system during period t, S 0 To optimize the storage capacity of the energy storage in the last period of the cycle, S e is the maximum storage capacity of the electric energy storage, P t e,ch , P t e,dis is the charging and discharging power of the energy storage in period t, P e,ch,max , P e,dis,max The maximum charging and discharging power of the electric energy storage; is the power generation state of the energy storage in period t, and a value of 1 represents the corresponding state;

[0060] Formula (3) represents the coupling transfer relationship between the storage capacity of the energy storage in adjacent time periods; Formula (4) represents that the storage capacity of the energy storage in the first time period of the optimization cycle should be equal to the storage capacity of the energy storage in the last time period of the previous optimization cycle, so as to achieve the connection and transfer of storage capacity; Formula (5) represents the storage capacity boundary of each time period of the energy storage, which is between 0 and the maximum storage capacity; Formula (6) and Formula (7) represent the operating boundaries of the energy storage during discharge and charging, respectively: during discharge, Take 1, When the value is 0, the energy storage discharge power is between 0 and the maximum discharge power, and the charging power is 0. Take 1, Take 0, the energy storage charging power is between 0 and the maximum charging power, and the discharge power is 0; Formula (8) shows that the energy storage cannot be charged and discharged at the same time;

[0061] Calculate the credible capacity of the wind-solar-storage combined power generation system based on the filtered net load curve;

[0062] like Figure 2 As shown, the net load curve is filtered as rolling filtering, and the initial filtering cycle is 1 day. After the current cycle filtering is completed, check whether the energy storage capacity is fully utilized. If the energy storage capacity is not fully utilized, the optimization time span is extended from 24 hours to 48 hours until the energy storage is fully utilized. When the first optimization cycle is N days, the second round of optimization starts from the data of the N+1th day, and the above steps are repeated until the net load data of 365 days a year is covered;

[0063] To calculate the credible capacity of the wind-solar-storage combined power generation system, first use the basic data to calculate the net load curve. The calculation formula is as follows:

[0064]

[0065] The maximum charging and discharging power of energy storage is a certain proportion of the installed capacity of new energy. e The calculation formula is as follows:

[0066] P e,ch,max =P e,dis,max =r e (C solar +C wind ) (11)

[0067] The net load curve P after filtering is obtained by rolling filtering using the established optimization model. Fnet , by arranging the above data from large to small, we can get the continuous load curve time series Continuous Net Load Curve Time Series and the filtered continuous net load curve time series

[0068] Set the allowable number of hours of load loss h, take the average value of the continuous load curve in the first h hours and the continuous net load curve after filtering, and then make a difference to obtain the reliable capacity of the wind-solar-storage combined power generation system. The calculation formula is as follows:

[0069]

[0070] Example

[0071] This example is based on the actual operation data of the Liaoning power grid in 2023 to calculate the credible capacity of the wind-solar-storage combined power generation system. The wind power output per unit curve, photovoltaic output per unit curve, and original load per unit curve are as follows: Figure 3 , Figure 4 , Figure 5 shown.

[0072] First, the net load curve is calculated using basic data, where P load,max =39.09 million KW, C wind =12.8 million KW, C solar =4.6 million KW, the calculated net load curve is as follows Figure 6 As shown;

[0073] Then take r e =0.25, S e =16 million KW·h, η e =0.95, and the net load curve after rolling filtering is as follows Figure 7 shown.

[0074] Continuous load curve, continuous net load curve, and filtered continuous net load curve are as follows: Figure 8 As shown, taking h = 8 hours, after configuring 4 million kilowatts of energy storage, it is calculated that the reliable capacity of new energy increases by 2.18 million kilowatts after configuring the energy storage.

[0075] Another aspect of the present invention further provides a reliable capacity assessment system for a wind-solar-storage combined power generation system, comprising:

[0076] A basic data acquisition unit, used to acquire basic data required for calculating a net load curve;

[0077] A net load curve calculation unit calculates a net load curve according to basic data;

[0078] The net load curve filtering unit performs rolling filtering on the net load curve, wherein the net load curve filtering unit also includes an optimization model establishment unit, which performs rolling filtering on the net load curve according to the established optimization model.

[0079] The reliable capacity calculation unit of the wind-solar-storage combined power generation system calculates the reliable capacity of the wind-solar-storage combined power generation system through the filtered net load curve.

[0080] It should be understood that, inspired by the technical concept of the present invention, those skilled in the art can make various improvements and changes based on the above description without departing from the content of the present invention, which still fall within the protection scope of the present invention.

[0081] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the claims.

[0082] It should be understood that the present invention is not limited to the precise construction shown in the above description and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A reliable capacity assessment method for a wind-solar-storage combined power generation system, characterized in that: The steps include: Obtain the basic data required to calculate the net load curve; Calculate the net load curve using basic data; Establish the objective function and energy storage operation model of the reliable capacity assessment method of the wind-solar-storage combined power generation system, and filter the net load curve; The reliable capacity of the wind-solar-storage combined power generation system is calculated based on the filtered net load curve.

2. A reliable capacity assessment method for a wind-solar-storage combined power generation system according to claim 1, characterized in that: The basic data include: original load per unit curve p load , wind power output per unit curve p wind , Photovoltaic output per unit curve p solar 、Maximum energy storage capacity S e 、Maximum charging power of energy storage P e,ch,max 、Maximum discharge power of energy storage P e,dis,max , Annual maximum load P load,max 、Wind power installed capacity C wind 、Photovoltaic installation C solar .

3. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: Calculate the net load curve The calculation formula is as follows: P net =p load ·P load,max -p wind ·C wind -p solar ·C solar (1) Among them, the original load per unit curve p load , annual maximum load P load,max , wind power output per unit curve p wind , wind power installed capacity C wind , photovoltaic output per unit curve p solar , Photovoltaic installation C solar .

4. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: The net load curve is filtered, including establishing the objective function of the reliable capacity assessment method of the wind-solar-storage combined power generation system. The objective function is as follows: In the formula, T represents the number of time periods in the optimization cycle, t represents the time period index within the cycle, represents the net load during period t; Indicates the charging power and discharging power of energy storage during period t; It represents the average net load within the optimization period T, and the calculation formula is as follows:

5. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: Filtering the net load curve includes establishing an energy storage optimization model. The energy storage optimization model is as follows: In the formula, dis represents discharge, ch represents charge, ΔT represents the time granularity, which is one hour; η e The charging and discharging efficiency of energy storage; is the storage capacity of the energy storage in period t, S0 is the storage capacity of the energy storage in the last period of the optimization cycle, S e is the maximum storage capacity of the electric energy storage, is the charging and discharging power of the energy storage in period t, P e,ch,max , P e,dis,max The maximum charging and discharging power of the electric energy storage; is the power generation state of the energy storage in period t, and a value of 1 represents the corresponding state.

6. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: The filtering of the net load curve is a rolling filtering, and the initial filtering cycle is 1 day. After the current cycle filtering is completed, check whether the energy storage capacity is fully utilized. If the energy storage capacity is not fully utilized, the optimization time span is extended from 24 hours to 48 hours until the energy storage is fully utilized. If the first optimization cycle is N days, the second round of optimization starts from the data of the N+1th day, and the above steps are repeated until the net load data of 365 days a year is covered.

7. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: To calculate the credible capacity of the wind-solar-storage combined power generation system, first use the basic data to calculate the net load curve. The calculation formula is as follows: The maximum charging and discharging power of energy storage is a certain proportion of the installed capacity of new energy. e , the calculation formula is as follows: P e,ch,max =P e,dis,max =r e (C solar +C wind ) (11) Then, the net load curve P after filtering is obtained by rolling filtering using the established optimization model. Fnet , Arrange the above data from large to small to get the continuous load curve time series Continuous Net Load Curve Time Series and the filtered continuous net load curve time series 8. The reliable capacity assessment method of a wind-solar-storage combined power generation system according to claim 1 is characterized in that: To calculate the credible capacity of the wind-solar-storage combined power generation system, it is necessary to set the allowable number of load loss hours h, take the average value of the continuous load curve in the first h hours and the continuous net load curve after filtering, and then make a difference to obtain the credible capacity of the wind-solar-storage combined power generation system. The calculation formula is as follows:

9. A reliable capacity assessment system for a wind, solar and storage combined power generation system, characterized in that: include: A basic data acquisition unit, used to acquire basic data required for calculating a net load curve; A net load curve calculation unit calculates a net load curve based on basic data; Net load curve filtering unit, which performs rolling filtering on the net load curve; The reliable capacity calculation unit of the wind-solar-storage combined power generation system calculates the reliable capacity of the wind-solar-storage combined power generation system by using the filtered net load curve.

10. A reliable capacity assessment system for a wind-solar-storage combined power generation system according to claim 9, characterized in that: The net load curve filtering unit also includes an optimization model building unit, which performs rolling filtering on the net load curve according to the built optimization model.

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