CN114726007A - Frequency modulation method, device, equipment and storage medium of wind power and energy storage combined system - Google Patents

Frequency modulation method, device, equipment and storage medium of wind power and energy storage combined system Download PDF

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Publication number
CN114726007A
CN114726007A CN202210501929.7A CN202210501929A CN114726007A CN 114726007 A CN114726007 A CN 114726007A CN 202210501929 A CN202210501929 A CN 202210501929A CN 114726007 A CN114726007 A CN 114726007A
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energy storage
wind
power
frequency
frequency modulation
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Chinese (zh)
Inventor
刘洋
李力
陆秋瑜
杨银国
郑耀东
闫斌杰
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Guangdong Power Grid Co Ltd
Electric Power Dispatch Control Center of Guangdong Power Grid Co Ltd
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Guangdong Power Grid Co Ltd
Electric Power Dispatch Control Center of Guangdong Power Grid Co Ltd
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Priority to CN202210501929.7A priority Critical patent/CN114726007A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/48—Controlling the sharing of the in-phase component
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H02J3/241—The oscillation concerning frequency
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

The application discloses a frequency modulation method, a frequency modulation device, frequency modulation equipment and a frequency modulation storage medium of a wind power energy storage combined system, wherein when the frequency of a power grid is merged into and is reduced, wind speed data of a wind power plant and rotor rotating speed data of a wind generating set are obtained, so that a frequency modulation control mode of the wind generating set at the corresponding wind speed is determined; if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the power grid, and assisting the wind turbine generator to recover the rotor rotating speed; and finally, if the frequency of the power grid is merged into the preset frequency modulation dead zone and the rotor rotating speed of the wind turbine generator is restored to the preset optimal rotating speed, charging the energy storage set until the SOC of the energy storage set is restored to the preset normal value, and judging that the frequency modulation is finished. The energy storage technology is used for compensating the power grid, the stable frequency of the power grid is guaranteed, and meanwhile the electric energy of the energy storage set is used for recovering the rotor rotating speed of the wind turbine generator, so that the normal operation of the wind turbine generator is recovered, and the stability of the combined system during grid connection is improved.

Description

Frequency modulation method, device, equipment and storage medium of wind power and energy storage combined system
Technical Field
The application relates to the technical field of energy storage configuration, in particular to a frequency modulation method, a frequency modulation device, frequency modulation equipment and a frequency modulation storage medium of a wind power and energy storage combined system.
Background
The wind power and energy storage combined system is a grid-connected operation combined system which connects a wind turbine generator and energy storage equipment into an infinite power grid system after passing through a parallel bus. Based on the requirement of intensive management, large-scale energy storage equipment is assembled at a grid-connected bus of a wind power plant consisting of a plurality of offshore wind turbines, so that the power complementation characteristics among different wind turbines can be effectively utilized, the number and the capacity of the energy storage equipment and a matched converter thereof can be greatly reduced, the utilization rate and the economical efficiency are improved, and the operation stability of a power grid system is enhanced.
However, when the existing wind power and energy storage combined system is incorporated into a power grid system, frequency disturbance often occurs, so that power generation is unstable. If the problem is not dealt with in time, the power transmission of the power grid is greatly disturbed, so that the output power is in shortage. Therefore, the frequency modulation needs to be carried out on the wind power energy storage system in time to ensure the stability of the system, but deep research on frequency modulation optimization after a large number of offshore wind power plants are put into operation is lacked at the present stage.
Disclosure of Invention
The application provides a frequency modulation method, a frequency modulation device, frequency modulation equipment and a frequency modulation storage medium of a wind power and energy storage combined system, and aims to solve the technical problem of unstable power generation caused by frequency disturbance when the current combined system is connected to a grid.
In order to solve the technical problem, in a first aspect, the application provides a frequency modulation method for a wind power and energy storage combined system, where the wind power and energy storage combined system includes a wind turbine generator and an energy storage group of a wind farm, and the frequency modulation method includes:
when the frequency of a power grid incorporated into the wind power energy storage combined system is reduced, acquiring wind speed data of a wind power plant and rotor rotating speed data of a wind power generator set;
if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the incorporated power grid and assisting the wind turbine generator to recover the rotor rotating speed;
and if the frequency of the power grid is recovered to the preset frequency modulation dead zone and the rotor rotating speed of the wind turbine generator is recovered to the preset optimal rotating speed, charging the energy storage set until the SOC of the energy storage set is recovered to the preset normal value, and judging that the frequency modulation of the wind turbine energy storage combined system is completed.
According to the method, when the frequency of a power grid incorporated into a wind power energy storage combined system is reduced, wind speed data of a wind power plant and rotor rotating speed data of a wind generating set are obtained, and a frequency modulation control mode of the wind generating set at the corresponding wind speed is determined; if the wind speed data is medium-low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the incorporated power grid and assisting the wind turbine generator to recover the rotor rotating speed, so that the incorporated power grid is compensated by using an energy storage technology, the frequency stability of the incorporated power grid is ensured, and meanwhile, the rotor rotating speed of the wind turbine generator is recovered by using the electric energy of the energy storage group to recover the normal operation of the wind turbine generator; and finally, if the frequency of the power grid is recovered to a preset frequency modulation dead zone and the rotor speed of the wind turbine generator is recovered to a preset optimal speed, charging the energy storage unit until the SOC of the energy storage unit is recovered to a preset normal value, and judging that the frequency modulation of the wind power energy storage combined system is completed, so that the frequency modulation of the combined system is realized, and the stability of the combined system during grid connection is improved.
Preferably, if the wind speed data is medium-low wind speed data and the rotor speed data is less than a preset lower limit of the speed, the energy storage group is controlled to be incorporated into a power grid for frequency modulation, and the wind turbine generator is assisted to recover the rotor speed, and the method includes the following steps:
if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the discharge of the energy storage group according to a preset frequency modulation requirement so as to modulate the frequency of the power grid merged into the power grid;
and assisting the wind turbine generator to recover the rotating speed of the rotor based on the discharging power of the energy storage set.
Preferably, according to presetting the frequency modulation demand, control the discharge of energy storage group to the frequency modulation is merged into the electric wire netting, includes:
determining an output power reference value of the energy storage group according to a preset frequency modulation requirement;
determining the discharge power of the energy storage group based on the output power reference value and the current state of charge of the energy storage group;
and controlling the energy storage group to discharge based on the discharge power so as to frequency modulate the merged power grid.
Preferably, the method for assisting the wind turbine generator to recover the rotor speed based on the discharge power of the energy storage unit comprises the following steps:
controlling the wind turbine generator to absorb energy based on the discharge power so as to recover the rotor speed of the wind turbine generator;
and when the rotating speed of the rotor of the wind turbine generator is recovered to the preset optimal rotating speed, reducing the discharge power of the energy storage unit by the preset reduction slope until the discharge power is zero.
Preferably, when the frequency of the power grid incorporated into the wind power and energy storage combined system is reduced, after acquiring wind speed data of the wind power plant and rotor speed data of the wind power generator set, the method further comprises the following steps:
if the wind speed data is high wind speed data, acquiring a frequency deviation merged into the power grid;
determining the output power of the energy storage group based on the frequency deviation;
and controlling the energy storage group to discharge based on the output power so as to frequency modulate the merged power grid.
Preferably, the determining the output power of the energy storage pack based on the frequency deviation comprises:
determining the output power of the energy storage group according to the frequency deviation by using a preset power calculation formula, wherein the preset power calculation formula is as follows:
Pv＝-λ×Δf；
wherein, Δ f is frequency deviation, λ is frequency modulation benefit coefficient of the energy storage group, PvIs the output power.
Preferably, when the frequency of the power grid incorporated into the wind power and energy storage combined system is reduced, after acquiring wind speed data of the wind power plant and rotor speed data of the wind power generator set, the method further comprises the following steps:
and if the wind speed data is medium and low wind speed data and the rotor rotating speed data is not less than the preset rotating speed lower limit value, reducing the rotor rotating speed of the wind turbine generator set so as to release the kinetic energy of the rotor and modulate the frequency of the rotor incorporated into the power grid.
In a second aspect, the present application provides a frequency modulation device of a wind power and energy storage combined system, where the wind power and energy storage combined system includes a wind turbine generator and an energy storage group of a wind farm, and the frequency modulation device includes:
the acquisition module is used for acquiring wind speed data of a wind power plant and rotor rotating speed data of a wind power generator set when the frequency of the wind power energy storage combined system merged into a power grid is reduced;
the frequency modulation module is used for controlling the energy storage group to modulate the frequency of the power grid and assisting the wind turbine generator to recover the rotor rotating speed if the wind speed data is medium-low wind speed data and the rotor rotating speed data is less than a preset rotating speed lower limit value;
and the charging module is used for charging the energy storage unit if the frequency of the power grid is recovered to a preset frequency modulation dead zone and the rotor rotating speed of the wind turbine generator is recovered to a preset optimal rotating speed until the SOC of the energy storage unit is recovered to a preset normal value, and judging that the frequency modulation of the wind power and energy storage combined system is completed.
In a third aspect, the present application provides a computer device, including a processor and a memory, where the memory is used to store a computer program, and the computer program is executed by the processor to implement the frequency modulation method of the wind power and energy storage combined system according to the first aspect.
In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the frequency modulation method of the wind power and energy storage combined system according to the first aspect.
Please refer to the relevant description of the first aspect for the beneficial effects of the second to fourth aspects, which are not repeated herein.
Drawings
Fig. 1 is a schematic flow chart of a frequency modulation method of a wind power and energy storage combined system according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a frequency modulation device of a wind power and energy storage combined system according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of a computer device according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
As described in the related art, when the existing wind power and energy storage combined system is incorporated into a power grid system, frequency disturbance often occurs, which results in unstable power generation. If the problem is not dealt with in time, the power transmission of the power grid is greatly disturbed, so that the output power is in shortage. Therefore, the frequency modulation needs to be carried out on the wind power energy storage system in time to ensure the stability of the system, but deep research on frequency modulation optimization after a large number of offshore wind power plants are put into operation is lacked at the present stage.
Therefore, the embodiment of the application provides a frequency modulation method of a wind power and energy storage combined system, which comprises the steps of acquiring wind speed data of a wind power plant and rotor rotating speed data of a wind turbine generator when the frequency of a power grid incorporated into the wind power and energy storage combined system is reduced, and determining a frequency modulation control mode of the wind turbine generator at a corresponding wind speed; if the wind speed data is medium-low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the merged power grid and assisting the wind turbine generator to recover the rotor rotating speed, so that the merged power grid is compensated by using an energy storage technology, the frequency stability of the merged power grid is ensured, and meanwhile, the rotor rotating speed of the wind turbine generator is recovered by using the electric energy of the energy storage group to recover the normal operation of the wind turbine generator; and finally, if the frequency of the power grid is recovered to a preset frequency modulation dead zone and the rotor speed of the wind turbine generator is recovered to a preset optimal speed, charging the energy storage unit until the SOC of the energy storage unit is recovered to a preset normal value, and judging that the frequency modulation of the wind power energy storage combined system is completed, so that the frequency modulation of the combined system is realized, and the stability of the combined system during grid connection is improved.
Referring to fig. 1, fig. 1 is a schematic flow chart of a frequency modulation method of a wind power and energy storage combined system according to an embodiment of the present disclosure. The frequency modulation method of the wind power and energy storage combined system can be applied to computer equipment, the computer equipment comprises but is not limited to equipment such as a smart phone, a notebook computer, a tablet computer, a desktop computer, a physical server and a cloud server, the computer equipment is in communication connection with the wind power and energy storage combined system, the wind power and energy storage combined system comprises a wind turbine generator and a plurality of energy storage groups of a wind power plant, and the capacity of each energy storage group comprises the capacity of a current transformer and the capacity of a battery pack. As shown in fig. 1, the frequency modulation method of the wind power and energy storage combined system of the embodiment includes steps S101 to S103, which are detailed as follows:
step S101, when the frequency of the wind power and energy storage combined system merged into a power grid is reduced, acquiring wind speed data of the wind power plant and rotor rotating speed data of the wind turbine generator;
and S102, if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the incorporated power grid and assisting the wind turbine generator to recover the rotor rotating speed.
In this step, medium and low wind speed refers to a wind level below 8. In order to meet the requirement of smoothing a wind power output curve, the capacity of the converter can be an average absolute error value of wind power prediction, and the average absolute error value is mainly related to the accuracy of a prediction algorithm. In order to realize more grid-connected power generation, the algorithm with the highest accuracy is adopted as far as possible. The energy storage group exists as an auxiliary device of the wind power generation system, the operation mode of the energy storage group is related to the characteristics of the wind power generation system, and the energy storage group can be designed into three modes:
mode one, in order to smooth the wind power output curve, the initial SOC of the battery pack is set to 50%, the energy storage system compensates in real time when the wind power fluctuates, and generally the "valley filling" condition of the energy storage system is greater than the "peak clipping" condition for the power deficit curve:
in the second mode, due to the anti-peak-load-transfer characteristic of the wind power, namely the time of active power demand is not matched with the time of supply, when the supply is greater than the demand, the initial SOC of the battery pack is set to be 25%, so that the abandoned wind can be reduced, and the redundant wind power can be transferred;
in the third mode, when the demand is greater than the supply condition, the initial SOC of the battery pack is set to be 80%, and the condition is the operation mode of the energy storage pack in most time, so that the rotation standby is effectively reduced, and the stable operation of offshore wind power grid connection is ensured;
the maximum efficiency of wind power generation is ensured through the mutual conversion among the three modes.
Optionally, when the wind turbine generator operates at a medium-low wind speed, the output power P of the wind turbine generator is less than or equal to PmaxWhen the system frequency is reduced, the wind turbine generator can participate in frequency modulation by releasing kinetic energy, and the energy storage set does not participate in frequency modulation at the moment. At the moment, if the rotating speed of the rotor of the wind turbine generator has a recovery requirement, the energy storage unit starts to release energy to support the rotating speed recovery process, and the phenomena of frequency secondary falling and system oscillation caused by the secondary shortage of the power grid power are avoided.
And S103, if the frequency of the power grid is recovered to a preset frequency modulation dead zone and the rotor speed of the wind turbine generator is recovered to a preset optimal speed, charging the energy storage unit until the SOC of the energy storage unit is recovered to a preset normal value, and judging that the frequency modulation of the wind power and energy storage combined system is finished.
In the step, when the frequency of the power grid is recovered to the dead zone and the rotating speed of the rotor is not equal to the optimal rotating speed required by MPPT control, the rotating speed of the wind generation set is recovered at first, and an instruction is sent to enable the energy storage set to help the wind generation set to recover the rotating speed of the rotor in consideration of the limitation of the running state of the system; when the rotor speed of the wind turbine generator is recovered to the optimal speed, the SOC of the energy storage unit starts to recover until the SOC recovers to a normal level, and the whole frequency modulation process is completed.
In an embodiment, on the basis of the embodiment shown in fig. 1, if the wind speed data is medium-low wind speed data and the rotor rotation speed data is smaller than a preset rotation speed lower limit value, controlling the energy storage group to perform frequency modulation on the merged power grid, and assisting the wind turbine generator to recover the rotor rotation speed includes:
if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the discharge of the energy storage set according to a preset frequency modulation requirement so as to modulate the frequency of the merged power grid;
and assisting the wind turbine generator to recover the rotor speed based on the discharge power of the energy storage set.
In this embodiment, when the wind turbine is operating at a medium-low wind speed, the output power P of the wind turbine is not greater than PmaxWhen the system frequency is reduced, the wind turbine generator can participate in frequency modulation by releasing kinetic energy, and the energy storage set does not participate in frequency modulation at the moment. If there is the recovery demand at this moment in wind turbine generator system rotor speed, the energy storage group begins to release energy and supports the rotational speed recovery process, avoids the frequency secondary of the vacancy initiation once more of grid power to fall and the system oscillation phenomenon, and at this moment, the control that the energy storage group helps rotor rotational speed to resume divide into two modules:
it should be noted that the energy storage group has different access modes according to different application scenarios, and the energy storage technology may be divided into a centralized energy storage technology and a distributed energy storage technology. The centralized energy storage technology is characterized in that the whole energy storage system which is large in capacity and easy to control and install in a centralized manner is connected to an alternating current bus and is independently used as an energy supply unit to maintain the frequency and voltage stability of the alternating current bus; the distributed energy storage technology is characterized in that an energy storage system with relatively small capacity is dispersedly arranged on the direct current bus side or the load unit side of micro power supplies such as photovoltaic power supplies, wind power supplies and the like, and forms an energy supply unit together with each micro power supply or directly supplies power to a load.
Compared with the centralized energy storage technology, the distributed energy storage technology has the advantages that the control is simple, the geographical distribution is wide, the distributed energy storage technology is flexible and convenient, and the like, which are not possessed by the centralized energy storage technology, and can independently control and realize the function of 'plug and play'. Meanwhile, the distributed energy storage technology can respond to output fluctuation changes of the distributed power supplies in the network in time, and local compensation can be rapidly achieved. In addition, the distributed energy storage technology can be divided into two system structures according to the difference of access points, the energy storage units are directly connected to the direct current bus side of the micro source in parallel to support the direct current bus voltage, and the DC/AC converters are independently configured at the output ends of the energy storage units and connected to the alternating current side of the micro source, so that the reference power at the network side can be quickly and accurately tracked, the distributed control and adjustment of the output power of each distributed energy storage unit can be realized, the respective power requirements can be met, and the flexibility of power scheduling of the whole distributed energy storage system can be improved.
Optionally, determining an output power reference value of the energy storage group according to the preset frequency modulation requirement; determining the discharge power of the energy storage group based on the output power reference value and the current state of charge of the energy storage group; and controlling the energy storage group to discharge based on the discharge power so as to frequency modulate the merged power grid.
In this optional embodiment, the energy storage group participating in the frequency modulation control is divided into two parts: a. obtaining an output power reference value of the energy storage group according to the frequency modulation requirement of the system; b. the energy storage group adjusts self discharge power according to the feedback of self SOC, and the output power reference value and the SOC at the moment are used as input quantity; the discharge power of the energy storage group participating in frequency modulation is jointly determined by the two parts.
Optionally, controlling the wind turbine to absorb energy based on the discharge power so as to recover the rotor speed of the wind turbine; and when the rotating speed of the rotor of the wind turbine generator is recovered to the preset optimal rotating speed, reducing the discharge power of the energy storage unit by using a preset reduction slope until the discharge power is zero.
In this alternative embodiment, the control of the energy storage pack to assist in rotor speed recovery is divided into two parts:
a portion of the demand for recovery of the rotational speed of the rotor,let Pb-refFor the output power obtained by the energy storage group according to the SOC state feedback of the energy storage group, when the rotor rotating speed has a recovery requirement at the moment t, the wind generation set starts to absorb energy to improve the rotating speed of the rotor, so that the energy storage group releases power to the maximum extent to compensate the power imbalance of the power grid at the moment; when the rotating speed recovery process is finished at the moment t, in order to avoid sudden impact on the power grid caused by sudden drop of the output power of the energy storage group, the energy storage group starts to reduce the output power in a slope mode until the output power is 0, and the slope of the output of the energy storage group is KrampThe ramp response of (c);
the power grid operation state limiting part is used for limiting the operation state of the power grid, when the rotor rotating speed recovery process is finished, the wind turbine generator does not absorb energy any more, and in order to avoid the influence of slope response output power on the power grid frequency, the operation state of the power grid is considered to limit the energy storage set to be additionally provided with an extra control cycle to generate PrfAt t1－t2In time, the energy storage group releases power to the maximum extent for rotor speed recovery without influencing the power grid frequency, and the module does not work at the moment and is used at the moment t2Later, the module starts to work, and when the wind turbine generator operates at a medium-low wind speed but the rotating speed of the rotor reaches the lower limit WminThe energy storage group can not participate in frequency modulation any more, when the power grid has frequency modulation requirements, the energy storage group participates in system frequency modulation at the moment, the wind turbine generator needs to be assisted to recover the rotating speed of the rotor, and at the moment, the energy storage group only needs to regulate self discharge power according to self SOC feedback.
In an embodiment, on the basis of the embodiment shown in fig. 1, after acquiring wind speed data of the wind farm and rotor speed data of the wind turbine generator when the frequency of the power grid incorporated into the wind power and energy storage combined system decreases, the method further includes:
if the wind speed data is high wind speed data, acquiring the frequency deviation of the merged power grid;
determining an output power of the energy storage bank based on the frequency deviation;
based on the output power. And controlling the energy storage group to discharge so as to carry out frequency modulation on the merged power grid.
In the present embodiment, high wind speed refers to wind of greater than or equal to 8 levelsForce rating. When the wind turbine generator operates at high wind speed, the output power P of the wind turbine generator is more than or equal to PmaxAnd at the moment, the output power of the wind turbine generator is kept unchanged and is the rated output power, when the system detects that the frequency is reduced, the wind turbine generator cannot reduce the rotating speed to release the stored kinetic energy to support the frequency, and if the system generates disturbance frequency reduction at the moment, the energy is uniformly released (namely discharged) through the energy storage assembly to participate in the frequency modulation of the wind power and energy storage combined system.
Optionally, determining the output power of the energy storage group according to the frequency deviation by using a preset power calculation formula, where the preset power calculation formula is:
Pv＝-λ×Δf；
wherein Δ f is the frequency deviation, λ is the frequency modulation efficiency coefficient of the energy storage bank, PvIs the output power.
In this alternative embodiment, the larger the capacity allocation of the energy storage pack from the perspective of the wind power generation system, the more significant the effects of stabilizing wind power fluctuations and reducing wind curtailment, but the investment and cost of the energy storage pack is so great that its capacity allocation problem must be discussed in terms of both technology and economy.
In an embodiment, on the basis of the embodiment shown in fig. 1, after acquiring wind speed data of the wind farm and rotor speed data of the wind turbine generator when the frequency of the power grid incorporated into the wind power and energy storage combined system decreases, the method further includes:
and if the wind speed data is medium and low wind speed data and the rotor rotating speed data is not less than the preset rotating speed lower limit value, reducing the rotor rotating speed of the wind turbine generator set so as to release the kinetic energy of the rotor and modulate the frequency of the merged power grid.
In this embodiment, for the fans with different wind speeds, the conditions that the wind turbine generator participates in the primary frequency modulation are slightly different. When the wind turbine generator with low wind speed does not have the frequency modulation requirement, the MPPT control is realized by adjusting the rotating speed of the rotor of the wind turbine generator, the rotating speed of the rotor of a fan running in the region is low, the kinetic energy released by the rotor is limited, and the rotating speed of the rotor can easily reach the lowest limit; when the control system detects that the frequency is reduced, the wind turbine generator releases the stored kinetic energy to support the transient frequency process of the system, a rotating speed protection method considering rotating speed feedback is added, and when the frequency modulation process is finished, the energy storage group is used for supporting the rotating speed recovery process. Compared with a fan in a low wind speed area, the wind turbine generator running at the medium wind speed has the advantages that the rotor rotating speed is higher, more kinetic energy can be utilized, and the stored kinetic energy needs to be released to participate in system frequency modulation when the frequency of a power grid is reduced. And the output power of the fan is kept unchanged and is rated output power, and when the control system detects that the frequency is reduced, the fan does not reduce the rotating speed and releases the stored kinetic energy to support the frequency.
In order to execute the frequency modulation method of the wind power and energy storage combined system corresponding to the method embodiment, corresponding functions and technical effects are achieved. Referring to fig. 2, fig. 2 shows a structural block diagram of a frequency modulation device of a wind power and energy storage combined system provided in an embodiment of the present application. For convenience of explanation, only the parts related to the present embodiment are shown, and the frequency modulation apparatus of the wind power and energy storage combined system provided in the embodiment of the present application includes:
the obtaining module 201 is configured to obtain wind speed data of the wind farm and rotor speed data of the wind turbine generator when a frequency of the wind power storage combined system, which is merged into a power grid, decreases;
the frequency modulation module 202 is configured to control the energy storage group to modulate the frequency of the merged power grid and assist the wind turbine generator to recover the rotor speed if the wind speed data is medium-low wind speed data and the rotor speed data is smaller than a preset lower speed limit value;
and the charging module 203 is used for charging the energy storage group if the frequency of the power grid is merged into and recovered to a preset frequency modulation dead zone, and the rotor rotating speed of the wind turbine generator is recovered to a preset optimal rotating speed until the state of charge (SOC) of the energy storage group is recovered to a preset normal value, and judging that the frequency modulation of the wind power and energy storage combined system is completed.
In an embodiment, the frequency modulation module 202 includes:
the discharging unit is used for controlling the discharging of the energy storage group according to a preset frequency modulation requirement to modulate the frequency of the merged power grid if the wind speed data is medium and low wind speed data and the rotor rotating speed data is less than a preset rotating speed lower limit value;
and the auxiliary unit is used for assisting the wind turbine generator to recover the rotating speed of the rotor based on the discharge power of the energy storage set.
In an embodiment, the discharge unit is specifically configured to:
determining an output power reference value of the energy storage group according to the preset frequency modulation requirement;
determining the discharge power of the energy storage group based on the output power reference value and the current state of charge of the energy storage group;
and controlling the energy storage group to discharge based on the discharge power so as to frequency modulate the merged power grid.
In an embodiment, the auxiliary unit is specifically configured to:
controlling the wind turbine generator to absorb energy based on the discharge power so as to recover the rotor speed of the wind turbine generator;
and when the rotating speed of the rotor of the wind turbine generator is recovered to a preset optimal rotating speed, reducing the discharge power of the energy storage unit by a preset reduction slope until the discharge power is zero.
In an embodiment, the frequency modulation apparatus further includes:
the second acquisition module is used for acquiring the frequency deviation of the merged power grid if the wind speed data is high wind speed data;
a determining module for determining the output power of the energy storage group based on the frequency deviation;
and the control module is used for controlling the energy storage group to discharge based on the output power so as to modulate the frequency of the merged power grid.
In an embodiment, the determining module is specifically configured to:
determining the output power of the energy storage group according to the frequency deviation by using a preset power calculation formula, wherein the preset power calculation formula is as follows:
Pv＝-λ×Δf；
wherein Δ f is the frequency deviation, λ is the frequency modulation efficiency coefficient of the energy storage bank, PvIs the output power.
In an embodiment, the frequency modulation apparatus further includes:
and the reduction module is used for reducing the rotor rotating speed of the wind turbine generator set to release the kinetic energy of the rotor and modulate the frequency of the merged power grid if the wind speed data is medium-low wind speed data and the rotor rotating speed data is not less than a preset rotating speed lower limit value.
The frequency modulation device of the wind power and energy storage combined system can implement the frequency modulation method of the wind power and energy storage combined system of the embodiment of the method. The alternatives in the above-described method embodiments are also applicable to this embodiment and will not be described in detail here. The rest of the embodiments of the present application may refer to the contents of the above method embodiments, and in this embodiment, details are not described again.
Fig. 3 is a schematic structural diagram of a computer device according to an embodiment of the present application. As shown in fig. 3, the computer device 3 of this embodiment includes: at least one processor 30 (only one shown in fig. 3), a memory 31, and a computer program 32 stored in the memory 31 and executable on the at least one processor 30, the processor 30 implementing the steps of any of the above-described method embodiments when executing the computer program 32.
The computer device 3 may be a computing device such as a smart phone, a tablet computer, a desktop computer, and a cloud server. The computer device may include, but is not limited to, a processor 30, a memory 31. Those skilled in the art will appreciate that fig. 3 is merely an example of the computer device 3, and does not constitute a limitation of the computer device 3, and may include more or less components than those shown, or combine some of the components, or different components, such as input output devices, network access devices, etc.
The Processor 30 may be a Central Processing Unit (CPU), and the Processor 30 may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 31 may in some embodiments be an internal storage unit of the computer device 3, such as a hard disk or a memory of the computer device 3. The memory 31 may also be an external storage device of the computer device 3 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, which are provided on the computer device 3. Further, the memory 31 may also include both an internal storage unit and an external storage device of the computer device 3. The memory 31 is used for storing an operating system, an application program, a BootLoader (BootLoader), data, and other programs, such as program codes of the computer program. The memory 31 may also be used to temporarily store data that has been output or is to be output.
In addition, an embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in any of the method embodiments described above.
The embodiments of the present application provide a computer program product, which when executed on a computer device, enables the computer device to implement the steps in the above method embodiments.
In several embodiments provided herein, it will be understood that each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
The above-mentioned embodiments are further detailed to explain the objects, technical solutions and advantages of the present application, and it should be understood that the above-mentioned embodiments are only examples of the present application and are not intended to limit the scope of the present application. It should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims (10)

1. A frequency modulation method of a wind power and energy storage combined system is characterized in that the wind power and energy storage combined system comprises a wind turbine generator and an energy storage unit of a wind power plant, and the frequency modulation method comprises the following steps:
when the frequency of the power grid incorporated into the wind power energy storage combined system is reduced, acquiring wind speed data of the wind power plant and rotor rotating speed data of the wind turbine generator;
if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the energy storage group to modulate the frequency of the merged power grid and assisting the wind turbine generator to recover the rotor rotating speed;
and if the frequency of the power grid is recovered to a preset frequency modulation dead zone and the rotor speed of the wind turbine generator is recovered to a preset optimal speed, charging the energy storage unit until the SOC of the energy storage unit is recovered to a preset normal value, and judging that the frequency modulation of the wind turbine energy storage combined system is completed.
2. The frequency modulation method of the wind power and energy storage combined system according to claim 1, wherein if the wind speed data is medium and low wind speed data and the rotor speed data is less than a preset lower speed limit, the method controls the energy storage group to modulate the frequency of the incorporated power grid and assists the wind turbine generator in recovering the rotor speed, and comprises the following steps:
if the wind speed data is medium and low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value, controlling the discharge of the energy storage set according to a preset frequency modulation requirement so as to modulate the frequency of the merged power grid;
and assisting the wind turbine generator to recover the rotor speed based on the discharge power of the energy storage set.
3. A frequency modulation method for a wind power and energy storage combined system according to claim 2, wherein said controlling discharge of said energy storage bank according to a preset frequency modulation requirement to modulate said frequency of said grid comprising:
determining an output power reference value of the energy storage group according to the preset frequency modulation requirement;
determining the discharge power of the energy storage group based on the output power reference value and the current state of charge of the energy storage group;
and controlling the energy storage group to discharge based on the discharge power so as to frequency modulate the merged power grid.
4. A frequency modulation method for a wind power and energy storage combined system according to claim 2, wherein the assisting of the wind turbine to recover the rotor speed based on the discharge power of the energy storage group comprises:
controlling the wind turbine generator to absorb energy based on the discharge power so as to recover the rotor speed of the wind turbine generator;
and when the rotating speed of the rotor of the wind turbine generator is recovered to a preset optimal rotating speed, reducing the discharge power of the energy storage unit by a preset reduction slope until the discharge power is zero.
5. The frequency modulation method of the wind power and energy storage combined system according to claim 1, wherein after acquiring the wind speed data of the wind farm and the rotor speed data of the wind turbine generator when the frequency of the power grid incorporated into the wind power and energy storage combined system decreases, the method further comprises:
if the wind speed data is high wind speed data, acquiring the frequency deviation of the merged power grid;
determining the output power of the energy storage group based on the frequency deviation;
and controlling the energy storage group to discharge based on the output power so as to frequency modulate the merging power grid.
6. A frequency modulation method of a wind power and energy storage combined system according to claim 5, wherein said determining the output power of the energy storage group based on the frequency deviation comprises:
determining the output power of the energy storage group according to the frequency deviation by using a preset power calculation formula, wherein the preset power calculation formula is as follows:
Pv＝-λ×Δf；
wherein Δ f is the frequency deviation, λ is the frequency modulation efficiency coefficient of the energy storage bank, PvIs the output power.
7. The frequency modulation method of the wind power and energy storage combined system according to claim 1, wherein after acquiring the wind speed data of the wind farm and the rotor speed data of the wind turbine generator when the frequency of the power grid incorporated into the wind power and energy storage combined system decreases, the method further comprises:
and if the wind speed data is medium and low wind speed data and the rotor rotating speed data is not less than the preset rotating speed lower limit value, reducing the rotor rotating speed of the wind turbine generator set to release the kinetic energy of the rotor and modulate the frequency of the merged power grid.
8. The utility model provides a frequency modulation device of wind-powered electricity generation energy storage combined system which characterized in that, wind-powered electricity generation energy storage combined system includes the wind turbine generator system and the energy storage group of wind-powered electricity generation field, frequency modulation device includes:
the acquisition module is used for acquiring wind speed data of the wind power plant and rotor rotating speed data of the wind turbine generator set when the frequency of the wind power energy storage combined system merged into a power grid is reduced;
the frequency modulation module is used for controlling the energy storage group to modulate the frequency of the incorporated power grid and assisting the wind turbine generator set to recover the rotor rotating speed if the wind speed data is medium-low wind speed data and the rotor rotating speed data is smaller than a preset rotating speed lower limit value;
and the charging module is used for charging the energy storage group if the frequency of the power grid is merged into and recovered to a preset frequency modulation dead zone, and the rotor rotating speed of the wind turbine generator is recovered to a preset optimal rotating speed until the state of charge (SOC) of the energy storage group is recovered to a preset normal value, and judging that the frequency modulation of the wind power and energy storage combined system is completed.
9. Computer arrangement, characterized in that it comprises a processor and a memory for storing a computer program which, when executed by the processor, implements a method for frequency modulation of a wind power and energy storage combined system according to any of claims 1 to 7.
10. A computer-readable storage medium, characterized in that it stores a computer program which, when being executed by a processor, implements a method for frequency modulation of a wind power and energy storage combined system according to any one of claims 1 to 7.
CN202210501929.7A 2022-05-09 2022-05-09 Frequency modulation method, device, equipment and storage medium of wind power and energy storage combined system Pending CN114726007A (en)

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