WO2024106665A1

WO2024106665A1 - Dc community power bidding and trading system

Info

Publication number: WO2024106665A1
Application number: PCT/KR2023/009184
Authority: WO
Inventors: 김창수; 최상봉
Original assignee: 한국전기연구원
Priority date: 2022-11-16
Filing date: 2023-06-29
Publication date: 2024-05-23
Also published as: KR20240072441A

Abstract

A DC community power bidding and trading system comprises a DC distribution network and a power bidding and trading control unit. The DC distribution network connects one or more electric vehicle charging stations, one or more buildings having solar power generators, and one or more energy storage devices. The power bidding and trading control unit preferentially allocates power produced by the solar power generators to the buildings in which the solar power generators are installed. In addition, if power remains after the preferential allocation, the power bidding and trading control unit can allocate the remaining power to other buildings and the energy storage devices in proportion to the amount of power bid, schedules same-day power trading through bidding one day in advance, and if a power trading supply-demand imbalance occurs on the current day, can adjust the supply-demand imbalance through the energy storage devices.

Description

DC Community Power Bidding Trading System

An embodiment of the present disclosure relates to a power bidding and trading system. Specifically, power suppliers and power users connected to the DC distribution network are organized into one DC community, and efficient power use is achieved through power trading between neighbors within the DC community. It relates to a DC community power bidding and trading system that can promote.

Distributed solar power generation (PV: Photovoltaics) is rapidly increasing due to the expansion of renewable energy supply and the RE100 policy. Solar power generation is installed at load centers such as rooftops of city buildings and outdoor parking lots, faithfully serving as a distributed power source.

Meanwhile, in order to alleviate the output volatility of solar power generation, the installation of energy storage systems (ESS) linked to solar power is increasing.

It is more efficient to supply power from solar power generators and energy storage devices through direct current (DC) rather than the traditional alternating current (AC) method, and in recent years, the number of DC-consuming power devices has been increasing in terms of power use.

In response to these environmental changes, DC distribution research is being actively conducted to efficiently utilize power supplied from solar power generators, energy storage devices, etc.

Meanwhile, the cost of maintaining supply and demand balance in the central system is increasing as it is difficult to predict power generation at a national level. As a result, it is possible to operate independent supply and demand separated from the AC grid and use power in local communities through neighboring power transactions (Peer-to-Peer (P2P) method) between prosumers within the power grid (e.g. DC community distribution grid). Research to improve efficiency is also being conducted in parallel.

However, in the operation of local DC community distribution networks, the expansion of small-scale distributed power sources such as solar power generators can lead to uncertainty in power generation output (e.g., when supply is insufficient compared to demand due to limitations in supply facilities such as solar power generators within the DC community). It is difficult to maximize the efficiency of power use through general power transactions between prosumers, such as market price formation within the DC community.

The embodiment of the present disclosure seeks to provide a DC community power bidding and trading system that can increase power use efficiency through special power trading between prosumers by linking solar power generators, ESS, electric vehicle chargers, etc. within the DC community.

An embodiment of the present disclosure seeks to provide a DC community power bidding and trading system that can provide reliability to power trading within the community despite the power volatility of solar power generators.

In addition, the embodiment of the present disclosure seeks to provide a DC community power bidding trading system in which DC community participants can achieve mutual win-win in terms of economic efficiency.

The DC community power bidding and trading system according to an embodiment of the present disclosure includes a DC distribution network, a power bidding and trading control unit, and the like.

A DC distribution network can connect one or more electric vehicle charging stations, one or more buildings equipped with solar generators, and one or more energy storage devices.

The power bidding and transaction control department can preferentially allocate power produced by solar power generators to buildings where solar power generators are installed.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may preferentially allocate stored power of the energy storage device to the electric vehicle charging station.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may set the price of power supplied by the energy storage device to the electric vehicle charging station at a single price.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit first allocates power produced by the solar power generator to the building where the solar power generator is installed, and if there is any power remaining, the remaining power is transferred to the energy storage device as the bid power amount. It can be allocated proportionally.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit first allocates the power produced by the solar power generator to the building where the solar power generator is installed, and if there is any power remaining, the remaining power is distributed to other buildings and energy storage devices. It can be allocated in proportion to the amount of electricity bid.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit schedules the same-day power trading through bidding a day in advance, and when a power trading supply and demand imbalance occurs on the same day, the supply and demand imbalance is corrected through an energy storage device. It can be adjusted.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may limit the bidding power amount of buildings and electric vehicle charging stations to be lower than the amount of power used the day before the bidding by a set percentage.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may control power trading scheduling and power supply and demand one day in advance by unit transaction time.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit connects the energy storage device to the external distribution network, and when a supply and demand imbalance occurs in the DC distribution network, the energy storage device receives external power from the external distribution network. It can be received, converted to DC power, and then supplied to the DC distribution grid.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may set the bidding price of the DC distribution network lower than the external price of the external distribution network.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit may set the bidding price of the DC distribution network to a single price.

In the DC community power bidding and trading system according to an embodiment of the present disclosure, the power bidding and trading control unit connects the building to an external distribution network and can supply external power to the building from the external distribution network when an imbalance in power supply and demand occurs in the building.

According to an embodiment of the present disclosure, the efficiency of power use can be greatly increased by converting power transactions between prosumers within the DC community to a preferential allocation method in consideration of the characteristics of the DC community.

According to an embodiment of the present disclosure, even if there is a change in solar power generation power, the energy storage device can further increase the reliability of power trading in the DC community by adjusting the imbalance in power supply and demand.

In addition, according to the embodiment of the present disclosure, participants in the DC community (buildings, electric vehicle charging stations, etc.) can use electricity at a low price, creating a win-win situation in terms of economic efficiency.

1 is a configuration diagram of a DC community power bidding and trading system according to an embodiment of the present disclosure.

Figure 2 illustrates a method of pre-scheduling power trading in a DC community power bidding and trading system according to an embodiment of the present disclosure.

Figure 3 illustrates power trading optimization through an energy storage device in a method of pre-scheduling power trading using a DC community power bidding trading system according to an embodiment of the present disclosure.

Figure 4 illustrates a method of adjusting supply and demand imbalance in the process of executing power trading in the DC community power bidding and trading system according to an embodiment of the present disclosure.

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to illustrative drawings.

In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present disclosure, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present disclosure, the detailed description may be omitted. When “comprises,” “has,” “consists of,” etc. mentioned in the specification are used, other parts may be added unless “only” is used. When a component is expressed in the singular, it can also include the plural, unless specifically stated otherwise.

Additionally, in describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being “connected,” “coupled,” or “connected,” the two or more components are directly “connected,” “coupled,” or “connected.” ", but it should be understood that two or more components and other components may be further "interposed" and "connected," "combined," or "connected." Here, other components may be included in one or more of two or more components that are “connected,” “coupled,” or “connected” to each other.

In the explanation of temporal flow relationships related to components, operation methods, production methods, etc., for example, temporal precedence relationships such as “after”, “after”, “after”, “before”, etc. Or, when a sequential relationship is described, non-continuous cases may be included unless “immediately” or “directly” is used.

On the other hand, when a numerical value or corresponding information (e.g. level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or corresponding information is related to various factors (e.g. process factors, internal or external shocks, It can be interpreted as including the error range that may occur due to noise, etc.).

The DC community power bidding and trading system according to an embodiment of the present disclosure may include a DC distribution network 100, an external distribution network 200, and a power bidding and trading control unit 300.

The DC distribution network 100 consists of a certain area as a DC community and connected to a DC network, including one or more buildings (B1 to B3) equipped with solar power generators (PV1 to PV3), and buildings without solar power generators. (B4), one or more electric vehicle charging stations (EV1, EV2), one or more energy storage devices (ESS1, ESS2), etc. can be connected.

Solar power generators (PV1~PV3) are installed on the rooftops of buildings (B1~B3) to produce DC power. They can be used by connecting multiple panel-type modules with multiple solar cells to form an array. You can.

Solar power generators (PV1 to PV3) can selectively supply produced power to buildings (B1 to B4), electric vehicle charging stations (EV1 and EV2), energy storage devices (ESS1 and ESS2), etc., but in the embodiment of the present disclosure, power is used. In order to greatly increase the efficiency, power is first supplied to buildings (B1 to B3) where solar power generators (PV1 to PV3) are installed, and if power remains, it is first supplied to energy storage devices (ESS1, ESS2), or other buildings and energy storage devices. It can be allocated and supplied to (ESS1, ESS2) according to a certain ratio.

The electric vehicle charging station (EV1, EV2) charges DC power to the electric vehicle and can receive electricity from solar power generators (PV1 to PV3), energy storage devices (ESS1, ESS2), etc. within the DC distribution network 100. In the embodiment of the present disclosure, in order to greatly increase the efficiency of power use, it can be configured to receive priority supply from the energy storage devices (ESS1 and ESS2).

Energy storage devices (ESS1, ESS2) receive and store power from solar power generators (PV1~PV3), external distribution networks (200), etc., and then store it when power is needed in buildings (B1~B4), electric vehicle charging stations (EV1, EV2), etc. can be supplied when

Energy storage devices (ESS1, ESS2) can be composed of a battery that stores electricity, a PCS (Power Conditioning System) that manages the battery, an EMS (Energy Management System), and a BMS (Battery Management System).

The external distribution network 200 is selectively connected to the DC distribution network 100 to use external power, and may be an AC power grid such as the KEPCO distribution network or a DC power grid such as a neighboring DC distribution network (not shown).

The external distribution network 200 is connected to buildings (B1 to B4), energy storage devices (ESS1, ESS2), etc., and selectively AC It can supply electric power or DC power.

The power bidding transaction control unit 300 receives bids for the required power from buildings (B1 to B4) and electric vehicle charging stations (EV1, EV2), and provides the required power to the buildings (B1 to B4) and electric vehicle charging stations (EV1, EV2) according to the allocation criteria. is allocated, and the allocated power can be supplied from solar power generators (PV1~PV3) and energy storage devices (ESS1, ESS2).

The power bidding transaction control unit 300 may preferentially allocate power produced by solar power generators (PV1 to PV3) to buildings (B1 to B3) in which the solar power generators (PV1 to PV3) are installed. In this case, the bidding conditions of buildings (B1 to B3) where solar power generators (PV1 to PV3) are installed, i.e., required amount of electricity, electricity price, etc., may not be considered.

The power bidding transaction control unit 300 first allocates the solar power generators (PV1 to PV3) to the buildings (B1 to B3) installed, and if there is any remaining power, first allocates the remaining power to the energy storage devices (ESS1 and ESS2), or It can be allocated to other buildings and energy storage devices (ESS1, ESS2) according to allocation criteria. Here, the allocation standard can be allocated in proportion to the amount of bid power if the bid prices are the same (e.g., when the power price within the DC distribution network is set to a single price), and if the bid prices are considered together, the bid price is higher. The amount of electricity bid can be allocated to the bidder first.

When the stored power of the energy storage devices (ESS1 and ESS2) exceeds the set power, the power bidding transaction control unit 300 may allocate the remaining power to the electric vehicle charging stations (EV1 and EV2). Even in this case, the remaining power can be allocated according to predetermined allocation criteria. When the bid prices are the same, the allocation criteria is proportional to the amount of bid power. If the bid prices are also considered, the bidder with the higher bid price can be allocated the amount of bid power first.

The power bidding transaction control unit 300 may preferentially allocate the stored power of the energy storage devices (ESS1 and ESS2) to the amount of bid power required by the electric vehicle charging stations (EV1 and EV2). In this case, the power bidding transaction control unit 300 bids all of the bid power to the electric vehicle charging stations (EV1 and EV2) at a single price, without considering the bidding conditions of the electric vehicle charging stations (EV1 and EV2), that is, the bid power amount and bid price. , or it can be allocated in proportion to the amount of electricity bid.

The power bidding transaction control unit 300 first allocates the stored power of the energy storage devices (ESS1 and ESS2) to the electric vehicle charging stations (EV1 and EV2) and, if there is any remaining power, bids the remaining power to the buildings (B1 to B4). That is, allocation can be made based on bid power amount, bid price, etc. As for allocation conditions, the required amount of power can be allocated first in the order of the highest bid price.

The power bidding transaction control unit 300 may schedule power trading on the same day (the day after the bidding date) through bidding one day in advance. During the bidding process, the power bidding transaction control unit 300 may limit the bidding power amount of buildings (B1 to B4) and electric vehicle charging stations (EV1, EV2) to be lower than the amount of power used the previous day by a set percentage (e.g., 10%). Through this, it is possible to prevent the daily power consumption of buildings (B1 to B4) or electric vehicle charging stations (EV1, EV2) from being less than the bid power amount. In this case, if a supply and demand imbalance occurs in the same-day power transaction, the power bidding transaction control unit 300 transfers the stored power of the energy storage devices (ESS1 and ESS2) to the buildings (B1 to B4) where the supply and demand imbalance occurred and the electric vehicle charging station (EV1 and EV2). ), the supply-demand imbalance (lack of required electricity) can be resolved by supplying in proportion to the amount of electricity bid.

The power bidding transaction control unit 300 may control the unit transaction time by setting the power transaction scheduling to a unit transaction time, for example, 5 minutes, 15 minutes, 30 minutes, 1 hour, etc. Here, the preferred unit transaction time can be set to 5 minutes.

The power bidding transaction control unit 300 connects the energy storage devices (ESS1 and ESS2) to an external distribution network 200 such as the KEPCO distribution network and an adjacent community distribution network, and when a supply and demand imbalance occurs in the DC distribution network 100, the External power can be received from the distribution network 200, converted to DC power in the energy storage devices ESS1 and ESS2, and then controlled to be supplied to the DC distribution network 100.

The power bidding transaction control unit 300 may set the bid price (electricity price) of the DC distribution network 100 to be lower than the external price (electricity price) of the external distribution network 200, for example, at 90% of the external price. .

The power bidding transaction control unit 300 may set the bidding price of the DC distribution network 100 to a single price (90% of the external price).

The power bidding transaction control unit 300 connects the buildings (B1 to B4) with the external distribution network (200), and when an imbalance in power supply and demand occurs in the buildings (B1 to B4), external power is transmitted from the external distribution network (200) to the building (B1). It can be controlled to supply to ~B4).

As shown in FIG. 2, the method of pre-scheduling power trading in the DC community power bidding trading system according to an embodiment of the present disclosure first determines the power generation amount of participating solar power generators (PV1 to PV3) and the building (B1). The load of ~B4) and the load of electric vehicle charging stations (EV1, EV2) are predicted for 24 hours (generation amount, load) in unit transaction time, for example, in 5-minute increments, based on usage data the day before the bid or over a certain period of time. (S11).

In step S12, solar power generators (PV1 to PV3) make sales bids in 5-minute increments based on the predicted power generation in step S11, and buildings (B1 to B4) make sales bids in 5-minute increments based on the predicted load in step S11. Purchase bids are made in minutes, and electric vehicle charging stations (EV1 and EV2) execute purchase bids in 5-minute increments based on the predicted load in step S11.

In step S13, the sales bid for solar power generators (PV1 to PV3) is assigned priority to the purchase bid for the building (B1 to B3) equipped with the solar power generator (PV1 to PV3) to execute a priority contract, and the electric vehicle The purchase bid for the charging station (EV1, EV2) executes the contract first by supplying power to the energy storage device (ESS1, ESS2).

In step S14, if there is a shortage of purchases of buildings (B1 to B4) and a surplus in sales of solar power generators (PV1 to PV3) and energy storage devices (ESS1, ESS2), in step S15 the energy storage device ( Optimize power trading supplied from ESS1, ESS2) to buildings (B1~B4). For example, the sales surplus of solar power generators (PV1~PV3) is first allocated in proportion to the purchase shortage of buildings (B1~B4), and then energy storage devices (ESS1, ESS2) are added to buildings (B1~B4). Additional allocations may be made for purchase shortfalls.

In step S15, the sales price of the energy storage devices ESS1 and ESS2 may be set to 90% or less of the power price of the external distribution network 200. To this end, the energy storage devices ESS1 and ESS2 can purchase external power from the external distribution network 200 at the point when the power price in the external distribution network 200 is lowest. For example, when the external distribution network 200 is the KEPCO distribution network, the energy storage devices ESS1 and ESS2 can purchase and store late-night power at the lowest price through the KEPCO distribution network.

In step S16, a supply contract is completed between the buildings (B1 to B4) and the energy storage devices (ESS1 and ESS2) based on the optimization transaction in step S15, and in the subsequent step (S17), all participants, i.e. solar The transaction contract between photovoltaic generators (PV1~PV3), buildings (B1~B4), electric vehicle charging stations (EV1, EV2), and energy storage devices (ESS1, ESS2), that is, same-day power transaction scheduling, is completed in 5 minutes.

As shown in FIG. 3, when the purchase/sale bid in step S21 and the priority contract for buildings (B1 to B3) equipped with solar power generators (PV1 to PV3) in step S22 are made, step S23 ), the process of proportionally allocating the remaining power of solar power generators (PV1 to PV3) to the remaining purchases of buildings (B1 to B4) and energy storage devices (ESS1 and ESS2) can be carried out.

In the process of allocating the remaining power from solar power generators (PV1 to PV3) to buildings (B1 to B4), a purchase shortage (power shortage) or a sales surplus (power surplus) may occur. In this case, as in steps S24 and S25, when a sales surplus occurs, the surplus power is sent to the energy storage devices (ESS1 and ESS2) for storage, and when a purchase shortage occurs, the stored power of the energy storage devices (ESS1 and ESS2) ( First allocate to electric vehicle charging stations (EV1, EV2) and the remaining stored power can be allocated in proportion to the purchase shortage of buildings (B1 to B4).

Meanwhile, as shown in FIG. 3, when the stored power of the energy storage devices (ESS1 and ESS2) is insufficient, the lowest price (e.g., late-night power) is charged from an external distribution network (e.g., KEPCO distribution network, other DC distribution network, etc.). You can purchase and save more.

As shown in FIG. 4, in the process of using power according to pre-scheduling as in step S31, a supply and demand imbalance (transaction difference, that is, actual power use difference) may occur as in step S32. In this case, as in step S33, the power supply and demand imbalance between the buildings (B1 to B4) and the electric vehicle charging stations (EV1 and EV2) can be adjusted using the stored power of the energy storage devices (ESS1 and ESS2). Therefore, in the embodiment of the present disclosure, it is desirable for the energy storage devices ESS1 and ESS2 to secure a level of stored power that can overcome the supply and demand imbalance error.

Meanwhile, in the embodiment of the present disclosure, a penalty may be imposed on buildings (B1 to B4) and electric vehicle charging stations (EV1 and EV2) that cause power supply and demand imbalance beyond the error range. The penalty may be a decrease in the power allocation ranking or a reduction in the amount of successful bid power by a certain ratio to the amount of bid power.

The above description is merely an illustrative explanation of the technical idea of the present disclosure, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present disclosure. In addition, the embodiments disclosed in the present disclosure are not intended to limit the technical idea of the present disclosure, but rather are for explanation, and therefore the scope of the technical idea of the present disclosure is not limited by these embodiments. The scope of protection of this disclosure should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this disclosure.

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application claims priority under Article 119(a) of the U.S. Patent Act (35 U.S.C. §119(a)) to Patent Application No. 10-2022-0153945 filed in Korea on November 16, 2022. All contents are hereby incorporated by reference into this patent application. In addition, this patent application claims priority for countries other than the United States for the same reasons as above, and the entire contents thereof are incorporated into this patent application by reference.

Claims

A DC distribution network connecting one or more electric vehicle charging stations, one or more buildings equipped with solar power generators, and one or more energy storage devices;

A DC community power bidding transaction system comprising a power bidding transaction control unit that preferentially allocates power produced by the solar generator to a building in which the solar generator is installed.
The method of claim 1, wherein the power bidding transaction control unit

A DC community power bidding transaction system that prioritizes the stored power of the energy storage device to the electric vehicle charging station.
The method of claim 2, wherein the power bidding transaction control unit

A DC community power bidding transaction system that sets the price of power supplied by the energy storage device to the electric vehicle charging station at a single price.
The method of claim 2, wherein the power bidding transaction control unit

A DC community power bidding transaction system that first allocates power produced by the solar power generator to the building where the solar power generator is installed and, if power remains, allocates the remaining power to the energy storage device in proportion to the amount of bid power.
The method of claim 2, wherein the power bidding transaction control unit

A DC community power bidding transaction system that first allocates power produced by the solar power generator to the building where the solar power generator is installed and, if power remains, allocates the remaining power to other buildings and the energy storage device in proportion to the amount of bid power.
The method of any one of claims 1 to 5, wherein the power bidding transaction control unit

Schedule same-day power transactions through bidding one day in advance,

A DC community power bidding trading system that adjusts the supply and demand imbalance through the energy storage device when an imbalance in power trading supply and demand occurs on the same day.
The method of claim 6, wherein the power bidding transaction control unit

A DC community power bidding transaction system that limits the bidding power amount of the building and electric vehicle charging station to a set ratio lower than the amount of power used the day before the bidding.
The method of claim 6, wherein the power bidding transaction control unit

A DC community power bidding transaction system that schedules power transactions the day before and controls power supply and demand on the same day by unit transaction time.
The method of claim 6, wherein the power bidding transaction control unit

By connecting the energy storage device to an external distribution network, when a supply and demand imbalance occurs in the DC distribution network, the energy storage device receives external power from the external distribution network, converts it into DC power, and supplies it to the DC distribution network. DC Community Power Bidding Trading System.
The method of claim 9, wherein the power bidding transaction control unit

A DC community power bidding transaction system that sets the bidding price of the DC distribution network lower than the external price of the external distribution network.
The method of claim 10, wherein the power bidding transaction control unit

A DC community power bidding trading system that sets the bidding price of the DC distribution network to a single price.
The method of claim 9, wherein the power bidding transaction control unit

A DC community power bidding transaction system that connects the building to the external distribution network and supplies external power to the building from the external distribution network when a power supply/demand imbalance occurs in the building.