New energy power generation active power smooth control method, system and storage medium
Technical Field
The invention relates to the technical field of new energy, in particular to a method and a system for smoothly controlling active power generated by new energy and a storage medium.
Background
At present, new energy power generation represented by wind power and photovoltaic is influenced and restricted by natural conditions such as wind speed and illumination, output power of the new energy power generation has randomness and volatility, electric energy quality and stability of a power grid are negatively influenced, and safe and stable operation of a power system is further influenced. The energy storage technology is taken as an electric energy handling device, and is considered as an effective means for controlling the output of new energy and improving the power fluctuation of the new energy when being applied to new energy power generation. The energy storage system is not a primary energy source, and has the problems of capacity limitation, operation health constraint and the like. Therefore, designing a new energy power fluctuation stabilizing strategy with reasonable and effective technical economy becomes the key of new energy popularization.
The chinese patent database discloses a patent application with a patent name of "wind-solar-storage combined power generation system active power coordination control method" in 2012, 10 month and 3 days, and the patent numbers thereof are: ZL201210167984.3, the method effectively utilizes the energy storage system to store and release electric energy by giving play to the complementary advantages of wind energy, light energy and energy storage resources, reasonably adjusts renewable energy sources such as wind and light and the like, and realizes that the output power of the wind-light-storage combined power generation system tracks and dispatches instructions like a conventional power supply. However, the method needs to be provided with a battery energy storage system, and the new energy combined power generation system is constructed into a schedulable power generation unit, so that the construction cost is high, and the application and popularization in a large-scale new energy grid-connected mode are limited to a certain extent.
The document "state of charge management strategy of energy storage system and evaluation of its impact" (vol.39, No. 8, pages 27-32 of power system automation 2015) proposes an SOC control strategy based on a low-pass filtering method with variable filter constants. The strategy responds to the low-frequency regulation requirement of the power grid, and further reduces the influence on fluctuation stabilization through a filter with a variable time constant; meanwhile, the battery can work in a shallow charging and discharging area through the effective control of the SOC (State of Charge), and the charging and discharging depth is reduced, so that the service life of the battery is prolonged. In the strategy, the design of the variable time constant filter actually slows down the SOC deviation degree of the energy storage system by changing the filtering depth, and the energy storage system SOC management strategy does not provide an active correction control strategy aiming at the SOC return median, so that the application effect of the strategy has certain limitation.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a new energy power generation active power smooth control method, a system and a storage medium, which can realize the complementation and offset of active fluctuation among new energy stations, effectively reduce the active fluctuation of new energy stations and reduce the grid-connected matching construction cost of the new energy stations.
The invention is realized by the following technical scheme:
in a first aspect, a new energy power generation active power smooth control method is provided, the method includes the following steps:
acquiring the total active power of power generation of all new energy stations in a regional power grid and the rated power of a new energy storage system;
calculating the active power smooth target deviation of the new energy station according to the active power smooth target of the new energy station and the total power generation active power of the new energy station;
determining a new energy storage system control target capable of meeting the active power smooth control requirement according to the active power smooth target deviation, the rated power and the state of charge of the new energy storage system;
carrying out smooth control on the active power of the new energy according to the determined control target of the new energy storage system;
the method for determining the control target of the new energy storage system comprises the following steps:
preliminarily determining a control target of the new energy storage system according to the active power smooth target deviation and the rated power of the new energy storage system;
determining an operation interval to which the current charge state of the new energy storage system belongs according to the pre-divided charge state operation interval of the new energy storage system;
correcting the preliminarily determined control target of the new energy storage system according to the determined operation interval;
The method for determining the operation interval of the current charge state of the new energy storage system comprises the following steps:
when the state of charge of the new energy storage system is in [ SOC ]low,SOChig]Determining the interval as an ideal operation interval within the interval;
when the state of charge of the new energy storage system is in [ SOC ]min,SOClow)∪(SOChigh,SOCmax]Determining the interval as an early warning operation interval within the interval;
when the state of charge of the new energy storage system is [0, SOC ]min)∪(SOCmax,100]Determining the interval as an operation forbidden interval within the interval;
wherein: SOChig、SOClowRespectively representing an ideal operation charge upper limit and an ideal operation charge lower limit of the new energy storage system; SOCmax、SOCminRespectively representing the maximum charge limit value and the minimum charge limit value of the new energy storage system;
the method for correcting the control target of the new energy storage system comprises the following steps:
a. if the current charge state of the new energy storage system is in an ideal operation interval, the control target of the new energy storage system does not need to be corrected;
b. if the current charge state of the new energy storage system is in the early warning operation interval, correcting the control target of the new energy storage system by adopting the following correction strategy:
of formula (II) to (III)'BESS-targ(k) New energy storage system after k time correctionA system control target; pBESS-targ(k) Representing a new energy storage system control target preliminarily determined at the moment k; delta P SOC(k) The correction quantity required for the new energy storage system to return to the ideal operation interval at the moment k is represented; delta Pavg(k) Representing the active power smooth target deviation of the new energy station at the moment k; pagc-rvup(k) Indicating the up-regulation standby of an AGC main control area at the k moment; pagc-rvdn(k) Indicating the lower regulation standby of the AGC main control area at the k moment; rrenew(k) Representing the output change rate of the new energy station at the moment k; ragc(k) The regulation rate of the AGC main control area at the k moment is shown; SOC (k) represents the state of charge of the new energy storage system at the moment k; pBESS-discRepresenting rated discharge power of the new energy storage system; pBESS-chargRepresenting the rated charging power of the new energy storage system; fagcA matching mark representing the adjustment capacity of the AGC main control area and the new energy fluctuation, wherein 1 represents that the AGC main control area can not meet the new energy fluctuation control requirement, and 0 represents that the AGC main control area can meet the new energy fluctuation control requirement;
c. if the current charge state of the new energy storage system is in the operation forbidden interval, correcting the control target of the new energy storage system by adopting the following correction strategy:
in the formula, FSOCAnd a matching mark representing the current state of charge of the new energy storage system and the adjustment requirement, wherein 1 represents that the current adjustment requirement can aggravate the state of charge of the new energy storage system to deviate from an ideal operation interval, and 0 represents that the current adjustment requirement can promote the state of charge of the new energy storage system to return to the ideal operation interval.
With reference to the first aspect, further, the active power smoothing target deviation is calculated by using formula (1):
ΔPavg(k)=Pavg(k)-Prenew-gen(k) (1)
in the formula: delta Pavg(k) Representing the active power smooth target deviation of the new energy station at the moment k; pavg(k) Representing an active power smoothing target of the new energy station at the moment k; prenew-gen(k) And the total active power generated by the new energy station at the moment k is shown.
With reference to the first aspect, further, the control target of the new energy storage system is preliminarily determined by using formula (2):
in the formula: delta Pavg(k) Representing the active power smooth target deviation of the new energy station at the moment k; pBESS-discRepresenting rated discharge power of the new energy storage system; pBESS-chargAnd representing the rated charging power of the new energy storage system.
With reference to the first aspect, further, when the state of charge of the new energy storage system is within the operation prohibition interval, the new energy storage system maintains the standby state until the state of charge of the new energy storage system returns to the ideal operation interval.
In a second aspect, a new energy power generation active power smoothing control system is provided, which includes:
an acquisition module: the system is used for acquiring the total active power of power generation of all new energy stations in the regional power grid and the rated power of a new energy storage system;
a calculation module: the active power smoothing target deviation calculation module is used for calculating the active power smoothing target deviation of the new energy station according to the active power smoothing target of the new energy station and the total power generation active power of the new energy station;
A determination module: the control method comprises the steps of determining a new energy storage system control target capable of meeting the active power smooth control requirement according to the active power smooth target deviation, the rated power and the state of charge of the new energy storage system;
an execution module: the system comprises a controller, a controller and a controller, wherein the controller is used for smoothly controlling the active power of the new energy according to a determined control target of the new energy storage system;
wherein the determining module comprises:
a preliminary determination module: the control method comprises the steps of preliminarily determining a control target of the new energy storage system according to the active power smooth target deviation and the rated power of the new energy storage system;
an operation interval division module: the operation interval is used for dividing the charge state of the new energy storage system;
an operation interval determination module: the method comprises the steps of determining an operation interval of the current charge state of the new energy storage system;
a correction module: the system comprises a control target correction module, a control target correction module and a control target correction module, wherein the control target correction module is used for correcting a preliminarily determined control target of the new energy storage system according to a determined operation interval to which the new energy storage system belongs;
the method for correcting the control target of the new energy storage system comprises the following steps:
a. if the current charge state of the new energy storage system is in an ideal operation interval, the control target of the new energy storage system does not need to be corrected;
b. If the current charge state of the new energy storage system is in the early warning operation interval, correcting the control target of the new energy storage system by adopting the following correction strategy:
of formula (II) to (III)'BESS-targ(k) Representing the control target of the new energy storage system corrected at the moment k; pBESS-targ(k) Representing a new energy storage system control target preliminarily determined at the moment k; delta PSOC(k) Means for representing that the state of charge of the new energy storage system returns to an ideal operation interval at the moment kCorrection is needed; delta Pavg(k) Representing the active power smooth target deviation of the new energy station at the moment k; pagc-rvup(k) Indicating the up-regulation standby of an AGC main control area at the k moment; pagc-rvdn(k) Indicating the lower regulation standby of the AGC main control area at the k moment; rrenew(k) Representing the output change rate of the new energy station at the moment k; ragc(k) The regulation rate of the AGC main control area at the k moment is shown; SOC (k) represents the state of charge of the new energy storage system at the moment k; pBESS-discRepresenting rated discharge power of the new energy storage system; pBESS-chargRepresenting the rated charging power of the new energy storage system; fagcA matching mark representing the adjustment capacity of the AGC main control area and the new energy fluctuation, wherein 1 represents that the AGC main control area can not meet the new energy fluctuation control requirement, and 0 represents that the AGC main control area can meet the new energy fluctuation control requirement;
c. If the current charge state of the new energy storage system is in the operation forbidden interval, correcting the control target of the new energy storage system by adopting the following correction strategy:
in the formula, FSOCAnd a matching mark representing the current state of charge of the new energy storage system and the adjustment requirement, wherein 1 represents that the current adjustment requirement can aggravate the state of charge of the new energy storage system to deviate from an ideal operation interval, and 0 represents that the current adjustment requirement can promote the state of charge of the new energy storage system to return to the ideal operation interval.
In a third aspect, a new energy power generation active power smooth control system is provided, which comprises a memory and a processor;
the memory is to store instructions;
the processor is configured to operate in accordance with the instructions to perform the steps of the method of any of the first aspects.
In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of the first aspect.
In conclusion, the method, the system and the storage medium for smoothly controlling the active power of new energy power generation provided by the invention realize the smooth control of the active power of new energy power generation through the complementation and offset of the active fluctuation among the new energy stations, can greatly reduce the dependence of new energy station grid connection on matching resources and adjustment standby, and save the construction cost of new energy station grid connection matching; the operation interval where the charge state of the energy storage system is located is subdivided, different correction algorithms are formulated according to different operation intervals, and the health management of the charge state of the energy storage system is realized while the stabilizing effect is ensured.
Drawings
In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings needed to be used in the embodiment of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic flow chart of an active power smoothing control method for new energy power generation according to an embodiment of the present invention;
fig. 2 is a schematic diagram of the division of the operation interval of the new energy storage system according to the embodiment of the invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
FIG. 1 is a flow chart of an active power smoothing control method for new energy power generation according to an embodiment of the invention; it should be understood that prior to implementing the method, a main Control area and a new energy logic Control area are established in an Automatic Generation Control (AGC) application of the local grid.
The main control area is used for implementing conventional area control of the interconnected power grid, and the control target is to maintain the frequency of the power grid within a control range and/or maintain the exchange power of the control area and other adjacent control areas to be a given planned value.
And the new energy logical control area is used for implementing monitoring of the active power output of the new energy and fluctuation stabilizing control. The new energy logical control area and the main control area are logically parallel control areas, but the new energy logical control area is physically affiliated to the main control area, namely, new energy stations and energy storage systems in the new energy logical control area are distributed in the boundary range of the main control area of the regional power grid. The main monitoring variable in the new energy logical control area is the active measurement of the new energy equivalent unit, namely the total active power of all new energy stations in the regional power grid. The monitoring variable is more intuitive in evaluation of the aggregation effect of the whole network new energy, and the matching resources and the adjustment standby dependence of the power grid on the grid-connected active fluctuation of the new energy stations can be greatly reduced through the complementation and offset effect of the active fluctuation among the new energy stations. The tracking target of the energy storage system in the new energy logical control area is the active fluctuation of the new energy equivalent unit, so that the expected adjustment instruction of the energy storage system is the active power smooth control requirement of new energy power generation, and the active power of the new energy power generation is corrected according to the rated charge-discharge capacity of the energy storage system.
As shown in fig. 1, the method for smoothly controlling active power generated by new energy according to the embodiment of the present invention includes:
The method comprises the following steps: the method comprises the following steps of obtaining the total active power of power generation of all new energy stations in a regional power grid and the rated power of a new energy storage system, and specifically comprises the following steps:
a new energy equivalent unit model is established in a new energy logical control area, and the new energy equivalent unit is equivalent virtual of all new energy stations (including wind power plants and photovoltaic stations) in a regional power grid. The total active power generation power measurement value obtained through the new energy equivalent unit model is the total active power generation power of all new energy stations in the regional power grid and is recorded as Prenew-gen。
Establishing new energy resources in new energy resource logic control areaThe energy storage system control object model is used for stabilizing power fluctuation of a new energy equivalent unit and managing the SOC of the model according to the embodiment of the invention, and the operation parameters of the model mainly comprise: rated discharge power P of new energy storage systemBESS-discRated charging power PBESS-chargMaximum charge limit value SOC of new energy storage systemmaxMinimum charge limit SOCmin。
Step two: calculating the active power smooth target deviation of the new energy station according to the active power smooth target of the new energy station and the total power generation active power of the new energy station; the specific method comprises the following steps:
with a period T exeAnd (second) updating the total generated active power measurement value of the new energy equivalent unit model at the current moment, and recording the total generated active power measurement value as Prenew-gen(k) Calculating an active power smoothing target Pavg(k) Smoothing target deviation delta P of active poweravg(k) And rate of change Rrenew(k) The following describes the calculation method of each variable by taking a moving average filtering algorithm as an example:
ΔPavg(k)=Pavg(k)-Prenew-gen(k) (2)
in the formula, k represents the current time, namely a calculation cycle sequence; prenew-gen(k-1) representing the total active power generated by the new energy station in the previous calculation period; prenew-gen(k-N +1) represents the total active power generated by the new energy station at the initial moment of the sliding window; n is the number of running average cycles.
Step three: determining a new energy storage system control target capable of meeting the active power smooth control requirement according to the active power smooth target deviation, the rated power and the state of charge of the new energy storage system; the method comprises the following steps:
in the formula: pBESS-targ(k) Representing a new energy storage system control target at the moment k;
step four: determining an operation interval to which the current charge state of the new energy storage system belongs according to the pre-divided operation interval of the charge state of the new energy storage system;
fig. 2 is a schematic diagram illustrating the division of the operation intervals of the new energy storage system according to the embodiment of the present invention.
When the state of charge of the new energy storage system is in [ SOC ]low,SOChig]Determining the interval as an ideal operation interval within the interval;
when the state of charge of the new energy storage system is in [ SOC ]min,SOClow)∪(SOChigh,SOCmax]Determining the interval as an early warning operation interval within the interval;
when the state of charge of the new energy storage system is [0, SOC ]min)∪(SOCmax,100]Determining the interval as an operation forbidden interval within the interval;
wherein: SOChig、SOClowAnd respectively representing an ideal operation charge upper limit and an ideal operation charge lower limit of the new energy storage system.
Step five: and correcting the control target of the new energy storage system according to the determined operation interval.
With a period Texe(second) updating the state of charge SOC (k) of the new energy storage system at the current moment of the new energy logic control area and up/down regulation standby P of AGC units of the main control areaagc-rvup(k)/Pagc-rvdn(k) And regulating the rate Ragc(k) And (4) information.
The correction method specifically comprises the following steps:
a. if the current charge state of the new energy storage system is in an ideal operation interval, the control target of the new energy storage system does not need to be corrected, namely the corrected control target P 'of the new energy storage system'BESS-targ(k)=PBESS-targ(k)。
b. If the current charge state of the new energy storage system is in an early warning operation interval, firstly judging whether the adjusting capacity of an AGC main control area can be matched with the active fluctuation of a new energy equivalent unit: when the regulation reserve (divided into an upper regulation reserve and a lower regulation reserve) of the AGC unit in the main control area is higher than the active fluctuation amplitude (mean deviation) of the new energy equivalent unit and the regulation rate is higher than the active change rate of the new energy equivalent unit, judging that the regulation capacity of the AGC main control area can be matched with the active fluctuation of the new energy equivalent unit; otherwise, matching cannot be performed.
Further, if the regulation capacity of the AGC main control area can be matched with the active power fluctuation of the new energy equivalent unit, the control instruction of the new energy storage system superposes the SOC correction amount on the basis of the smooth regulation requirement, and SOC management is actively carried out; if the adjusting capacity of the AGC main control area cannot be matched with the active power fluctuation of the new energy equivalent unit, the new energy storage system takes priority on the adjustment support of the AGC unit, and the control instruction only takes the calculation result of the smooth control requirement and does not consider the influence on the SOC change trend of the energy storage system.
Specifically, the control target of the new energy storage system is corrected by adopting the following correction strategy:
in the formula,. DELTA.PSOC(k) The correction quantity required for the new energy storage system to return to the ideal operation interval at the moment k is represented; delta Pavg(k) Representing the smooth target deviation of the active power of the new energy station at the moment k; pagc-rvup(k) AGC master control indicating k timeUpper regulation of the zone for standby; rrenew(k) Representing the output change rate of the new energy station at the moment k; ragc(k) The regulation rate of the AGC main control area at the k moment is shown; SOC (k) represents the state of charge of the new energy storage system at the moment k; fagcAnd a matching mark for indicating the adjustment capacity of the AGC main control area and the new energy fluctuation, wherein 1 represents that the AGC main control area can not meet the new energy fluctuation control requirement, and 0 represents that the AGC main control area can meet the new energy fluctuation control requirement.
Correction amount Δ PSOC(k) The correction value is larger as the deviation of the SOC from an ideal operation interval is farther, and the maximum correction value is the energy storage rated charging/discharging power; the correction amount becomes smaller as the deviation from the ideal operating range becomes closer, and the correction amount becomes zero when the SOC reaches the ideal limit value.
c. If the current charge state of the new energy storage system is in the operation forbidden interval, correcting the control target of the new energy storage system by adopting the following correction strategy:
in the formula, FSOCAnd a matching mark representing the current state of charge of the new energy storage system and the adjustment requirement, wherein 1 represents that the current adjustment requirement can aggravate the state of charge of the new energy storage system to deviate from an ideal operation interval, and 0 represents that the current adjustment requirement can promote the state of charge of the new energy storage system to return to the ideal operation interval.
When the current charge state of the new energy storage system is in the operation forbidden interval, the new energy storage system maintains the standby state, and neither charging control nor discharging control is executed until the charge state of the new energy storage system returns to the ideal operation interval.
Step six: and performing smooth control on the active power of the new energy according to the modified control target of the new energy storage system.
Therefore, the embodiment of the invention provides a new energy power generation active power fluctuation stabilizing method based on a new energy logical control area and a new energy equivalent unit in a regional power grid, fluctuation difference exchange and cancellation under natural conditions are carried out by utilizing different power generation types (including wind power and photovoltaic) of new energy and power generation space-time complementarity of each new energy station, and then the fluctuation of the new energy station is subjected to stabilizing control in a larger range of a power grid level. Compared with the mode that power fluctuation suppression is respectively carried out on each new energy station on the grid-connected side, the method and the system can greatly reduce the dependence on matching resources and adjustment standby and save the grid-connected matching construction cost of the new energy station. Meanwhile, the SOC operation interval of the new energy storage system and the regulation capacity of the AGC unit are also considered, the SOC operation interval of the new energy storage system is divided into three areas, namely an ideal operation interval, an early warning operation interval and a forbidden operation interval, and different correction calculation methods are adopted for control instructions of the new energy storage system in different operation intervals.
The new energy power generation active power smooth control system provided by the embodiment of the invention can be used for loading and executing the new energy power generation active power smooth control method, and comprises the following steps:
An acquisition module: the system is used for acquiring the total active power of power generation of all new energy stations in the regional power grid and the rated power of a new energy storage system;
a calculation module: the active power smoothing target deviation calculation module is used for calculating the active power smoothing target deviation of the new energy station according to the active power smoothing target of the new energy station and the total power generation active power of the new energy station;
a determination module: the control method comprises the steps of determining a new energy storage system control target capable of meeting the active power smooth control requirement according to the active power smooth target deviation, the rated power and the state of charge of the new energy storage system;
an execution module: and the method is used for smoothly controlling the active power of the new energy according to the determined control target of the new energy storage system.
Specifically, the determination module includes:
a preliminary determination module: the control method comprises the steps of preliminarily determining a control target of the new energy storage system according to the active power smooth target deviation and the rated power of the new energy storage system;
an operation interval division module: the operation interval is used for dividing the charge state of the new energy storage system;
an operation interval determination module: the method comprises the steps of determining an operation interval of the current charge state of the new energy storage system;
a correction module: and the method is used for correcting the preliminarily determined control target of the new energy storage system according to the determined operation interval.
The new energy power generation active power smooth control system provided by the invention can also be as follows: comprising a memory and a processor; the memory is to store instructions;
the processor is used for operating according to the instruction to execute the steps of the new energy power generation active power smooth control method.
The invention also provides a computer readable storage medium, on which a computer program is stored, which program, when being executed by a processor, realizes the steps of the aforementioned new energy power generation active power smoothing control method.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.