KR102337562B1 - Simulator and simulation method for establishing optimal operating plan of pv-ess system of grid-connected sales operator in commercial virtual power plant - Google Patents

Abstract

The present invention relates to a simulator and a simulation method for establishing an optimal operating plan of a photovoltaic energy storage system (PV-ESS) of a grid-connected sales operator in a commercial virtual power plant for profit creation. According to the present invention, time-specific backfeed cost calculation is performed in a PV-ESS-connected system in a commercial virtual power plant to calculate the maximum backfeed cost value. As a result, the time-specific discharge amount (backfeed amount) can be determined and the sales operator's profit can be maximized.

Description

A simulator and a simulation method for establishing an optimal operation plan for a grid-connected sales operator's PV-ESS system in a commercial virtual power plant system COMMERCIAL VIRTUAL POWER PLANT}

The present invention is to establish an optimal operation (operation) plan of a PV-ESS (Photovoltaic-Energy Storage System) system of a grid-connected sales operator within a commercial virtual power plant (C-VPP) system for profit creation. As a simulator and a simulation method for In the commercial virtual power plant (C-VPP) system that can maximize the sales operator's profits by calculating the maximum value of the transport cost by it's about

Virtual Power Plant (VPP) is a system for connecting and controlling various Distributed Energy Resources (DERs) using Information and Communication Technology (ICT) and automatic control technology to operate as a single power plant. ), which integrates distributed energy resources (DER) into a cloud-based platform, connects with the system operating system, and operates by remote control using sensors.

1 is a conceptual diagram of a general virtual power plant.

As shown in FIG. 1, a virtual power plant (VPP) integrates distributed energy resources (DER) such as small-scale renewable energy power generation facilities and energy storage systems (ESS) scattered by region using cloud-based software to form a single power plant. As a management system, it is possible to optimize the operation and management of distributed energy resources by integrating and operating various distributed energy resources (DERs) like a single power plant through networking using information and communication technology.

A virtual power plant (VPP) is not a power plant physically located in a specific place, but has the same effect as supplying electricity, and solves technical problems in system operation that may occur due to the recent increase in distributed energy resources (DER) and provides integrated resources. economic value can be created. This is a representative business model of the BTM (Behind-The-Meter or Beyond-The-Meter) market that produces and trades electricity at the bottom of the meter at the end of the distribution system.

2 is a structural diagram of a general virtual power plant.

As shown in Figure 2, the virtual power plant (VPP) is a demand-based VPP (Demand Side VPP) and a supply-based VPP (Supply Side VPP) according to the configuration of the distributed energy resource (DER), and a commercial VPP (Commercial-VPP) according to the purpose of use It can be classified into technical-VPP (Technical-VPP) and each mixed type is also possible. Among them, commercial VPP (C-VPP) is a power plant whose purpose is to generate profits by participating in the power market as a central feed generator of a small-scale distributed energy resource (DER).

Renewable energy that uses solar power and wind power as energy sources is a representative distributed energy resource (DER). However, since distributed energy resources (DER) use solar and wind power as energy sources, they are greatly affected by climatic factors. In the end, it is necessary to establish an optimal operation plan for the PV-ESS system that can maximize the profit of the grid-connected seller within the commercial VPP system due to the uncertainty of the amount of generation of distributed energy resources (DER) and the amount of electricity demand.

Meanwhile, in Korea, there is a trend to actively supply PV (Photovoltaic), one of renewable energies, through the Renewable Energy 3020, the 8th Basic Plan for Power Supply and Demand, and the 2nd National Energy Basic Plan. In particular, when PV and ESS (Energy Storage System) are connected and operated, a high Renewable Energy System (Renewable Energy System) weight is given.

Most of the PV-ESS system operation methods of grid-connected sales operators are optimized for Korea's PV support policy. The operation method currently applied to the PV-ESS system is usually based on the 'SMP (System Marginal Pirce) + REC (Renewable Energy Certificates)' weight from a specific time to a specific time in PV. All of the generated power is charged in the ESS, and after a certain time, all of it is sent back to Korea Electric Power (KEPCO).

This conventional PV-ESS system operation method determines the optimal operation plan of the PV-ESS system based on external factors such as the currently applied electricity rate method, REC support policy, and SMP (system limit price). Although it is possible to improve the efficiency to some extent, the optimal operation method of this conventional PV-ESS system was insufficient in maximizing profits from the viewpoint of increasing the profits of sales operators within the commercial VPP system.

In addition, as the optimal operation technology of the conventional virtual power plant, it is a model that assumes that the generation of revenue or the use of resources changes in a linear ratio. Based on Integer Linear Programming (MILP), a technique to apply the meta-heuristic method according to the size of the problem and the optimization cycle has been proposed. There was a limit to maximizing profits.

KR 10-1770064 B1, 2017. 08. 14., "Virtual power plant simulator and optimal operation simulation method for virtual power plant". KR 10-1813836 B1, 2017. 12. 22., "A method for simulating the optimal operation of a virtual power plant using a virtual power plant simulator". KR 10-1636411 B1, 2016. 06. 29., "A device for generating an optimal operation plan model of a virtual power plant (VPP), and a method for generating an optimal operating plan model using a device for generating an optimal operation plan model of a virtual power plant (VPP)".

Young-Hyeok Cho, Seung-Yeop Baek, Dae-Yul Jeong, Won-Yong Choi (2018), Case Study of Renewable Energy-focused Virtual Power Plant (VPP) Element Technology Development, Korean Society for Management and Information Science. Young-hyeok Cho, Seung-yeop Baek, Dae-yul Jeong, Won-yong Choi (2018), A case study on the development of renewable energy-focused virtual power plant (VPP) element technology, the Korean Society for Management and Information Studies, virtual power plant operation strategy optimization technology.

In order to maximize the profit of the sales operator within the commercial VPP system, factors affecting the efficiency improvement should be reflected when establishing the optimal operation plan of the PV-ESS system. In other words, factors that change according to changes in PV generation and power demand according to climatic factors should be reflected when establishing the optimal operation plan for the PV-ESS system of the grid-connected seller.

However, in the operation method of the PV-ESS system of the grid-connected sales operator according to the prior art, there is a limit in providing the optimal operation efficiency because the change value of the factors that change the PV power generation amount is not reflected when the operation plan is established. In other words, there was a limit to efficiency as the operation plan was established by reflecting only the current electricity rate method, the current REC support policy, and SMP.

Therefore, the present invention considers REC weight, ESS charging capacity (maximum charging capacity), PCS (Power Conversion System) capacity, and PV power production to operate a PV-ESS system within a commercial virtual power plant (C-VPP) system. The purpose of this is to provide a simulator and a simulation method for establishing the optimal operation plan of the PV-ESS system of the grid-connected sales operator within the commercial virtual power plant system that can maximize the sales operator's profits.

In the present invention for achieving the above object, the ESS (Energy Storage System) charging time zone is located within the PV (Photovoltaic) power production start time zone to the end time zone, and the ESS discharge time zone including the PV power production start time zone is the ESS charging time zone In the simulator for establishing the optimal operation plan of the PV-ESS-linked system of the sales operator in the commercial virtual power plant system, the REC weight is large compared to an ESS accumulated charge calculation unit that accumulates the amount of charge charged in the ESS from the start time of PV power production that starts to produce electricity in a charging capacity excess determination unit for determining whether the ESS maximum charging capacity is exceeded by comparing the ESS accumulated charging amount for each time period calculated by the ESS accumulated charging quantity calculating unit and the ESS maximum charging capacity, respectively; As a result of the determination of the charging capacity excess determination unit, if the ESS accumulated charging amount exceeds the ESS maximum charging capacity, calculating the marginal transport cost for each time period within the previous time period of the first time when the ESS accumulated charging amount exceeds the ESS maximum charging capacity marginal return cost calculator; The ESS accumulated charging amount of the first time period is fixed to the ESS maximum charging capacity, and within the range from the start time of power production of the PV to the first time period, the marginal reverse transfer of the limiting transfer cost for each time period calculated through the limit transfer cost calculation unit an ESS discharge amount calculation unit that calculates the ESS discharge amount for each time period according to a preset operating condition in the order of the costly time period; Based on the marginal transport cost calculated through the marginal transport cost calculator, the ESS discharge amount calculated by the ESS discharge amount calculator for each time period is multiplied by the marginal transport cost for the corresponding time period according to the operating conditions and a return charge calculation unit for calculating a total return charge for each operation condition by summing up the return charges calculated according to the driving conditions; and the total reverse charge calculated for each operation condition is compared with each other through the reverse charge calculation unit to select the operating condition with the highest total return charge, and the ESS discharge amount calculated under the selected operation condition is used as the ESS optimal discharge amount to optimize the ESS It provides a simulator for establishing an optimal operation plan of a PV-ESS system of a grid-connected sales operator within a commercial virtual power plant system, characterized in that it includes an ESS optimal operation plan determining unit that determines an operation plan.

In addition, the operating conditions are CASE1, which calculates all of the power production produced in the PV power production start time zone as the ESS discharge amount, the PV power production start time zone, and the ESS charging time zone in the previous time zone of the first time zone. and CASE2 for calculating the amount of ESS discharge in each time period in which the marginal reversal cost is greatest, and the ESS discharge amount calculation unit calculates the same capacity as the amount of power produced in the PV power production start time in the CASE1 in the PV power production start time zone. Calculated as the ESS discharge amount to be discharged in _, and in CASE2, the excess capacity exceeding the ESS maximum charging capacity is calculated as the ESS discharge amount at the PV power production start time, and then the power produced in the PV power production start time Calculating the amount of ESS discharge to discharge the remaining capacity after subtracting the excess capacity exceeding the ESS maximum charging capacity in the time period with the greatest marginal transport cost in the time period preceding the first time period within the range of the ESS charging time period. can do.

In addition, the ESS discharge amount calculation unit calculates the ESS accumulated charge amount in the excess time period exceeding the ESS maximum charge capacity again when the ESS accumulated charge amount again exceeds the ESS maximum charge capacity in the time period after the first time period. fixed to the capacity, and sequentially calculates the amount of ESS discharge to be discharged for each time period with a large marginal transport cost during the previous time period in excess of the ESS maximum charging capacity, and the ESS discharge amount calculation unit calculates the ESS accumulated charge amount after the excess time If the ESS maximum charging capacity is exceeded again and the time period is the first or second time period after the ESS charging time period, the ESS accumulated charge amount of the first or second time period is fixed as the ESS maximum charging capacity and sequentially calculates the ESS discharge amount for each time zone with the largest marginal transport cost among the previous time zones of the first or second time zone, and the ESS discharge amount calculation unit calculates the ESS accumulated charge amount in the time zone after the first or second time zone. In the case of the same as the ESS maximum charging capacity, it may be characterized in that the PCS (Power Conversion System) maximum capacity is calculated as the ESS discharge amount in the corresponding time period.

In addition, the present invention for achieving the above object is that the ESS (Energy Storage System) charging time zone is located within the PV (Photovoltaic) power production start time zone to the end time zone, and the ESS discharge time zone including the PV power production start time zone is the ESS The REC weight is large compared to the charging time period, and the ESS starts charging from the time after the PV power production start time. In (a) the process of accumulating the amount of charge to be charged in the ESS from the PV power production start time period when the PV starts to produce electric power, and calculating the ESS accumulated charge amount for each time period; (b) determining whether the ESS maximum charging capacity is exceeded by comparing the ESS accumulated charging amount for each time period calculated by the ESS accumulated charging amount calculation unit and the ESS maximum charging capacity, respectively; (c) as a result of the determination, when the ESS accumulated charging amount exceeds the ESS maximum charging capacity, calculating the marginal transport cost for each time period within the previous time period of the first time when the ESS accumulated charging amount exceeds the ESS maximum charging capacity; (d) fixing the ESS accumulated charging amount of the first time period to the ESS maximum charging capacity, and calculating the marginal return cost for each time period calculated through the limit transfer cost calculator within the range from the start time of power production of the PV to the first time period The process of calculating the amount of ESS discharge for each time period according to the preset operating conditions in the order of the time period in which the marginal transport cost is the largest; (e) Multiply the ESS discharge amount for each time period calculated by the ESS discharge amount calculation unit according to the operating conditions based on the marginal return cost calculated through the marginal return cost calculator and the marginal return cost for the time period, calculating each of , and summing up the station charges calculated according to the operating conditions to calculate a total station charges for each operating condition; and (f) comparing the total transport charges calculated for each operating condition through the reverse transport charge calculation unit, select the operating condition with the highest total transport charge, and use the ESS discharge amount calculated in the selected operating condition as the ESS optimal discharge amount including the process of determining the ESS optimal operation plan,

The marginal return cost provides a simulation method for establishing an optimal operation plan of the PV-ESS system of the grid-connected sales operator in the commercial virtual power plant system, characterized in that calculated by [Equation 1] below.

[Equation 1]

Marginal return cost = SMP + REC × REC unit price × REC weight

Here, it is SMP (System Marginal Pirce) and REC (Renewable Energy Certificates).

In addition, the operating conditions are CASE1, which calculates all of the power production produced in the PV power production start time zone as the ESS discharge amount, the PV power production start time zone, and the ESS charging time zone in the previous time zone of the first time zone. Including CASE2 that calculates the amount of ESS discharge in each time period with the largest marginal reversal cost, in the process (d), the PV power production starts with the same capacity as the power production in the PV power production start time in the CASE1 Calculated as the ESS discharge amount to be discharged in the time zone _, and in CASE2, the excess capacity exceeding the ESS maximum charging capacity is calculated as the ESS discharge amount in the PV power production start time, and then the power produced in the PV power production start time Calculating the amount of ESS discharge to be discharged from the production amount by subtracting the excess capacity that exceeds the maximum ESS charging capacity in the order of the time period with the greatest marginal return cost in the time period preceding the first time period within the ESS charging time range can be done with

In addition, in the process (d), when the ESS accumulated charge amount again exceeds the ESS maximum charge capacity in the time period after the first time period, the ESS accumulated charge amount in the excess time period exceeding the ESS maximum charge capacity again is set to the ESS maximum Fixed to the charging capacity, and sequentially calculating the amount of ESS to be discharged for each time period with a large marginal transport cost among the previous time periods in excess of the ESS maximum charging capacity, and in the process (d), the ESS after the excess time If the accumulated charging amount exceeds the ESS maximum charging capacity again, and the time period is the first or second time period after the ESS charging time period, the ESS accumulated charge amount of the first or second time period is set to the ESS maximum charging capacity , and sequentially calculate the amount of ESS discharge for each time zone with the largest marginal transport cost among the previous time zones of the first or second time zone, and in the process (d), ESS accumulation in the time period after the first or second time period When the charging amount is the same as the ESS maximum charging capacity, it may be characterized in that the PCS (Power Conversion System) maximum capacity is calculated as the ESS discharge amount in the corresponding time period.

As described above, according to the simulator and the simulating method according to the present invention, when establishing the optimal operation plan of the PV-ESS-linked system of the sales operator within the commercial virtual power plant (C-VPP) system, REC weight, ESS by time period By optimizing the ESS discharge amount by calculating the discharge time period and the ESS discharge amount (reverse transfer amount) at which the reverse charge is the maximum in consideration of the accumulated charge capacity, the maximum ESS charge capacity, the maximum PCS (Power Conversion System) capacity, and the PV power production. When operating a PV-ESS-linked system within a commercial virtual power plant (C-VPP) system, it is possible to maximize the sales operator's profits.

1 is a conceptual diagram of a general virtual power plant.
2 is a structural diagram of a general virtual power plant.
3 is a block diagram of a simulator according to an embodiment of the present invention;
4 to 6 are diagrams illustrating driving conditions of a simulator according to an embodiment of the present invention.
7 and 8 are flowcharts of a simulation method according to an embodiment of the present invention.
9 to 13 are diagrams illustrating characteristics of a PV-ESS system to which a simulation method according to an embodiment of the present invention is applied.
14 to 30 are diagrams graphing the results of [Table 1] to [Table 17].

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

In this specification, the ESS discharge amount and the ESS backflow amount are mixed for convenience of explanation, but are interpreted as the same meaning. In addition, the return charge and the return charge are also interpreted as the same meaning.

In order to maximize the profit of the seller in the PV-ESS system of the grid-connected seller within the commercial virtual power plant (C-VPP) system, it is necessary to transfer the equipment back during the time when the transfer cost is maximum. Therefore, in the present invention, the optimal operation plan of the PV-ESS system is established through an algorithm that maximizes the transport cost, thereby maximizing the profit of the sales operator.

In the present invention, in order to maximize the profit of the grid-linked sales operator within the commercial virtual power plant (C-VPP) system, the maximum value of the reverse transport cost is obtained by calculating the transport fee for each time period. At this time, in order to calculate the retransmission cost, it is calculated by considering the REC weight when retransmitting in the linked sales business among the ESS sales businesses. And, in order to maximize the cost of the reverse transfer, the amount of discharge (reverse transfer) for each time period is determined according to the amount of PV power production and the amount of charge of the ESS.

In the present invention, the following four prerequisites must be satisfied when establishing the optimal operation plan of the PV-ESS system to maximize the profit of the seller or operator of the PV-ESS system.

(1) Premise 1: Since the ESS installation cost is relatively expensive compared to the PV installation cost, if the maximum ESS charging capacity is larger than that of storing all the PV power produced in one day, the economic feasibility is lowered. Therefore, in the PV-ESS-linked sales business, it is most profitable to reverse all electricity produced on the same day from PV, so all electricity produced on the same day is reversed. Here, 'the same day' is defined as the time from the time when the PV starts to produce power to the time before the time when the PV starts to produce power the next day.

(2) Premise 2: The current REC weight is 4 times from 17:00 to 10:00 the next day, and 1.5 times for the rest of the time zone (see FIG. 5). Therefore, in order to maximize the profit by maximizing the return charge, all ESSs are discharged until the time when the PV starts to produce electricity.

(3) Premise 3: The amount of ESS charging should be at its maximum capacity during the time when the reverse transport rate (marginal transport cost × reverse transport amount) is the most expensive. This is because, in the time when the station fee is the most expensive, the station charge can be maximized only when the amount of ESS charge reaches the maximum capacity (refer to FIG. 6 ).

(4) Premise 4: The capacity of the PCS (Power Conversion System) that can be transferred back to the maximum per day from the ESS must be equal to or greater than the PV power production per day. The reason is that, in 'Premise 1', the electricity generated from the PV on the same day is set to be transmitted back on the same day. After all, in order to discharge all the electricity produced in the PV and charged in the ESS in one day, the total capacity of the PCS must be equal to or greater than the maximum daily capacity.

The establishment of the optimal operation plan of the PV-ESS system of the grid-connected sales operator within the commercial virtual power plant (C-VPP) system of the present invention is to determine the optimal ESS operation (operation) plan while satisfying the above premises. That is, it can be optimized by determining the charge/discharge operation plan of the ESS in which the power produced by the PV of each time period can be charged to or discharged from the ESS at any time, and the back-transmission cost paid by the seller can be maximized.

First, in the present invention, the marginal return cost is proposed as an index (priority of the return period due to ESS discharge) for determining the optimal operation plan of the PV-ESS system of the grid-connected sales operator.

The marginal back-transmission cost can be calculated, for example, with a back-transmission fee meter, which is the amount paid by the seller (customer) when the power produced by the PV is back-returned. For example, it can be calculated by [Equation 1] below.

[Equation 1]

Marginal return cost = SMP + REC × REC unit price × REC weight

Based on this, it is possible to construct an optimal algorithm that maximizes the transport cost, and use this to establish an optimal operation plan for the PV-ESS system of the grid-connected sales operator.

Hereinafter, with reference to the accompanying drawings, a simulator and simulation for establishing an optimal operation plan of the PV-ESS system of the grid-connected sales operator within the commercial virtual power plant (C-VPP) system in which the profit of the connected sales operator is maximized The method will be explained.

3 is a configuration diagram of a simulator according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating an ESS charging time zone and a PV power production time zone in the PV-ESS system according to the present invention as an example.

As shown in Figure 4, for example, the power generation time zone ( t _{PV_int} ~ t _{PV_fin} ) of the PV ( 1 ) is set from 9:00 to 18:00, and the ESS charging time zone ( t _{ESS_int} ~ t _{ESS_fin} ) is from 10:00 to 16:00. Here, t _{PV_int} is the PV power generation start time zone, t _{PV_fin} is the PV power generation end time zone, and t _{ESS_int} is ESS charging start time, t _{ESS_fin} is It means the end time of ESS charging.

3 and 4, the simulator 10 according to the embodiment of the present invention operates the PV-ESS system of the grid-connected sales operator in the commercial virtual power plant (C-VPP) system, the sales operator's profit Establish an optimal operation plan for this maximizing PV-ESS system.

The simulator 10 according to the embodiment of the present invention accumulates the amount of charge for each time period charged in the ESS 2 within the time period ( t _{PV_int} ~ t _{PV_fin ) (see FIG. 4 ) in which the PV 1 generates power.} and an ESS accumulated charge calculation unit 11 for calculating the ESS accumulated charge amount ( ESS _{cum_charge ).}

The ESS accumulated charge calculation unit 11 calculates the ESS for each time zone within the PV power production time period ( t _{PV_int} ~ t _{PV_fin} ) when the ESS (2) only charges and does not discharge the power produced in the PV (1) on the same day. Calculate the accumulated charge ( ESS _{cum_charge ).} At this time, the time point at which the ESS accumulated charge amount ( ESS _{cum_charge} ) is calculated is from the time period ( t _{PV_int} ) when PV(1) starts power generation. This is because the electricity generated by PV(1) must be returned to KEPCO(3) on the same day (refer to 'Premise 1').

4 , as an example, when the time period ( t _{PV_int} ~ t _{PV_fin} ) in which the PV(1) generates power is 9:00 to 18:00, the time period in which the ESS(2) charges the power produced by the PV(1) ( t _{ESS_int} ~ t _{ESS_fin} ) is set from 10:00 to 16:00. In this case, the ESS accumulated charge calculation unit 11 sequentially accumulates the charge from _{9:00 to 24:00} , which is the PV power production start time zone ( t PV_int ), and from 1 pm to the time before the PV power production start time zone ( t _{PV_int -1).} to calculate the ESS accumulated charge ( ESS _{cum_charge ).}

The charge capacity excess determination unit 12 compares the ESS accumulated charge amount ( ESS _{cum_charge} ) by time period calculated by the ESS accumulated charge amount calculation unit 11 and the ESS maximum charge capacity ( ESS _{max_charge} ) to compare the ESS maximum charge capacity ( ESS _{max_charge} ) determining whether more than a, and if it exceeds, the first time (t _limit) fixed (set) to the maximum charge capacity ESS (ESS _{max_charge)} the accumulated charge ESS (ESS _{cum_charge)} from exceeding.

The marginal back-transmission cost calculation unit 13 calculates the marginal back- _transmission cost (back trans _kW ) per kW for each time in the previous time zone of the first time zone ( t _limit ) exceeding the ESS maximum charging capacity ( ESS max_charge ) for the first time. The marginal back-transmission cost per kW in time n can be obtained by [Equation 3] below.

FIG. 5 is a diagram illustrating REC weights in the ESS charging/discharging time zone shown in FIG. 4 , and FIG. 6 is a diagram illustrating the calculated marginal back-transmission cost in the ESS charging/discharging time zone shown in FIG. 4 .

The marginal forwarding cost calculator 13 calculates the marginal forwarding cost for each time zone based on the REC weight of the ESS charging/discharging time zone shown in FIG. 5 .

The ESS discharge amount calculation unit 14 calculates the limit retransmission cost for each time period calculated during the previous time period of the first time period t _limit that starts to exceed the ESS maximum charge capacity ( ESS _{max_charge ) (see [Equation 3] and FIG. 6)} ESS _discharge is calculated in the time period with the largest marginal transport cost.

The ESS discharge amount calculation unit 14 may calculate the ESS discharge amount by dividing it into two operating conditions (CASE1, CASE2). That is, the operating condition is discharged at the PV electricity generation start time (t _{PV_int)} to maximize profits because expensive backhaul limit compared to ESS charge time (t _{ESS_int} ~ t _{ESS_fin)} in the PV power generation start time (t _{PV_int)} relative to size It is decided by considering the amount of discharge to be performed first.

Operation condition 1 (CASE1)

As a driving condition for discharging all of the power output produced in the PV power generation start time (t _{PV_int),} the same capacity as the power output produced in the PV power generation start time (t _{PV_int)} in the PV power generation start time (t _{PV_int)} Calculate the amount of ESS _{discharge to be discharged ( ESS discharge ).} The reason is that, as described above, in the PV power production start time period ( t _{PV_int ), the marginal transport} cost is relatively large compared to the ESS charging time period (t _{ESS_int ~ t ESS_fin ).}

Operating condition 2 (CASE2)

_{Within the} PV power production start time zone ( t PV_int ) and the ESS charging time zone ( t _{ESS_int} ~ t _{ESS_fin} ), the operating condition for discharging the ESS during the time period with the largest marginal return cost in the previous time period of the first time period ( t _{limit ).} , ESS produced at the maximum charge capacity (ESS _{max_charge)} starts the excess capacity of PV power generation exceeds the time (t _{PV_int)} ESS discharge amount (ESS _discharge) to calculate and, PV power generation start time (t _{PV_int)} in the power The remaining capacity after subtracting the excess capacity exceeding the ESS maximum charging capacity ( ESS _{max_charge} ) from the production amount (the amount of ESS to be discharged in the PV power production start time period ( t _{PV_int} )) is within the range _{of the ESS charging time period (t ESS_int} ~ t _{ESS_fin )} The ESS _discharge is calculated in the order of the time period with the greatest marginal transport cost in the time period preceding the first time period ( t _limit).

Backhaul rate calculation section 15 calculates the backhaul rates by using a threshold backhaul costs of the calculated the calculated limit backhaul costs ESS discharge amount calculating unit 14 as an index ESS discharge amount (ESS _discharge) and the corresponding time zone. For example, n Using the ESS _discharge calculated in the time period and the marginal transport cost in the time period n, n The time zone can be calculated as in [Equation 2] below.

[Equation 2]

n Time zone reverse charge = Marginal transport cost in time n × n ESS discharge amount over time

Then, the station charge calculation unit 15 calculates the station fee within the corresponding time zone through [Equation 2], and calculates the sum by adding the station fee calculated based on the calculation for each driving condition.

The ESS optimal operation plan determining unit 16 compares the total repatriation charges calculated for each operating condition (CASE1, CASE2) through the repatriation rate calculation unit 15, and the amount of ESS discharge under the operating condition in which the total repatriation rate is the largest. is determined as the optimal discharge amount and applied to the establishment of the optimal operation plan of the PV-ESS system.

For example, the ESS optimal operation plan determining unit 16 determines an operation condition with a large reverse charge in the following two operation conditions (CASE1 and CASE2), and then determines the discharge amount as the ESS optimal discharge amount ( ESS ^opt _discharge ). 'CASE1' is an operating condition that discharges all the charge in the ESS(2) at 9 o'clock, the ESS discharge time, and 'CASE2' is the operating condition that exceeds the ESS maximum charge capacity ( ESS _{max_charge ) at 9 o'clock, the ESS discharge time.} Discharging the excess and discharging the remaining amount (the amount of charge charged in the ESS(2) at _{9:00 -} the excess exceeding the ESS maximum charge capacity ( ESS max_charge )) during the time period with the highest marginal transport cost within the ESS charging time. driving conditions.

In addition, the ESS optimal operation plan determining unit 16 compares the reverse transportation charges calculated in the operating conditions of 'CASE1' and 'CASE2' with each other to determine the operation condition with a large return charge, and determines the discharge time and room rate under the operation conditions. The total amount is determined as the ESS ^opt _discharge. The ESS ^opt _discharge determined in this way is provided to the ESS (2) and applied to the ESS optimal operation plan.

In addition, the ESS optimal operation plan determining unit 16 sequentially performs the above-described method when the ESS accumulated charge amount ( ESS _{cum_charge} ) exceeds the ESS maximum charge capacity ( ESS _{max_charge ) within the ESS charging time period (t ESS_int} ~ t _{ESS_fin )} It is repeatedly carried out to determine the optimal amount of discharge for which the reverse charge is the maximum.

In addition, the ESS optimal operation plan determining unit 16 determines that the ESS accumulated charge amount ( ESS _{cum_charge} ) exceeds the ESS maximum charge capacity ( ESS _{max_charge} ) in the _{ESS discharge time period after the ESS charging time period (t ESS_int} ~ t _{ESS_fin ).} The ESS discharge amount is fixed to the ESS maximum charge capacity ( ESS _{max_charge} ), and the optimal discharge amount is determined in the time period when the reverse charge is the highest in the previous time period.

7 and 8 are flowcharts illustrating a simulation method according to an embodiment of the present invention.

Referring to FIG. 7 , the ESS accumulated charge amount ( ESS _{cum_charge} ) is calculated based on the PV power generation time period ( t _{PV_int} ~ t _{PV_fin} ) (S1, S2). ESS of accumulated charge point PV power generation start time (t _{PV_int)} from and, PV power generation start time (t _{PV_int)} 24 when, PV power generation start time at the time 1 (t _{PV_int)} in calculating the (ESS _{cum_charge)} It is sequentially calculated in the order of the previous time period ( t _{PV_int -1).} At this time, the ESS(2) only charges the power generated by the PV(1) and does not discharge it.

Then, the time obtained by the 'S2' classified ESS accumulated charge (ESS _{cum_charge)} and ESS maximum charge capacity (ESS _{max_charge)} a comparison to ESS accumulate charge up to a specific time within the ESS charge time _{(t ESS_int ~ t ESS_fin) (} ESS _{cum_charge)} if one exceeds the ESS maximum charge capacity (ESS _{max_charge),} ESS maximum charge capacity (ESS _{max_charge)} the ESS accumulated charge (ESS _{cum_charge)} to the first time (t _limit1) starts to exceed the ESS maximum charge capacity ( ESS _{max_charge} ) is fixed (set) (S3).

Thereafter, the limit back trans _kW per kW is calculated in the previous time period of the first time period ( t _limit1 ) (hereinafter referred to as the 'first excess time period') exceeding the ESS maximum charging capacity ( ESS _{max_charge ) for the first time.} (S4). The marginal back-transmission cost per kW in time n can be obtained by [Equation 3] below.

[Equation 3]

back trans ⁿ _kW = SMP _n + REC _n /1,000 × REC unit price _n × REC weight _n

If the operation conditions are CASE1, calculated with a PV power generation start time (t _{PV_int)} ESS discharge amount (ESS _discharge 1) to be discharged in the same capacity and power output PV power generation start time (t _{PV_int)} produced in or time of day Calculate the reverse charge for the time period using the ESS _discharge amount ( ESS discharge 1 ) and the marginal return cost ( back trans _kW ) for the time period, and then add the return charge obtained in 'CASE1' to the total return charge (∑back trans CHG1). ) is calculated (S5 to S7).

After that, if the operating condition is 'CASE2', the ESS accumulated charge amount ( ESS _{cum_charge} ) and the ESS maximum charge capacity ( ESS _{max_charge} ) in the first excess time period ( t _limit1 ) using the calculated marginal back trans _{kW as an index} To be the same, the ESS _discharge amount ( ESS discharge 2 ) is calculated from the PV power generation start time zone ( t _{PV_int} ) to the first excess time zone ( t _limit1 ) (S5, S6'). At this time, the ESS _discharge amount calculated for each time period ( ESS discharge 2 ) is determined within the range of '0≤ ESS _discharge 2 ≤PCS maximum capacity'.

In process S6', the ESS _discharge amount ( ESS discharge 2 ) is sequentially calculated from the PV power production start time ( t _{PV_int} ) to the first excess time period ( t _limit1 ) for each time zone with the largest back trans _kW. do. For example, ESS produced at the maximum charge capacity (ESS _{max_charge)} the excess exceeds the capacity of the PV electricity generation start time (t _{PV_int)} ESS discharge amount (ESS _discharge 2) by calculation and, PV power generation start time (t _{PV_int)} in which The remaining capacity after subtracting the excess capacity exceeding the ESS maximum charging capacity ( ESS _{max_charge} ) (the amount of ESS discharge calculated from the PV power production start time period ( t _{PV_int} )) is the range of the ESS charging time period (t _{ESS_int} ~ t _{ESS_fin )} Calculate the amount of ESS discharge ( ESS discharge 2 ) to be _{discharged in the} order of the time period having the largest back trans _kW in the time period preceding the first excess time period ( t _{limit1 ) in the} And, the ESS _discharge amount ( ESS discharge 2 ) calculated in this way is sequential in the order of the largest back trans _kW within the interval from the PV power generation start time zone ( t _{PV_int} ) to the first excess time zone ( t _{limit1 ).} will be discharged to

After that, using the ESS _discharge amount for each time period ( ESS discharge 2 ) calculated in step S6 ' and the marginal return cost ( back trans _kW ) for the time period, calculate the return charge for the corresponding time zone, and then use the By summing them up, the total return charge (∑back trans CHG2) is calculated (S7').

Hereinafter, the processes S1 to S8 will be described in combination with a single operation PV-ESS linked system as an example. At this time, the characteristics of the PV-ESS linked system are shown in FIGS. 9 to 13 below.

9 to 13 are views illustrating an example for explaining a simulation method according to an embodiment of the present invention, and FIG. 9 is the raw load of the PV-ESS system by time period, FIG. is the SMP unit price for each time period, FIG. 12 is a view showing the electricity rate per KW for each time period, and FIG. 13 is a view showing the maximum PV power generation capacity, the maximum ESS charging capacity, and the maximum PCS capacity.

In order to explain the present invention, as an example, the accumulated ESS charge amount for each time period of the PV-ESS system having the characteristics and unit price conditions as shown in FIGS. [Table 1] below shows the calculation and arrangement of the repatriation fee. At this time, as shown in FIG. 13, the ESS maximum charging capacity is 600 kW, and the PCS maximum capacity is 200 kW.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1068 - 1068 222.8 - 2 1068 - 1068 220.6 - 3 1068 - 1068 219.3 - 4 1068 - 1068 216.0 - 5 1068 - 1068 215.5 - 6 1068 - 1068 217.9 - 7 1068 - 1068 220.8 - 8 1068 - 1068 221.8 - 9 24 - 24 230.3 - 10 97 - 97 138.6 - 11 230 - 230 140.0 - 12 419 - 419 140.2 - 13 611 - 611 137.3 - 14 782 - 782 140.0 - 15 932 - 932 141.0 - 16 1023 - 1023 141.0 - 17 1065 - 1065 234.2 - 18 1068 - 1068 234.2 - 19 1068 - 1068 234.3 - 20 1068 - 1068 234.4 - 21 1068 - 1068 233.7 - 22 1068 - 1068 232.2 - 23 1068 - 1068 231.3 - 24 1068 - 1068 230.5 -

As shown in [Table 1] and FIG. 14 above, as in process S2 , based on the time period ( t _PVint ~ t _PVfin ) during which PV(1) produces power, the ESS accumulated charge amount ( ESS _{cum_charge} ) for each time period is sequentially calculated, respectively. do.

And, if the ESS maximum charging capacity ( ESS _{max_charge} ) exceeds 600kW from 13:00 out of the ESS charging time period (t _{ESS_int} ~t _{ESS_fin} ) from 10:00 to 16:00, before the time period exceeding the ESS maximum charging capacity ( ESS _{max_charge ) 600kW} Discharge (reverse) to the ESS (2) should be performed during the time period by calculating the amount of discharge to be discharged from 9:00 to 12:00. The results are shown in [Table 2] and FIG. 15 below.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1068 - 1068 222.8 - 2 1068 - 1068 220.6 - 3 1068 - 1068 219.3 - 4 1068 - 1068 216.0 - 5 1068 - 1068 215.5 - 6 1068 - 1068 217.9 - 7 1068 - 1068 220.8 - 8 1068 - 1068 221.8 - 9 24 - 24 230.3 - 10 97 - 97 138.6 - 11 230 - 230 140.0 - 12 419 - 419 140.2 - 13 (611) - 611 137.3 - 14 782 - 782 140.0 - 15 932 - 932 141.0 - 16 1023 - 1023 141.0 - 17 1065 - 1065 234.2 - 18 1068 - 1068 234.2 - 19 1068 - 1068 234.3 - 20 1068 - 1068 234.4 - 21 1068 - 1068 233.7 - 22 1068 - 1068 232.2 - 23 1068 - 1068 231.3 - 24 1068 - 1068 230.5 -

As shown in [Table 2] above, if the ESS maximum charge capacity ( ESS _{max_charge ) exceeds 600kW from 13:00 during the ESS charging time period (t ESS_int} ~t _{ESS_fin} ) between 10:00 and 16:00, as in process S3, the maximum ESS charge The ESS accumulated charge amount ( ESS _{cum_charge} ) at 13:00, which is the first time period when the capacity ( ESS _{max_charge} ) starts to exceed 600 kW (hereinafter referred to as the 'first excess time period ( t _limit1 )'), is the ESS maximum charge capacity ( ESS _{max_charge} ) 600 kW is fixed (set) (refer to [Table 3]), and based on this, the amount of discharge is calculated within the previous time period, 9 o'clock to 12 o'clock. The results are shown in [Table 3] and FIG. 16 .

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1068 - 1068 222.8 - 2 1068 - 1068 220.6 - 3 1068 - 1068 219.3 - 4 1068 - 1068 216.0 - 5 1068 - 1068 215.5 - 6 1068 - 1068 217.9 - 7 1068 - 1068 220.8 - 8 1068 - 1068 221.8 - 9 24 - 24 230.3 - 10 97 - 97 138.6 - 11 230 - 230 140.0 - 12 419 - 419 140.2 - 13 (600) - 600 137.3 - 14 782 - 782 140.0 - 15 932 - 932 141.0 - 16 1023 - 1023 141.0 - 17 1065 - 1065 234.2 - 18 1068 - 1068 234.2 - 19 1068 - 1068 234.3 - 20 1068 - 1068 234.4 - 21 1068 - 1068 233.7 - 22 1068 - 1068 232.2 - 23 1068 - 1068 231.3 - 24 1068 - 1068 230.5 -

And, among the time zones between 9:00 and 12:00, which is the time period before 13:00, the first excess time zone ( t _{limit1 ), 9:00 (limit back-transfer in [Table 3]) Calculate} the discharge amount ('611kW - 600kW = 11kW') that satisfies the ESS maximum charge capacity ( ESS max_charge ) 600kW from the cost '230.3'). The results are shown in [Table 4] and FIG. 17 below.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1057 - 1057 222.8 - 2 1057 - 1057 220.6 - 3 1057 - 1057 219.3 - 4 1057 - 1057 216.0 - 5 1057 - 1057 215.5 - 6 1057 - 1057 217.9 - 7 1057 - 1057 220.8 - 8 1057 - 1057 221.8 - 9 24 (-11) 13 230.3 (2,533) 10 86 - 86 138.6 - 11 219 - 219 140.0 - 12 408 - 408 140.2 - 13 (600) - 600 137.3 - 14 771 - 771 140.0 - 15 921 - 921 141.0 - 16 1012 - 1012 141.0 - 17 1054 - 1054 234.2 - 18 1057 - 1057 234.2 - 19 1057 - 1057 234.3 - 20 1057 - 1057 234.4 - 21 1057 - 1057 233.7 - 22 1057 - 1057 232.2 - 23 1057 - 1057 231.3 - 24 1057 - 1057 230.5 -

As shown in [Table 4], 9 o'clock (ESS discharge time zone) and 10 o'clock to 12 o'clock (ESS charging time zone), which are the time periods before the first excess time period ( t _limit1 ) exceeding the ESS maximum charge capacity ( ESS _{max_charge )} There is a difference in the marginal return cost. That is, the marginal transport cost is relatively large in the ESS discharge time period. Therefore, it is possible to maximize profits by discharging all of the ESS at 9 o'clock, which is the discharge time of the ESS. That is, all 24kW of the ESS accumulated charge ( ESS _{cum_charge} ) accumulated in the ESS (2) is discharged at 9 o'clock (CASE1). The results are shown in [Table 5] and FIG. 18 below.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1044 - 1044 222.8 - 2 1044 - 1044 220.6 - 3 1044 - 1044 219.3 - 4 1044 - 1044 216.0 - 5 1044 - 1044 215.5 - 6 1044 - 1044 217.9 - 7 1044 - 1044 220.8 - 8 1044 - 1044 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 - 206 140.0 - 12 395 - 395 140.2 - 13 587 - 587 137.3 - 14 758 - 758 140.0 - 15 908 - 908 141.0 - 16 999 - 999 141.0 - 17 1041 - 1041 234.2 - 18 1044 - 1044 234.2 - 19 1044 - 1044 234.3 - 20 1044 - 1044 234.4 - 21 1044 - 1044 233.7 - 22 1044 - 1044 232.2 - 23 1044 - 1044 231.3 - 24 1044 - 1044 230.5 -

And, in order to determine the result of [Table 4] and the result of [Table 5], that is, under what operating conditions, the maximum return charge is, as shown in [Table 4], ESS at 9 o'clock when the marginal transfer cost is large. 11kW of excess exceeding the maximum charging capacity ( ESS _{max_charge} ) is primarily discharged, and the difference value ('24kW - 11kW = 13kW') after the first discharge at 9:00 is the marginal return cost during the time period between 10:00 and 12:00. Discharge occurs at 12 o'clock (marginal return cost is '140.2'), which is the largest time period (CASE2). The results are shown in [Table 6] below, and a graph of the results is shown in FIG. 19 .

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1044 - 1044 222.8 - 2 1044 - 1044 220.6 - 3 1044 - 1044 219.3 - 4 1044 - 1044 216.0 - 5 1044 - 1044 215.5 - 6 1044 - 1044 217.9 - 7 1044 - 1044 220.8 - 8 1044 - 1044 221.8 - 9 24 (-11) 13 230.3 (2,533) 10 86 - 86 138.6 - 11 219 - 219 140.0 - 12 408 (-13) 395 140.2 (1,823) 13 587 - 587 137.3 - 14 758 - 758 140.0 - 15 908 - 908 141.0 - 16 999 - 999 141.0 - 17 1041 - 1041 234.2 - 18 1044 - 1044 234.2 - 19 1044 - 1044 234.3 - 20 1044 - 1044 234.4 - 21 1044 - 1044 233.7 - 22 1044 - 1044 232.2 - 23 1044 - 1044 231.3 - 24 1044 - 1044 230.5 -

Through processes S6 to S7, as shown in [Table 5], the total return charge (5,527) (CASE1), and through processes S6' to S7', the return charge obtained from the result of [Table 6] ('2,533 + 1,823 = 4356') Compare with (CASE2) (Step S8).

As a result of comparison, if the reverse transport fee of CASE1 is larger than that of CASE2, the optimal ESS operation plan is established based on CASE1. That is, the ESS ^opt _discharge is determined under CASE1 and discharge conditions.

On the other hand, in Figure 8, the result obtained through the process of S8, that is the discharge time of day ESS optimized based on the discharge amount, ESS charge time (t _{ESS_int} ~ t _{ESS_fin)} ESS accumulated charge is within the range (ESS _{cum_charge)} The ESS maximum charge capacity When ( ESS _{max_charge} ) is exceeded again, the time period to be discharged and the ESS ^opt _discharge are determined in the same manner as in processes 'S2' to 'S5' (S9). At this time, the discharge time period and ESS ^opt _discharge determined in process 'S8' do not change.

As an example, under the same conditions as in [Table 7] and FIG. 20 below, as an example, the ESS charging time period ( t _{ESS_int} ~ Within t _{ESS_fin} ), the ESS accumulated charge amount ( ESS _{cum_charge} ) exceeds the ESS maximum charge capacity ( ESS _{max_charge} ) from 14:00 to 16:00 after the first excess time period ( t _limit1 ) ('758kW - 600kW = 158kW') Then, the amount of discharge of the ESS is calculated between 10:00 and 13:00, which is the time period before the time period exceeding the ESS maximum charge capacity ( ESS _{max_charge} ) (hereinafter referred to as the 'second excess time period ( t _{limit2 )').}

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 1044 - 1044 222.8 - 2 1044 - 1044 220.6 - 3 1044 - 1044 219.3 - 4 1044 - 1044 216.0 - 5 1044 - 1044 215.5 - 6 1044 - 1044 217.9 - 7 1044 - 1044 220.8 - 8 1044 - 1044 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 - 206 140.0 - 12 395 395 140.2 - 13 587 - 587 137.3 - 14 (758) - 758 140.0 - 15 908 - 908 141.0 - 16 999 - 999 141.0 - 17 1041 - 1041 234.2 - 18 1044 - 1044 234.2 - 19 1044 - 1044 234.3 - 20 1044 - 1044 234.4 - 21 1044 - 1044 233.7 - 22 1044 - 1044 232.2 - 23 1044 - 1044 231.3 - 24 1044 - 1044 230.5 -

As shown in [Table 7], the result obtained through the process 'S8', that is, the discharge amount of 24kW is discharged at 9 o'clock.

And, in the above-described way, ESS maximum charge capacity (ESS _{max_charge)} a second excess time (t _limit2) of ESS accumulated charge at 14:00 starts to exceed (ESS _{cum_charge)} the ESS maximum charge capacity (ESS _{max_charge)} 600kW , and calculate the amount of ESS discharge between 10:00 and 13:00, which is the previous time period. The results are shown in [Table 8] and FIG. 21 below.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 886 - 886 222.8 - 2 886 - 886 220.6 - 3 886 - 886 219.3 - 4 886 - 886 216.0 - 5 886 - 886 215.5 - 6 886 - 886 217.9 - 7 886 - 886 220.8 - 8 886 - 886 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 - 206 140.0 - 12 395 395 140.2 - 13 587 - 587 137.3 - 14 (600) - 600 140.0 - 15 750 - 750 141.0 - 16 841 - 841 141.0 - 17 883 - 883 234.2 - 18 886 - 886 234.2 - 19 886 - 886 234.3 - 20 886 - 886 234.4 - 21 886 - 886 233.7 - 22 886 - 886 232.2 - 23 886 - 886 231.3 - 24 886 - 886 230.5 -

And, ESS accumulated charge from 14:00 (ESS _{cum_charge)} The ESS maximum charge capacity (ESS _{max_charge)} when fixed to 600kW, the following Table 9, and as shown in Figure 22, the second excess time (t _limit2) of 14 during the previous time From 10:00 to 13:00, the discharge amount is calculated ('758kW - 600kW = 158kW') in the 12 o'clock time zone, the time when the marginal return cost is the highest, and discharges.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 886 - 886 222.8 - 2 886 - 886 220.6 - 3 886 - 886 219.3 - 4 886 - 886 216.0 - 5 886 - 886 215.5 - 6 886 - 886 217.9 - 7 886 - 886 220.8 - 8 886 - 886 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 - 206 140.0 - 12 395 (-158) 237 140.2 (27,685) 13 429 - 429 137.3 - 14 (600) - 600 140.0 - 15 750 - 750 141.0 - 16 841 - 841 141.0 - 17 883 - 883 234.2 - 18 886 - 886 234.2 - 19 886 - 886 234.3 - 20 886 - 886 234.4 - 21 886 - 886 233.7 - 22 886 - 886 232.2 - 23 886 - 886 231.3 - 24 886 - 886 230.5 -

In addition, as shown in [Table 10] and FIG. 23 below , after 14:00, the second excess time period ( t _limit2 ), the ESS accumulated charge amount ( ESS _{cum_charge} ) exceeds the ESS maximum charge capacity ( ESS _{max_charge} ) ('750kW - 600kW = 150kW'), in the same way, between 10:00 and 14:00 in the time period before 15:00 , which is the time period exceeding the ESS maximum charging capacity ( ESS _{max_charge} ) (hereinafter referred to as the 'third excess time period ( t _{limit3 )'), the ESS} The amount of discharge is calculated, and the calculated amount of discharge must be discharged from the ESS (2).

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 886 - 886 222.8 - 2 886 - 886 220.6 - 3 886 - 886 219.3 - 4 886 - 886 216.0 - 5 886 - 886 215.5 - 6 886 - 886 217.9 - 7 886 - 886 220.8 - 8 886 - 886 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 - 206 140.0 - 12 395 (158) 237 140.2 (27,685) 13 429 - 429 137.3 - 14 600 - 600 140.0 - 15 (750) - 750 141.0 - 16 841 - 841 141.0 - 17 883 - 883 234.2 - 18 886 - 886 234.2 - 19 886 - 886 234.3 - 20 886 - 886 234.4 - 21 886 - 886 233.7 - 22 886 - 886 232.2 - 23 886 - 886 231.3 - 24 886 - 886 230.5 -

[Table 11], and as shown in Figure 24, again ESS maximum charge capacity (ESS _{max_charge)} a third excess time (t _limit3) of the ESS accumulated charge ESS maximum charge capacity of from 15:00 to begin to exceed (ESS _{max_charge)} It is fixed at 600kW, and the amount of ESS discharge is calculated between 10:00 and 14:00, which is the time before that.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 736 - 736 222.8 - 2 736 - 736 220.6 - 3 736 - 736 219.3 - 4 736 - 736 216.0 - 5 736 - 736 215.5 - 6 736 - 736 217.9 - 7 736 - 736 220.8 - 8 736 - 736 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 (600) - 600 141.0 - 16 691 - 691 141.0 - 17 733 - 733 234.2 - 18 736 - 736 234.2 - 19 736 - 736 234.3 - 20 736 - 736 234.4 - 21 736 - 736 233.7 - 22 736 - 736 232.2 - 23 736 - 736 231.3 - 24 736 - 736 230.5 -

In [Table 11], the ESS accumulated charge amount ( ESS _{cum_charge ) at 15:00} , the third excess time period ( t limit3 ), is fixed to the ESS maximum charge capacity ( ESS _{max_charge} ) 600kW, and between 10:00 and 14:00, the previous time period Calculate the amount of discharge ('750kW - 600kW = 150kW'). In addition, the discharge amount is calculated based on the maximum capacity (200kW) of the PCS in order to discharge the maximum at 12:00, when the marginal return cost is the largest between 10:00 and 14:00 ('158kW + 42kW = 200kW'). At this time, 200kW, which is the standard of the maximum discharge amount, is the maximum capacity of the PCS. And, the remaining discharge amount ('150kW - 42kW = 108kW') is discharged at 11 o'clock, which has the second largest marginal return cost in the previous time period.

And, as shown in [Table 12] and FIG. 25 below, after the third excess time period ( t _limit3 ), the ESS charging time period (t _{ESS_int} ~ t _{ESS_fin)} again ESS accumulated charge (ESS _{cum_charge)} The ESS maximum charge capacity (ESS _{max_charge)} excess ( '691kW - 600kW = 91kW' in if any), the in the 10 16 hours prior to time 4 excess time (t _limit4) The amount of ESS to be discharged is calculated because the discharge has to be made between 15:00 and 15:00.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 736 - 736 222.8 - 2 736 - 736 220.6 - 3 736 - 736 219.3 - 4 736 - 736 216.0 - 5 736 - 736 215.5 - 6 736 - 736 217.9 - 7 736 - 736 220.8 - 8 736 - 736 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 600 - 600 141.0 - 16 (691) - 691 141.0 - 17 733 - 733 234.2 - 18 736 - 736 234.2 - 19 736 - 736 234.3 - 20 736 - 736 234.4 - 21 736 - 736 233.7 - 22 736 - 736 232.2 - 23 736 - 736 231.3 - 24 736 - 736 230.5 -

As shown in [Table 13] and FIG. 26 below, the ESS accumulated charge amount ( ESS _{cum_charge} ) at 16:00, the fourth excess time period ( t _limit4 ) that starts to exceed the ESS maximum charge capacity ( ESS _{max_charge} ) again, is the ESS maximum charge capacity ( ESS _{max_charge} ) It is fixed at 600kW, and the amount of ESS discharge is calculated from 10:00 to 15:00, which is the time period before that.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 645 - 645 222.8 - 2 645 - 645 220.6 - 3 645 - 645 219.3 - 4 645 - 645 216.0 - 5 645 - 645 215.5 - 6 645 - 645 217.9 - 7 645 - 645 220.8 - 8 645 - 645 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 (600) (-91) 509 141.0 (12,832) 16 600 - 600 141.0 - 17 642 - 642 234.2 - 18 645 - 645 234.2 - 19 645 - 645 234.3 - 20 645 - 645 234.4 - 21 645 - 645 233.7 - 22 645 - 645 232.2 - 23 645 - 645 231.3 - 24 645 - 645 230.5 -

That is, the discharge amount ('691kW - 600kW = 91kW') is calculated in the time zone of 15:00, which is the time zone where the marginal transport cost is the highest, among the time zone 10 to 15 o'clock before _16:00 , which is the fourth excess time zone ( t limit4 ).

On the other hand, as shown in [Table 14] and FIG. 27 below, the ESS accumulated charge amount ( ESS _{cum_charge} ) should be the maximum capacity during the time period when the station fee is the most expensive. Therefore, the ESS accumulated charge amount ( ESS _{cum_charge} ) at 17:00, the first discharge time of the ESS discharge time zone, must be equal to the ESS maximum charge capacity ( ESS _{max_charge} ) of 600 kW (refer to 'Premise 3'). Therefore, the ESS discharge amount is fixed at 600 kW during the first discharge time period of 17:00.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 603 - 603 222.8 - 2 603 - 603 220.6 - 3 603 - 603 219.3 - 4 603 - 603 216.0 - 5 603 - 603 215.5 - 6 603 - 603 217.9 - 7 603 - 603 220.8 - 8 603 - 603 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 600 (-91) 509 141.0 (12,832) 16 600 - 558 141.0 - 17 (600) - 600 234.2 - 18 603 - 603 234.2 - 19 603 - 603 234.3 - 20 603 - 603 234.4 - 21 603 - 603 233.7 - 22 603 - 603 232.2 - 23 603 - 603 231.3 - 24 603 - 603 230.5 -

And, as shown in [Table 15] and FIG. 28 below, the first discharge time exceeding the ESS maximum charge capacity ( ESS _{max_charge} ) of the ESS discharge time period, that is, the fifth time exceeding the fifth time period ( t _limit5 ), from 10 o'clock to 16 Discharge is calculated by calculating the amount of discharge ('642kW - 600kW = 42kW') at 16:00, when the marginal return cost is the highest in the city.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 603 - 603 222.8 - 2 603 - 603 220.6 - 3 603 - 603 219.3 - 4 603 - 603 216.0 - 5 603 - 603 215.5 - 6 603 - 603 217.9 - 7 603 - 603 220.8 - 8 603 - 603 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 600 (-91) 509 141.0 (12,832) 16 600 (-42) 600 141.0 (5,923) 17 (600) - 600 234.2 - 18 603 - 603 234.2 - 19 603 - 603 234.3 - 20 603 - 603 234.4 - 21 603 - 603 233.7 - 22 603 - 603 232.2 - 23 603 - 603 231.3 - 24 645 - 603 230.5 -

In addition, as shown in [Table 16] and FIG. 29 below, after the fifth excess time period ( t _limit5 ), the second discharge time period exceeding the ESS maximum charge capacity ( ESS _{max_charge} ), the sixth excess time period ( t _limit6 ) From 10:00 to 17:00, the discharge amount ('603kW - 600kW = 3kW') is calculated during the 17:00 time when the marginal return cost is the maximum, and the calculated discharge amount is discharged.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 600 - 600 222.8 - 2 600 - 600 220.6 - 3 600 - 600 219.3 - 4 600 - 600 216.0 - 5 600 - 600 215.5 - 6 600 - 600 217.9 - 7 600 - 600 220.8 - 8 600 - 600 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 600 (-91) 509 141.0 (12,832) 16 600 (-42) 558 141.0 (5,923) 17 (600) (-3) 597 234.2 (703) 18 (600) - 600 234.2 - 19 600 - 600 234.3 - 20 600 - 600 234.4 - 21 600 - 600 233.7 - 22 600 - 600 232.2 - 23 600 - 600 231.3 - 24 600 - 600 230.5 -

And, as shown in [Table 17] and Fig. 30 below, since the ESS cumulative charge amount ( ESS _{cum_charge} ) does not change after the sixth time limit ( t _limit6 ), the maximum capacity of the PCS sequentially from the time period where the marginal transport cost is large in the ESS discharge time zone (200kW) until the ESS potential becomes '0'.

slot ESS
accumulated charge Optimum ESS discharge amount
(backflow) after discharge
ESS potential marginal shipping cost reverse charge One 0 - 0 222.8 - 2 0 - 0 220.6 - 3 0 - 0 219.3 - 4 0 - 0 216.0 - 5 0 - 0 215.5 - 6 0 - 0 217.9 - 7 0 - 0 220.8 - 8 0 - 0 221.8 - 9 24 (-24) 0 230.3 (5,527) 10 73 - 73 138.6 - 11 206 (-108) 98 140.0 (15,118) 12 287 (-200) 87 140.2 (28,048) 13 279 - 279 137.3 - 14 450 - 450 140.0 - 15 600 (-91) 509 141.0 (12,832) 16 600 (-42) 558 141.0 (5,923) 17 600 (-3) 597 234.2 (703) 18 600 (-200) 400 234.2 (46,848) 19 400 (-200) 200 234.3 (46,867) 20 200 (-200) 0 234.4 (46,873) 21 0 - 0 2033.7 - 22 0 - 0 232.2 - 23 0 - 0 231.3 - 24 0 - 0 230.5 -

As described above, in the present invention, when establishing an optimal operation plan for a PV-ESS-linked system of a sales operator within a commercial virtual power plant (C-VPP) system, the REC weight and the ESS by time period are used as the index of the marginal transport cost for each time period. The ESS optimal operation plan is provided by calculating the ESS discharge amount (reverse transfer amount) at which the reverse transfer rate is the maximum in consideration of the accumulated charge capacity, the maximum ESS charge capacity, the maximum PCS (Power Conversion System) capacity, and the PV power production. By operating a PV-ESS-linked system based on this, it is possible to maximize the profits of sales operators.

As described above, although preferred embodiments of the present invention have been described and illustrated using specific terms, such terms are only for clearly describing the present invention. In addition, it is apparent that various changes and changes can be made to the embodiments and described terms of the present invention without departing from the spirit and scope of the following claims. Such modified embodiments should not be individually understood from the spirit and scope of the present invention, but should be considered to fall within the scope of the claims of the present invention.

10: Simulator
11: ESS cumulative charge calculation unit
12: charge capacity excess judgment unit
13: marginal return cost calculation unit
14: ESS discharge amount calculator
15: Reverse fare calculator
16: ESS optimal operation plan decision unit

Claims (6)

The ESS (Energy Storage System) charging time zone is located within the PV (Photovoltaic) power production start time zone to the end time zone, and the ESS discharge time zone including the PV power production start time zone has a greater REC weight than the ESS charging time zone, and the ESS is In the simulator for establishing the optimal operation plan of the PV-ESS-linked system of the sales operator within the commercial virtual power plant system that starts charging from the time after the PV power production start time,
an ESS cumulative charging amount calculation unit that accumulates the amount of charge charged in the ESS from the PV power production start time when PV starts to produce electricity and calculates the ESS accumulated charge amount by time period;
a charging capacity excess determination unit for determining whether the ESS maximum charging capacity is exceeded by comparing the ESS accumulated charging amount for each time period calculated by the ESS accumulated charging quantity calculating unit and the ESS maximum charging capacity, respectively;
As a result of the determination of the charging capacity excess determination unit, if the ESS accumulated charging amount exceeds the ESS maximum charging capacity, calculating the marginal transport cost for each time period within the previous time period of the first time when the ESS accumulated charging amount exceeds the ESS maximum charging capacity marginal return cost calculator;
The ESS accumulated charging amount of the first time period is fixed to the ESS maximum charging capacity, and within the range from the start time of power production of the PV to the first time period, the marginal reverse transfer of the limiting transfer cost for each time period calculated through the limit transfer cost calculation unit an ESS discharge amount calculation unit that calculates the ESS discharge amount for each time period according to a preset operating condition in the order of the costly time period;
Based on the marginal transport cost calculated through the marginal transport cost calculator, the ESS discharge amount calculated by the ESS discharge amount calculator for each time period is multiplied by the marginal transport cost for the corresponding time period according to the operating conditions and a return charge calculation unit for calculating a total return charge for each operation condition by summing up the return charges calculated according to the driving conditions; and
The ESS optimal operation is performed by comparing the total reverse charge calculated for each operating condition through the reverse charge calculation unit, select the operating condition with the highest total return charge, and use the ESS discharge amount calculated under the selected operation condition as the ESS optimal discharge amount ESS optimal operation plan determining unit that determines the plan; including,
The operating conditions are CASE1, which calculates all of the power production produced in the PV power production start time zone as ESS discharge amount, the PV power production start time zone, and the limit reversal in the previous time zone of the first time within the range of the PV power production start time zone and the ESS charging time zone. Including CASE2, which calculates the amount of ESS discharge during the time of greatest cost,
The ESS discharge amount calculation unit calculates the same capacity as the amount of power produced in the PV power production start time in _{CASE1 as the ESS discharge amount to be discharged in the PV power production start time,} and in CASE2, exceeds the ESS maximum charging capacity After calculating the excess capacity to be the ESS discharge amount in the PV power production start time period, the remaining capacity after subtracting the excess capacity exceeding the ESS maximum charging capacity from the power production in the PV power production start time period is calculated as the ESS charging time period Calculating the amount of ESS discharge to be discharged in the order of the time period with the largest marginal return cost in the time period preceding the first time period within the range,
A simulator for establishing an optimal operation plan of a PV-ESS system of a grid-connected sales operator within a commercial virtual power plant system, characterized in that.
delete The method of claim 1,
The ESS discharge amount calculation unit, when the ESS accumulated charge amount again exceeds the ESS maximum charge capacity in the time period after the first time period, calculates the ESS accumulated charge amount in the excess time period exceeding the ESS maximum charge capacity again as the ESS maximum charge capacity and sequentially calculate the amount of ESS discharge to be discharged for each time zone with a large marginal transport cost among the previous time zones in excess of the ESS maximum charging capacity,
If the ESS discharge amount calculation unit exceeds the ESS maximum charging capacity again after the excess time, and the time period is the first or second time period after the ESS charging time period, the first or second Fixing the accumulated ESS charge amount of the time zone as the ESS maximum charge capacity, and sequentially calculating the ESS discharge amount for each time zone with the largest marginal transport cost among the previous time zones of the first or second time zone,
The ESS discharge amount calculation unit calculates the PCS (Power Conversion System) maximum capacity as the ESS discharge amount of the time period when the ESS accumulated charge amount of the time period after the first or second time period is the same as the ESS maximum charge capacity,
A simulator for establishing an optimal operation plan of a PV-ESS system of a grid-connected sales operator within a commercial virtual power plant system, characterized in that.
The ESS (Energy Storage System) charging time zone is located within the PV (Photovoltaic) power production start time zone to the end time zone, and the ESS discharge time zone including the PV power production start time zone has a greater REC weight than the ESS charging time zone, and the ESS is In the simulation method for establishing the optimal operation plan of the PV-ESS-linked system of the sales operator within the commercial virtual power plant system that starts charging from the later time zone of the PV power production start time,
(a) accumulating the amount of charge in the ESS from the PV power production start time period when the PV starts to produce electricity through the ESS accumulated charge amount calculation unit to calculate the ESS accumulated charge amount for each time period;
(b) determining whether the ESS maximum charging capacity is exceeded by comparing the ESS accumulated charging amount for each time period calculated by the ESS accumulated charging amount calculating unit and the ESS maximum charging capacity through the charging capacity excess determination unit;
(c) As a result of the determination, if the ESS accumulated charge exceeds the ESS maximum charging capacity, the marginal transfer cost for each time zone is performed through the marginal transfer cost calculation unit within the previous time period of the first time when the ESS accumulated charge exceeds the ESS maximum charge capacity. the process of calculating;
(d) The ESS accumulated charge amount of the first time period is fixed to the ESS maximum charge capacity through the ESS discharge amount calculation unit, and the limiting reversal cost calculation unit calculates it within the range from the power generation start time of the PV to the first time period The process of calculating the amount of ESS discharge for each time period according to the preset operating conditions in the order of the time period in which the marginal transfer cost is the largest among the limit transfer costs for each time period;
(e) the ESS discharge amount for each time period calculated by the ESS discharge amount calculation unit according to the operating conditions through the return charge calculation unit based on the marginal return cost calculated by the marginal return cost calculation unit, and the marginal return cost for the time period calculating a total return charge for each operation condition by multiplying each time to calculate a return charge for each time period, and summing up the calculated return charge according to the driving condition; and
(f) Through the ESS optimal operation plan determining unit, the total return charges calculated for each operating condition are compared with each other in the reverse transportation charge calculation unit, and the operating condition with the highest total return charge is selected, and the ESS discharge amount calculated under the selected operation conditions The process of determining the ESS optimal operation plan with including,
The operating conditions are CASE1, which calculates all of the power production produced in the PV power production start time zone as ESS discharge amount, the PV power production start time zone, and the limit reversal in the previous time zone of the first time within the range of the PV power production start time zone and the ESS charging time zone. Including CASE2, which calculates the amount of ESS discharge during the time of greatest cost,
In the process (d), the same capacity as the amount of power produced in the PV power production start time in _{CASE1 is calculated as the ESS discharge amount to be discharged in the PV power production start time,} and in CASE2, the ESS maximum charging capacity is After calculating the excess capacity as the ESS discharge amount in the PV power production start time period, the remaining capacity after subtracting the excess capacity exceeding the ESS maximum charging capacity from the power output produced in the PV power production start time period is the ESS charge Calculating the amount of ESS discharge to be discharged in the order of the time period with the greatest marginal return cost in the time period preceding the first time period within the time period range,
The marginal return cost is calculated by [Equation 1] below,
[Equation 1]
Marginal return cost = SMP + REC × REC unit price × REC weight
Here, it is SMP (System Marginal Pirce) and REC (Renewable Energy Certificates).
A simulation method for establishing an optimal operation plan of a PV-ESS system of a grid-connected sales operator within a commercial virtual power plant system, characterized in that.
delete 5. The method of claim 4,
In the process (d), if the ESS accumulated charging amount again exceeds the ESS maximum charging capacity in the time period after the first time period, the ESS accumulated charging amount in the excess time period exceeding the ESS maximum charging capacity again is calculated as the ESS maximum charging capacity , and sequentially calculate the amount of ESS discharge to be discharged for each time period with a large marginal transport cost among the previous time periods in excess of the ESS maximum charging capacity,
In the process (d), if the accumulated ESS charging amount after the excess time exceeds the ESS maximum charging capacity again, and the time period is the first or second time period after the ESS charging time period, the first or two Fixing the ESS accumulated charge amount of the first time period as the ESS maximum charge capacity, sequentially calculating the ESS discharge amount for each time period with the largest marginal transport cost among the previous time periods of the first or second time period,
In the process (d), if the accumulated ESS charge amount of the time zone after the first or second time zone is the same as the ESS maximum charge capacity, calculating the PCS (Power Conversion System) maximum capacity as the ESS discharge amount of the corresponding time zone,
A simulation method for establishing an optimal operation plan of a PV-ESS system of a grid-connected sales operator within a commercial virtual power plant system, characterized in that.

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