Method for generalizing and evaluating generating capacity of small hydropower based on reservoir engineering characteristic parameters

Abstract

The application proposes a small hydropower generation capacity generalization evaluation method based on reservoir engineering characteristic parameters, discloses a small hydropower generation capacity generalization calculation method based on reservoir engineering characteristic parameters, the method collects reservoir engineering characteristic parameters of power stations, calculates the net water head and reservoir capacity corresponding to the current water level, selects the experience value of similar generator units as the unit comprehensive output coefficient K, and calculates the adjustable water quantity, full-load flow and inflow, and finally obtains the small hydropower peak full-load hour value. The method overcomes the shortcomings that the reservoir and unit characteristic data of a large number of early construction small hydropower stations are not complete, especially the NHQ curve and water level-reservoir capacity curve data are missing, takes the full-load hour as an index to quantify the small hydropower generation capacity, and provides a scientific basis for the dispatching and management of small hydropower.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of small hydropower optimization scheduling in power system operation analysis, and particularly to a small hydropower generation capacity generalization evaluation method based on reservoir engineering characteristic parameters. BACKGROUND

[0002] As an important part of renewable energy, small hydropower, the study of small hydropower peak generation capacity quantitative analysis method, improve the flexibility of small hydropower as a whole, can promote the efficient consumption of renewable energy, ease the shortage of electricity supply. The traditional method requires the hydropower station to have more accurate water level storage capacity relationship, flow channel head loss characteristics, generator efficiency, tail water level change characteristics and water regime monitoring data, which is not suitable for the calculation of small hydropower. The method is based on the reservoir engineering characteristic parameters, and the small hydropower generation capacity is quantitatively calculated through the real-time monitoring data of water level and output, which overcomes the shortcomings of incomplete data of early construction small hydropower reservoir and unit characteristics, especially the missing of NHQ curve and water level storage capacity curve data, and quantifies the small hydropower generation capacity with full load hours as an index, which takes into account the operability and production precision requirements. SUMMARY

[0003] The present application proposes a small hydropower generation capacity generalization evaluation method based on reservoir engineering characteristic parameters, which belongs to a small hydropower generation capacity generalization calculation method based on reservoir engineering characteristic parameters. The method calculates the small hydropower full load hours according to the real-time monitoring data of the power station and the reservoir engineering characteristic parameters, and is used for evaluating the small hydropower peak generation capacity, providing a basis for flexible resource optimization configuration for dispatching. The method can be applied to adjustable small hydropower with real-time monitoring data of water level and output, but NHQ curve and water level storage capacity curve data are missing, and is used for fine analysis of the peak capacity of small hydropower.

[0004] The present application adopts the following technical scheme.

[0005] The small hydropower generation capacity generalization evaluation method based on reservoir engineering characteristic parameters can be used to calculate the small hydropower generation capacity of small hydropower stations, including the following steps:

[0006] Step S1, collecting reservoir engineering characteristic parameters and unit installed capacity of the power station to be evaluated;

[0007] Step S2, obtaining the real-time monitoring upstream and downstream water levels Z t上 , Z t下 and generator active power P t of the power station to be evaluated at the current time t, and calculating the net head H t ;

[0008] Step S3, selecting the similar generator comprehensive output coefficient empirical value K tBased on the registered reservoir engineering characteristic parameters, the current reservoir capacity C is calculated using generalization. t ;

[0009] Step S4: Based on the current warehouse capacity C t and the reservoir capacity C corresponding to the dead water level l Calculate the adjustable water volume C s And based on the current time t, the storage capacity C t Compared to the storage capacity C at the previous time t-1 t-1 Calculate the reservoir capacity difference flow rate Q C ;

[0010] Step S5: Based on the unit's overall output coefficient K t and the current water head H t Active power output of the unit P t Calculate the full power generation flow rate Q of the power plant n Power generation flow Q t Combined with the storage capacity difference flow rate Q C Calculate the inbound flow Q r ;

[0011] Step S6: Based on the current adjustable water volume C s , power plant full power generation flow Q n Inbound flow Q r The number of full-load hours T of the power plant to be evaluated was obtained. t .

[0012] In step S1, the reservoir engineering characteristic parameters include: normal high water level and corresponding reservoir capacity, dead water level and corresponding reservoir capacity, and tailwater level.

[0013] In step S2, the water purification head H t Real-time monitoring of upstream water level by the power station Z t上 and downstream water level Z t下 The calculation is based on the drop in elevation, and the formula is H. t =Z t上 -Z t下 ;

[0014] In the formula, all water levels are in meters (m).

[0015] In step S3, the current storage capacity C is calculated. t The specific calculation steps are as follows:

[0016] Step S31: As the head increases, the flow rate through the generator decreases and the water consumption rate of the generator decreases, but the overall output coefficient does not change much. As the output of the generator increases, the flow rate through the generator increases at the same head, the water consumption rate of the generator remains unchanged, and the overall output coefficient remains unchanged. Therefore, in the generalized calculation of this step, a constant value is taken as the overall output coefficient of the power station.

[0017] Select the same capacity of the power plant experience as the evaluation of the unit power plant K t , the evaluation of the power plant in each power scene and water level are the same typical value;

[0018] If the evaluation of the power plant has the unit NHQ curve data, then the power plant in the current water level Z t and active power P t The integrated output coefficient K t ;

[0019]

[0020] In the formula, H t is the net head obtained from step 2, unit m; N t is the corresponding unit output value in the curve data corresponding to the current active power P t , unit kW; Q is the corresponding flow in the curve data, unit m 3 / s;

[0021] Similarly, the integrated output coefficient K t of the power plant at the current water level Z n full is

[0022]

[0023] At this time, N n is the rated active power value of the unit, unit kW;

[0024] Step S32, according to the upstream water level Z t上 at t, calculate the corresponding storage C t ;

[0025] According to the dead water level Z l and the corresponding storage C l , the normal high water level Z h and the corresponding storage C h of the reservoir engineering characteristic parameters, based on the straight line slope method to calculate the water level Z t上 corresponding storage C t :

[0026]

[0027] In the formula, the water level unit is m, and the storage unit is 10 m 3 .

[0028] If the comprehensive output coefficient of the power station with the same installed capacity is similar in the year adjacent to the construction time of the small hydropower station, and the range is between 7 and 9, when the NHQ curve data of the unit of the power station to be evaluated is lacking, the empirical data of the power station with the same installed capacity is directly applied to obtain the comprehensive output coefficient in step S3. Specifically, the comprehensive output coefficient K is approximately 8.4 when the installed capacity is less than 30 MW, approximately 8.5 when the installed capacity is between 30 and 40 MW, approximately 8.6 when the installed capacity is between 40 and 50 MW, and approximately 8.7 when the installed capacity is more than 50 MW.

[0029] Step S4 includes the following steps.

[0030] Step S41, the adjustable water volume C t is calculated according to the current water level and reservoir capacity C s .

[0031] C s = C t -C l .

[0032] Step S42, the reservoir capacity difference flow Q C is calculated according to the reservoir capacity C t and C t-1 of adjacent time.

[0033]

[0034] In the formula, the unit of the reservoir capacity is 10,000 m 3 , the time interval of adjacent time is one hour, and the unit of the reservoir capacity difference flow is m 3 / s.

[0035] Step S5 includes the following steps.

[0036] Step S51, the full-load flow Q n of the power station is calculated according to the unit comprehensive output coefficient K t and the current time net water head H t .

[0037]

[0038] In the formula, P n is the installed capacity of the power station, the unit is MW; H t is the net water head, the unit is m; Q n is the full-load flow at the current time, the unit is m 3 / s.

[0039] Step S52, the power station generation flow Q t is calculated according to the unit comprehensive output coefficient K t and the active power P t of the power station.

[0040]

[0041] In the formula, P t is the active power output of the unit, in MW; H t is the net water head obtained from step 2, in m; Q t is the current power station power generation flow, in m 3 / s.

[0042] In step S53, the reservoir storage capacity difference flow Q C is calculated according to the reservoir storage capacity difference flow Q r :

[0043] Q r = Q c + Q t ;

[0044] In the formula, the flow units are all m 3 / s.

[0045] In step S6, the full-load hours T s are calculated according to the adjustable water volume C n , the power station full-load flow Q r obtained from step 5, and the reservoir storage flow Q t , and the formula is:

[0046]

[0047] In the formula, the adjustable water volume C s is in ten thousand m 3 ; the full-load flow Q n and the reservoir storage flow Q r are in m 3 / s.

[0048] The application discloses a small hydropower generation capacity generalization calculation method based on reservoir engineering characteristic parameters, which collects reservoir engineering characteristic parameters of a power station, calculates a net water head and a reservoir storage capacity corresponding to a current water level, selects an experience value of a similar generator set as a unit comprehensive output coefficient K, and calculates an adjustable water volume, a full-load flow and a reservoir storage flow, so that a small hydropower peak full-load hour value is obtained. The application has the following innovative points: for the small hydropower peak generation capacity calculation problem caused by the incomplete reservoir and unit characteristic data, a small hydropower generation capacity generalization calculation method based on reservoir engineering characteristic parameters is provided, the small hydropower full-load hours are calculated based on the reservoir engineering characteristic parameters and water level and output real-time monitoring data, so that the small hydropower peak generation capacity is represented, the operability and accuracy requirements in the dynamic response of real-time data and missing data processing are considered, and a scientific basis is provided for the scheduling and management of the small hydropower.

[0049] Compared with the traditional method, the present application has at least the following beneficial technical effects:

[0050] The present application is aimed at the problem of calculating the peak power generation capacity of small hydropower station with incomplete reservoir and unit characteristic data, and proposes a general calculation method of small hydropower generation capacity based on reservoir engineering characteristic parameters. The method calculates the full-load hours of small hydropower station based on reservoir engineering characteristic parameters and real-time monitoring data of water level and output, so as to represent the peak power generation capacity of small hydropower station. The method takes into account the operability and accuracy requirements in the use of real-time data and missing data processing dynamic response, and provides a scientific basis for the scheduling and management of small hydropower station.

[0051] The present application calculates the full-load hours of small hydropower station based on real-time monitoring data of power station and reservoir engineering characteristic parameters, which can be used to evaluate the peak power generation capacity of small hydropower station and provide a basis for flexible resource optimization configuration in scheduling.

[0052] The present application overcomes the shortcomings of incomplete reservoir and unit characteristic data of a large number of early construction small hydropower stations, especially the missing NHQ curve and water level-storage capacity curve data. The method quantifies the power generation capacity of small hydropower station with full-load hours as an indicator, and provides a scientific basis for the scheduling and management of small hydropower station. The method can be applied to adjustable small hydropower stations with real-time monitoring data of water level and output, but missing NHQ curve and water level-storage capacity curve data, and can be used for fine analysis of the peak capacity of small hydropower station.

[0053] The traditional method ignores the schedulability of small hydropower station, and considers the output of small hydropower station as an uncontrollable resource similar to wind and light, and does not have peak power generation capacity. Compared with the traditional method, the method provided by the present application provides a peak power generation model of adjustable small hydropower station, which provides a basis for realizing the flexible adjustment of small hydropower station as a whole and participating in the optimization scheduling to relieve the tight power supply. BRIEF DESCRIPTION OF DRAWINGS

[0054] The present application will be further described in detail below in combination with the drawings and specific embodiments:

[0055] The present application will be further described in detail below in combination with the drawings and specific embodiments: Figure 1 is a flowchart of the general calculation method of small hydropower generation capacity of the present application. DETAILED DESCRIPTION

[0056] In order to make the purpose and technical scheme of the present application clearer and more convenient to understand, the present application will be further described in detail below in combination with the drawings and embodiments. The specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0057] The present application aims at the calculation difficulty of the peak power generation capacity of small hydropower station with missing NHQ curve and water level storage curve data, and proposes a small hydropower generation capacity generalization calculation method based on reservoir engineering characteristic parameters, which can calculate the peak power generation capacity of small hydropower station through real-time monitoring data of engineering technical parameters, water level and output, and is helpful to improve the flexibility of small hydropower as a whole, and takes into account the efficient consumption of renewable energy and the demand for power supply.

[0058] As shown in Figure 1 , the small hydropower generation capacity generalization evaluation method based on reservoir engineering characteristic parameters can be used to calculate the small hydropower generation capacity of small hydropower station, which includes the following steps:

[0059] Step S1, collecting reservoir engineering characteristic parameters and unit installed capacity of the power station to be evaluated;

[0060] Step S2, obtaining real-time monitoring upstream and downstream water levels Z t上 , Z t下 and generator active power P t of the power station to be evaluated at the current time t, and calculating the net water head H t ;

[0061] Step S3, selecting a similar generator comprehensive output coefficient empirical value K t , and calculating the current storage capacity C t based on the recorded reservoir engineering characteristic parameters;

[0062] Step S4, calculating the adjustable water volume C s based on the current storage capacity C t and the dead water level corresponding storage capacity C l , and calculating the storage capacity difference flow Q C based on the storage capacity C t at the current time t and the storage capacity C t-1 at the previous time t-1;

[0063] Step S5, calculating the power station full-load flow Q n , the power generation flow Q t based on the unit comprehensive output coefficient K t and the current time net water head H t , unit active power P t , and calculating the inflow Q r by combining the storage capacity difference flow Q C ;

[0064] Step S6, obtaining the full-load hours T t of the power station to be evaluated based on the current adjustable water volume C s , the power station full-load flow Q n and the inflow Q r .

[0065] In step S1, the reservoir engineering characteristic parameters include: normal high water level of reservoir and corresponding reservoir capacity, dead water level and corresponding reservoir capacity, tail water level.

[0066] In step S2, the net water head H t is calculated by real-time monitoring the upstream water level Z t上 and the downstream water level Z t下 of the power station, and the calculation formula is H t = Z t上 -Z t下 .

[0067] In the formula, the units of each water level are m.

[0068] In step S3, the specific calculation steps of the current reservoir capacity C t are as follows:

[0069] In step S31, with the increase of the water head of the same power station, the flow through the machine of the same unit output decreases, the water consumption rate of the unit decreases, but the comprehensive output coefficient changes little; with the increase of the unit output, the flow through the machine under the same water head increases, the water consumption rate of the unit is unchanged, and the comprehensive output coefficient is unchanged, so in the generalization calculation of this step, a constant value is taken as the comprehensive output coefficient of the power station;

[0070] The experience value of the same installed capacity power station is selected as the comprehensive output coefficient K t of the unit of the power station to be evaluated, and at this time the same typical value is taken at each output scene and water level of the power station to be evaluated;

[0071] If the power station to be evaluated has unit NHQ curve data, the comprehensive output coefficient K t of the power station at the current water level Z t and active power output P t is calculated according to the following formula:

[0072]

[0073] In the formula, H t is the net water head obtained from step 2, and the unit is m; N t is the unit output value corresponding to the current active power output P t found in the curve data, and the unit is kW; Q is the corresponding flow through the machine in the curve data, and the unit is m 3 / s;

[0074] Similarly, the comprehensive output coefficient K t of the power station at the current water level Z n full load is

[0075]

[0076] At this time, Nn P is the rated active power value of the unit, in kW;

[0077] Step S32, according to the upstream water level Z t上 at time t, the corresponding reservoir capacity C t is calculated;

[0078] According to the dead water level Z l and the corresponding reservoir capacity C l , the normal high water level Z h and the corresponding reservoir capacity C h in the water reservoir engineering characteristic parameters, the water level Z t上 and the corresponding reservoir capacity C t are calculated based on the straight line slope method:

[0079]

[0080] In the formula, the water level unit is m, and the reservoir capacity unit is ten thousand m 3 .

[0081] If the comprehensive output coefficient of the power station with the same installed capacity in the year adjacent to the construction time of the small hydropower station is similar, and the range is between 7 and 9, then when the unit NHQ curve data of the power station to be evaluated is lacking, the empirical data of the power station with the same installed capacity is directly used to obtain the comprehensive output coefficient in step S3. Specifically, the comprehensive output system K is valued as follows: for installed capacity within 30 MW, the K value is approximately 8.4; for installed capacity of 30-40 MW, the K value is approximately 8.5; for installed capacity of 40-50 MW, the K value is approximately 8.6; and for installed capacity above 50 MW, the K value is approximately 8.7.

[0082] Step S4 includes the following steps.

[0083] Step S41, according to the current water level reservoir capacity C t , the adjustable water volume C s is calculated as:

[0084] C s = C t -C l ;

[0085] Step S42, according to the reservoir capacity C t and C t-1 at adjacent time, the reservoir capacity difference flow Q C is calculated as:

[0086]

[0087] In the formula, the reservoir capacity unit is ten thousand m 3 , the time interval of adjacent time is one hour, and the reservoir capacity difference flow unit is m 3 / s.

[0088] Step S5 comprises the following steps;

[0089] Step S51, according to the unit comprehensive output coefficient K t and the current net water head H t , calculate the power station full load flow Q n is:

[0090]

[0091] In the formula, P n is the installed capacity of the power station, unit: MW; H t is the net water head, unit: m; Q n is the current full load flow, unit: m 3 / s;

[0092] Step S52, according to the unit comprehensive output coefficient K t and the power station active power P t , calculate the power station power generation flow Q t is:

[0093]

[0094] In the formula, P t is the unit active power, unit: MW; H t is the net water head obtained from step 2, unit: m; Q t is the current power station power generation flow, unit: m 3 / s;

[0095] Step S53, according to the reservoir capacity difference flow Q C , calculate the reservoir inflow Q r is:

[0096] Q r = Q c + Q t ;

[0097] In the formula, the flow unit is m 3 / s.

[0098] In step S6, according to the adjustable water volume C s and the power station full load flow Q n and the reservoir inflow Q r obtained from step 5, calculate the full load hours T t The formula is:

[0099]

[0100] In the formula, the adjustable water volume C s unit: ten thousand m 3 ; full load flow Qn and the storage flow Q r in m 3 / s.

[0101] Embodiments:

[0102] In this example, a small hydropower station with real-time water level monitoring data is selected, and its engineering characteristic parameters are collected as shown in Table 1.

[0103] The traditional method ignores the dispatchability of small hydropower and considers small hydropower output as an uncontrollable resource similar to wind and light, and does not have peak power generation capacity. Using the method proposed in the present application, if the upstream water level and downstream water level at the current time are 610.23 m and 446 m respectively, the upstream water level at the previous time is 610.45 m, and the current active power output is 35 MW, then the adjustable small hydropower can at least peak full power for 91 h. Compared with the traditional method, the present application provides a peak power generation model for adjustable small hydropower, which provides a basis for realizing the flexible adjustment of the whole small hydropower and participating in the optimization of dispatching to relieve the tight power supply.

[0104] Table 1 Small hydropower reservoir engineering characteristic parameter table to be evaluated

[0105]

[0106] The above content only illustrates the technical idea of the present application and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. A method for generalizing and evaluating the generating capacity of small hydropower based on reservoir engineering characteristic parameters, which can be used to calculate the generating capacity of small hydropower, characterized in that: The method comprises the following steps: Step S1, collecting the power station reservoir engineering characteristic parameters and unit installed capacity to be evaluated; Step S2, acquiring real-time monitoring upstream and downstream water levels Z of the power station to be evaluated at current time t t上 , t下 and generator active power P t , calculating current time net water head H t ; Step S3, selecting similar generator set comprehensive output coefficient empirical value K t , according to the recorded reservoir engineering characteristic parameter generalization calculation current reservoir capacity C t ; Step S4, calculating the adjustable water volume C t and the corresponding water volume C l of the dead water level, calculating the adjustable water volume C s , and calculating the water volume difference flow Q c based on the water volume C t at the current time t and the water volume C t-1 at the previous time t-1; Step S5, according to the unit comprehensive output coefficient K t and the current net water head H t , unit active power P t Calculate the full-load flow of the power station Q n , power generation flow Q t , combined with the storage capacity difference flow Q c Calculate the storage flow Q r ; Step S6, according to the current adjustable water volume C s , the power station full load flow Q n , the incoming flow Q r , get the power station full load hours T t ; In step S1, the reservoir engineering characteristic parameters include: normal high water level of the reservoir and corresponding reservoir capacity, dead water level and corresponding reservoir capacity, tail water level; In step S2, the water purification head H t is calculated by real-time monitoring of the upstream water level Z t上 and the downstream water level Z t下 , and the difference between the two, according to the formula H t = Z t上 - Z t下 . In the formula, the units of each water level are m; In step S3, the current reservoir capacity C is calculated t The specific calculation steps are as follows: Step S31, assuming that with the increase of water head of the same power station, the over-machine flow of the same unit output decreases, the water consumption rate of the unit decreases, but the comprehensive output coefficient changes little; with the increase of the unit output, the over-machine flow under the same water head increases, the water consumption rate of the unit is unchanged, and the comprehensive output coefficient is unchanged, so in the generalization calculation of this step, a constant value is taken as the comprehensive output coefficient of the power station; The experience value of the same capacity power station is selected as the comprehensive output coefficient K of the evaluated power station unit t At this time, the same typical value is taken for the evaluated power station under each output scene and water level If the power plant to be evaluated has unit NHQ curve data, the overall output coefficient K of the power plant at the current water level Z t and active power output P t is calculated according to the following formula t ; In the formula, H t is the net water head obtained from step 2, in m; N t is the current active power P t corresponding to the unit output value, in kW; Q is the corresponding flow of the unit in the curve data, in m 3 / s; The electric station at the current water level Z t The overall power factor K at full power n To At this time, N n is the rated active power output value of the unit, in kW; Step S32, according to the upstream water level Z t上 , calculate the corresponding storage capacity C t ; According to the dead water level Z l and the corresponding reservoir capacity C l , the normal high water level Z h and the corresponding reservoir capacity C h , the numerical value of the water level Z t上 corresponding to the reservoir capacity C t is calculated based on the straight line slope method. In the formula, the water level unit is m, and the reservoir capacity unit is ten thousand m 3 .

2. The method for small hydropower generation capacity generalization assessment based on reservoir engineering characteristic parameters according to claim 1, characterized in that: If the comprehensive output coefficients of the power stations with the same installed capacity in the years adjacent to the construction time of the small hydropower station are similar and the ranges are all between 7 and 9, then when the unit NHQ curve data of the power station to be evaluated is lacking, the empirical data of the power station with the same installed capacity is directly used to obtain the comprehensive output coefficient in step S3; specifically, the comprehensive output system K is valued as follows: for the installed capacity of 30 MW or less, the K value is approximately taken as 8.4; for the installed capacity of 30-40 MW, the K value is approximately taken as 8.5; for the installed capacity of 40-50 MW, the K value is approximately taken as 8.6; for the installed capacity of 50 MW or more, the K value is approximately taken as 8.

7.

3. The method for small hydropower generation capacity generalization assessment based on reservoir engineering characteristic parameters according to claim 1, characterized in that: Step S4 comprises the following steps: Step S41, according to the current water level storage capacity C t , the adjustable water volume C s is calculated as: C s = C t - C l ; Step S42, calculate the reservoir capacity difference flow Qx according to the reservoir capacity C t and C t-1 at the adjacent time, and the reservoir capacity difference flow Qx is: In the formula, the storage capacity unit is ten thousand m 3 , the adjacent time interval is one hour, and the storage capacity difference flow unit is m 3 / s.

4. The method for small hydropower generation capacity generalization assessment based on reservoir engineering characteristic parameters according to claim 3, characterized in that: Step S5 comprises the following steps: Step S51: Based on the unit's overall output coefficient K t and the current water head H t Calculate the full-capacity power generation of the power plant, Q. n for: In the formula, P n is the installed capacity of the power station, in MW; H t is the net water head, in m; Q n is the full-load flow at the current time, in m 3 / s; Step S52, according to the unit integrated output coefficient K t and power station active power P t , calculate the power station power flow Q t is: In the formula, P t is the active power output of the unit, in MW; H t is the net water head obtained from step 2, in m; Q t is the power plant power flow at the current time, in m 3 / s; Step S53, calculating the warehouse capacity difference flow Q c based on the warehouse capacity difference Q r : Q r = Q c + Q t ; wherein the flow rate units are all m 3 / s.

5. The method for small hydropower generation capacity generalization assessment based on reservoir engineering characteristic parameters according to claim 4, characterized in that: In step S6, the adjustable water volume C s and the power station full-load flow Q n and the storage flow Q r , the full-load hours T t The formula is: In the formula, the adjustable water amount C s Unit: ten thousand m 3 ; full discharge flow Q n and the reservoir inflow Q r Unit: m 3 / s.

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