CN105896617A

CN105896617A - Assessment method for wind power regulation reserve capacity considering active control of wind generator

Info

Publication number: CN105896617A
Application number: CN201610431374.8A
Authority: CN
Inventors: 汪震; 周昌平; 杨正清
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2016-06-16
Filing date: 2016-06-16
Publication date: 2016-08-24
Anticipated expiration: 2036-06-16
Also published as: CN105896617B

Abstract

本发明公开了一种计及风机有功主动控制的风电调节备用容量评估方法。该方法首先采用基于风电场历史出力数据统计的方式获取在一定置信水平下能满足平滑风电场出力上、下波动需求的风电场基础备用容量；进一步，在考虑风机层面降载运行控制下建立风场调频容量优化模型；最后，采用风电场调频容量对获取的风场基础备用容量进行修正，得到整个风电场备用容量的评估结果。该发明旨在考虑风机有功控制策略下，充分发挥风电参与系统的调频能力，在保证系统可靠性的前提下尽可能减少风电场所需的备用容量，进而降低备用成本，提高系统运行的经济性。相应的评估结果可以作为系统调度及风电场备用容量配置的有效参考依据。The invention discloses a method for evaluating the reserve capacity of wind power regulation taking into account the active control of wind turbines. This method first obtains the basic reserve capacity of the wind farm that can meet the demand for smooth wind farm output fluctuations under a certain level of confidence by means of statistics based on the historical output data of the wind farm; Finally, the frequency regulation capacity of the wind farm is used to correct the acquired basic reserve capacity of the wind farm, and the evaluation result of the reserve capacity of the entire wind farm is obtained. The invention aims to give full play to the frequency modulation capability of the wind power participating system under the consideration of the active power control strategy of the wind turbine, and reduce the backup capacity required by the wind farm as much as possible under the premise of ensuring the reliability of the system, thereby reducing the backup cost and improving the economy of the system operation . The corresponding evaluation results can be used as an effective reference for system scheduling and wind farm reserve capacity allocation.

Description

A wind power regulation reserve capacity evaluation method considering active power control of wind turbines

技术领域technical field

本发明涉及一种风电场备用容量评估方法，尤其是涉及一种计及风机有功主动控制的风电调节备用容量评估方法。The invention relates to a method for evaluating the reserve capacity of a wind farm, in particular to a method for evaluating the reserve capacity of wind power regulation taking into account the active control of wind power.

背景技术Background technique

随着电力系统风电渗透率的不断增加，风电固有的间歇性、波动性及反调峰特性等已成为阻碍风电发展的关键性问题。因此需要为风电场提供足够的备用容量来参与风电并网时的频率调节。但考虑到风电的高渗透率，以一种经济的方式来安排传统的火电、水电机组备用是大力发展风电必须解决的问题。另一方面，随着风机有功主动控制技术的快速发展，一些风力发电机组已经能够参与不同级别的系统调频。因此风力发电机组提供系统调频的潜力已越来越受到电力行业以及研究者们的注意。With the continuous increase of wind power penetration in the power system, the inherent intermittency, volatility and anti-peaking characteristics of wind power have become key issues hindering the development of wind power. Therefore, it is necessary to provide sufficient reserve capacity for wind farms to participate in frequency regulation when wind power is connected to the grid. However, considering the high penetration rate of wind power, arranging the backup of traditional thermal power and hydropower units in an economical way is a problem that must be solved when vigorously developing wind power. On the other hand, with the rapid development of wind turbine active power control technology, some wind turbines have been able to participate in different levels of system frequency regulation. Therefore, the potential of wind turbines to provide system frequency regulation has attracted more and more attention from the power industry and researchers.

传统上，电力系统的运行备用用于平滑电力负荷的波动，以满足任何系统组件失效情况下的需要。根据作用时间的长短，通常可将运行备用划分为一次备用(30s内)、二次备用(10～15min)和三系备用(小时级别)。Traditionally, operational reserves in power systems have been used to smooth out fluctuations in electrical loads in the event of failure of any system component. According to the length of the action time, the running standby can usually be divided into primary standby (within 30s), secondary standby (10-15min) and three-series standby (hour level).

依据中国风电并网的技术规范，风场操作员需要提前向系统操作员递交风电预测曲线，相应的系统操作员要实现安排额外的备用容量来解决风电的不确定性带来的问题，从而维持系统潮流的稳定。因此，需要上、下调的备用容量来补偿风电实际出力与预测曲线的上、下偏差值。为充分发挥风电参与系统的调频能力，得到更为准确的风电场风电调节备用容量评估方法，本发明公开了一种计及风机有功主动控制的风电调节备用容量评估方法。According to China's wind power grid-connected technical specifications, wind farm operators need to submit wind power forecast curves to system operators in advance, and corresponding system operators must implement additional reserve capacity to solve problems caused by wind power uncertainties, so as to maintain The stability of the system flow. Therefore, up and down reserve capacity is needed to compensate for the up and down deviation between the actual output of wind power and the forecast curve. In order to give full play to the frequency modulation capability of the wind power participating system and obtain a more accurate evaluation method for the wind power regulation reserve capacity of the wind farm, the invention discloses a wind power regulation reserve capacity evaluation method considering the active control of the wind turbine.

发明内容Contents of the invention

为解决上述问题，本文发明提出了一种计及风机有功主动控制的风电调节备用容量评估方法，定量求取风电场所需的备用容量。In order to solve the above problems, this paper proposes a wind power regulation reserve capacity evaluation method that takes into account the active power control of wind turbines, and quantitatively obtains the reserve capacity required by the wind farm.

本发明的技术方案采用如下步骤：Technical scheme of the present invention adopts following steps:

1)基于历史数据统计对风电场基础备用容量进行初步评估；1) Preliminary evaluation of the basic reserve capacity of the wind farm based on historical data statistics;

2)对风机调频控制策略建模；2) Modeling of fan frequency modulation control strategy;

3)考虑风机有功主动控制策略，对风场调频容量评估；3) Consider the active power control strategy of wind turbines, and evaluate the frequency modulation capacity of wind farms;

4)考虑风场调频容量，建立风电调节备用容量修正模型，对步骤1)初步评估的风电调节备用容量进行修正。4) Considering the frequency modulation capacity of the wind farm, a wind power regulation reserve capacity correction model is established to correct the wind power regulation reserve capacity initially evaluated in step 1).

上述技术方案中，所述的步骤1)基于历史数据统计的风电场基础备用上/下调备用容量R⁺/R^-评估采用以下公式得到：In the above-mentioned technical scheme, described step 1) based on historical data statistics, the wind farm basic reserve up/down reserve capacity R ⁺ /R ^- evaluation is obtained by the following formula:

P⁺＝max{P_i}-avg{P_i}P ⁺ ＝max{P _i }-avg{P _i }

P^-＝avg{P_i}-min{P_i}P ^- ＝avg{P _i }-min{P _i }

${p p}_{j j}^{+ +} = = Pr PR o o b b (({P P}^{+ +} \leq \leq {R R}_{j j}^{+ +}))$

${p p}_{j j}^{- -} = = Pr PR o o b b (({P P}^{- -} \leq \leq {R R}_{j j}^{- -}))$

${R R}^{+ +} = = m m i i n no {{{R R}_{j j}^{+ +} | | {p p}_{j j}^{+ +} &GreaterEqual; &Greater Equal; {λ λ}^{+ +}}}$

${R R}^{- -} = = m m i i n no {{{R R}_{j j}^{- -} | | {p p}_{j j}^{- -} &GreaterEqual; &Greater Equal; {λ λ}^{- -}}}$

其中，P_i为采集的风电场历史出力数据时间序列；P⁺为每小时内风电出力最大值与平均值之差；P^-为每小时内风电出力平均值与最小值之差；即：P⁺/P^-表示以每小时内风电出力平均值为参考值时，每小时内风电出力上/下波动的最大限度；表示离散的标准化上/下调备用容量值，根据风场的实际出力情况人为设定；表示统计风电场年出力数据中每小时内风电出力上/下波动的最大限度P⁺/P^-不超过的概率；λ⁺/λ^-表示平滑风电波动的置信水平，根据风场出力的需求而定；R⁺/R^-表示基于历史数据统计的风电场基础备用上/下容量，为概率不小于置信水平λ⁺/λ^-前提下选定的离散标准化上/下调备用容量的最小值。Among them, P _i is the time series of historical wind power output data collected; P ⁺ is the difference between the maximum value and the average value of wind power output per hour; P ^- is the difference between the average value and minimum value of wind power output per hour; that is: P ⁺ /P ^- Indicates the maximum up/down fluctuation of wind power output per hour when the average value of wind power output per hour is taken as the reference value; Indicates the discrete standardized up/down reserve capacity value, which is artificially set according to the actual output of the wind farm; Indicates the maximum value P ⁺ /P ^- of wind power output up/down fluctuations per hour in the statistical wind farm annual output data, not exceeding λ ⁺ /λ ^- indicates the confidence level of smooth wind power fluctuations, which is determined according to the demand for wind farm output; R ⁺ /R ^- indicates the basic reserve up/down capacity of wind farms based on historical data statistics, which is the probability Not less than the confidence level λ ⁺ /λ ^- the selected discrete normalized up/down reserve capacity minimum value.

所述的步骤2)风机调频控制策略建模具体描述为：The step 2) fan frequency modulation control strategy modeling is specifically described as:

①正常情况下关闭桨距角控制，风机维持运行在降载运行点P₀；① Under normal circumstances, the pitch angle control is turned off, and the fan maintains operation at the load-reduced operating point P ₀ ;

②当需要上调备用时，风机运行状态从降载运行点P₀移动到最大功率跟踪点MPPT点，增加风机出力以减小向下的波动；② When it is necessary to increase the backup, the operating state of the fan moves from the load-reduction operating point P ₀ to the maximum power tracking point MPPT, and the output of the fan is increased to reduce the downward fluctuation;

③当需要下调备用时，启动桨距角控制，进一步减少风机出力以减小向上的波动。③ When it is necessary to lower the reserve, start the pitch angle control, further reduce the output of the fan to reduce the upward fluctuation.

所述的步骤3)考虑风机有功主动控制策略的风场上/下调频容量ΔR⁺/ΔR^-评估方法如下：The step 3) considering the active power control strategy of the wind farm for the wind field up/down frequency regulation capacity ΔR ⁺ /ΔR ^- evaluation method is as follows:

ΔR⁺＝P_MPPT-P₀＝K_r·P_MPPT ΔR ⁺ ＝P _MPPT -P ₀ ＝K _r P _MPPT

ΔR^-＝P₀-P_m(β)ΔR ^- ＝P ₀ -P _m (β)

ΔR⁺/ΔR^-＝R⁺/R^- ΔR ⁺ /ΔR ^- = R ⁺ /R ^-

其中，P_MPPT为风机以最大功率运行时的功率输出，P_m(β)为风机降载运行功率输出。前两式表示考虑转子转速控制及桨距角控制的上、下调频容量的修正值，它们分别与修正前的基础备用容量成比例。风力发电机组的空气动力学模型如下描述：Among them, P _MPPT is the power output of the fan when it is running at the maximum power, and P _m (β) is the power output of the fan when the load is reduced. The first two formulas represent the correction values of the up and down frequency regulation capacity considering the rotor speed control and the pitch angle control, and they are respectively proportional to the basic reserve capacity before correction. The aerodynamic model of the wind turbine is described as follows:

${P P}_{m m} ((β β)) = = \frac{11}{22} {C C}_{p p} ((λ λ,, β β)) {ρAv ρAv}_{w w}^{33}$

${C C}_{p p} ((λ λ,, β β)) = = 0.73 0.73 ((\frac{151151}{{λ λ}_{i i}} - - 0.58 0.58 β β - - 0.002 0.002 {β β}^{2.14 2.14} - - 13.2 13.2)) {e e}^{- - 18.4 18.4 / / {λ λ}_{i i}}$

1/λ_i＝1/(λ-0.02β)-0.003/(1+β³)1/λ _i ＝1/(λ-0.02β)-0.003/(1+β ³ )

λ＝ω_rR/v_w λ=ω _r R/v _w

其中，K_r为调频容量的等级系数，即风机降载运行的降载比；P₀为风力发电机组稳态运行时的功率输出；λ和β表示风机的叶尖速比和桨距角；ρ表示空气密度，A表示叶片扫掠的面积，ω_r表示风机转子转速；R表示风机叶片半径，v_w表示风速。Among them, K _r is the grade coefficient of the frequency regulation capacity, that is, the load reduction ratio of the fan under load reduction operation; P ₀ is the power output of the wind turbine in steady state operation; λ and β represent the tip speed ratio and pitch angle of the fan; ρ represents the air density, A represents the swept area of the blade, ω _r represents the speed of the fan rotor; R represents the radius of the fan blade, and v _w represents the wind speed.

约束条件：Restrictions:

风机转子转速约束： Fan rotor speed constraint:

桨距角调节范围约束：0≤β≤β^max Pitch angle adjustment range constraint: 0≤β≤β ^max

降载比约束： Derating ratio constraints:

其中，风机转子转速约束由风机技术规格设置，桨距角调节范围及降载比约束根据经验设置。Among them, the fan rotor speed constraints are set by the fan technical specifications, and the pitch angle adjustment range and load reduction ratio constraints are set based on experience.

所述的步骤4)考虑风场调频容量的风电调节备用容量的修正模型采用如下方法建立：Described step 4) considers the correction model of the wind power regulation reserve capacity of wind farm frequency regulation capacity to adopt the following method to establish:

${R R}_{00}^{+ +} = = {R R}^{+ +} - - {ΔR ΔR}^{+ +}$

${R R}_{00}^{- -} = = {R R}^{- -} - - {ΔR ΔR}^{- -}$

其中，表示考虑风机有功主动控制下提供的调频容量对于风电调节上/下调备用容量修正后的值。in, Indicates the corrected value for the wind power regulation up/down reserve capacity considering the frequency regulation capacity provided under the active control of wind turbine active power.

本发明的有益效果是：The beneficial effects of the present invention are:

本发明旨在考虑风机有功控制策略下，充分发挥风电参与系统的调频能力，在保证系统可靠性的前提下尽可能减少风电场所需的备用容量，进而降低备用成本，提高系统运行的经济性。相应的评估结果可以作为系统调度及风电场备用容量配置的有效参考依据。The present invention aims to give full play to the frequency modulation capability of the wind power participating system under the consideration of the active power control strategy of the wind turbine, and reduce the backup capacity required by the wind farm as much as possible under the premise of ensuring the reliability of the system, thereby reducing the backup cost and improving the economy of the system operation . The corresponding evaluation results can be used as an effective reference for system scheduling and wind farm reserve capacity allocation.

附图说明Description of drawings

图1上/下调基础备用容量评估示意图；Figure 1 Schematic diagram of the assessment of the base reserve capacity for up/down adjustments;

图2是某一时段的备用容量概率统计图；Fig. 2 is a probability statistical diagram of reserve capacity in a certain period of time;

图3转速控制及桨距角控制协同作用原理图；Fig. 3 Schematic diagram of synergy between speed control and pitch angle control;

图4 00:00-01:00时段风场下调基础备用容量概率柱形图；Fig. 4 Histogram of the probability of lowering the basic reserve capacity of the wind field during 00:00-01:00;

图5不同置信水平下风场各时段上/下调备用容量。Figure 5 Up/Down the reserve capacity of the wind farm at each time period under different confidence levels.

具体实施方式detailed description

下面结合附图及具体实施例对本发明作进一步详细说明。The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

本发明方法包括以下步骤：The inventive method comprises the following steps:

2)风机调频控制策略建模；2) Modeling of fan frequency modulation control strategy;

4)考虑风场调频容量，建立风电调节备用容量修正模型，对风电场基础备用容量进行修正。4) Considering the frequency regulation capacity of the wind farm, a wind power regulation reserve capacity correction model is established to correct the basic reserve capacity of the wind farm.

所述的步骤1)中的基于历史数据统计的风电场基础备用上/下调容量R⁺/R^-评估具体如下：The assessment of the basic reserve up/down adjustment capacity R ⁺ /R- ^of wind farms based on historical data statistics in step 1) is specifically as follows:

图1和图2给出了基于历史数据统计的风电场基础备用容量评估原理。风电场SCADA周期性的采集出力数据时间序列为P_i，其中i表示数据的下标号。将整年的出力数据按1小时为时间间隔划分为24个时间段，每个时间段内，可以统计出这段时间内出力的平均值和最大/小值，以及以风电出力平均值为参考值时，每个时间段内风电出力上/下波动的最大限度P⁺/P^-。一般情况下，假定风电波动具有较稳定的统计特性是合理的，因此可以画出各时段内上/下调备用容量的概率曲线如图2所示。在图2、表1中，...，分别表示离散的标准化上/下调备用容量值，根据风场的实际出力情况人为设定。对于给定的上/下调备用容量风场出力最大上/下波动限度P⁺/P^-不超过的概率可以根据图2中的各时段概率统计曲线求出。当给定平滑风电波动的置信水平λ⁺/λ^-时，相应需要的上/下调备用容量水平R⁺/R^-也可由概率统计曲线得出。Figure 1 and Figure 2 show the principle of wind farm basic reserve capacity evaluation based on historical data statistics. The time series of output data collected periodically by SCADA of the wind farm is P _i , where i represents the subscript number of the data. Divide the output data of the whole year into 24 time periods at intervals of 1 hour. In each time period, the average value and maximum/minimum value of output during this period can be calculated, and the average value of wind power output can be used as a reference value, the maximum P ⁺ /P ^- of wind power output up/down fluctuations in each time period. In general, it is reasonable to assume that wind power fluctuations have relatively stable statistical characteristics, so the probability curve of increasing/decreasing reserve capacity in each period can be drawn as shown in Figure 2. In Figure 2 and Table 1, ..., Respectively represent discrete standardized up/down reserve capacity values, which are artificially set according to the actual output of the wind farm. For a given up/down reserve capacity The maximum upper/lower fluctuation limit of wind field output P ⁺ /P ^- shall not exceed The probability It can be calculated according to the probability statistics curve of each period in Fig. 2. When the confidence level λ ⁺ /λ ^- of smooth wind power fluctuation is given, the corresponding required up/down reserve capacity level R ⁺ /R ^- can also be obtained from the probability statistics curve.

基于历史数据统计的风电场基础备用上/下调备用容量R+/R-评估可用以下步骤得到：Based on the statistics of historical data, the R+/R- evaluation of the basic reserve up/down reserve capacity of the wind farm can be obtained by the following steps:

①将整年的出力数据按1小时为时间间隔划分为24个时间段；① Divide the output data of the whole year into 24 time periods at intervals of 1 hour;

②每个时间段内，按如下公式统计风电出力上/下波动的最大限度P⁺/P^-，并得到如表1所示的各时段备用容量概率统计表；②In each time period, calculate the maximum P ⁺ /P ^- of wind power output up/down fluctuation according to the following formula, and obtain the probability statistics table of reserve capacity in each period as shown in Table 1;

P⁺＝max{P_i}-avg{P_i}P ⁺ ＝max{P _i }-avg{P _i }

P^-＝avg{P_i}-min{P_i}P ^- ＝avg{P _i }-min{P _i }

表1上/下调基础备用容量概率统计示意表Table 1 Probabilistic Statistical Chart of Up/Down Base Reserve Capacity

③对于每个时间段，根据图2并按下式求出风电场各时间段的上/下调备用容量。③For each time period, calculate the up/down reserve capacity of the wind farm for each time period according to Figure 2 and the following formula.

所述的步骤2)风机调频控制策略建模具体描述如下:Described step 2) fan frequency modulation control strategy modeling concrete description is as follows:

风机的有功主动控制策略包括基于旋转动能释放的短时过载运行、变流器过载运行以及降载运行等。本发明考虑的是风电场二/三次备用容量的评估，因次只考虑包含转子转速控制及桨距角控制的降载运行控制策略。降载运行控制策略是指使风机在偏离最大功率跟踪(Maximum Power Point Tracking,MPPT)点运行，从而为系统调频提供一定的备用容量。降载运行控制包含转子转速控制和桨距角控制两种方式。其中，转子转速控制改变的是风机功率跟踪曲线，即从MPPT曲线变为降载曲线；桨距角控制改变的是风机捕获的气动功率曲线，如图所示。图中P_a为风机正常运行MPPT点时的稳态输出，单独采用转子转速控制时，其降载运行输出为P_d，转子转速控制下可提供的调频容量为(P_a-P_d)；单独采用桨距角控制时，其降载运行输出为P_c，桨距角控制下可提供的调频容量为(P_a-P_c)。若同时考虑转子转速控制与桨距角控制策略，则其降载运行输出为P_b，此刻可提供的调频容量为(P_a-P_b)。综合利用两种控制方式，能在保证尽可能输出更多风电的基础上，为风机参与调频提供尽可能多的备用容量。为了求得综合利用转子转速控制以及桨距角控制下风电场提供的调频容量，采取以下的控制策略：The active power control strategies of wind turbines include short-term overload operation based on the release of rotational kinetic energy, converter overload operation, and load reduction operation. The present invention considers the evaluation of the secondary/tertiary reserve capacity of the wind farm, and therefore only considers the load reduction operation control strategy including rotor speed control and pitch angle control. The load reduction operation control strategy is to make the wind turbine operate at a point deviated from the Maximum Power Point Tracking (MPPT), so as to provide a certain reserve capacity for system frequency regulation. The load reduction operation control includes rotor speed control and pitch angle control. Among them, the rotor speed control changes the fan power tracking curve, that is, from the MPPT curve to the load reduction curve; the pitch angle control changes the aerodynamic power curve captured by the fan, as shown in the figure. In the figure, P _a is the steady-state output of the fan at the MPPT point in normal operation. When the rotor speed control is used alone, the output of the reduced load operation is P _d , and the frequency modulation capacity that can be provided under the rotor speed control is (P _a -P _d ); When the pitch angle control is used alone, the output of the reduced load operation is P _c , and the frequency modulation capacity available under the pitch angle control is (P _a -P _c ). If the rotor speed control and the pitch angle control strategy are considered at the same time, the output of the load reduction operation is P _b , and the available frequency regulation capacity at this moment is (P _a -P _b ). The comprehensive utilization of the two control methods can provide as much spare capacity as possible for wind turbines to participate in frequency regulation on the basis of ensuring as much wind power output as possible. In order to obtain the frequency modulation capacity provided by the wind farm under comprehensive utilization of rotor speed control and pitch angle control, the following control strategy is adopted:

①正常情况下关闭桨距角控制，风机维持运行在降载运行点P₀，即图中的d点；① Under normal circumstances, the pitch angle control is turned off, and the fan is maintained at the load-reduced operating point P ₀ , which is point d in the figure;

②当需要上调备用时，风机运行状态从降载运行点P₀，即图中的d点，移动到MPPT点，即图中的a点，增加风机出力以减小向下的波动；② When it is necessary to increase the backup, the fan operating state moves from the load-reduction operating point P ₀ , that is, point d in the figure, to the MPPT point, that is, point a in the figure, and the output of the fan is increased to reduce the downward fluctuation;

③当需要下调备用时，启动桨距角控制，进一步减少风机出力以减小向上的波动，使风机运行状态从图中的d点移动到b点。③When it is necessary to lower the standby, start the pitch angle control, further reduce the output of the fan to reduce the upward fluctuation, and move the operating state of the fan from point d to point b in the figure.

ΔR⁺＝P_MPPT-P₀＝K_r·P_MPPT ΔR ⁺ ＝P _MPPT -P ₀ ＝K _r P _MPPT

ΔR^-＝P₀-P_m(β)ΔR ^- ＝P ₀ -P _m (β)

ΔR⁺/ΔR^-＝R⁺/R^- ΔR ⁺ /ΔR ^- = R ⁺ /R ^-

1/λ_i＝1/(λ-0.02β)-0.003/(1+β³)1/λ _i ＝1/(λ-0.02β)-0.003/(1+β ³ )

λ＝ω_rR/v_w λ=ω _r R/v _w

约束条件：Restrictions:

风机转子转速约束： Fan rotor speed constraint:

降载比约束： Derating ratio constraint:

${R R}_{00}^{+ +} = = {R R}^{+ +} - - {ΔR ΔR}^{+ +}$

${R R}_{00}^{- -} = = {R R}^{- -} - - {ΔR ΔR}^{- -}$

采用本发明方法进行风电场备用容量评估能够充分发挥风电参与系统的调频能力，在保证系统可靠性的前提下尽可能减少风电场所需的备用容量，进而降低备用成本，提高系统运行的经济性。相应的评估结果可以作为系统调度及风电场备用容量配置的有效参考依据。Using the method of the present invention to evaluate the reserve capacity of wind farms can give full play to the frequency modulation capability of the wind power participating system, and reduce the reserve capacity required by the wind farm as much as possible under the premise of ensuring system reliability, thereby reducing the reserve cost and improving the economy of system operation. . The corresponding evaluation results can be used as an effective reference for system scheduling and wind farm reserve capacity allocation.

本发明的具体实施例如下：Specific embodiments of the present invention are as follows:

我们采用所提方法对所示风电场进行备用容量评估。采集风电场年出力数据后，根据风场选定的风机机型以及风机正常状态下风速与输出功率曲线，可对本发明提出的方法进行验证。We use the proposed method to evaluate the reserve capacity of the wind farms shown. After collecting the annual output data of the wind farm, the method proposed by the present invention can be verified according to the fan type selected in the wind farm and the wind speed and output power curve of the fan under normal conditions.

采用本发明方法对实施例进行仿真计算，结果如下：Adopt the inventive method to carry out simulation calculation to embodiment, the result is as follows:

图给出了风场00:00-01:00时段下调备用容量概率柱形图，从柱形图中可以知道，当给定置信水平λ^-后即可从图中得出该时段内的备用容量。图给出了置信水平分别为98.5％和96.5％时，风场24时段的上、下调备用容量曲线图。从图中可以发现当设定的置信水平越高，风电调节所需的备用容量越大。这是因为置信水平越高，说明需要平滑的风电出力波动越大，则所需的备用容量也越大。此外，随着置信水平的增加，各时段之间备用容量的差异也增大，这是因为置信水平高表示平滑波动的要求越高，各时段之间的差异性会体现的更明显。从图中还可以发现，无论置信水平高或低，风场白天所需的备用容量要略小于夜间，说明夜间的风资源更丰富平稳，而白天的风资源波动性更显著。而经调频容量的修正后，风电场的上、下调备用容量的变化基本上在5％范围内，说明调频容量的大小相较于基于历史统计的风电场基础备用容量而言很小，仅起到修正与精确化的作用，基础备用容量起决定性作用。The figure shows the histogram of the probability of reducing the reserve capacity of the wind field during the period of 00:00-01:00. It can be known from the histogram that when the confidence level λ- is given, the reserve capacity in this ^period can be obtained from the figure. capacity. The figure shows the curves of the up and down reserve capacity of the wind farm for 24 periods when the confidence levels are 98.5% and 96.5% respectively. It can be seen from the figure that the higher the set confidence level is, the larger the reserve capacity required for wind power regulation will be. This is because the higher the confidence level, the greater the fluctuation of wind power output that needs to be smoothed, and the greater the required reserve capacity. In addition, as the confidence level increases, the difference in reserve capacity between periods also increases, because a high confidence level means higher requirements for smoothing fluctuations, and the differences between periods will be more obvious. It can also be seen from the figure that no matter whether the confidence level is high or low, the reserve capacity required by the wind farm during the day is slightly smaller than that at night, indicating that the wind resources at night are more abundant and stable, while the wind resources fluctuate more significantly during the day. However, after the correction of the frequency regulation capacity, the change of the up-and-down reserve capacity of the wind farm is basically within the range of 5%. To the correction and precision, the basic reserve capacity plays a decisive role.

上述具体实施方式用来解释说明本发明，而不是对本发明进行限制，在本发明的精神和权利要求的保护范围内，对本发明做出的任何修改和改变，都落入本发明的保护范围。The specific embodiments above are used to explain the present invention, rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modification and change made to the present invention will fall into the protection scope of the present invention.

Claims

1. A method for evaluating the reserve capacity of wind power regulation considering the active control of fan active power, characterized in that it comprises the following steps:

1) Preliminary evaluation of the basic reserve capacity of the wind farm based on historical data statistics;

2) Modeling of fan frequency modulation control strategy;

3) Consider the active power control strategy of wind turbines, and evaluate the frequency modulation capacity of wind farms;

4) Considering the frequency modulation capacity of the wind farm, a wind power regulation reserve capacity correction model is established to correct the wind power regulation reserve capacity initially evaluated in step 1).

2. A method for assessing a wind power regulation reserve capacity considering wind turbine active power active control according to claim 1, characterized in that: described step 1) based on historical data statistics of wind farm basic reserve up/down adjustment reserve capacity R ⁺ /R ^- Evaluation is obtained using the following formula:

P ⁺ ＝max{P _i }-avg{P _i }

P ^- ＝avg{P _i }-min{P _i }

{p p}_{j j}^{+ +} = = Pr PR o o b b (({P P}^{+ +} \leq \leq {R R}_{j j}^{+ +}))

{p p}_{j j}^{- -} = = Pr PR o o b b (({P P}^{- -} \leq \leq {R R}_{j j}^{- -}))

{R R}^{+ +} = = m m i i n no {{{R R}_{j j}^{+ +} | | {p p}_{j j}^{+ +} &GreaterEqual; &Greater Equal; {λ λ}^{+ +}}}

{R R}^{- -} = = m m i i n no {{{R R}_{j j}^{- -} | | {p p}_{j j}^{- -} &GreaterEqual; &Greater Equal; {λ λ}^{- -}}}

Among them, P _i is the time series of historical wind power output data collected; P ⁺ is the difference between the maximum value and the average value of wind power output per hour; P ^- is the difference between the average value and minimum value of wind power output per hour; that is: P ⁺ /P ^- Indicates the maximum up/down fluctuation of wind power output per hour when the average value of wind power output per hour is taken as the reference value; Indicates the discrete standardized up/down reserve capacity value, which is artificially set according to the actual output of the wind farm; Indicates the maximum value P ⁺ /P ^- of wind power output up/down fluctuations per hour in the statistical wind farm annual output data, not exceeding λ ⁺ /λ ^- indicates the confidence level of smooth wind power fluctuations, which is determined according to the demand for wind farm output; R ⁺ /R ^- indicates the basic reserve up/down capacity of wind farms based on historical data statistics, which is the probability Not less than the confidence level λ ⁺ /λ ^- the selected discrete normalized up/down reserve capacity minimum value.

3. A method for evaluating the reserve capacity of wind power regulation considering active power control of wind turbines according to claim 1, characterized in that: the step 2) modeling of wind turbine frequency modulation control strategy is specifically described as:

① Under normal circumstances, the pitch angle control is turned off, and the fan maintains operation at the load-reduced operating point P ₀ ;

② When it is necessary to increase the backup, the operating state of the fan moves from the load-reduction operating point P ₀ to the maximum power tracking point MPPT, and the output of the fan is increased to reduce the downward fluctuation;

③ When it is necessary to lower the backup, start the pitch angle control, further reduce the output of the fan to reduce the upward fluctuation.

4. A method for evaluating the reserve capacity of wind power regulation considering the active control of wind turbines according to claim 1, characterized in that: the step 3) considers the wind field up/down frequency regulation capacity ΔR of the active power control strategy of wind turbines ⁺ /ΔR ^- The evaluation method is as follows:

ΔR ⁺ ＝P _MPPT -P ₀ ＝K _r P _MPPT

ΔR ^- ＝P ₀ -P _m (β)

ΔR ⁺ /ΔR ^- = R ⁺ /R ^-

Among them, P _MPPT is the power output of the fan when it is running at the maximum power, and P _m (β) is the power output of the fan when the load is reduced. The first two formulas represent the correction values of the up and down frequency regulation capacity considering the rotor speed control and the pitch angle control, and they are respectively proportional to the basic reserve capacity before correction. The aerodynamic model of the wind turbine is described as follows:

{P P}_{m m} ((β β)) = = \frac{11}{22} {C C}_{p p} ((λ λ,, β β)) {ρAv ρAv}_{w w}^{33}

{C C}_{p p} ((λ λ,, β β)) = = 0.73 0.73 ((\frac{151151}{{λ λ}_{i i}} - - 0.58 0.58 β β - - 0.002 0.002 {β β}^{2.14 2.14} - - 13.2 13.2)) {e e}^{- - 18.4 18.4 / / {λ λ}_{i i}}

1/λ _i ＝1/(λ-0.02β)-0.003/(1+β ³ )

λ=ω _r R/v _w

Among them, K _r is the grade coefficient of the frequency regulation capacity, that is, the load reduction ratio of the fan under load reduction operation; P ₀ is the power output of the wind turbine in steady state operation; λ and β represent the tip speed ratio and pitch angle of the fan; ρ represents the air density, A represents the swept area of the blade, ω _r represents the speed of the fan rotor; R represents the radius of the fan blade, and v _w represents the wind speed.

Restrictions:

Fan rotor speed constraint:

Pitch angle adjustment range constraint: 0≤β≤β ^max

Derating ratio constraints:

Among them, the fan rotor speed constraints are set by the fan technical specifications, and the pitch angle adjustment range and load reduction ratio constraints are set based on experience.

5. A kind of method for evaluating the reserve capacity of wind power regulation considering the active control of wind turbines according to claim 1, characterized in that: said step 4) the correction model of the reserve capacity of wind power regulation considering the frequency modulation capacity of the wind farm adopts the following Method build:

{R R}_{00}^{+ +} = = {R R}^{+ +} - - {ΔR ΔR}^{+ +}

{R R}_{00}^{- -} = = {R R}^{- -} - - {ΔR ΔR}^{- -}

in, Indicates the corrected value for the wind power regulation up/down reserve capacity considering the frequency regulation capacity provided under the active control of wind turbine active power.