CN108551164B - Voltage stability control method and device for direct-current micro-grid - Google Patents

Voltage stability control method and device for direct-current micro-grid Download PDF

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CN108551164B
CN108551164B CN201810231367.2A CN201810231367A CN108551164B CN 108551164 B CN108551164 B CN 108551164B CN 201810231367 A CN201810231367 A CN 201810231367A CN 108551164 B CN108551164 B CN 108551164B
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power supply
distributed power
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microgrid
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CN108551164A (en
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寇凌峰
盛万兴
吴鸣
刘海涛
季宇
徐毅虎
侯小刚
屈小云
李蕊
孙丽敬
徐斌
骆晨
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State Grid Corp of China SGCC
China Electric Power Research Institute Co Ltd CEPRI
Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd
State Grid Anhui Electric Power Co Ltd
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State Grid Corp of China SGCC
China Electric Power Research Institute Co Ltd CEPRI
Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd
State Grid Anhui Electric Power Co Ltd
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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
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/10—Parallel operation of dc sources
    • 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
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

Abstract

The invention relates to a voltage stability control method and a device for a direct current micro-grid, wherein the method comprises the following steps: and determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply, and adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply. The invention provides a voltage stability control method for a direct current micro-grid, which aims to realize optimal power sharing by adopting a full-distributed control method to control the direct current micro-grid and utilizing cooperative control between adjacent distributed power supplies without configuring a micro-grid central controller, improve the utilization rate of renewable energy sources, combine a constant micro-increment rate principle and a consistency algorithm and introduce a target function to calculate the target power output quantity of the distributed power supplies, and reduce the power generation cost of a system on the basis of realizing the stability and the power balance of the bus voltage of a micro-grid system.

Description

Voltage stability control method and device for direct-current micro-grid
Technical Field
The invention relates to the field of direct-current micro-grid scheduling, in particular to a method and a device for controlling voltage stability of a direct-current micro-grid.
Background
The micro-grid is a small power generation and distribution cluster organically integrating a distributed generator, a load, an energy storage system, a current transformer and a monitoring and protecting device. The microgrid may be classified into an ac microgrid and a dc microgrid. Compared with an alternating-current micro-grid, the direct-current micro-grid has the characteristics of low cost, high operation efficiency, simplicity in control and the like. With the emergence of a large number of dc loads, the importance and necessity of dc microgrid has received a great deal of attention.
At present, there are two main methods for controlling the voltage stability of the dc bus of the dc microgrid: centralized and distributed. In the centralized control scheme, a micro-grid central controller needs to be arranged, and the micro-grid central controller sends a control instruction to a controlled unit after acquiring all power generation units and load information and performing complex calculation processing, so as to realize the control target of the system. The communication network required by the control mode is extremely large, complex and high in cost, and meanwhile, under the condition that communication fails or is not timely communicated, the system cannot make timely and effective response, and the safety and reliability of the system are affected.
Disclosure of Invention
The invention provides a voltage stabilization control method and a voltage stabilization control device for a direct current micro-grid, and aims to realize optimal power sharing by adopting a full-distributed control method to control the direct current micro-grid and utilizing cooperative control between adjacent distributed power supplies without configuring a micro-grid central controller, improve the utilization rate of renewable energy, calculate the target power output quantity of the distributed power supplies by utilizing a consistency algorithm and introducing a target function, and reduce the system power generation cost on the basis of realizing the stabilization and power balance of the bus voltage of a micro-grid system.
The purpose of the invention is realized by adopting the following technical scheme:
the improvement of a voltage stabilization control method for a direct current micro-grid is that the method comprises the following steps:
determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
and adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply.
Preferably, the determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply comprises:
according to the cost micro-increment rate of the distributed power supply, the target power output quantity P of the ith distributed power supply at the kth sampling moment is determined by using a consistency algorithm according to the following formula i (k)：
Figure BDA0001602649980000021
In the above formula, i belongs to [1, N ]]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity P of ith distributed power supply at k sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure BDA0001602649980000022
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure BDA0001602649980000023
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure BDA0001602649980000024
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment.
Further, the cost incremental rate of the distributed power supply is determined according to the following formula:
Figure BDA0001602649980000025
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure BDA0001602649980000026
parameters that are the upper and lower limits of the output power of the ith distributed power source.
Further, an objective function of the direct current microgrid at the k-th sampling time is determined according to the following formula:
Figure BDA0001602649980000027
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time, epsilon i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure BDA0001602649980000028
as bus bar electricityPressing the nominal value, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
Further, the power adaptation amount of the direct current microgrid at the kth sampling moment is determined according to the following formula:
Figure BDA0001602649980000029
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And the (k-1) sub-table represents the measured value of the bus voltage at the k-1 sampling moment.
Preferably, the adjusting the power injected into the dc microgrid by the distributed power supply by using the target power output quantity of the distributed power supply includes:
controlling the power injected into the direct-current micro-grid by the distributed power supply to be the target power output quantity P of the ith distributed power supply at the kth sampling moment by utilizing a DC/DC or AC/DC converter of the distributed power supply i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
In a dc microgrid voltage stabilization control apparatus, the improvement comprising:
the determining unit is used for determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
and the adjusting unit is used for adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply.
Further, the determining unit includes:
a determining module, configured to determine, according to the cost incremental rate of the distributed power sources, a target power output amount P of the ith distributed power source at the kth sampling time by using a consistency algorithm according to the following formula i (k)：
Figure BDA0001602649980000031
In the above formula, i is belonged to [1, N]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity P of ith distributed power supply at k sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure BDA0001602649980000032
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure BDA0001602649980000033
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure BDA0001602649980000034
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment.
Further, the cost incremental rate of the distributed power supply is determined according to the following formula:
Figure BDA0001602649980000035
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure BDA0001602649980000036
parameters that are the upper and lower limits of the output power of the ith distributed power source.
Further, an objective function of the direct current microgrid at the k-th sampling time is determined according to the following formula:
Figure BDA0001602649980000037
in the above formula, Δ p (k) is the power adaptation amount, epsilon, of the dc microgrid at the kth sampling time i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure BDA0001602649980000041
is the nominal value of the bus voltage, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
Further, the power adaptation amount of the direct current microgrid at the k-th sampling moment is determined according to the following formula:
Figure BDA0001602649980000042
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And the (k-1) sub-table represents the measured value of the bus voltage at the k-1 sampling moment.
Preferably, the adjusting unit includes:
a control module, configured to control, by using a DC/DC or AC/DC converter of the distributed power source, power injected into the DC microgrid by the distributed power source to be a target power output amount P of the ith distributed power source at the kth sampling time i (k) If the ith distributed power supply outputs the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
The invention has the beneficial effects that:
according to the technical scheme provided by the invention, the target power output quantity of the distributed power supply is determined according to the cost micro-increment rate of the distributed power supply, and the power injected into the direct-current micro-grid by the distributed power supply is regulated by utilizing the target power output quantity of the distributed power supply, so that a micro-grid central controller is not required to be configured, the single-point fault of a line is effectively avoided, and the operation reliability of the direct-current micro-grid is improved;
the technical scheme provided by the invention is that an objective function Q is introduced i Calculating the target power output quantity of the distributed power supply, and reducing the system power generation cost on the basis of realizing the stability and power balance of the bus voltage of the microgrid system when the target power output quantities at the current sampling moment and the last sampling moment meet the requirement of a consistency algorithm; on the other hand, the direct-current microgrid is controlled by a full-distributed control method of adjusting the power injected into the direct-current microgrid by the distributed power sources by using the target power output quantity of the distributed power sources, optimal power sharing is realized by using cooperative control between adjacent distributed power sources, and the utilization rate of renewable energy sources is improved.
Drawings
FIG. 1 is a flow chart of a DC microgrid voltage stabilization control method of the present invention;
fig. 2 is a schematic view of an application scenario of a dc microgrid voltage stabilization control method in an embodiment of the present invention;
fig. 3 is a schematic diagram of a simplified equivalent model of the bus voltage of the dc microgrid according to a method for controlling the voltage stability of the dc microgrid in an embodiment of the present invention;
fig. 4 is a schematic structural diagram of a voltage stabilization control apparatus for a dc microgrid according to the present invention.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
The invention provides a voltage stability control method for a direct current micro-grid, which comprises the following steps as shown in figure 1:
101. determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
102. and adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply.
Further, the step 101 includes:
according to the cost micro-increment rate of the distributed power supply, the target power output quantity P of the ith distributed power supply at the kth sampling moment is determined by using a consistency algorithm according to the following formula i (k)：
Figure BDA0001602649980000051
In the above formula, i is belonged to [1, N]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity, P, of the ith distributed power supply at the kth sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure BDA0001602649980000052
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure BDA0001602649980000053
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure BDA0001602649980000054
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment.
Specifically, the cost incremental rate of the distributed power supply is determined according to the following formula:
Figure BDA0001602649980000055
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure BDA0001602649980000061
parameters that are the upper and lower limits of the output power of the ith distributed power source.
Specifically, an objective function of the direct current microgrid at the kth sampling time is determined according to the following formula:
Figure BDA0001602649980000062
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time, epsilon i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure BDA0001602649980000063
is the nominal value of the bus voltage, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
Determining the power adaptation amount of the direct current microgrid at the kth sampling moment according to the following formula:
Figure BDA0001602649980000064
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And the (k-1) sub-table represents the measured value of the bus voltage at the k-1 sampling moment.
Further, after obtaining the target power output quantity of the distributed power source, the step 102 includes:
controlling the power injected into the direct-current microgrid by the distributed power supply by using a DC/DC or AC/DC converter of the distributed power supply to be a target power output quantity P of the ith distributed power supply at the kth sampling moment i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
For example, as shown in fig. 2, the network topology of the electrical grid cyber-physical system is combined by a plurality of intelligent systems (agents), each Agent being composed of two parts, a processor and a communicator. The processor is responsible for controlling the operation of the method and the sending of control instructions. The controller receives external discrete signals and simultaneously monitors the running state of local physical equipment and samples local physical information (including voltage, current and the like) in real time, and then the controller needs to process the collected information according to a set rule and send a control instruction to the local equipment, so that the accurate and efficient running of the whole microgrid system is ensured.
Setting that a micro-grid comprises a renewable energy distributed power supply (comprising a photovoltaic system, a wind generating set and the like) and a traditional distributed power supply; k is the sampling time, and the sampling time is 0.1 second.
According to the cost micro-increment rate of the distributed power supply, the target power output quantity P of the ith distributed power supply at the kth sampling moment is determined by using a consistency algorithm according to the following formula i (k)：
Figure BDA0001602649980000071
In the above formula, i is belonged to [1, N]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the ithThe total number of distributed power supplies adjacent to each distributed power supply, k is sampling time, and P is i (k) Target power output quantity, P, of the ith distributed power supply at the kth sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure BDA0001602649980000072
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure BDA0001602649980000073
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure BDA0001602649980000074
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment.
Specifically, the cost incremental rate of the distributed power supply is determined according to the following formula:
Figure BDA0001602649980000075
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure BDA0001602649980000076
parameters of the upper limit and the lower limit of the output power of the ith distributed power supply
Figure BDA0001602649980000077
Only when the output power P of the ith distributed power supply i Satisfy P i min ＜P i ＜P i max The above formula is significant.
Determining a target function of the direct current microgrid at the kth sampling moment according to the following formula:
Figure BDA0001602649980000078
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time; epsilon i Coefficient of power balance of DC microgrid, mu i Is the coefficient of bus voltage stabilization, let ε i ＝0.01，μ i ＝0.02；
Figure BDA0001602649980000079
Is the nominal value of the bus voltage, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
Fig. 3 shows a simplified equivalent model diagram of a dc microgrid bus voltage, from which fig. 3 the following relationship can be derived:
Figure BDA00016026499800000710
in the above formula, P DG Total power value P provided for distributed power supply in direct current micro-grid ESS Total power value, P, provided for energy storage in a DC microgrid load For the total load demand in the DC microgrid, P loss The total loss of the line in the direct current micro-grid is obtained.
Discretization of the above equation yields:
Figure BDA0001602649980000081
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And the (k-1) sub-table represents the measured value of the bus voltage at the k-1 sampling moment.
Further, the target power output of the distributed power supply is obtainedAfter the sampling, controlling the power injected into the direct current micro-grid by the distributed power supply by using a DC/DC or AC/DC converter of the distributed power supply to be the target power output quantity P of the ith distributed power supply at the kth sampling moment i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
When | P i (k)-P i When (k-1) | is less than or equal to 0.1, the target power output quantity P i (k) The total generation cost of the distributed power supply of the DC microgrid tends to be the smallest, i.e.
Figure BDA0001602649980000082
The power of the DC microgrid is balanced, i.e.
Figure BDA0001602649980000083
The bus voltage remains relatively stable, i.e.
Figure BDA0001602649980000084
Objective function
Figure BDA0001602649980000085
Converging to zero.
Wherein, the power generation cost of the ith distributed power supply at the kth sampling moment is determined according to the following formula
Figure BDA0001602649980000086
Figure BDA0001602649980000087
The present invention also provides a voltage stabilization control apparatus for a dc microgrid, as shown in fig. 4, the apparatus includes:
the determining unit is used for determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
and the adjusting unit is used for adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply.
Further, the determining unit includes:
a determining module, configured to determine, according to the cost incremental rate of the distributed power sources, a target power output amount P of the ith distributed power source at the kth sampling time by using a consistency algorithm according to the following formula i (k)：
Figure BDA0001602649980000088
In the above formula, i is belonged to [1, N]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity P of ith distributed power supply at k sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure BDA0001602649980000091
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure BDA0001602649980000092
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure BDA0001602649980000093
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment.
Specifically, the cost incremental rate of the distributed power supply is determined according to the following formula:
Figure BDA0001602649980000094
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure BDA0001602649980000095
parameters that are the upper and lower limits of the output power of the ith distributed power source.
Specifically, an objective function of the direct current microgrid at the kth sampling time is determined according to the following formula:
Figure BDA0001602649980000096
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time, epsilon i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure BDA0001602649980000097
is the nominal value of the bus voltage, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
Determining the power adaptation quantity of the direct current microgrid at the kth sampling moment according to the following formula:
Figure BDA0001602649980000098
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And the (k-1) sub-table represents the measured value of the bus voltage at the k-1 sampling moment.
Further, after obtaining the target power output quantity of the distributed power supply, the adjusting unit includes:
a control module for controlling the power injected into the DC microgrid by the distributed power supply to be the third power by using a DC/DC or AC/DC converter of the distributed power supplyTarget power output quantity P of i distributed power supplies at k-th sampling moment i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
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.
Finally, it should be noted that: although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (8)

1. A voltage stabilization control method for a direct current microgrid is characterized by comprising the following steps:
determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
adjusting the power injected into the direct current micro-grid by the distributed power supply by using the target power output quantity of the distributed power supply;
the determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply comprises the following steps:
according to the cost micro-increment rate of the distributed power supply, determining the target power output quantity P of the ith distributed power supply at the kth sampling moment by using a consistency algorithm according to the formula i (k)：
Figure FDA0003605690130000011
In the above formula, i belongs to [1, N ]]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity P of ith distributed power supply at k sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, and delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment, Q i * (k) The target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure FDA0003605690130000012
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure FDA0003605690130000013
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment is obtained;
the adjusting the power injected into the direct current micro-grid by the distributed power supply by using the target power output quantity of the distributed power supply comprises the following steps:
controlling the power injected into the direct-current micro-grid by the distributed power supply to be the target power output quantity P of the ith distributed power supply at the kth sampling moment by utilizing a DC/DC or AC/DC converter of the distributed power supply i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
2. The method of claim 1, wherein the cost incremental rate of the distributed power source is determined as follows:
Figure FDA0003605690130000014
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min Is the ith distributed typeThe lower limit of the output power of the power supply,
Figure FDA0003605690130000021
parameters that are the upper and lower limits of the output power of the ith distributed power source.
3. The method of claim 1, wherein the objective function of the dc microgrid at the kth sampling time is determined as follows:
Figure FDA0003605690130000022
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time, epsilon i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure FDA0003605690130000023
is the nominal value of the bus voltage, V DC (k) Is the bus voltage measured value at the k-th sampling moment.
4. The method of claim 3, wherein the power adaptation amount of the DC microgrid at a kth sampling time is determined as follows:
Figure FDA0003605690130000024
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And (k-1) the sub-table represents the measured values of the bus voltage at the k-1 sampling moment.
5. A DC microgrid voltage stabilization control apparatus, comprising:
the determining unit is used for determining the target power output quantity of the distributed power supply according to the cost micro-increment rate of the distributed power supply;
the adjusting unit is used for adjusting the power injected into the direct current micro-grid by the distributed power supply by utilizing the target power output quantity of the distributed power supply;
the determination unit includes:
a determining module, configured to determine, according to the cost incremental rate of the distributed power sources, a target power output amount P of the ith distributed power source at the kth sampling time by using a consistency algorithm according to the following formula i (k)：
Figure FDA0003605690130000025
In the above formula, i is belonged to [1, N]N is the total number of the distributed power supplies, j belongs to [1, N ] i ],n i Is the total number of distributed power supplies adjacent to the ith distributed power supply, k is the sampling time, P i (k) Target power output quantity, P, of the ith distributed power supply at the kth sampling time i (k-1) is the target power output quantity of the ith distributed power supply at the k-1 sampling moment, delta i Is the sampling coefficient of the ith distributed power supply at the kth sampling moment, delta t is the time difference between the kth sampling moment and the (k-1) th sampling moment,
Figure FDA0003605690130000026
the target function of the direct current micro-grid at the kth sampling moment is obtained;
Figure FDA0003605690130000031
for the cost incremental rate of the ith distributed power supply at the kth sampling instant,
Figure FDA0003605690130000032
the cost micro-increment rate of the ith distributed power supply at the k-1 sampling moment is obtained;
the adjusting unit includes:
a control module for controlling the power injected into the DC microgrid by the distributed power supply by using a DC/DC or AC/DC converter of the distributed power supply asTarget power output quantity P of ith distributed power supply at k-th sampling moment i (k) If the ith distributed power supply has the target power output quantity P at the kth sampling moment i (k) Satisfy | P i (k)-P i And (k-1) is less than or equal to 0.1 and maintained for 2 seconds, and the target output power is stopped to be updated.
6. The apparatus of claim 5, wherein the cost incremental rate of the distributed power source is determined as follows:
Figure FDA0003605690130000033
in the above formula, α i 、β i 、γ i Is a factor of the power generation cost of the ith distributed power supply, P i Is the output power of the ith distributed power supply, P i max Is the upper limit, P, of the output power of the ith distributed power supply i min The lower limit of the output power of the ith distributed power supply,
Figure FDA0003605690130000034
parameters that are the upper and lower limits of the output power of the ith distributed power source.
7. The apparatus of claim 5, wherein the objective function of the DC microgrid at a kth sampling time is determined as follows:
Figure FDA0003605690130000035
in the above formula, Δ p (k) is the power adaptation amount of the dc microgrid at the kth sampling time, epsilon i Coefficient of power balance of DC microgrid, mu i Is a factor in the stabilization of the bus voltage,
Figure FDA0003605690130000036
as bus bar electricityPressing the nominal value, V DC (k) Is the bus voltage measurement at the kth sampling instant.
8. The apparatus of claim 7, wherein the power adaptation amount of the DC microgrid at a kth sampling time is determined as follows:
Figure FDA0003605690130000037
in the above formula, C is the capacitance value of the equivalent capacitor of the DC microgrid, V DC And (k-1) the sub-table represents the measured values of the bus voltage at the k-1 sampling moment.
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