CN116207798A

CN116207798A - Inertia control method and device for wind farm and wind farm controller

Info

Publication number: CN116207798A
Application number: CN202111443442.XA
Authority: CN
Inventors: 左美灵
Original assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Current assignee: Beijing Goldwind Science and Creation Windpower Equipment Co Ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-06-02

Abstract

Provided are a wind farm inertia control method and device and a wind farm controller. The inertia control method of the wind power plant comprises the following steps: when the grid-connected point frequency of the wind power plant meets the inertia response condition of the current inertia frequency modulation control mode, determining an inertia active adjustment quantity required to be adjusted by the wind power plant; determining the inertia active reserve of the wind power plant; determining an inertia active adjustment amount of a wind generating set in the wind farm based on the inertia active adjustment amount required to be adjusted by the wind farm and the inertia active standby amount of the wind farm; and controlling the corresponding wind generating set to carry out inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set.

Description

Inertia control method and device for wind farm and wind farm controller

Technical Field

The present disclosure relates generally to the field of power technology, and more particularly, to a method and apparatus for inertia control of a wind farm and a wind farm controller.

Background

With the continuous expansion of the wind power access scale of the power system, the scheduling problem and the operation pressure of the power system are increasingly remarkable, and a system scheduling department has to schedule a traditional unit to hold more frequency modulation capacity so as to ensure the smooth absorption of wind power. On the one hand, the operation pressure of the traditional unit and the complexity of system scheduling operation are increased, and on the other hand, the economic and environmental protection benefits brought by wind power grid connection are reduced or offset. With the improvement of the control technology of the wind generating set, the wind generating set can participate in system frequency modulation to a certain extent. In the actual operation of the power grid, when the electric quantity consumption is not matched with the electric quantity supply, tiny components with smaller change and shorter fluctuation period can be caused to appear in the frequency of the power grid, and the frequency disturbance can finish the power grid load compensation by adjusting the power output by the wind generating set, so as to correct the fluctuation of the frequency of the power grid.

Disclosure of Invention

Exemplary embodiments of the present disclosure provide a wind farm inertia control method, apparatus, and wind farm controller, which can effectively adjust a grid frequency by controlling inertia of a wind farm.

According to a first aspect of an embodiment of the present disclosure, there is provided a method for controlling inertia of a wind farm, including: when the grid-connected point frequency of the wind power plant meets the inertia response condition of the current inertia frequency modulation control mode, determining an inertia active adjustment quantity required to be adjusted by the wind power plant; determining the inertia active reserve of the wind power plant; determining an inertia active adjustment amount of a wind generating set in the wind farm based on the inertia active adjustment amount required to be adjusted by the wind farm and the inertia active standby amount of the wind farm; and controlling the corresponding wind generating set to carry out inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set.

Optionally, the inertia frequency modulation control mode includes: a first inertia frequency modulation control mode and/or a second inertia frequency modulation control mode; the inertia response conditions of the first inertia frequency modulation control mode include: the frequency of the grid-connected point exceeds a first frequency response dead zone, the frequency change rate of the grid-connected point exceeds a frequency change rate response dead zone, and the change direction of the frequency of the grid-connected point is the same as the change direction of the frequency of the grid-connected point; and/or inertia response conditions for the second inertia frequency modulation control mode include: the grid tie-in frequency is lower than the rated frequency of the power grid and the second frequency response dead zone.

Optionally, when the inertia response condition of the current inertia frequency modulation control mode is satisfied, the step of determining the inertia active adjustment amount required for wind farm adjustment includes: under the condition that the current inertia frequency modulation control mode is a first inertia frequency modulation control mode, when inertia response conditions of the first inertia frequency modulation control mode are met, determining an inertia active adjustment quantity required to be adjusted by the wind power plant based on a wind power plant inertia time constant, a power grid rated frequency, a rated power or active power initial value of the wind power plant and a grid-connected point frequency change rate; and/or under the condition that the current inertia frequency modulation control mode is the second inertia frequency modulation control mode, determining an inertia active adjustment amount required to be adjusted by the wind power plant based on the wind power plant inertia coefficient, the rated power or the active power initial value of the wind power plant when the inertia response condition of the second inertia frequency modulation control mode is met.

Optionally, the inertia control method further includes: when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are met at the same time, the corresponding wind generating set is controlled to carry out inertia active adjustment only according to the determined inertia active adjustment quantity of the wind generating set, and the primary frequency modulation control is not carried out on the wind generating set at the same time.

Optionally, the step of determining the inertia active reserve of the wind farm includes: determining inertia rising active standby power and inertia falling active standby power of each wind generating set meeting preset conditions in a wind power plant; taking the sum of the inertia rising active standby power of each wind generating set meeting the preset condition as the inertia rising active standby amount of the wind power plant; and reducing the sum of the active standby power of inertia of each wind generating set meeting the preset condition as the active standby amount of inertia of the wind power plant.

Optionally, the preset condition includes: the current actual power of the wind generating set is larger than the minimum power and smaller than the rated power, and the wind generating set is controllable.

Optionally, the step of determining the inertia increasing active standby power and the inertia decreasing active standby power of each wind generating set meeting the preset condition in the wind farm includes: determining the inertia rising active standby power of each wind generating set based on the set inertia coefficient, rated power and current actual power of each wind generating set meeting preset conditions; and determining the active standby power of the inertia reduction of the wind generating set based on the set inertia coefficient, rated power, current actual power and minimum power of each wind generating set meeting preset conditions.

Optionally, the step of determining the inertia active adjustment amount of the wind turbine generator set within the wind farm based on the inertia active adjustment amount requiring wind farm adjustment and the inertia active reserve amount of the wind farm comprises: when the inertia active adjustment quantity required to be adjusted by the wind farm is larger than 0, determining the inertia rising active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the first inertia adjustment proportionality coefficient and the inertia rising active standby power of the typhoon generator set; when the inertia active adjustment quantity required to be adjusted by the wind farm is smaller than 0, determining the inertia reduction active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the second inertia adjustment proportionality coefficient and the active standby power of the inertia drop of the typhoon generator set; wherein the first inertial measurement unit adjusts a scaling factor as: the ratio of the active inertia adjustment amount required to be adjusted by the wind power plant to the active inertia reserve amount of the wind power plant; the second inertia adjustment scaling factor is: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reduction reserve amount of the wind farm.

Optionally, according to the determined inertia active adjustment amount of the wind generating set, the step of controlling the corresponding wind generating set to perform inertia active adjustment includes: according to the determined inertia active adjustment quantity and inertia adjustment speed of the wind generating set, controlling the corresponding wind generating set to perform inertia active adjustment; the inertia adjustment speed of the wind generating set is determined based on rated power and inertia control speed preset values of the wind generating set.

Optionally, the inertia control method further includes: and aiming at each wind generating set for carrying out inertia active power adjustment, when the time for carrying out inertia active power adjustment of the typhoon generating set reaches a preset time threshold value, controlling the typhoon generating set to stop carrying out inertia active power adjustment.

According to a second aspect of embodiments of the present disclosure, there is provided an inertia control apparatus of a wind farm, including: the wind power plant adjustment amount determining unit is configured to determine an inertia active adjustment amount required to be adjusted by the wind power plant when the grid-connected point frequency of the wind power plant meets the inertia response condition of the current inertia frequency modulation control mode; a reserve determination unit configured to determine an inertia active reserve of the wind farm; a single machine adjustment amount determination unit configured to determine an inertia active adjustment amount of a wind turbine generator set within the wind farm based on an inertia active adjustment amount requiring wind farm adjustment and an inertia active standby amount of the wind farm; and the adjusting control unit is configured to control the corresponding wind generating set to perform inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set.

Optionally, the field adjustment amount determining unit is configured to determine, when the current inertia frequency modulation control mode is the first inertia frequency modulation control mode and the inertia response condition of the first inertia frequency modulation control mode is satisfied, an inertia active adjustment amount required to be adjusted by the wind farm based on a wind farm inertia time constant, a rated frequency of a power grid, a rated power or active power initial value of the wind farm, and a grid-connected point frequency change rate; and/or the field adjustment amount determining unit is configured to determine an inertia active adjustment amount of the wind power field to be adjusted based on the wind power field inertia coefficient, the rated power or the active power initial value of the wind power field when the inertia response condition of the second inertia frequency modulation control mode is satisfied under the condition that the current inertia frequency modulation control mode is the second inertia frequency modulation control mode.

Optionally, the adjusting control unit is configured to control the corresponding wind generating set to perform inertia active adjustment according to the determined inertia active adjustment amount of the wind generating set only when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are satisfied at the same time, and not perform primary frequency modulation control on the wind generating set at the same time.

Alternatively, the reserve amount determining unit is configured to: determining inertia rising active standby power and inertia falling active standby power of each wind generating set meeting preset conditions in a wind power plant; taking the sum of the inertia rising active standby power of each wind generating set meeting the preset condition as the inertia rising active standby amount of the wind power plant; and reducing the sum of the active standby power of inertia of each wind generating set meeting the preset condition as the active standby amount of inertia of the wind power plant.

Optionally, the standby amount determining unit is configured to determine an inertia rise active standby power of each wind generating set based on a set inertia coefficient, rated power and current actual power of the wind generating set which meet preset conditions; and determining the active standby power of the inertia reduction of the wind generating set based on the set inertia coefficient, rated power, current actual power and minimum power of each wind generating set meeting preset conditions.

Optionally, the stand-alone adjustment amount determining unit is configured to determine, when the inertia active adjustment amount required for adjustment of the wind farm is greater than 0, an inertia rise active adjustment amount of each wind turbine generator set satisfying a preset condition as: the product between the first inertia adjustment proportionality coefficient and the inertia rising active standby power of the typhoon generator set; when the inertia active adjustment quantity required to be adjusted by the wind farm is smaller than 0, determining the inertia reduction active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the second inertia adjustment proportionality coefficient and the active standby power of the inertia drop of the typhoon generator set; wherein the first inertial measurement unit adjusts a scaling factor as: the ratio of the active inertia adjustment amount required to be adjusted by the wind power plant to the active inertia reserve amount of the wind power plant; the second inertia adjustment scaling factor is: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reduction reserve amount of the wind farm.

Optionally, the adjusting control unit is configured to control the corresponding wind generating set to perform inertia active adjustment according to the determined inertia active adjustment amount and inertia adjustment rate of the wind generating set; the inertia adjustment speed of the wind generating set is determined based on rated power and inertia control speed preset values of the wind generating set.

Optionally, the adjusting control unit is further configured to control the wind generating set to stop performing the active inertia adjustment when the time of performing the active inertia adjustment of the wind generating set reaches a preset time threshold.

According to a third aspect of embodiments of the present disclosure, there is provided a computer readable storage medium storing a computer program which, when executed by a processor, causes the processor to perform the inertia control method of a wind farm as described above.

According to a fourth aspect of embodiments of the present disclosure, there is provided a wind farm controller comprising: a processor; and a memory storing a computer program which, when executed by the processor, causes the processor to perform the inertia control method of a wind farm as described above.

According to the inertia control method and device for the wind power plant and the wind power plant controller, the power grid frequency can be effectively adjusted by controlling the inertia of the wind power plant.

Furthermore, it is proposed according to an exemplary embodiment of the present disclosure that: two inertia response control methods which can meet the inertia control requirements of different power grids; triggering corresponding inertia control through different triggering conditions; the inertia control and the primary frequency modulation control are effectively and smoothly connected and transited; the effect distinction of primary frequency modulation and inertia control is realized through different active control rates; and selecting a distribution queue and a control rate through different frequency modulation control working condition modes.

Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

Drawings

The foregoing and other objects and features of exemplary embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings which illustrate the embodiments by way of example, in which:

FIG. 1 illustrates a flowchart of a method of inertia control of a wind farm according to an exemplary embodiment of the present disclosure;

FIGS. 2 and 3 illustrate schematic diagrams of inertia responses according to exemplary embodiments of the present disclosure;

FIG. 4 illustrates a logic control diagram of a first inertial frequency modulation control mode according to an exemplary embodiment of the present disclosure;

FIG. 5 illustrates a control logic diagram of inertia frequency modulation and chirping engagement according to an exemplary embodiment of the present disclosure;

FIG. 6 illustrates a logic control diagram of a second inertia frequency modulation control mode according to an exemplary embodiment of the present disclosure;

FIG. 7 illustrates a logic control diagram of computer group standby power in accordance with an exemplary embodiment of the present disclosure;

FIG. 8 illustrates an overall flowchart of a method of inertia control of a wind farm according to an exemplary embodiment of the present disclosure;

fig. 9 shows a block diagram of a structure of an inertia control apparatus of a wind farm according to an exemplary embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments will be described below in order to explain the present disclosure by referring to the figures.

Fig. 1 illustrates a flowchart of a method of inertia control of a wind farm according to an exemplary embodiment of the present disclosure. As an example, the inertia control method may be performed by a controller of a wind farm.

Referring to fig. 1, in step S10, when the grid-connected point frequency of the wind farm meets the inertia response condition of the current inertia frequency modulation control mode, an active inertia adjustment amount required for wind farm adjustment is determined.

The current inertia frequency modulation control mode is the inertia frequency modulation control mode currently set. The inertia active adjustment amount required for wind farm adjustment is the active adjustment amount triggered by inertia required for wind farm adjustment, i.e. the active power amount adjusted by inertia. Hereinafter, the inertia active adjustment amount that needs wind farm adjustment is also referred to as Δp or DeltP.

As an example, inertia frequency modulation control modes may include: a first inertia frequency modulation control mode and/or a second inertia frequency modulation control mode. It should be appreciated that the inertia frequency modulation control mode may also include other modes, which are not limited in this disclosure. For example, the increasing mode is a control response in which the active power is increased by the inertia increasing section when the amount of active power up-regulation by the pitch system is insufficient due to a frequency change.

In step S20, an inertia active reserve amount of the wind farm is determined.

In step S30, an active inertia adjustment amount of the wind turbine generator set in the wind farm is determined based on the active inertia adjustment amount requiring adjustment of the wind farm and the active inertia reserve amount of the wind farm.

In step S40, according to the determined inertia active adjustment amount of the wind generating set, the corresponding wind generating set is controlled to perform inertia active adjustment. For example, inertia active regulation may be achieved by invoking rotor kinetic energy of the wind turbine.

For the first inertial quantity FM control mode

As an example, the inertia response conditions of the first inertia frequency modulation control mode may include: the frequency of the grid-connected point exceeds the first frequency response dead zone, the frequency change rate of the grid-connected point exceeds the frequency change rate response dead zone, and the change direction of the frequency of the grid-connected point is the same as the change direction of the frequency of the grid-connected point. In addition, the inertia response conditions of the first inertia frequency modulation control mode may further include: the wind farm output is greater than a proportion of the wind farm rated power, for example, greater than 20% of the wind farm rated power.

Regarding the condition that the frequency of the grid-connected point exceeds the first frequency response dead zone (also called as an action dead zone), the grid-connected point is divided into over-frequency and under-frequency working conditions, and the upper boundary value f of the first frequency response dead zone _dbo ＝f _n +OFDBForInertia, where f _n Representing the rated frequency of the power grid, OFDBForInertia represents the over-frequency dead zone of inertia, and the lower boundary value f of the first frequency response dead zone _dbu ＝f _n Ufdbfortinia, wherein ufdbfortinia represents an underfrequency dead zone of inertia. When the frequency of the grid connection point is higher than f _dbo Or lower than f _dbu When it is determined that the grid-connected point frequency exceeds the first frequency response dead zone.

Regarding the frequency change rate of the grid-connected point exceeding the frequency change rate response dead zone, the frequency change rate is divided into over-frequency and under-frequency working conditions, and the two dead zones are represented by positive numbers, wherein the over-frequency change rate response dead zone is ODfDtDeadband, and the under-frequency change rate response dead zone is UDfDtDeadband. And when the frequency change rate of the grid connection point is higher than ODfDtDeadband when the frequency is over-frequency or higher than UDfDtDeadband when the frequency is under-frequency, determining that the frequency change rate of the grid connection point exceeds a frequency change rate response dead zone.

As an example, the same direction of the frequency change of the grid-connected point as the direction of the frequency change rate of the grid-connected point may refer to: the frequency of the grid-connected point is higher than the rated frequency of the power grid, and the frequency of the grid-connected point is continuously increased upwards, namely the direction of the change of the frequency of the grid-connected point and the direction of the change rate of the frequency of the grid-connected point are both upward; or the frequency of the grid-connected point is lower than the rated frequency of the power grid, and the frequency of the grid-connected point is continuously reduced downwards, namely, the change direction of the frequency of the grid-connected point and the change rate of the frequency of the grid-connected point are downward. For example, as shown in fig. 2, assuming that the rated frequency of the power grid is 50Hz, each of the time periods t0 to t7 in fig. 2 changes according to a frequency of a certain rate (as shown by a solid line in fig. 2), and it is the time periods t0 to t1 and t4 to t5 that actually satisfy the inertia response condition of the first inertia frequency modulation control mode.

As shown in fig. 3, when the system frequency (i.e., grid tie frequency) is higher than the nominal frequency and crosses the chirped dead zone, the station may reduce the active power output according to the chirped curve and may not continue to reduce when the active modulation reaches the set point, e.g., the modulation clipping set point may be 10% pn at chirped power. When the wind turbine is operating normally and the active force is greater than 20% pn, the wind turbine may respond to the system frequency rate of change when the grid tie frequency rate of change exceeds a threshold (e.g., 0.05H/s).

As an example, in the case where the current inertia frequency modulation control mode is the first inertia frequency modulation control mode, when the inertia response condition of the first inertia frequency modulation control mode is satisfied, the inertia active adjustment amount that needs to be adjusted by the wind farm may be determined based on the wind farm inertia time constant, the rated frequency of the grid, the rated power or active power initial value of the wind farm, and the grid-tie point frequency change rate. The initial value of the active power of the wind power plant is the initial value of the active power before the full-field frequency modulation starts.

As an example, when the inertia response condition of the first inertia frequency modulation control mode is satisfied, the inertia active adjustment amount Δp that needs to be adjusted by the wind farm may be determined by formula (1) based on the wind farm inertia time constant, the grid rated frequency, the rated power or active power initial value of the wind farm, and the grid-tie point frequency change rate.

Wherein:

Δp—active power change amount required for wind farm regulation, unit: kW;

T _J -wind farm inertia time constant, unit: s, for example, typically take values from 4s to 12s;

f _N -power system rated frequency, unit: hz;

f-wind farm grid-connected point frequency, unit: hz;

P _N -wind farm rated capacity, unit: w.

FIG. 4 illustrates a logic control diagram of a first inertial frequency modulation control mode according to an exemplary embodiment of the present disclosure. As shown in fig. 4, the frequency change rate of the grid-connected point can be limited in the calculation, and the frequency change rate is divided into an over-frequency working condition and an under-frequency working condition, the cut-off value of the over-frequency change rate is ODfDtCutOff, the cut-off value of the low-frequency change rate is UDfDtCutOff, and when the frequency change rate of the grid-connected point exceeds the corresponding cut-off value, the cut-off value is used as the final frequency change rate to perform subsequent calculation, so that the total instruction of the full-field inertia is generated. For example, the total command for full farm inertia may be a command for controlling a wind turbine generator set within the farm to make active adjustments for inertia.

For example, the inertia frequency modulation control mode is to set two inertia control modes: 1) Inertia dfdt boost mode; 2) Inertia dfdt power-down mode.

It should be appreciated that the amount of active inertia adjustment that requires adjustment of the wind farm may be a positive adjustment (i.e., an amount of active power that requires the wind farm to increase by inertia) or a negative adjustment (i.e., an amount of active power that requires the wind farm to decrease by inertia). When the inertia active adjustment quantity required to be adjusted by the wind farm is a positive adjustment quantity, the inertia control mode is an inertia dfdt power increasing mode; when the inertia active adjustment amount required to be adjusted by the wind farm is a negative adjustment amount, the inertia control mode is an inertia dfdt power reduction mode.

As an example, in the case where the current inertia frequency modulation control mode is the first inertia frequency modulation control mode, when the inertia response condition of the first inertia frequency modulation control mode is satisfied, it may be determined that the inertia active adjustment amount Δppax that needs wind farm adjustment is not less than 10% of the rated power, the response time is not more than 1S, and the allowable deviation is not more than 2% of the rated power.

The present disclosure considers that the inertia response and the control speed and control manner of the chirped PFR are different, so the two control manners can be performed in a serial manner, and the inertia response is prioritized, and the chirped PFR is performed a plurality of times. After the inertia active adjustment quantity required to be adjusted by the wind farm and the active adjustment quantity required to be adjusted by the wind farm for primary frequency modulation are calculated each time, serial processing of control instructions is required, and therefore connection control is required. The engagement control is shown in fig. 5. The on-off switch (e.g., enabled "1" in fig. 5) outputs the total command logic according to primary frequency modulation and inertia, and when satisfied simultaneously, inertia is prioritized, frequency modulated, and not controlled simultaneously.

As can be seen from fig. 5, the pure PFR command is a combination of the PFR command and the inertia response command, for example, if there is only the PFR command, the PFR command is taken as the pure PFR command; if only the inertia response instruction exists, the inertia response instruction is used as a pure frequency modulation instruction; if there is both a chirped PFR command and an inertia response command, and the magnitude of the inertia response command exceeds a certain threshold (indicating that it is not 0), the inertia response command is taken as a pure chirped command. If the inertia frequency modulation response condition is not met, the inertia frequency modulation response condition can be set according to the working condition mode when the primary frequency modulation PFR droop control is performed: 1) A pitch power mode; 2) A pitch power reduction mode; 3) Braking resistance power down mode.

As an example, when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are satisfied at the same time, the corresponding wind turbine generator set may be controlled to perform inertia active adjustment only according to the determined inertia active adjustment amount of the wind turbine generator set, without performing primary frequency modulation control on the wind turbine generator set at the same time. Specifically, when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are satisfied at the same time, the corresponding wind generating set is controlled to perform inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set at first, but the primary frequency modulation control is not performed on the wind generating set. That is, when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are satisfied at the same time, inertia frequency modulation is preferentially triggered, and when inertia frequency modulation is not needed, primary frequency modulation can be performed.

With respect to the second inertia frequency modulation control mode

As an example, the inertia response conditions of the second inertia frequency modulation control mode may include: the grid tie-in frequency is lower than the rated frequency of the power grid and the second frequency response dead zone.

As an example, in the case where the current inertia frequency modulation control mode is the second inertia frequency modulation control mode, when the inertia response condition of the second inertia frequency modulation control mode is satisfied, the inertia active adjustment amount that needs to be adjusted by the wind farm may be determined based on the wind farm inertia coefficient, the rated power or the active power initial value of the wind farm.

As an example, when the inertia response condition of the second inertia frequency modulation control mode is satisfied, the inertia active adjustment amount Δp that needs to be adjusted by the wind farm may be determined based on the wind farm inertia coefficient, the rated power of the wind farm, or the active power initial value using equation (2).

ΔP＝WFInerPCoeff*P (2)

Wherein:

Δp—wind farm active power variance, unit: kW;

wfinorpcoeff—wind farm inertia coefficient, for example, may be greater than 6%;

p-wind farm power reference Pn (i.e., the rated power of the wind farm) or P0 (i.e., the active power initial value of the wind farm).

In other words, in the second inertia frequency modulation control mode, the inertia active adjustment amount is independent of how much Δf the frequency exceeds the dead zone, and only the difference between triggered and non-triggered is present. As an example, the inertia response time may be set, for example, to 10S.

Further, as an example, the droop control as the PFR is no longer responsive at low frequency conditions, i.e., primary frequency modulation is no longer performed. That is, as an example, when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are simultaneously satisfied, the corresponding wind turbine generator set is controlled to perform inertia active adjustment only according to the determined inertia active adjustment amount of the wind turbine generator set, without simultaneously performing primary frequency modulation control on the wind turbine generator set.

And in the second inertia frequency modulation control mode, setting an inertia dfdt power increasing mode by the frequency modulation control working condition mode. And the control time of inertia is set according to the fixed value, if the control time exceeds the controllable time, the active power variation of the inertia of the wind power plant is cleared to 0, and the frequency modulation control working condition mode is cleared to 0.

As an example, control logic for the second inertia frequency modulation control mode may be as shown in fig. 6.

Active reserve amount concerning inertia of wind farm

The standby power can be divided into an inertia increasing active standby power and an inertia decreasing active standby power. Triggering inertia response is to call the two standby powers for distribution.

As an example, an inertia increasing active standby power and an inertia decreasing active standby power of each wind generating set meeting preset conditions in a wind farm may be determined; then, taking the sum of the inertia rising active standby power of each wind generating set meeting the preset condition as the inertia rising active standby amount of the wind power plant; and reducing the sum of the active standby power of inertia of each wind generating set meeting the preset condition as the active standby amount of inertia of the wind power plant.

As an example, the preset condition may include: the current actual power of the wind generating set is larger than the minimum power and smaller than the rated power, and the wind generating set is controllable. The minimum power may be a preset real-time power lower limit. The wind generating set can be controlled by the wind generating set, and can feed back a signal that the controllable flag bit is set, normally communicate with a wind farm controller and be in a grid-connected state.

As an example, the inertia rise active standby power of each wind turbine generator set may be determined based on the set inertia coefficient, the rated power, and the current actual power of the wind turbine generator set that satisfy the preset condition.

For example, when the following condition is satisfied: when the measured power MeasP is larger than the minimum power PFCMinP and smaller than the rated power RatedP, the unit is controllable, and the inertia switch fixed value dfdtInertiacomd (i.e. the inertia switch is enabled) is started, the inertia rising active standby power (i.e. the inertia response increasable power) is calculated.

For example, the stand-alone inertia rise active standby power pwrpuplnerdfdt=the unit inertia coefficient wtinopcoeff is rated power RatedP, limited to not exceed RatedP-MeasP.

As an example, the active standby power of the inertia drop of the wind turbine generator set may be determined based on the set inertia coefficient, the rated power, the current actual power, and the minimum power of each wind turbine generator set that satisfies the preset condition.

For example, when the following condition is satisfied: when the measured power MeasP is larger than the minimum power PFCMinP and smaller than the rated power Rated P, the unit is controllable and the inertia switch fixed value DfdtInertian cmd is started, the active standby power of the inertia reduction (namely, the power of the inertia response can be reduced) is calculated.

For example, the stand-alone inertia reduced active standby power pwrpdowindfddt=the unit inertia coefficient wtinopcoeff is rated power RatedP, limited to not exceed MeasP-PFCMinP.

As an example, logic regarding the backup power of a computer group (fan) may be as shown in fig. 7.

Active inertia adjustment for determining a wind turbine in a wind farm

Considering that the capacity of each unit is similar in inertia response, the power-up proportion and the power-down proportion of inertia can be calculated respectively according to the proportion distribution mode, and the power-up proportion and the power-down proportion are distributed after proportional limiting (not more than 1) processing is carried out.

When the frequency modulation control working condition mode=the inertia dfdt power increasing mode, namely the full-scale active force is required to be increased, the inertia rise active adjustment quantity of each wind generating set meeting the preset condition is calculated.

When the frequency modulation control working condition mode=inertia dfdt power reduction mode, namely the full-scale active output needs to be reduced, the inertia power reduction adjustment quantity of each wind generating set meeting the preset condition is calculated.

As an example, when the inertia active adjustment amount that needs to be adjusted by the wind farm is greater than 0, the inertia rise active adjustment amount of each wind turbine generator set that satisfies the preset condition may be determined as: the product between the first inertia adjustment proportionality coefficient and the inertia rising active standby power of the typhoon generator set; wherein the first inertial measurement unit adjusts a scaling factor as: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reserve amount of the wind farm is required.

As an example, when the inertia active adjustment amount that needs to be adjusted by the wind farm is less than 0, the inertia drop active adjustment amount of each wind turbine generator set that satisfies the preset condition may be determined as: the product between the second inertia adjustment proportionality coefficient and the active standby power of the inertia drop of the typhoon generator set; wherein the second inertia adjustment scaling factor is: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reduction reserve amount of the wind farm.

Further, as an example, in step S40, the corresponding wind turbine generator set may be controlled to perform inertia active adjustment according to the determined inertia active adjustment amount and inertia adjustment rate of the wind turbine generator set; the inertia adjustment rate of the wind generating set can be determined based on rated power and an inertia control rate preset value of the wind generating set.

The present disclosure contemplates that the rate of inertia response control is different from the primary PFR, and a relatively fast rate must be employed, which distinguishes between unit rates when dispensing instructions.

As an example, the inertia boost and buck power may be the same or different for the active control rate of the genset, e.g., may be controlled at the rate deltap_rate = insertial rate x Pn x 0.01, where insertial rate is the inertia control rate preset.

In addition, as an example, for each wind generating set that performs inertia active adjustment, when the time of the current inertia active adjustment of the wind generating set reaches a preset time threshold, the wind generating set may be controlled to stop performing the current inertia active adjustment.

As an example, the overall flow of the inertia control method with respect to the wind farm may be as shown in fig. 8.

As an example, the wind farm level control system may start up three preset primary frequency modulation function programs (pitch modulation, inertia modulation and pitch+inertia modulation) according to requirements respectively for the frequency variation situation of the power grid system, where the functions calculate a full-farm power variation instruction corresponding to the frequency variation situation, and allocate the instruction to a single machine in a communication manner, and each grid-connected unit performs related adjustment according to the instruction.

In the prior art, a wind farm level control system does not have a mode of respectively starting three frequency modulation functions under different working conditions, inertia does not contain two directions of power up and power down, and the existing variable pitch and inertia frequency modulation mode is that inertia power-increasing active control is started when a unit variable pitch does not have the capacity of adjusting.

According to an exemplary embodiment of the present disclosure, it is proposed that: 1) The starting mode of inertia adjustment, the power adjustment direction comprises two modes of inertia rising power and inertia falling power; 2) The starting mode of variable pitch frequency modulation comprises a mode of frequency variation, and comprises variable pitch power up and variable pitch power down; 3) When inertia and pitch are started simultaneously, inertia frequency modulation can be triggered preferentially, and after the frequency change rate returns to the dead zone, pitch frequency modulation is triggered again.

According to an exemplary embodiment of the present disclosure, two inertia response control methods are proposed; the two methods can meet the inertia control requirements of different power grids; triggering corresponding inertia control through different triggering conditions; the inertia control and the primary frequency modulation control are effectively and smoothly connected and transited; the effect distinction of primary frequency modulation and inertia control is realized through different active control rates; and selecting a distribution queue and a control rate through different frequency modulation control working condition modes.

As shown in fig. 9, an inertia control apparatus of a wind farm according to an exemplary embodiment of the present disclosure includes: a field adjustment amount determining unit 10, a reserve amount determining unit 20, a stand-alone adjustment amount determining unit 30, and an adjustment control unit 40.

Specifically, the farm adjustment amount determining unit 10 is configured to determine an inertia active adjustment amount that requires wind farm adjustment when the grid tie-in frequency of the wind farm satisfies the inertia response condition of the current inertia frequency modulation control mode.

The reserve determination unit 20 is configured to determine an inertia active reserve of the wind farm.

The stand-alone adjustment amount determination unit 30 is configured to determine an inertia active adjustment amount of the wind turbine generator set within the wind farm based on the inertia active adjustment amount requiring adjustment of the wind farm and the inertia active standby amount of the wind farm.

The adjustment control unit 40 is configured to control the corresponding wind turbine generator set to perform inertia active adjustment according to the determined inertia active adjustment amount of the wind turbine generator set.

As an example, inertia frequency modulation control modes may include: a first inertia frequency modulation control mode and/or a second inertia frequency modulation control mode.

As an example, the inertia response conditions of the first inertia frequency modulation control mode may include: the frequency of the grid-connected point exceeds the first frequency response dead zone, the frequency change rate of the grid-connected point exceeds the frequency change rate response dead zone, and the change direction of the frequency of the grid-connected point is the same as the change direction of the frequency of the grid-connected point.

As an example, the farm adjustment amount determining unit 10 may be configured to determine, in the case where the current inertia frequency modulation control mode is the first inertia frequency modulation control mode, an inertia active adjustment amount that requires wind farm adjustment based on a wind farm inertia time constant, a grid rated frequency, a rated or active power initial value of the wind farm, a grid-tie-point frequency change rate when an inertia response condition of the first inertia frequency modulation control mode is satisfied.

As an example, the farm adjustment amount determining unit 10 may be configured to determine the inertia active adjustment amount that requires wind farm adjustment based on the wind farm inertia coefficient, the rated power of the wind farm, or the active power initial value when the inertia response condition of the second inertia modulation control mode is satisfied in the case where the current inertia modulation control mode is the second inertia modulation control mode.

As an example, the adjustment control unit 40 may be configured to control the corresponding wind turbine generator set to perform inertia active adjustment according to only the determined inertia active adjustment amount of the wind turbine generator set, without performing primary frequency modulation control on the wind turbine generator set at the same time, when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are satisfied at the same time.

As an example, the reserve amount determination unit 20 may be configured to: determining inertia rising active standby power and inertia falling active standby power of each wind generating set meeting preset conditions in a wind power plant; taking the sum of the inertia rising active standby power of each wind generating set meeting the preset condition as the inertia rising active standby amount of the wind power plant; and reducing the sum of the active standby power of inertia of each wind generating set meeting the preset condition as the active standby amount of inertia of the wind power plant.

As an example, the preset condition may include: the current actual power of the wind generating set is larger than the minimum power and smaller than the rated power, and the wind generating set is controllable.

As an example, the reserve amount determining unit 20 may be configured to determine an inertia increasing active reserve power of each wind turbine generator set that satisfies the preset condition based on the set inertia coefficient, the rated power, and the current actual power of the wind turbine generator set; and determining the active standby power of the inertia reduction of the wind generating set based on the set inertia coefficient, rated power, current actual power and minimum power of each wind generating set meeting preset conditions.

As an example, the stand-alone adjustment amount determining unit 30 may be configured to determine, when the inertia active adjustment amount required for wind farm adjustment is greater than 0, an inertia rise active adjustment amount of each wind turbine generator set satisfying a preset condition as: the product between the first inertia adjustment proportionality coefficient and the inertia rising active standby power of the typhoon generator set; when the inertia active adjustment quantity required to be adjusted by the wind farm is smaller than 0, determining the inertia reduction active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the second inertia adjustment proportionality coefficient and the active standby power of the inertia drop of the typhoon generator set; wherein the first inertial measurement unit adjusts a scaling factor as: the ratio of the active inertia adjustment amount required to be adjusted by the wind power plant to the active inertia reserve amount of the wind power plant; the second inertia adjustment scaling factor is: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reduction reserve amount of the wind farm.

As an example, the adjustment control unit 40 may be configured to control the corresponding wind turbine generator set to perform inertia active adjustment according to the determined inertia active adjustment amount and inertia adjustment rate of the wind turbine generator set; the inertia adjustment speed of the wind generating set is determined based on rated power and inertia control speed preset values of the wind generating set.

As an example, the adjustment control unit 40 may be further configured to control the typhoon generator set to stop performing the inertia active adjustment when the time for which the inertia active adjustment is performed by the typhoon generator set reaches a preset time threshold value for each wind generator set performing the inertia active adjustment.

It should be appreciated that specific processes performed by the inertia control apparatus of the wind farm according to the exemplary embodiment of the present disclosure have been described in detail with reference to fig. 1 to 8, and related details will not be repeated here.

It should be understood that the individual units in the inertia control apparatus of a wind farm according to an exemplary embodiment of the present disclosure may be implemented as hardware components and/or software components. The individual units may be implemented, for example, using a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), depending on the processing performed by the individual units as defined.

Exemplary embodiments of the present disclosure provide a computer readable storage medium storing a computer program, which when executed by a processor, causes the processor to perform the inertia control method of a wind farm as described in the above exemplary embodiments. The computer readable storage medium is any data storage device that can store data which can be read by a computer system. Examples of the computer readable storage medium include: read-only memory, random access memory, compact disc read-only, magnetic tape, floppy disk, optical data storage device, and carrier waves (such as data transmission through the internet via wired or wireless transmission paths).

A wind farm controller according to an exemplary embodiment of the present disclosure includes: a processor (not shown) and a memory (not shown), wherein the memory stores a computer program which, when executed by the processor, causes the processor to perform the inertia control method of a wind farm as described in the above exemplary embodiments.

Although a few exemplary embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

1. An inertia control method for a wind farm, comprising:

when the grid-connected point frequency of the wind power plant meets the inertia response condition of the current inertia frequency modulation control mode, determining an inertia active adjustment quantity required to be adjusted by the wind power plant;

determining the inertia active reserve of the wind power plant;

determining an inertia active adjustment amount of a wind generating set in the wind farm based on the inertia active adjustment amount required to be adjusted by the wind farm and the inertia active standby amount of the wind farm;

and controlling the corresponding wind generating set to carry out inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set.

2. The inertia control method of claim 1, wherein the inertia frequency modulation control mode includes: a first inertia frequency modulation control mode and/or a second inertia frequency modulation control mode;

the inertia response conditions of the first inertia frequency modulation control mode include: the frequency of the grid-connected point exceeds a first frequency response dead zone, the frequency change rate of the grid-connected point exceeds a frequency change rate response dead zone, and the change direction of the frequency of the grid-connected point is the same as the change direction of the frequency of the grid-connected point; and/or

The inertia response conditions of the second inertia frequency modulation control mode include: the grid tie-in frequency is lower than the rated frequency of the power grid and the second frequency response dead zone.

3. The inertia control method of claim 2, wherein the step of determining an active inertia adjustment amount that requires adjustment of the wind farm when the inertia response condition of the current inertia frequency modulation control mode is satisfied comprises:

under the condition that the current inertia frequency modulation control mode is a first inertia frequency modulation control mode, when inertia response conditions of the first inertia frequency modulation control mode are met, determining an inertia active adjustment quantity required to be adjusted by the wind power plant based on a wind power plant inertia time constant, a power grid rated frequency, a rated power or active power initial value of the wind power plant and a grid-connected point frequency change rate;

and/or the number of the groups of groups,

and when the current inertia frequency modulation control mode is the second inertia frequency modulation control mode and the inertia response condition of the second inertia frequency modulation control mode is met, determining the inertia active adjustment quantity required to be adjusted by the wind power plant based on the wind power plant inertia coefficient, the rated power or the active power initial value of the wind power plant.

4. The inertia control method of claim 2, further comprising:

when the primary frequency modulation response condition and the inertia response condition of the current inertia frequency modulation control mode are met at the same time, the corresponding wind generating set is controlled to carry out inertia active adjustment only according to the determined inertia active adjustment quantity of the wind generating set, and the primary frequency modulation control is not carried out on the wind generating set at the same time.

5. The inertia control method of claim 1, wherein the step of determining an active reserve of inertia of the wind farm comprises:

determining inertia rising active standby power and inertia falling active standby power of each wind generating set meeting preset conditions in a wind power plant;

taking the sum of the inertia rising active standby power of each wind generating set meeting the preset condition as the inertia rising active standby amount of the wind power plant;

and reducing the sum of the active standby power of inertia of each wind generating set meeting the preset condition as the active standby amount of inertia of the wind power plant.

6. The inertia control method of claim 5, wherein the preset conditions include: the current actual power of the wind generating set is larger than the minimum power and smaller than the rated power, and the wind generating set is controllable.

7. The inertia control method of claim 5, wherein determining the inertia increasing active standby power and the inertia decreasing active standby power for each wind turbine generator set within the wind farm that meets the predetermined condition comprises:

determining the inertia rising active standby power of each wind generating set based on the set inertia coefficient, rated power and current actual power of each wind generating set meeting preset conditions;

And determining the active standby power of the inertia reduction of the wind generating set based on the set inertia coefficient, rated power, current actual power and minimum power of each wind generating set meeting preset conditions.

8. The inertia control method of claim 5, wherein the step of determining the inertia active adjustment amount of the wind turbine generator set within the wind farm based on the inertia active adjustment amount of the wind farm requiring adjustment of the wind farm and the inertia active reserve amount of the wind farm comprises:

when the inertia active adjustment quantity required to be adjusted by the wind farm is larger than 0, determining the inertia rising active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the first inertia adjustment proportionality coefficient and the inertia rising active standby power of the typhoon generator set;

when the inertia active adjustment quantity required to be adjusted by the wind farm is smaller than 0, determining the inertia reduction active adjustment quantity of each wind generating set meeting the preset condition as follows: the product between the second inertia adjustment proportionality coefficient and the active standby power of the inertia drop of the typhoon generator set;

wherein the first inertial measurement unit adjusts a scaling factor as: the ratio of the active inertia adjustment amount required to be adjusted by the wind power plant to the active inertia reserve amount of the wind power plant;

The second inertia adjustment scaling factor is: the ratio of the active inertia adjustment amount required to be adjusted by the wind farm to the active inertia reduction reserve amount of the wind farm.

9. The inertia control method according to claim 1, wherein the step of controlling the corresponding wind turbine generator set to perform inertia active adjustment according to the determined inertia active adjustment amount of the wind turbine generator set includes:

according to the determined inertia active adjustment quantity and inertia adjustment speed of the wind generating set, controlling the corresponding wind generating set to perform inertia active adjustment;

the inertia adjustment speed of the wind generating set is determined based on rated power and inertia control speed preset values of the wind generating set.

10. The inertia control method of claim 1, further comprising:

and aiming at each wind generating set for carrying out inertia active power adjustment, when the time for carrying out inertia active power adjustment of the typhoon generating set reaches a preset time threshold value, controlling the typhoon generating set to stop carrying out inertia active power adjustment.

11. An inertia control apparatus for a wind farm, comprising:

the wind power plant adjustment amount determining unit is configured to determine an inertia active adjustment amount required to be adjusted by the wind power plant when the grid-connected point frequency of the wind power plant meets the inertia response condition of the current inertia frequency modulation control mode;

A reserve determination unit configured to determine an inertia active reserve of the wind farm;

a single machine adjustment amount determination unit configured to determine an inertia active adjustment amount of a wind turbine generator set within the wind farm based on an inertia active adjustment amount requiring wind farm adjustment and an inertia active standby amount of the wind farm;

and the adjusting control unit is configured to control the corresponding wind generating set to perform inertia active adjustment according to the determined inertia active adjustment quantity of the wind generating set.

12. A computer readable storage medium storing a computer program, which when executed by a processor causes the processor to perform the method of inertia control of a wind farm according to any of claims 1 to 10.

13. A wind farm controller, the wind farm controller comprising:

a processor;

a memory storing a computer program which, when executed by a processor, causes the processor to perform the inertia control method of a wind farm according to any of claims 1 to 10.