CN110994644A - Inverter active current priority distribution method and system under frequency disturbance - Google Patents

Inverter active current priority distribution method and system under frequency disturbance Download PDF

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CN110994644A
CN110994644A CN201911226817.XA CN201911226817A CN110994644A CN 110994644 A CN110994644 A CN 110994644A CN 201911226817 A CN201911226817 A CN 201911226817A CN 110994644 A CN110994644 A CN 110994644A
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value
current
grid
active current
inverter
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CN110994644B (en
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张健
魏巍
李文锋
陶向宇
王官宏
王晖
贾媛
李莹
艾东平
赵旭峰
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State Grid Corp of China SGCC
China Electric Power Research Institute Co Ltd CEPRI
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State Grid Corp of China SGCC
China Electric Power Research Institute Co Ltd CEPRI
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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
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • 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
    • H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
    • H02J3/16—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by adjustment of reactive power
    • 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
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation

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  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a method and a system for preferentially distributing active current of an inverter under frequency disturbance, wherein the method comprises the following steps: acquiring power data of a grid-connected point of the new energy unit; when the new energy source unit is in frequency disturbance, calculating according to the electric power data to obtain an original active current adjustment value; calculating to obtain a dynamically distributed reactive current adjustment value according to the original active current adjustment value; adjusting the inverter of the new energy source unit according to the dynamically distributed reactive current adjustment value and the original active current adjustment value, and acquiring power data of a grid-connected point of the new energy source unit again; judging whether the new energy unit recovers the steady-state operation or not according to the re-collected power data; according to the method and the system, the dynamic distribution control is performed on the basis of the frequency control output, so that the new energy unit can effectively participate in the voltage control and the frequency control of the power system.

Description

Inverter active current priority distribution method and system under frequency disturbance
Technical Field
The invention relates to the technical field of electric power, in particular to a method and a system for preferentially distributing active current of an inverter under frequency disturbance.
Background
In the case of large-scale renewable energy penetrating into the power system, the frequency regulation and voltage regulation of the power system are still undertaken by the conventional synchronous unit, meanwhile, the intermittent, fluctuating and incomplete controllability of the renewable energy cause the frequency and voltage problems of the system to be more prominent, and meanwhile, during the grid fault, the new energy unit may also protect the action from being disconnected, further deteriorating the stability of the system, such as the great british power failure occurring in 8, 9 and 2019, the wind farm and distributed photovoltaic are disconnected due to lightning strike, further deteriorating the system frequency, causing low-frequency load shedding action, cutting off about 5% of load, causing great power failure, and therefore, power electronic equipment (such as wind power and photovoltaic) is required to participate in the frequency and voltage regulation of the system. The active current and reactive current control of the power electronic equipment are decoupled, when the power electronic equipment simultaneously participates in frequency regulation and voltage regulation of a power system, the situation that the adjustable capacity cannot simultaneously meet the regulation requirements of the active power and the reactive power may occur, and under the condition of frequency disturbance, how to distribute the active power and the reactive power to enable the distribution to be more balanced and reasonable is a problem to be solved urgently.
Disclosure of Invention
In order to solve the problem that abnormal conditions may be caused by unbalanced proportion distribution of active and reactive currents under the condition of frequency disturbance in the background art, the invention provides a method and a system for preferentially distributing the active current of an inverter under the condition of frequency disturbance, wherein the method and the system obtain a scheme for preferentially considering the active power distribution in a bearable current range of the inverter by performing dynamic distribution control on the basis of voltage control and frequency control output under the condition of frequency disturbance, and the method for preferentially distributing the active current of the inverter under the condition of frequency disturbance comprises the following steps:
acquiring power data of a grid-connected point of a new energy source unit, wherein the power data comprises grid-connected point voltage and power grid frequency;
monitoring the grid-connected point voltage and the power grid frequency, and if the grid-connected point voltage is not in a dead zone and the power grid frequency is in the dead zone, judging that the system energy unit is under frequency disturbance;
when the new energy source unit is in frequency disturbance, calculating according to the electric power data to obtain an original active current adjustment value;
calculating to obtain a dynamically distributed reactive current adjustment value according to the original active current adjustment value;
and adjusting the inverter of the new energy source unit according to the dynamically distributed reactive current adjustment value and the original active current adjustment value.
Further, electric power data of the grid-connected point of the new energy source unit is collected again;
and judging whether the new energy source unit recovers the steady-state operation or not according to the re-collected power data.
Further, calculating to obtain a dynamically allocated reactive current adjustment value according to the original active current adjustment value, including:
judging whether the grid-connected point current adjusted by the original active current adjustment value meets the current threshold limit of the inverter or not;
if the current value does not meet the regulation value, under the condition of keeping the original active current regulation value, the reactive current is regulated to enable the grid-connected point current to meet the current threshold limit of the inverter, and the regulation value of the reactive current at the moment is taken as the reactive current regulation value under dynamic distribution.
Further, the determining whether the grid-connected point current adjusted by the original active current adjustment value satisfies the current threshold limit of the inverter includes:
calculating whether the root mean square value of the actual reactive current value and the active current reference value is within the current threshold limiting range of the inverter; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure BDA0002302454180000021
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta' systemdordThe value is adjusted for the original active current.
Further, in a case that an original active current adjustment value is maintained, adjusting a reactive current so that the grid-connected point current satisfies a current threshold limit of the inverter, includes:
gradually reducing the reactive current value on the basis of the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
The inverter active current priority distribution system under the frequency disturbance comprises:
the acquisition unit is used for acquiring and obtaining power data of a grid-connected point of the new energy unit, wherein the power data comprises grid-connected point voltage, grid-connected point current and grid frequency;
the steady-state monitoring unit is used for monitoring the voltage of the grid-connected point and the frequency of the power grid, and if the voltage of the grid-connected point is not in a dead zone and the frequency of the power grid is in the dead zone, the energy unit is judged to be under frequency disturbance;
the adjustment control unit is used for calculating and obtaining an original active current adjustment value according to input power data;
the dynamic distribution unit is used for calculating and obtaining a reactive current adjustment value after dynamic distribution according to the original active current adjustment value;
the current adjusting unit is used for adjusting an inverter of the new energy source unit according to the dynamically distributed reactive current adjusting value and the original active current adjusting value;
further, the acquisition unit is used for acquiring the power data of the grid-connected point of the new energy source unit again after the current adjustment unit completes adjustment; and the steady-state monitoring unit is used for judging whether the new energy source unit recovers steady-state operation according to the newly collected power data.
Further, the dynamic allocation unit is configured to determine whether the grid-connected point current adjusted by the original active current adjustment value satisfies a current threshold limit of the inverter;
if the current value does not meet the preset regulation value, the dynamic distribution unit is used for regulating the reactive current under the condition of keeping the original active current regulation value, so that the grid-connected point current meets the current threshold limit of the inverter, and the regulation value of the reactive current at the moment is taken as the reactive current regulation value under dynamic distribution.
Further, the dynamic allocation unit is configured to calculate whether a root mean square value of an actual reactive current value and an active current reference value is within a current threshold limit range of the inverter; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure BDA0002302454180000041
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta' systemdordThe value is adjusted for the original active current.
Further, the dynamic allocation unit is used for gradually reducing the reactive current value on the basis of the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
The invention has the beneficial effects that: the technical scheme of the invention provides a method and a system for preferentially distributing the active current of an inverter under frequency disturbance, and the method and the system obtain the optimal active and reactive current distribution scheme within the bearable current range of the inverter by performing dynamic distribution control on the basis of frequency control output under the condition that only frequency is disturbed, thereby ensuring that a new energy unit can effectively participate in voltage control and frequency control of a power system.
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A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:
fig. 1 is a flowchart of an inverter active current priority allocation method under frequency disturbance according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a voltage-frequency dynamic allocation control according to an embodiment of the present invention;
FIG. 3 is a diagram illustrating an original active current reactive current distribution control according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of the proportional distribution of active and reactive currents under frequency disturbance according to an embodiment of the present invention;
fig. 5 is a structural diagram of an inverter active current priority distribution system under frequency disturbance according to an embodiment of the present invention.
Detailed Description
The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.
Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.
Fig. 1 is a flowchart of an inverter active current priority allocation method under frequency disturbance according to an embodiment of the present invention;
step 110, acquiring power data of a grid-connected point of the new energy unit, wherein the power data comprises grid-connected point voltage, grid-connected point current and grid frequency;
the use scenario of the embodiment is that renewable energy is accessed to a power system; the method comprises the steps of collecting power data of a grid-connected point when a new energy unit (such as a wind turbine generator set and a photovoltaic generator set) of renewable energy is connected to a power grid.
Step 120, monitoring the grid-connected point voltage and the power grid frequency, and if the grid-connected point voltage is not in a dead zone and the power grid frequency is in the dead zone, judging that the system energy unit is under frequency disturbance;
judging whether the new energy source unit is in the condition of voltage disturbance or not by monitoring the running state of the grid-connected point voltage and judging whether the running state is in a preset dead zone or not; whether the new energy unit is in the condition of frequency disturbance is judged by monitoring the running state of the grid-connected point frequency and whether the running state is in a preset dead zone; in this embodiment, the problem of disturbance is solved by implementing proportional distribution of active and reactive currents in consideration of the fact that the new energy source unit is only in frequency disturbance.
Step 130, when the new energy source unit is in frequency disturbance, calculating according to the electric power data to obtain an original active current adjustment value;
further, as shown in fig. 2, an original reactive current adjustment value may be obtained through a voltage control link according to an input grid-connected point voltage, a grid-connected point current, and a voltage reference value; and calculating to obtain an original active current distribution value through a frequency control link according to the input power grid frequency and the frequency reference value. In this embodiment, to implement the active current priority distribution, only the frequency control link is used to adjust the active current to obtain the original active current adjustment value Δ I ″dord
Specifically, a schematic diagram of transfer functions of the voltage control link and the frequency control link is shown in fig. 3; inputting the grid-connected point voltage, the grid-connected point current and the grid frequency, and obtaining the original active current adjustment value delta I' through the flow direction of the transfer function as shown in fig. 3dord；
Step 140, calculating to obtain a dynamically distributed reactive current adjustment value according to the original active current adjustment value;
as shown in fig. 2, since the active power is preferentially distributed and the reactive power is not suitable for the voltage control link, only the original active current adjustment value Δ I ″ is inputdordAnd outputting the active current adjusting value after dynamic distribution through dynamic distribution control. Specifically, the method comprises the following steps:
step 141, judging whether the grid-connected point current adjusted by the original active current adjustment value meets the current threshold limit of the inverter;
calculating whether the root mean square value of the actual reactive current value and the active current reference value is within the current threshold limiting range of the inverter; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure BDA0002302454180000064
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta I-dordThe value is adjusted for the original active current.
And 142, if the current value is not satisfied, under the condition that the original active current adjustment value is kept, adjusting the reactive current to enable the grid-connected point current to satisfy the current threshold limit of the inverter, and taking the adjustment value of the reactive current at the moment as the reactive current adjustment value under dynamic distribution.
Gradually reducing the reactive current value on the basis of the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
And 150, adjusting the inverter of the new energy source unit according to the dynamically distributed reactive current adjustment value and the original active current adjustment value.
Further, after the step 150, the method further includes:
the power data of the grid-connected point of the new energy source unit is collected again;
and judging whether the new energy source unit recovers the steady-state operation or not according to the re-collected power data.
For the dynamic allocation method of step 140, fig. 4 is a schematic diagram of the proportional allocation of active and reactive currents under the frequency disturbance according to the embodiment of the present invention; by taking the active current as an abscissa and the reactive current as an ordinate, a coordinate system is established to illustrate the inverter active current priority distribution method under the frequency disturbance, as shown in fig. 4:
vector quantity
Figure BDA0002302454180000071
The projection on the abscissa is the actual active current value; vector quantity
Figure BDA0002302454180000072
The projection on the ordinate is the actual reactive current value; vector quantity
Figure BDA0002302454180000073
The current value is the current value under the integration of the actual active current value and the reactive current value, and the value of the current value cannot exceed the range of a circle in the graph, wherein the range of the circle in the graph is the current threshold limit of the inverter.
Vector quantity
Figure BDA0002302454180000074
Parallel to the abscissa, the vector representation of the original active current adjustment value is based on the actual reactive current value and the actual active current value (i.e. taking a as a starting point);
if the point C is beyond the circle of the graph (i.e., the calculated RMS value I ″) as described aboveordI.e., OC out of the range of the circle), it indicates that the adjusted current exceeds the current threshold limit of the inverter;
in order to ensure the preferential distribution of the active current, on the basis of the point C, the active current value is ensured to be unchanged, the reactive current value is gradually reduced, so that the point C moves to a point B on a circle along a direction parallel to the ordinate, and the adjusted vector
Figure BDA0002302454180000075
The projection on the abscissa is the reactive current adjustment value after dynamic distribution; and vector
Figure BDA0002302454180000076
There is no adjustment on the abscissa, which projects as the original active current adjustment value.
Fig. 5 is a structural diagram of an inverter active current priority distribution system under a frequency disturbance according to an embodiment of the present invention, and as shown in fig. 5, the system includes:
the acquisition unit 510 is used for acquiring and obtaining power data of a grid-connected point of the new energy unit, wherein the power data comprises grid-connected point voltage, grid-connected point current and grid frequency;
a steady-state monitoring unit 520, where the steady-state monitoring unit 520 is configured to monitor the grid-connected point voltage and the grid frequency, and if the grid-connected point voltage is not in a dead zone and the grid frequency is in the dead zone, determine that the grid energy unit is under frequency disturbance;
an adjustment control unit 530, wherein the adjustment control unit 530 is configured to calculate and obtain an original active current adjustment value according to input power data;
further, the adjusting and controlling unit 530 is configured to calculate and obtain an original active current distribution value according to the input grid frequency and the frequency reference value.
A dynamic allocation unit 540, where the dynamic allocation unit 540 is configured to calculate and obtain a dynamically allocated reactive current adjustment value according to the original active current adjustment value;
further, the dynamic allocation unit 540 is configured to determine whether the grid-connected point current adjusted by the original active current adjustment value meets the current threshold limit of the inverter;
if the current value does not meet the preset dynamic distribution value, the dynamic distribution unit 540 is configured to adjust the reactive current under the condition that the original active current adjustment value is maintained, so that the grid-connected point current meets the current threshold limit of the inverter, and the adjustment value of the reactive current at this time is taken as the reactive current adjustment value under dynamic distribution.
Further, the dynamic allocation unit 540 is configured to calculate whether a root mean square value of the actual reactive current value and the active current reference value is within a current threshold limit range of the inverter; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure BDA0002302454180000081
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta I-dordThe value is adjusted for the original active current.
Further, the dynamic allocation unit 540 is configured to gradually decrease the reactive current value based on the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
A current adjusting unit 550, where the current adjusting unit 550 is configured to adjust an inverter of the new energy source unit according to the dynamically allocated reactive current adjustment value and an original active current adjustment value;
the acquisition unit 510 is configured to acquire the power data of the grid-connected point of the new energy source unit again after the current adjustment unit 550 completes adjustment; the steady-state monitoring unit 520 is configured to determine whether the new energy source unit recovers steady-state operation according to the re-collected power data.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Reference to step numbers in this specification is only for distinguishing between steps and is not intended to limit the temporal or logical relationship between steps, which includes all possible scenarios unless the context clearly dictates otherwise.
Moreover, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the disclosure and form different embodiments. For example, any of the embodiments claimed in the claims can be used in any combination.
Various component embodiments of the disclosure may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The present disclosure may also be embodied as device or system programs (e.g., computer programs and computer program products) for performing a portion or all of the methods described herein. Such programs implementing the present disclosure may be stored on a computer-readable medium or may be in the form of one or more signals. Such a signal may be downloaded from an internet website or provided on a carrier signal or in any other form.
It should be noted that the above-mentioned embodiments illustrate rather than limit the disclosure, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several systems, several of these systems may be embodied by one and the same item of hardware.
The foregoing is directed to embodiments of the present disclosure, and it is noted that numerous improvements, modifications, and variations may be made by those skilled in the art without departing from the spirit of the disclosure, and that such improvements, modifications, and variations are considered to be within the scope of the present disclosure.

Claims (10)

1. A method for preferentially distributing active current of an inverter under frequency disturbance comprises the following steps:
acquiring power data of a grid-connected point of a new energy source unit, wherein the power data comprises grid-connected point voltage and power grid frequency;
monitoring the grid-connected point voltage and the power grid frequency, and if the grid-connected point voltage is not in a dead zone and the power grid frequency is in the dead zone, judging that the system energy unit is under frequency disturbance;
when the new energy source unit is in frequency disturbance, calculating according to the electric power data to obtain an original active current adjustment value;
calculating to obtain a dynamically distributed reactive current adjustment value according to the original active current adjustment value;
and adjusting the inverter of the new energy source unit according to the dynamically distributed reactive current adjustment value and the original active current adjustment value.
2. The method of claim 1, wherein: after the inverter of the new energy source unit is adjusted according to the dynamically allocated reactive current adjustment value and the original active current adjustment value, the method further includes:
the power data of the grid-connected point of the new energy source unit is collected again;
and judging whether the new energy source unit recovers the steady-state operation or not according to the re-collected power data.
3. The method of claim 1, wherein: calculating to obtain a dynamically distributed reactive current adjustment value according to the original active current adjustment value, wherein the method comprises the following steps:
judging whether the grid-connected point current adjusted by the original active current adjustment value meets the current threshold limit of the inverter or not;
if the current value does not meet the regulation value, under the condition of keeping the original active current regulation value, the reactive current is regulated to enable the grid-connected point current to meet the current threshold limit of the inverter, and the regulation value of the reactive current at the moment is taken as the reactive current regulation value under dynamic distribution.
4. The method of claim 3, wherein: the judging whether the grid-connected point current adjusted by the original active current adjustment value meets the current threshold limit of the inverter includes:
calculating whether the root mean square value of the actual reactive current value and the active current reference value is within the current threshold limiting range of the inverter; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure FDA0002302454170000021
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta I-dordThe value is adjusted for the original active current.
5. The method of claim 4, wherein: in the case of keeping the original active current adjustment value, adjusting the reactive current so that the grid-connected point current satisfies the current threshold limit of the inverter, including:
gradually reducing the reactive current value on the basis of the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
6. An inverter active current priority distribution system under frequency disturbance, the system comprising:
the acquisition unit is used for acquiring and obtaining power data of a grid-connected point of the new energy unit, and the power data comprises grid-connected point voltage and grid frequency;
the steady-state monitoring unit is used for monitoring the voltage of the grid-connected point and the frequency of the power grid, and if the voltage of the grid-connected point is not in a dead zone and the frequency of the power grid is in the dead zone, the energy unit is judged to be under frequency disturbance;
the adjustment control unit is used for calculating and obtaining an original active current adjustment value according to input power data;
the dynamic distribution unit is used for calculating and obtaining a reactive current adjustment value after dynamic distribution according to the original active current adjustment value;
and the current adjusting unit is used for adjusting the inverter of the new energy source unit according to the dynamically distributed reactive current adjusting value and the original active current adjusting value.
7. The system of claim 6, wherein:
the acquisition unit is used for acquiring the power data of the grid-connected point of the new energy source unit again after the current adjustment unit completes adjustment; and the steady-state monitoring unit is used for judging whether the new energy source unit recovers steady-state operation according to the newly collected power data.
8. The system of claim 6, wherein:
the dynamic distribution unit is used for judging whether the grid-connected point current regulated by the original active current regulation value meets the current threshold limit of the inverter or not;
if the current value does not meet the preset regulation value, the dynamic distribution unit is used for regulating the reactive current under the condition of keeping the original active current regulation value, so that the grid-connected point current meets the current threshold limit of the inverter, and the regulation value of the reactive current at the moment is taken as the reactive current regulation value under dynamic distribution.
9. The system of claim 8, wherein:
the dynamic distribution unit is used for calculating whether the root mean square value of the actual reactive current value and the active current reference value is within the current threshold limit range of the inverter or not; the active current reference value is the sum of the actual active current value and an original active current adjustment value;
the root mean square value I ″ordThe calculation method is as follows:
Figure FDA0002302454170000031
wherein, Idord0Is the actual active current value, Iqord0Is the actual reactive current value; delta I-dordThe value is adjusted for the original active current.
10. The system of claim 8, wherein:
the dynamic distribution unit is used for gradually reducing the reactive current value on the basis of the actual reactive current;
and when the root mean square value of the adjusted reactive current value and the active current reference value reaches the current threshold limit of the inverter, taking the reduced reactive current value interval as a reactive current adjustment value under dynamic allocation.
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