Frequency modulation method for new energy station

Abstract

The invention discloses a frequency modulation method for a new energy station, and relates to the technical field of power system frequency control, and the method comprises the steps: monitoring a wind driven generator, and obtaining rotating speed monitoring data and wind monitoring data; judging the rotating speed monitoring data based on the wind monitoring data, and if the rotating speed changes, marking the wind power data to obtain wind marking data; analyzing the wind mark data, and determining the wind power conversion sensitivity under different wind driven generator states; monitoring the output frequency of the grid-connected point to obtain frequency monitoring data, judging the frequency monitoring data based on the rotating speed monitoring data to obtain rotating speed mark data, and analyzing the rotating speed mark data to obtain rotating speed conversion sensitivity; and based on the wind power conversion sensitivity and the rotating speed conversion sensitivity, obtaining the overall sensitivity of the grid connection point, and adjusting the wind driven generator based on the overall sensitivity. The method has the effect of improving the grid-connected frequency modulation stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system frequency control, in particular to a frequency modulation method of a new energy station. BACKGROUND

[0002] With the deep adjustment of global energy structure and the accelerated promotion of the "double carbon" target, new energy power generation technologies represented by wind power and photovoltaic power generation are widely used due to their clean and low-carbon characteristics, and their penetration rate in the power system continues to rise. However, the output of wind power plants has significant intermittency and volatility, which makes the wind power plant grid-connected subject to natural conditions such as wind speed, resulting in unstable system frequency.

[0003] In the prior art, energy storage devices are arranged in the wind power plant, and the output frequency deficiency is compensated by using the energy storage devices to ensure the stability of the output frequency. However, since the power output of the wind power plant is obtained by rectification through a converter, the rectification mechanism of the converter is fixed, so when the external environment changes, the output result of the converter is first detected, and then the energy storage device is controlled according to the output result change, so that the frequency modulation process is not timely, resulting in fluctuations in the output frequency, which needs to be improved. SUMMARY

[0004] In order to improve the grid-connected frequency modulation stability, the present application provides a frequency modulation method of a new energy station.

[0005] The present application provides a frequency modulation method of a new energy station, which adopts the following technical scheme: A frequency modulation method of a new energy station, comprising: Obtaining the grid-connected frequency requirement of a grid-connected point and the power generation power of a wind power generator, and grouping the wind power generators in the wind power plant according to the grid-connected frequency requirement and the power generation power to determine the wind power generators required to be connected to each grid-connected point; Based on the grid-connected frequency requirement, the wind power generators connected to the grid-connected point are controlled to determine the initial state of each wind power generator on the grid-connected point, and the speed reference data and the wind reference data are obtained; Monitoring the speed of the wind power generator to obtain speed monitoring data, and monitoring the environmental information of the wind power generator to obtain wind monitoring data; Monitoring the wind data change of the wind monitoring data to obtain a change time point, and judging the speed monitoring data based on the change time point to determine whether the speed of the wind power generator at the corresponding time point changes, if the speed changes, the wind data is marked to obtain wind marked data; Analyzing the wind marked data to determine the wind power conversion sensitivity under different wind power generator states; The output frequency of the grid-connected point is monitored to obtain frequency monitoring data, the time point when the rotational speed changes is determined based on the rotational speed monitoring data to obtain a rotational speed time point, and the frequency monitoring data is judged based on the rotational speed time point to determine whether the output frequency of the grid-connected point at the corresponding time point changes; If the output frequency changes, the rotational speed data is marked to obtain rotational speed marking data, and the rotational speed marking data is analyzed to determine the sensitivity of the output frequency under different rotational speeds to obtain rotational speed conversion sensitivity; Based on the wind power conversion sensitivity and the rotational speed conversion sensitivity, the overall sensitivity of the grid-connected point is obtained, and the overall fluctuation range of the wind power generator is determined based on the overall sensitivity, and the wind power generator is adjusted based on the overall fluctuation range.

[0006] Preferably, the rotational speed monitoring data and the rotational speed reference data are difference calculated to obtain a rotational speed fluctuation value, and the rotational speed fluctuation value is counted based on the time data to obtain a rotational speed fluctuation curve; Obtain the yaw data of the wind power generator, and based on the yaw data and the wind direction data in the wind monitoring data, determine the deviation data between the wind power generator and the wind direction; Obtain the fan working data of the wind power generator, and based on the fan working data, the deviation data and the wind speed data in the wind monitoring data, determine the force of the wind on the fan under different wind monitoring data to obtain wind power data; The wind power data and the wind power reference data are difference calculated to obtain a wind power fluctuation value, and based on the built-in first comparison threshold, the wind power fluctuation value is screened to obtain the wind power fluctuation value exceeding the first comparison threshold, and the time point corresponding to the wind power fluctuation value is read to obtain the wind power change time point; Based on the wind power change time point, the rotational speed fluctuation value of the rotational speed fluctuation curve is read to obtain the to-be-judged rotational speed fluctuation data, and the to-be-judged rotational speed fluctuation data is compared with the built-in second comparison threshold, the wind power change time point corresponding to the to-be-judged rotational speed fluctuation data greater than the second comparison threshold is marked to obtain a marked time point; Based on the marked time point, the wind power fluctuation value is marked to obtain wind marking data.

[0007] Preferably, S51, based on the marked time point, the data change amount of the rotational speed monitoring data at the corresponding time point is determined to determine the rotational speed change amount; S52, based on the fan working data of the variable time point, the wind marking data is divided to determine the wind marking data under the same fan working data, and is recorded as a state marking group; S53, draw the wind power rotational speed change curve between the wind marking data and the rotational speed change amount in the state marking group; S54, judging the wind speed change curve based on artificial intelligence, determining the change relationship between wind speed and rotation speed under different fan blade working states, and determining the wind speed conversion sensitivity under different fan blade working states based on the change relationship.

[0008] Preferably, based on the wind speed change curve, the change relationship between wind speed and rotation speed under different fan blade working states is obtained and recorded as wind speed change relationship; Based on the wind speed change relationship, the rotation speed monitoring data is calculated to determine the change amount of wind speed when the rotation speed changes by one standard rotation speed unit, and the minimum wind speed change amount is obtained; Based on the minimum wind speed change amount, the wind speed data is matched to determine whether there is a change amount equal to the minimum wind speed change amount in the wind speed data. If it is determined that there is, the rotation speed monitoring data is matched according to the time point corresponding to the minimum wind speed change amount to determine whether the rotation speed monitoring data has changed; If it is determined that there is a change, the standard unit is taken as the minimum change unit of rotation speed change, and based on the minimum change unit of rotation speed and the wind speed change relationship, the corresponding wind speed conversion sensitivity is constructed; If it is determined that the rotation speed monitoring data has not changed, the wind speed change amount when the rotation speed changes by two standard rotation speed units is determined according to the wind speed change relationship, and the process is repeated until the time point corresponding to the wind speed change amount matches the rotation speed monitoring data successfully.

[0009] Preferably, based on the built-in frequency fluctuation threshold, the frequency monitoring data is filtered to obtain the time point at which the output frequency fluctuation is greater than the frequency fluctuation threshold, and the time point is marked as the frequency fluctuation time point; Based on the frequency fluctuation time point, the rotation speed monitoring data is read to obtain the to-be-judged rotation speed data; The to-be-judged rotation speed data and the rotation speed reference data are difference calculated to determine the rotation speed change amount, and the frequency monitoring data at the frequency fluctuation time point and the frequency fluctuation threshold are difference calculated to obtain the frequency change amount; The rotation speed change amount and the frequency change amount are correspondingly grouped to obtain the rotation speed frequency group data; The multiple rotation speed frequency group data are statistically analyzed to determine the rotation speed change relationship, and based on the rotation speed change relationship and the built-in standard frequency unit, the rotation speed monitoring data and the frequency monitoring data are verified to determine the minimum change amount between the rotation speed and the frequency, and based on the minimum change amount, the rotation speed conversion sensitivity between the rotation speed and the frequency is determined.

[0010] Preferably, S81, based on the minimum change amount of rotation speed in the wind speed conversion sensitivity and the minimum change amount of frequency in the rotation speed conversion sensitivity, the wind speed conversion sensitivity and the rotation speed conversion sensitivity are coupled to obtain the overall sensitivity between wind speed and frequency; S82, determine a fluctuation range of the wind acting on the wind turbine according to the minimum variation of the frequency in the overall sensitivity, to obtain an overall fluctuation range; S83, record the wind monitoring data at the current time point as current wind data, record the fan working data at the current time point as real-time state data, judge the current wind data based on the real-time state data, and determine the current wind force acting on the wind turbine by the current wind data; S84, judge the frequency monitoring data to determine the frequency change trend, and judge the working state of the wind turbine based on the frequency change trend, the current wind force and the overall fluctuation range to obtain adjustment data; S85, adjust the working state of the wind turbine to the data edge of the overall fluctuation range based on the adjustment data.

[0011] Preferably, S841, if the frequency change trend is a downward trend, the current wind force is calculated according to the upper limit of the overall fluctuation range, to obtain first adjustment difference data; S842, obtain the maximum conversion coefficient of the fan, and determine the maximum wind force that can be reached based on the current wind data and the maximum conversion coefficient; S843, compare the maximum wind force with the first adjustment difference data to determine whether the maximum wind force meets the requirements of the first adjustment difference data, if it is determined that the requirements of the first adjustment difference data are met, the first adjustment data of the fan of the wind turbine under the current wind data is determined according to the first adjustment difference data; S844, if it is determined that the requirements of the first adjustment difference data are not met, obtain the braking coefficient of the braking system, and adjust the braking coefficient of the braking system according to the difference between the first adjustment difference data and the maximum wind force, to obtain second adjustment data; S845, if the frequency change trend is an upward trend, the current wind force is calculated according to the lower limit of the overall fluctuation range, to obtain second adjustment difference data, and the wind turbine is adjusted according to the second adjustment difference data, to obtain third adjustment data of the wind turbine.

[0012] In summary, the present application includes at least one of the following beneficial technical effects: By using the grid-connected frequency requirement of the grid-connected point and the power generation power of the wind power generator, the number of wind power generators required to be connected under the corresponding grid-connected frequency requirement is determined, so that a large number of wind power generators in the wind power station are processed separately, the accuracy of monitoring and adjustment is improved, the initial state of the wind power station when connected to the grid is determined by using the adjustment result when connected to the grid, so as to determine the reference value, and the rotational speed monitoring data and wind monitoring data in the operation of the wind power generator are evaluated based on the reference value, the sensitivity of the rotational speed of the wind power generator to the wind power and the sensitivity of the output frequency change to the rotational speed are determined, and then the wind power generator can be adjusted in advance according to the rotational speed conversion sensitivity and the wind power conversion sensitivity, so that the wind power generator can quickly respond when the output frequency changes, so as to maintain the stability of the output frequency. The wind power variation relationship is calculated by means of the built-in standard rotational speed unit, it is determined whether there is a corresponding minimum wind power variation in the wind power data, and it is determined whether there is corresponding data variation in the rotational speed monitoring data when the minimum wind power variation occurs, so as to determine the minimum variation between wind power and rotational speed, so that the wind power conversion sensitivity constructed is more convincing and more consistent with the actual situation, the accuracy of the frequency modulation result is improved when frequency modulation, and the stability of the output frequency is ensured. By judging the working state of the fan blade, it is determined whether the adjustment amount required by the frequency change trend can be met by only adjusting the conversion coefficient between the fan blade and the wind, when it is determined that the maximum wind action force that can be converted by the wind power generator can meet the first to-be-adjusted difference value data, the first to-be-adjusted difference value data is directly taken as the final adjustment target of the wind power generator fan blade to adjust the wind power generator fan blade, so that the adjustment process reduces the variation of the wind power generator operation to the greatest extent, and then the adjusted wind power generator is still within the wind power conversion sensitivity and rotational speed conversion sensitivity range, thereby improving the adjustment accuracy, and when the maximum wind action force cannot meet the first to-be-adjusted difference value data, the brake system is adjusted to gradually release the restriction of the brake system on the rotational speed of the wind power generator, so that the rotational speed of the wind power generator can reach the rotational speed corresponding to the upper limit of the overall fluctuation range, thereby making the entire adjustment process stable, and thereby maintaining the stability of the output frequency. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The step flow chart of the frequency modulation method of the new energy station of the present embodiment. DETAILED DESCRIPTION

[0014] The following will be described in detail with reference to the accompanying Figure 1 The present application will be further described in detail.

[0015] The present application discloses a frequency modulation method for a new energy station.

[0016] Embodiment: AsFigure 1 The frequency modulation method of the new energy field station shown in the application comprises the following steps: S1, obtaining the grid-connected frequency requirement of the grid-connected point and the power generation power of the wind power generator, and grouping the wind power generators in the wind power field station according to the grid-connected frequency requirement and the power generation power to determine the wind power generators required to be connected to each grid-connected point; S2, based on the grid-connected frequency requirement, the wind power generators connected to the grid-connected point are regulated and controlled to determine the initial state of each wind power generator on the grid-connected point, and the speed reference data and the wind reference data are obtained; wherein the speed data is the speed required to match the power grid when connected to the grid, that is, when the speed reaches the speed data, it means that the output frequency reaches the grid-connected requirement.

[0017] S3, monitoring the speed of the wind power generator to obtain speed monitoring data, and monitoring the environmental information of the wind power generator to obtain wind monitoring data; S4, monitoring the wind monitoring data to obtain the change time point, and judging the speed monitoring data based on the change time point to determine whether the speed of the wind power generator at the corresponding time point changes, if the speed changes, the wind data is marked to obtain wind marking data; S5, analyzing the wind marking data to determine the wind power conversion sensitivity under different wind power generator states; the sensitivity value refers to the influence of the change value of the wind speed or the change value of the wind direction on the speed when the adjustment is positive. For example, if the speed increases or decreases by one unit, the change value of the wind power increases or decreases by n units.

[0018] S6, monitoring the output frequency of the grid-connected point to obtain frequency monitoring data, determining the time point when the speed changes based on the speed monitoring data to obtain the speed time point, and judging the frequency monitoring data based on the speed time point to determine whether the output frequency of the grid-connected point at the corresponding time point changes; S7, if the output frequency changes, the speed data is marked to obtain speed marking data, the speed marking data is analyzed to determine the sensitivity of the output frequency under different speeds, and the speed conversion sensitivity is obtained; S8, based on the wind power conversion sensitivity and the speed conversion sensitivity, the overall sensitivity of the grid-connected point is obtained, the overall fluctuation range of the wind power generator is determined based on the overall sensitivity, and the wind power generator is adjusted based on the overall fluctuation range.

[0019] In this embodiment, the number of wind power generators required to be connected under the corresponding grid frequency requirement is determined by using the grid frequency requirement of the grid connection point and the power generation power of the wind power generator, so that a large number of wind power generators in the wind power station are processed separately, the accuracy of monitoring and adjustment is improved, the initial state of the wind power station when connected to the grid is determined by using the adjustment result when connected to the grid, so as to determine the reference value, and the rotational speed monitoring data and wind monitoring data of the wind power generator in operation are evaluated based on the reference value, the sensitivity of the rotational speed of the wind power generator to the wind power is determined, and the sensitivity of the output frequency change to the rotational speed is determined, and then the wind power generator can be adjusted in advance according to the rotational speed conversion sensitivity and the wind power conversion sensitivity, so that the wind power generator can quickly respond when the output frequency changes, so as to maintain the stability of the output frequency.

[0020] For example, by determining the output frequency required to be maintained by the wind power station when the grid is connected, the final adjustment target is determined, assuming that the grid frequency requirement is 50Hz, because when the active power supply in the wind power station system is greater than the load demand, the system frequency will rise, and vice versa, if the load demand is greater than the active power, the system frequency will decrease, so when the grid load is certain, the required active power output by the wind power station can be effectively determined, and then the number of wind power generators required to be connected to each grid connection point can be determined according to the power generation power of each wind power generator. Assuming that there are four wind power generators a, b, c and d, and the output power is 1, and the required power of the grid connection point is 2, then a and b can be connected as a group, and c and d can be connected as a group in two grid connection points, so as to ensure the stability of the grid connection, only a and b need to be monitored, and c and d need to be monitored, which reduces the data variables of each grid connection point, makes the analysis more convenient, and improves the analysis efficiency and accuracy. At the same time, the power generation power of the wind power generator is matched and grouped, so that the wind energy is fully utilized, the wind energy utilization rate is improved, and the waste of natural resources is reduced.

[0021] After determining the wind power generators required to be connected to each grid connection point, in order to ensure the stability of the connection of each grid connection point, the wind power generators in the wind power station are adjusted by artificial adjustment, so as to obtain the initial working state of each wind power generator in the wind power station, that is, when the wind power generator reaches the corresponding reference data, the connection of the grid connection point has stability, so that the complex power data is quantized into the running state of the wind power generator.

[0022] When the state of each grid-connected point of the wind turbine is determined, the speed of the wind turbine and the environmental information are monitored to determine whether the speed of the wind turbine changes and whether the external environment (wind speed and wind direction) changes. Since the output power of the wind turbine is determined by the speed, and the speed of the wind turbine is determined by the force of the wind acting on the fan blades, monitoring the speed and the external environment can effectively determine the change state of the wind turbine.

[0023] By monitoring the wind monitoring data and combining the speed monitoring data, it can be determined how much change in the force of the wind acting on the fan blades will cause a change in the speed. For example, if the force of the wind acting on the fan blades increases by 10, the speed will increase by 1. Thus, the conversion relationship between wind and speed is determined. However, the wind turbine converts wind into speed with a certain degree of sensitivity, rather than real-time accurate conversion. For example, the relationship between wind and speed is that if the force of the wind acting on the fan blades increases by 10, the speed will increase by 1. However, this data conversion relationship does not mean that if the force of the wind acting on the fan blades increases by 1, the speed will increase by 0.1. Therefore, the sensitivity of the conversion of wind into speed needs to be determined, so that the wind turbine can be adjusted in time when the external environment changes, to ensure the stability of the output power and thus the stability of the output frequency.

[0024] Similarly, the sensitivity between the speed and the output frequency is determined to determine the relationship between them. Thus, the influence of the external environment (wind speed and wind direction) on the output frequency when it changes can be determined, so that the wind turbine can be adjusted in time using the redundancy between them when the external environment changes, to ensure that the state of the wind turbine always remains in the initial state and improve the stability of the grid connection.

[0025] In step S4, the wind monitoring data is monitored for wind data changes, the change time point is obtained, and the speed monitoring data is judged based on the change time point to determine whether the speed of the wind turbine at the corresponding time point changes. If the speed changes, the wind data is marked to obtain wind marked data, including the following steps: S41, the speed monitoring data is difference calculated with the speed reference data to obtain the speed fluctuation value, and the speed fluctuation value is counted based on the time data to obtain the speed fluctuation curve; wherein the speed reference data is the speed generated when the output frequency meets the demand.

[0026] S42, the yaw data of the wind turbine is obtained, and the deviation data between the wind turbine and the wind direction is determined based on the yaw data and the wind direction data in the wind monitoring data; wherein the deviation data is the direction angle when the wind changes direction and the wind turbine does not adjust accordingly.

[0027] S43, obtaining the fan working data of the wind turbine, and determining the force of the wind on the fan under different wind monitoring data based on the fan working data, the deviation data and the wind speed data in the wind monitoring data, to obtain the wind data; wherein the wind data refers to the force of the wind on the wind turbine at each moment.

[0028] S44, performing difference calculation on the wind data and the wind reference data to obtain the wind fluctuation value, and performing screening on the wind fluctuation value based on the built-in first comparison threshold to obtain the wind fluctuation value exceeding the first comparison threshold, and reading the time point corresponding to the wind fluctuation value to obtain the wind change time point; wherein the speed reference value and the wind reference data are the same, both referring to the required wind force when the output power reaches the demand.

[0029] S45, performing speed fluctuation value reading on the speed fluctuation curve based on the wind change time point to obtain the to-be-judged speed fluctuation data, and comparing the to-be-judged speed fluctuation data with the built-in second comparison threshold, and marking the wind change time point corresponding to the to-be-judged speed fluctuation data greater than the second comparison threshold to obtain the marked time point; wherein the marked time point refers to the time point at which the speed changes when the wind changes.

[0030] S46, marking the wind fluctuation value based on the marked time point to obtain the wind marked data. Wherein the wind marked data refers to the wind monitoring data that can cause speed change.

[0031] In this embodiment, based on the relationship between the fan of the wind turbine and the wind monitoring data, the monitored wind monitoring data is converted into wind data of the wind acting on the fan, and then the variable wind monitoring data is normalized into unified wind data, which simplifies the data judgment complexity. By judging the wind fluctuation of the wind data, the wind fluctuation time point is determined, and the speed fluctuation curve is read and judged based on the wind change time point, so as to determine whether the speed changes correspondingly when the wind changes. Through screening of a large amount of wind monitoring data and speed monitoring data, the accuracy of the to-be-judged data is ensured, and the accuracy of the sensitivity judgment is improved.

[0032] For example, the output frequency of the connected power grid is fixed, and the fixed output frequency corresponds to fixed output power, and the fixed output power corresponds to fixed speed, so the speed in the initial state is taken as the reference value of the wind turbine, the speed of the wind turbine is judged to determine whether the speed of the wind turbine changes, the difference between the speed monitoring data and the speed reference data is calculated, and the calculated difference is counted to obtain the speed fluctuation curve.

[0033] Meanwhile, the wind acting force on the fan blade is determined by judging the wind speed data and the wind direction data in the wind monitoring data and the fan blade working data of the wind turbine. Since the wind resource is a natural resource which is uncontrollable and not stable and sustainable by human beings, there is a slight fluctuation. Therefore, the first comparison threshold is used as a judgment standard of the wind force change to judge the wind force and determine whether the wind force acting on the wind turbine changes.

[0034] When it is determined that the wind force acting on the wind turbine exceeds the normal fluctuation range, the corresponding speed is read to determine whether the corresponding speed changes. For example, the wind force is 10, and under normal circumstances, the wind force can be determined to be in a ±0.5 fluctuation range due to the characteristics of the wind. When the wind force exceeds the ±0.5 fluctuation range, it is determined that the wind force changes. At this time, the change of the wind force may be caused by the change of the wind speed or the change of the wind direction. The speed is read at the time point when the change of the wind force is determined, for example, at 00:30. The speed at 00:30 is read, and it is determined whether the speed changes at this time. If the speed also changes, it indicates that the change of the wind force at the marked time point causes the change of the speed of the wind turbine. Therefore, the wind force change and the speed change need to be uniformly analyzed to determine the conversion relationship between them.

[0035] In step S5, the wind marking data is analyzed to determine the wind force conversion sensitivity under different states of the wind turbine, including the following steps: S51, based on the marked time point, the data change amount of the speed monitoring data at the corresponding time point is determined to determine the speed change amount; S52, based on the fan blade working data at the fluctuation time point, the wind marking data is divided to determine the wind marking data under the same fan blade working data, and is recorded as a state marking group; S53, a wind speed change curve between the wind marking data and the speed change amount in the state marking group is drawn; S54, the wind speed change curve is judged based on artificial intelligence to determine the fluctuation relationship between the wind force and the speed under different fan blade working states, and the wind force conversion sensitivity under different fan blade working states is determined based on the fluctuation relationship.

[0036] Exemplary, after determining which wind monitoring data can cause the wind turbine speed change, the wind monitoring data change amount and the wind turbine speed change amount are used to build a data change relationship, so that the sensitivity of the wind turbine to wind changes can be determined. However, due to the different fan working states, the wind force acting on the same wind monitoring data is different, so it is necessary to divide the wind monitoring data according to the fan working data, so as to ensure the accuracy of the data to be analyzed, and then improve the sensitivity of the wind turbine speed to the wind speed.

[0037] In step S54, the wind speed change curve is judged based on artificial intelligence, the variation relationship between wind and speed under different fan working states is determined, and the wind speed conversion sensitivity under different fan working states is determined based on the variation relationship, including the following steps: S541, based on the wind speed change curve, the variation relationship between wind and speed under different fan working states is obtained and recorded as wind variation relationship; S542, based on the wind variation relationship, the speed monitoring data is calculated to determine the wind variation amount when the speed changes by one standard speed unit, and the minimum wind variation amount is obtained; S543, based on the minimum wind variation amount, the wind data is matched to determine whether there is a minimum wind variation amount in the wind data, if it is determined that there is, the speed monitoring data is matched according to the time point corresponding to the minimum wind variation amount, to determine whether the speed monitoring data has changed; S544, if it is determined that the change has occurred, the standard unit is taken as the minimum variation unit of the speed change, and the corresponding wind speed conversion sensitivity is constructed based on the minimum variation unit of the speed and the wind variation relationship; S545, if it is determined that the speed monitoring data has not changed, the wind variation amount when the speed changes by two standard speed units is determined according to the wind variation relationship, until the time point corresponding to the wind variation amount is matched with the speed monitoring data.

[0038] In this embodiment, the built-in standard speed unit is used to calculate the wind variation relationship, to determine whether there is a corresponding minimum wind variation amount in the wind data, and to determine whether the speed monitoring data has corresponding data variation when the minimum wind variation amount appears, so as to determine the minimum variation amount between wind and speed. The wind speed conversion sensitivity constructed is more convincing and more consistent with the actual situation, which improves the accuracy of the frequency modulation result and ensures the stability of the output frequency.

[0039] Exemplarily, due to the inertia of the rotation speed of the wind turbine in the conversion of the wind monitoring data, it is possible that the rotation speed of the wind turbine changes only when the force acting on the fan blade reaches a certain value. For example, when the wind force acting on the fan blade increases by 20, the rotation speed of the wind turbine changes, and the rotation speed increases by 2. At this time, the data relationship between the two is 10:1, that is, the rotation speed increases by 1 for every 10 increase in the wind force. However, in the actual process, due to the inertia, when the wind force increases by 10, the rotation speed does not increase by 1. Therefore, the inertia (i.e., the minimum change amount) between the wind force and the rotation speed needs to be determined according to the wind monitoring data and the rotation speed monitoring data, and then the sensitivity of the rotation speed of the wind turbine to the wind force is determined. For example, the sensitivity is 20:2, that is, the rotation speed increases by 2 for every 20 increase in the wind force, and the rotation speed does not change in the interval from 0 to 20 increase in the wind force. The determined sensitivity is more consistent with the actual situation, and the accuracy of the determination is improved.

[0040] In step S7, if the output frequency changes, the rotation speed data is marked to obtain rotation speed marked data, and the rotation speed marked data is analyzed to determine the sensitivity of the output frequency at different rotation speeds to obtain rotation speed conversion sensitivity, including the following steps: S71, based on the built-in frequency fluctuation threshold, the frequency monitoring data is filtered to obtain the time point at which the output frequency fluctuation is greater than the frequency fluctuation threshold, and the time point is marked as a frequency fluctuation time point; S72, based on the frequency fluctuation time point, the rotation speed monitoring data is read to obtain the to-be-judged rotation speed data; S73, the to-be-judged rotation speed data is difference calculated with the rotation speed reference data to determine the rotation speed change amount; the frequency monitoring data at the frequency fluctuation time point is difference calculated with the frequency fluctuation threshold to obtain the frequency change amount; S74, the rotation speed change amount and the frequency change amount are correspondingly grouped to obtain rotation speed frequency group data; S75, the multiple rotation speed frequency group data are statistically analyzed to determine the rotation speed change relationship, and based on the rotation speed change relationship and the built-in standard frequency unit, the rotation speed monitoring data and the frequency monitoring data are verified to determine the minimum change amount between the rotation speed and the frequency, and based on the minimum change amount, the rotation speed conversion sensitivity between the rotation speed and the frequency is determined.

[0041] For example, when judging the sensitivity between frequency and rotating speed, the output frequency is fixed when grid-connected, so the frequency fluctuation is screened to determine the rotating speed change value when the frequency changes, and then the data relationship between the frequency change and the rotating speed change is constructed, and the data relationship between the two is determined. Similarly, the minimum change between the two needs to be judged to further determine the sensitivity of the frequency change to the rotating speed change, and then the sensitivity between wind power and rotating speed and the sensitivity between rotating speed and frequency are used to provide fluctuation redundancy space for the adjustment of the wind power generator when the external environment (wind speed, wind direction) changes., and then the system can adjust the relevant working data of the wind power generator before the fluctuation redundancy space collapses to ensure the stability of the output frequency and improve the stability of the grid-connected access.

[0042] In step S8, the overall sensitivity of the grid-connected point is obtained based on the wind power conversion sensitivity and the rotating speed conversion sensitivity, and the overall fluctuation range of the wind power generator is determined based on the overall sensitivity, and the wind power generator is adjusted based on the overall fluctuation range, including the following steps: S81, based on the minimum change of the rotating speed in the wind power conversion sensitivity and the minimum change of the frequency in the rotating speed conversion sensitivity, the wind power conversion sensitivity and the rotating speed conversion sensitivity are coupled to obtain the overall sensitivity between wind power and frequency; S82, according to the minimum change of the frequency in the overall sensitivity, the fluctuation range of the wind acting on the wind power generator is determined to obtain the overall fluctuation range; S83, the wind monitoring data at the current time point is recorded as the current wind data, and the blade working data at the current time point is recorded as the real-time state data, and the current wind data is judged based on the real-time state data. Determine the current wind force acting on the wind power generator by the current wind data; S84, judge the frequency monitoring data to determine the frequency change trend, judge the working state of the wind power generator based on the frequency change trend, the current wind force and the overall fluctuation range to obtain the adjustment data; S85, adjust the working state of the wind power generator to the data edge of the overall fluctuation range based on the adjustment data.

[0043] Exemplary, after determining the sensitivity of the rotation speed to the wind force and the sensitivity of the frequency to the rotation speed, the sensitivity of the frequency to the wind force is determined by coupling the two, that is, when the wind force reaches how much, the frequency will change, and the amount of change of the frequency is determined by real-time monitoring of the frequency monitoring data to determine the trend of the frequency change. If the load in the power grid increases, the required power needs to increase, and under the condition that the output power does not increase, the corresponding output frequency will decrease, resulting in unstable grid connection. In order to ensure stable grid connection, the output frequency needs to be pulled up, and the pull-up of the output frequency corresponds to the increase of the output power. Therefore, the wind force acting on the wind turbine needs to be adjusted to improve the output power and pull up the output frequency. Since the output frequency is still in a safe state, the output frequency cannot be adjusted in advance. In order to ensure that the output frequency can be adjusted in time when the output frequency decreases or increases to maintain the stability of the output frequency, the working state of the wind turbine in the current wind farm needs to be at the edge of the overall fluctuation range, so that the wind turbine can be adjusted most quickly to maintain the stability of the output frequency when the output frequency changes.

[0044] In step S84, the frequency monitoring data is judged to determine the trend of the frequency change, and the working state of the wind turbine is judged based on the trend of the frequency change, the current wind force and the overall fluctuation range to obtain adjustment data, including the following steps: S841, if the trend of the frequency change is a downward trend, then the current wind force is calculated by difference according to the upper limit of the overall fluctuation range to obtain first adjustment difference data; S842, the maximum conversion coefficient of the fan blade is obtained, and the maximum wind force that can be reached is determined based on the current wind data and the maximum conversion coefficient; S843, the maximum wind force is compared with the first adjustment difference data to determine whether the maximum wind force meets the requirements of the first adjustment difference data. If it is determined that the requirements of the first adjustment difference data are met, then the first adjustment data of the fan blade of the wind turbine under the current wind data is determined according to the first adjustment difference data; S844, if it is determined that the requirements of the first adjustment difference data are not met, then the braking coefficient of the braking system is obtained, and the braking coefficient of the braking system is adjusted according to the difference between the first adjustment difference data and the maximum wind force to obtain second adjustment data; wherein the second adjustment data includes adjustment data of the fan blade and adjustment data of the braking system.

[0045] S845, if the trend of the frequency change is an upward trend, then the current wind force is calculated by difference according to the lower limit of the overall fluctuation range to obtain second adjustment difference data, and the wind turbine is adjusted according to the second adjustment difference data to obtain third adjustment data of the wind turbine.

[0046] In the embodiment, when the working state of the wind turbine is adjusted, the working state of the fan blade is determined to determine whether the adjustment amount required by the frequency change trend can be met by adjusting the conversion coefficient between the fan blade and the wind, when it is determined that the maximum wind force that can be converted by the wind turbine can meet the first to-be-adjusted difference value data, the first to-be-adjusted difference value data is directly taken as the final adjustment target of the fan blade of the wind turbine to adjust the fan blade of the wind turbine, so that the adjustment process reduces the variation of the operation of the wind turbine to the greatest extent, and then the adjusted wind turbine is still within the wind conversion sensitivity and speed conversion sensitivity range, thereby improving the adjustment accuracy, and when the maximum wind force cannot meet the first to-be-adjusted difference value data, the brake system is adjusted to gradually release the restriction of the brake system on the speed of the wind turbine, so that the speed of the wind turbine can reach the speed corresponding to the upper limit of the overall fluctuation range, and then the entire adjustment process has stability, thereby maintaining the stability of the output frequency.

[0047] For example, due to the fluctuation of the load in the power grid, the demand for output power is also fluctuant, which leads to instability of the output frequency. In order to ensure the stability of the output frequency, the working state of the wind turbine needs to be adjusted according to the change trend of the output frequency, so that the wind turbine is at the edge position affecting the variation of the output frequency, so that the wind power station can respond in time when the fluctuation of the output frequency exceeds the normal fluctuation, and the output frequency is stabilized in time to ensure the stability of the output frequency.

[0048] During the adjustment process, the fan blade angle of the wind turbine is adjusted first, that is, the action of the wind on the fan blade is increased or reduced, and the speed sensitivity to the wind is ensured to be unchanged, so that the adjustment effect is controllable and optimal. If the maximum action of the wind on the fan blade still cannot meet the change of the frequency, the brake system needs to be used to increase the conversion of the wind force to fully ensure the safety and stability of the grid connection.

[0049] Compared with the existing frequency regulation method of the new energy station, the stability of the grid connection frequency regulation is improved.

[0050] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A frequency modulation method for a new energy station, characterized in that, The method comprises the following steps: S1, acquiring the grid frequency requirement of the grid connection point and the power generation power of the wind power generator, and grouping the wind power generators in the wind power station according to the grid frequency requirement and the power generation power to determine the wind power generators required to be connected to each grid connection point; S2, based on the grid frequency requirement, the wind power generators connected to the grid connection point are regulated to determine the initial state of each wind power generator on the grid connection point, and the speed reference data and the wind reference data are obtained; S3, the speed of the wind power generator is monitored to obtain the speed monitoring data, and the environmental information of the wind power generator is monitored to obtain the wind monitoring data; S4, the wind monitoring data is monitored for wind data change, the change time point is obtained, and the speed monitoring data is judged based on the change time point to determine whether the speed of the wind power generator at the corresponding time point changes, if the speed changes, the wind data is marked to obtain the wind marked data; S5, the wind marked data is analyzed to determine the wind power conversion sensitivity under different wind power generator states; S6, the output frequency of the grid connection point is monitored to obtain the frequency monitoring data, the time point when the speed changes is determined based on the speed monitoring data, the speed time point is obtained, and the output frequency of the grid connection point at the corresponding time point is determined based on the speed time point to determine whether the output frequency changes; S7, if the output frequency changes, the speed data is marked to obtain the speed marked data, the speed marked data is analyzed to determine the sensitivity of the output frequency under different speeds, and the speed conversion sensitivity is obtained; S8, based on the wind power conversion sensitivity and the speed conversion sensitivity, the overall sensitivity of the grid connection point is obtained, the overall fluctuation range of the wind power generator is determined based on the overall sensitivity, and the wind power generator is adjusted based on the overall fluctuation range.

2. The frequency modulation method of a new energy station according to claim 1, characterized in that: Step S4 comprises: The speed monitoring data and the speed reference data are difference calculated to obtain the speed fluctuation value, and the speed fluctuation value is counted based on the time data to obtain the speed fluctuation curve; The yaw data of the wind power generator is acquired, and based on the yaw data and the wind direction data in the wind monitoring data, the deviation data between the wind power generator and the wind direction is determined; The fan working data of the wind power generator is acquired, and based on the fan working data, the deviation data and the wind speed data in the wind monitoring data, the force of the wind on the fan under different wind monitoring data is determined to obtain the wind data; The wind data and the wind reference data are difference calculated to obtain the wind fluctuation value, and based on the built-in first comparison threshold, the wind fluctuation value is filtered to obtain the wind fluctuation value exceeding the first comparison threshold, and the time point corresponding to the wind fluctuation value is read to obtain the wind change time point; Based on the wind change time point, the speed fluctuation value of the speed fluctuation curve is read to obtain the to-be-judged speed fluctuation data, and the to-be-judged speed fluctuation data is compared with the built-in second comparison threshold, the wind change time point corresponding to the to-be-judged speed fluctuation data greater than the second comparison threshold is marked to obtain the marked time point; Based on the marked time point, the wind fluctuation value is marked to obtain the wind marked data.

3. The frequency modulation method of a new energy station according to claim 2, characterized in that: Step S5 comprises: S51, determine the speed change amount corresponding to the time point based on the marking time point; S52, divide the wind mark data based on the fan working data at the change time point, determine the wind mark data under the same fan working data, and mark it as a state mark group; S53, draw a wind speed change curve between the wind mark data and the speed change amount in the state mark group; S54, determine the change relationship between wind and speed under different fan working states based on the wind speed change curve, and determine the wind conversion sensitivity under different fan working states based on the change relationship.

4. The frequency modulation method of a new energy station according to claim 3, characterized in that: Step S54 includes: Based on the wind speed change curve, the change relationship between wind and speed under different fan working states is obtained and marked as wind change relationship; Based on the wind change relationship, the speed monitoring data is calculated to determine the change amount of wind when the speed changes by one standard speed unit, and the minimum wind change amount is obtained; Based on the minimum wind change amount, the wind data is matched to determine whether there is a case where the change amount is the minimum wind change amount in the wind data. If it is determined that there is, the speed monitoring data is matched according to the time point corresponding to the minimum wind change amount to determine whether the speed monitoring data has changed; If it is determined that the change has occurred, the standard unit is taken as the minimum change unit of the speed change, and the corresponding wind conversion sensitivity is constructed based on the minimum change unit of the speed and the wind change relationship; If it is determined that the speed monitoring data has not changed, the change amount of wind when the speed changes by two standard speed units is determined according to the wind change relationship until the time point corresponding to the wind change amount is matched successfully with the speed monitoring data.

5. The frequency modulation method of a new energy station according to claim 4, characterized in that: Step S7 includes: Based on the built-in frequency fluctuation threshold, the frequency monitoring data is filtered to obtain the time point at which the output frequency fluctuation is greater than the frequency fluctuation threshold, and the time point is marked as a frequency fluctuation time point; Based on the frequency fluctuation time point, the speed monitoring data is read to obtain the speed data to be judged; The speed change amount is determined by difference calculation between the speed data to be judged and the speed reference data, and the frequency change amount is obtained by difference calculation between the frequency monitoring data at the frequency fluctuation time point and the frequency fluctuation threshold; The speed frequency group data is obtained by corresponding grouping of the speed change amount and the frequency change amount; The speed change relationship is determined by mathematical statistics of the multiple speed frequency group data, and the speed monitoring data and the frequency monitoring data are verified based on the speed change relationship and the built-in standard frequency unit to determine the minimum change amount between the speed and the frequency, and the speed conversion sensitivity between the speed and the frequency is determined based on the minimum change amount.

6. The frequency modulation method of a new energy station according to claim 5, characterized in that: Step S8 includes: S81, based on the minimum change amount of the speed in the wind conversion sensitivity and the minimum change amount of the frequency in the speed conversion sensitivity, the wind conversion sensitivity and the speed conversion sensitivity are coupled to obtain the overall sensitivity between wind and frequency; S82, determine the fluctuation range of the wind acting on the wind turbine according to the minimum change amount of the frequency in the overall sensitivity to obtain the overall fluctuation range; S83, record the wind monitoring data at the current time point as current wind data, record the fan working data at the current time point as real-time state data, judge the current wind data based on the real-time state data, and determine the current wind force acting on the wind turbine by the current wind data; S84, judge the frequency monitoring data to determine the frequency change trend, judge the working state of the wind turbine based on the frequency change trend, the current wind force and the overall fluctuation range, and obtain the adjustment data; S85, adjust the working state of the wind turbine to the data edge of the overall fluctuation range based on the adjustment data.

7. The frequency modulation method of a new energy station according to claim 6, characterized in that: Step S84 includes: S841, if the frequency change trend is a downward trend, calculate the difference value of the current wind force according to the upper limit value of the overall fluctuation range to obtain first adjustment difference data; S842, obtain the maximum conversion coefficient of the fan, and determine the maximum wind force that can be reached based on the current wind data and the maximum conversion coefficient; S843, compare the maximum wind force with the first adjustment difference data to determine whether the maximum wind force meets the requirements of the first adjustment difference data, if it is determined that the requirements of the first adjustment difference data are met, determine the first adjustment data of the fan blade of the wind turbine under the current wind data according to the first adjustment difference data; S844, if it is determined that the requirements of the first adjustment difference data are not met, obtain the braking coefficient of the braking system, and adjust the braking coefficient of the braking system according to the difference between the first adjustment difference data and the maximum wind force to obtain second adjustment data; S845, if the frequency change trend is an upward trend, calculate the difference value of the current wind force according to the lower limit value of the overall fluctuation range to obtain second adjustment difference data, and adjust the wind turbine according to the second adjustment difference data to obtain third adjustment data of the wind turbine.

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