KR20200126122A - Distributed scheduling method in dynamic virtual plants and apparatus thereof - Google Patents

Abstract

Disclosed are a distributed scheduling method for a dynamic virtual power plant and an apparatus thereof. The method of performing distributed scheduling on each distributed energy resource (DER) constituting a dynamic virtual power plant includes the following steps of: (a) obtaining a set including a global power production target amount and a plurality of candidate power profiles; (b) selecting a current power profile so as to maximize profits of the distributed energy resource by using the set; and (c) controlling the power profile of the distributed energy resource such that a difference between profits corresponding to the power profiles of the distributed energy resource and another distributed energy resource stays within an allowable value in regard to controlling the power profile of the distributed energy resource so as to satisfy the global power production target amount with reference to the power profile of the other distributed energy resource. Therefore, the present invention has an advantage of enabling even small-scale new renewable energy plants to participate in the markets.

Description

Distributed scheduling method in dynamic virtual plants and apparatus thereof TECHNICAL FIELD

The present invention relates to a fairness-aware distributed scheduling method and apparatus for a dynamic virtual power plant.

The enactment of domestic laws and regulations made it possible for private businesses to trade electricity. For distributed power sources such as new and renewable energy, intermediate operators are participating in the power transaction. However, in the case of an intermediate business operator, the goal is to find the optimum point at which the profit of the intermediate business operator is maximized in consideration of the generation, demand, and cost used in power transactions.

The conventional centralized power scheduling method has a problem in that power scheduling is determined so as to maximize the profits of intermediate operators rather than the profits of each individual distributed power supply. In addition, due to the method of maximizing the amount of power generation supplied by the largest generator, there is a problem that it is virtually impossible for small-scale power generators producing new and renewable energy to participate in the market.

(01) Korean Patent Application Publication No. 10-2018-0010850 (2018.01.31)

The present invention is to provide a method and apparatus for distributed scheduling for a dynamic virtual power plant.

In addition, the present invention is to provide a distributed scheduling method and apparatus for a dynamic virtual power plant that enables fairness-aware distributed scheduling between local groups included in the dynamic virtual power plant.

According to an aspect of the present invention, a method for distributed scheduling for a dynamic virtual power plant is provided.

According to an embodiment of the present invention, in the distributed scheduling method in each distributed energy resource (DER) constituting a dynamic virtual power plant, (a) including a global power production target amount and a plurality of candidate power profiles Obtaining a set; (b) using the set to select a power profile such that the benefit of the distributed energy resource is maximized; And (c) a benefit corresponding to the power profile of the other distributed energy resource and the distributed energy resource in adjusting the power profile of the distributed energy resource to meet the global power production target amount by referring to the power profile of the other distributed energy resource. A distributed scheduling method comprising the step of adjusting the power profile of the distributed energy resource so that the difference of is within an allowable value may be provided.

Each of the plurality of power profiles may include a power value for each time unit.

In the step (c), the power profile of the distributed energy resource may be adjusted by referring to the power profile of the other distributed energy resources so that the sum of the amount of power according to the power profile of each distributed energy resource approaches the target amount of global power generation. .

After step (b), it may further include the step of sharing the power profile with the other distributed energy resources.

The step (c) may be repeatedly performed until the power profile shared by the other distributed energy resources and the power profile of the distributed energy resource converge through consensus.

According to another aspect of the present invention, an apparatus for distributed scheduling of distributed energy resources forming a dynamic virtual power plant is provided.

According to an embodiment of the present invention, there is provided a scheduling apparatus included in a distributed energy resource forming a dynamic virtual power plant, comprising: a communication unit for obtaining a set including a target amount of global power generation and a plurality of power profiles; And a scheduling unit for selecting a power profile to maximize the profit of the distributed energy resource using the set, wherein the scheduling unit includes the distributed energy resource to meet the global power production target amount by referring to the power profile of other distributed energy resources. In adjusting the power profile of the distributed energy resource, the power profile of the distributed energy resource is adjusted so that the difference between each benefit corresponding to the power profile of the other distributed energy resource and the distributed energy resource is within an allowable value. I can.

The distributed energy resource may include at least one of at least one electric vehicle (EV), an energy storage device, a solar discharge system, and a home appliance.

The scheduling unit may adjust the power profile of the distributed energy resource by referring to the power profile of the other distributed energy resources so that the sum of the power amounts according to the power profile of each distributed energy resource approaches the global power production target amount.

According to another embodiment of the present invention, there is provided a dynamic virtual power plant, comprising: a first distributed energy resource; And a second distributed energy resource, wherein the first distributed energy resource and the second distributed energy resource each have a local power production amount by each of the first distributed energy resource and the second distributed energy resource. A dynamic virtual power plant, characterized in that for deriving a power profile such that a difference in profit according to the power profile of the first distributed energy resource and the second distributed energy resource is within an allowable value with reference to the power profile of the adjacent distributed energy resource to satisfy Can be provided.

Each of the first distributed energy resource and the second distributed energy resource may select a power profile that maximizes the profit of each of the first distributed energy resource and the second distributed energy resource from among a plurality of power profiles.

By providing a distributed scheduling method and apparatus for a dynamic virtual power plant according to an embodiment of the present invention, there is an advantage in that fairness-aware distributed scheduling between local groups included in the dynamic virtual power plant is possible.

Through this, the present invention also has an advantage of preventing the occurrence of distributed energy resources that are excluded during power generation scheduling in a dynamic virtual power plant.

In addition, the present invention has the advantage of enabling small-scale renewable energy generators to participate in the market.

1 is a block diagram schematically showing the configuration of a dynamic virtual power plant according to an embodiment of the present invention.
2 is a diagram illustrating a process of charging and discharging distributed energy resources included in a dynamic virtual power plant according to an embodiment of the present invention.
3 is a flowchart illustrating a scheduling optimization process according to an embodiment of the present invention.
4 is a block diagram schematically showing an internal configuration of a scheduling apparatus according to an embodiment of the present invention.

Singular expressions used in the present specification include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional elements or steps. In addition, terms such as "... unit" and "module" described in the specification mean units that process at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically showing the configuration of a dynamic virtual power plant according to an embodiment of the present invention.

Referring to FIG. 1, a dynamic virtual power plant 100 according to an embodiment of the present invention includes a plurality of distributed energy resources 110.

At least one of the plurality of distributed energy resources 110 may include electric vehicles (EV). Among the distributed energy resources 110, the EV may include sensitive personal information that is not desired to be shared with others, such as an individual's mobility pattern and battery capacity due to its characteristics. In addition, EV is not a fixed resource in one place, but a mobile resource, which is not fixed to a single virtual power plant.

That is, the dynamic virtual power plant 100 has a characteristic that is dynamically formed according to the participation characteristics of the EV. Since the method of configuring the dynamic virtual power plant itself is not related to the main thesis of the present invention, a separate description thereof will be omitted. Accordingly, in an embodiment of the present invention, a method of distributed scheduling for each distributed energy resource in a state in which a dynamic virtual power plant including at least one EV is already formed will be described.

In addition, according to an embodiment of the present invention, there may be a type capable of charging and discharging only and a type capable of charging and discharging only an EV from a grid. It is assumed that EVs of all types make occasional visits to the charging station, and that it can be connected to the charging station for charging or discharging and for both charging and discharging.

In addition, when the EV is connected to the charging station, it is assumed that it is not connected to the charging station for a long time and maintains the connection state. In addition, it is assumed that the EV does not always participate in the dynamic virtual power plant, and participates in the dynamic virtual power plant as needed.

In addition, although not specified in FIG. 1, the dynamic virtual power plant may be directly connected to the grid operation server, and may be connected to the grid operation server through a separate distributed energy resource aggregator that manages distributed energy resources. have.

2 is a brief description of a process of charging and discharging distributed energy resources included in a dynamic virtual power plant according to an embodiment of the present invention.

In step 210, the distributed energy resources form a group, thereby dynamically forming a virtual power plant. In order to facilitate understanding and explanation, in FIG. 2, it will be assumed that the distributed energy resource is EV, and this will be mainly described. The EV dynamically forms a virtual power plant to participate in the market, but since the formation of such a dynamic virtual power plant itself is not related to the subject matter of the present invention, a separate description thereof will be omitted.

In step 215, the distributed energy resource is a scheduling process, and a charge/discharge profile is derived.

For example, it is assumed that there is a scheduling set including a candidate schedule (profile). For each candidate schedule, the power (watts) for each time unit is described so that the energy production plan for the distributed energy resource during the production phase can be defined.

In each candidate schedule, positive power means that the distributed energy resource discharges energy to the grid, and negative power means that the distributed energy resource charges and discharges energy from the grid. .

In a schedule set including each candidate schedule (power profile) for each time unit, the EV may derive its (EV) charge/discharge profile by selecting a candidate schedule suitable for each time unit. In FIG. 2, since the charging/discharging process is mainly described, it is referred to as a charging/discharging profile, but hereinafter, the profile will be collectively referred to as a power profile from the viewpoint of power generation.

It should be understood that this power profile includes a candidate schedule for each time unit for both charge and discharge and discharge.

As described above, in deriving its own power profile, the distributed energy resource may derive the power profile by selecting a candidate schedule for each time unit so that the benefit of the distributed energy resource is maximized.

When derivation of the power profile of each distributed energy resource is completed, an optimization algorithm is performed to finally determine a schedule according to actual power production (or charging, discharging, etc.) of each distributed energy resource.

As already described above, the distributed energy resource according to an embodiment of the present invention does not communicate with all distributed energy resources forming a dynamic virtual power plant, but only communicates with the distributed energy resource adjacent to the distributed energy resource. It is possible.

Accordingly, in order to finally determine the actual schedule of each distributed energy resource so that each distributed energy resource forming a dynamic virtual power plant meets the global target, an optimization process must be performed based on the power profile of each distributed energy resource. This will be described in more detail below with reference to FIG. 3.

When the optimization process for each of the distributed energy resources is completed, in step 220, the distributed energy resource performs planned charging and discharging according to the final power profile.

A dynamic virtual power plant can not only contribute to the grid by generating power according to the power profile, but can also contribute to moving loads from slots with higher prices to slots with lower prices.

In other words, the net energy production from the dynamic virtual power plant to the grid is the sum (positive or negative) of the power generated by the distributed energy resources included in the dynamic virtual power plant.

In FIG. 2, a basic process of generating power according to a power profile by each distributed energy resource included in a dynamic virtual power plant has been described. Hereinafter, a method of optimizing the power profile of each distributed energy resource will be described.

3 is a flow chart showing a scheduling optimization process according to an embodiment of the present invention. It is assumed that each step described below is performed by a scheduling device included in each distributed energy resource. The scheduling device 300 may be provided as a component of distributed energy resources, or may be a separate device interlocked with each distributed energy resource.

For the convenience of understanding and explanation, it is assumed that each distributed energy resource forming a dynamic virtual power plant has a power profile initially derived so that its own profit is maximized by selecting a candidate schedule according to each time unit.

In step 310, the scheduling device 300 shares a power profile derived from other distributed energy resources.

The scheduling device 300 may perform communication only with neighboring distributed energy resources. Communication is performed only with neighboring distributed energy resources, but through this process, both other distributed energy resources and the current power profile can be shared.

In step 315, the scheduling device 300 obtains a power profile selected from each of the other distributed energy resources at the current time from the other distributed energy resources.

As already mentioned above, the power profile includes a power (watt) value for each time unit. Accordingly, the distributed energy resource may each select a power profile capable of maximizing its own profit from a plurality of power profiles.

In step 320, the scheduling device 300 optimizes the power profile of the distributed energy resource by referring to the power profile obtained from the other distributed energy resource.

This will be described in more detail.

In an embodiment of the present invention, a scheduling problem in a dynamic virtual power plant may be modeled as a multiple-choice combinatorial optimization problem (MC-COP). MC-COP is a problem of maximizing or minimizing an object function in selecting one element from each set.

As already described above, each distributed energy resource may acquire a set including a plurality of power profiles. In a set containing power profiles, each distributed energy resource can select a power profile that can maximize its benefit at the present time.

는 i번째 분산 에너지 자원의 j번째 스케쥴(프로파일)이라 칭하기로 한다. 또한,

는 i번째 분산 에너지 자원의 스케쥴 개수라 정의하기로 한다. 또한, c는 글로벌 전력 생산 목표량(전력 벡터)라 가정하기로 한다. 본 발명의 일 실시예에서 스케쥴은 전력 프로파일로 이해되어야 할 것이다. For example, it is assumed that the number of distributed energy resources in a dynamic virtual power plant is m.

Will be referred to as the j-th schedule (profile) of the i-th distributed energy resource. In addition,

Is defined as the number of schedules of the i-th distributed energy resource. In addition, it is assumed that c is the global power production target amount (power vector). In one embodiment of the present invention, the schedule should be understood as a power profile.

는 q-차원 벡터로 표현될 수 있다. For example, given the operating time q (e.g. 8 hours) of a dynamic virtual power plant, and given each time unit (e.g., 1 hour), c and

Can be expressed as a q-dimensional vector.

Therefore, scheduling can be defined by an equation as shown in equation (1).

In Equation 1, the target function may be a difference between the global power production target amount and the sum of the local power production amount according to the power profile derived by each distributed energy resource.

A variance equation for the optimization problem for each distributed energy resource considering both the global target function and the local target function was proposed by Hinrichs et.al.

In the distributed scheduling according to an embodiment of the present invention, sharing the power profile of each distributed energy resource may share sensitive personal information, so it is reluctant to share it with a central authority for optimization.

Instead, as already mentioned above, each individual distributed energy resource is optimized for the current time in several neighboring distributed energy resources so that negotiations between the distributed energy resources constituting the dynamic virtual power plant can be converged through an optimization process. You can share your profile.

This can be expressed as Equation 2.

는 글로벌 목표와 각 분산 에너지 자원의 목표를 조절하는 변수를 나타낸다. In Equation 2

Represents the global target and the variable that controls the target of each distributed energy resource.

)(즉, 로컬 전력 생산량)의 합인 것을 알 수 있다. 대상 함수는 글로벌 전력 생산 목표량과 각 그룹의 실제 에너지 생산량 사이의 로컬 관점에서의 생산량의 차이의 합이다. In Equation 2, the target function is the target function of the individual distributed energy resource (

) (That is, the amount of local power produced). The target function is the sum of the difference between the global power production target and the actual energy production for each group in terms of local production.

Distributed scheduling in Equation 2 has the following constraints.

(i) COHDA does not consider any important economic motives (benefits) between participating distributed energy resources in each of the distributed energy resources participating in the dynamic virtual power plant. In other words, each distributed energy resource derives a power profile to maximize its own profit.

(ii) COHDA does not take into account the issue of fairness.

The distributed scheduling algorithm of Equation 2 may reach an agreement that sacrifices the benefit of a specific distributed energy resource when only the global power production target is satisfied. For example, in the worst case, a schedule may be selected that excludes power generation of specific distributed energy resources such that certain distributed energy resources cannot have any benefit.

In the case of the objective function included in Equation 2, since there is no information on direct profit (profit) in the penalty component, it cannot directly contribute to profit.

Accordingly, in an embodiment of the present invention, distributed scheduling may be performed by directly considering financial motivation of each distributed energy resource and fairness between each distributed energy resource. This will be described.

와 같은 벡터로 주어지는 것을 가정하기로 한다. 분산 스케쥴링 모델을 단순화하기 위해 소비 가격은 생산 가격의 마이너스인 것을 가정하여 이를 중심으로 설명하기로 한다.Each power generation cost is

Let's assume that it is given by the same vector. In order to simplify the distributed scheduling model, it is assumed that the consumption price is negative of the production price, and this will be mainly explained.

이라 가정하기로 한다. 즉,

는 i번째 분산 에너지 자원의 비용 벡터로 정의될 수 있다.In order to calculate the profit, we need the cost vector of each distributed energy resource,

I will assume this. In other words,

May be defined as the cost vector of the ith distributed energy resource.

의 i번째 분산 에너지 자원에 대한 전력 프로파일(스케쥴)이 결정되면, 분산 에너지 자원에 대한 이익은 수학식 3과 같이 계산될 수 있다.

When the power profile (schedule) for the i-th distributed energy resource is determined, the benefit for the distributed energy resource may be calculated as in Equation 3.

는 내적 연산자(inner product operator)이다. 따라서, 각 분산 에너지 자원은 자신의 이익(

)이 극대화되도록 전력 프로파일을 도출하기를 원한다. here,

Is the inner product operator. Therefore, each distributed energy resource has its own benefit (

We want to derive the power profile so that) is maximized.

For fairness of profits, in an embodiment of the present invention, a difference in profits between distributed energy resources may be designed to be limited.

In other words, fairness can be preserved when the difference in profits between distributed energy resources is less than the allowable value (F). Therefore, this can be expressed as Equation 4.

In Equation 4, the difference in profits (maximum and minimum profits) between the distributed energy resources may be scheduled to be less than or equal to the allowable value (F) in consideration of the cost of generating power for the distributed energy resources.

In summary, in the scheduling apparatus 300 according to an embodiment of the present invention, after each distributed energy resource shares a power profile between other distributed energy resources, the difference in profit between the distributed energy resources is less than the allowable value (F). It is less than or equal to, and can perform a process of optimizing the power profile of each distributed energy resource to meet the global power production target.

4 is a block diagram schematically showing an internal configuration of a scheduling apparatus according to an embodiment of the present invention.

Referring to FIG. 4, a scheduling device 300 according to an embodiment of the present invention includes a communication unit 410, a scheduling unit 415, a memory 420, and a processor 425.

The communication unit 410 is a means for transmitting and receiving data with other devices through a communication network. For example, the communication unit 410 may receive a target amount of global power generation from a central server. In addition, the communication unit 410 may receive a power profile from another distributed energy resource, and may transmit a power profile derived by a distributed energy resource included in the scheduling device 300 to another distributed energy resource.

The scheduling unit 415 selects one power profile that maximizes its own profit at the current time by using a set including a plurality of candidate schedules (power profiles). In addition, the scheduling device 300 shares each derived power profile (optimum power profile) with other distributed energy resources, and can adjust the power profile of the distributed energy resource to meet the global amount of power generation. have. At this time, the scheduling unit 415 according to an embodiment of the present invention provides a difference in profit corresponding to the power profile of the distributed energy resources forming the dynamic virtual power plant to be less than or equal to the allowable value (F). The power profile can be adjusted.

That is, the scheduling unit 415 derives a power profile for the distributed energy resource without information on other distributed energy resources forming a dynamic virtual power plant, and then shares the power profile with other distributed energy resources through an optimization process. The optimization process can be performed by repeatedly performing the process of negotiating the power profile. Through this, the scheduling device 300 according to an embodiment of the present invention resolves unfairness in which the benefit of a specific distributed energy resource participating in a dynamic virtual power plant is significantly less, and enables the power profile of each distributed energy resource to be derived. I can.

The memory 420 stores various instructions (program codes) required to perform the fairness-aware distributed scheduling method according to an embodiment of the present invention, and various data derived from this process.

The processor 425 is a means for controlling internal components of the scheduling device 300 according to an embodiment of the present invention (for example, the communication unit 410, the scheduling unit 415, the memory 420, etc.) to be.

The apparatus and method according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in the computer software field. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes hardware devices specially configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of the program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

The above-described hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

So far, the present invention has been looked at around the embodiments. Those of ordinary skill in the art to which the present invention pertains will be able to understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the above description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

100: dynamic virtual power plant
110: distributed energy resource

Claims (11)

In the distributed scheduling method in each distributed energy resource (DER) constituting a dynamic virtual power plant,
(a) obtaining a set including a global power generation target amount and a plurality of candidate power profiles;
(b) using the set to select a current power profile such that the benefit of the distributed energy resource is maximized; And
(c) In adjusting the power profile of the distributed energy resource to meet the global power production target amount by referring to the power profile of the other distributed energy resource, the profit corresponding to the power profile of the other distributed energy resource and the distributed energy resource And adjusting the power profile of the distributed energy resource so that the difference is within a tolerance.
The method of claim 1,
Distributed scheduling method, characterized in that the plurality of power profiles each include a power value for each time unit.
The method of claim 1,
The step (c),
And adjusting the power profile of the distributed energy resource by referring to the power profile of the other distributed energy resource such that the sum of the power profile of each distributed energy resource is close to the global power production target amount.
The method of claim 1,
After step (b),
Distributed scheduling method further comprising the step of sharing the power profile with the other distributed energy resources.
The method of claim 1,
The step (c),
A distributed scheduling method, characterized in that the power profile shared by the other distributed energy resources and the power profile of the distributed energy resource are repeatedly performed until convergence by consensus.
A recording medium product on which a program code for performing the method according to any one of claims 1 to 5 is recorded.
In the scheduling device included in the distributed energy resources forming a dynamic virtual power plant,
A communication unit for obtaining a set including a target amount of global power generation and a plurality of power profiles;
Including a scheduling unit for determining a power profile to maximize the profit of the distributed energy resource using the set,
The scheduling unit,
In adjusting the power profile of the distributed energy resource to meet the global power production target amount by referring to the power profile of the other distributed energy resource, the difference between the profit according to the power profile of the other distributed energy resource and the distributed energy resource is within an allowable value. And adjusting the power profile of the distributed energy resource so that it is possible.
The method of claim 7,
The distributed energy resource comprises at least one of at least one electric vehicle (EV), an energy storage device, a solar discharge system, and a home appliance.
The method of claim 7,
The scheduling unit,
And adjusting the power profile of the distributed energy resource by referring to the power profile of the other distributed energy resource so that the sum of the power amounts according to the power profile of each distributed energy resource approaches the global power production target amount.
In the dynamic virtual power plant,
A first distributed energy resource; And
Including a second distributed energy resource,
Each of the first distributed energy resource and the second distributed energy resource,
The first distributed energy resource and the second distributed energy resource by referring to the power profile of adjacent distributed energy resources so that the amount of local power produced by each of the first distributed energy resource and the second distributed energy resource meets a global power production target amount. Dynamic virtual power plant, characterized in that the power profile is derived so that the difference in profit according to the power profile of is within a tolerance.
The method of claim 10,
Each of the first distributed energy resource and the second distributed energy resource,
A dynamic virtual power plant, characterized in that selecting a power profile that maximizes the profit of each of the first distributed energy resource and the second distributed energy resource from among a plurality of power profiles.

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