Energy storage device charging and discharging process management device

Abstract

The present invention relates to an ESS charge and discharge process management device, and more particularly to an ESS charge and discharge process management device that minimizes the average discharge amount in a time period of maximum load while maintaining the charge and discharge efficiency of an energy storage device, thereby preventing a reduction in a customer base load that is a basis for bidding for power demand response.

Description

Technical Field

[0001] The present invention relates to an energy storage system (ESS) charge and discharge process management device, and more specifically, to an ESS charge and discharge process management device that minimizes the average discharge amount in a maximum load time period while maintaining the charge and discharge efficiency of the energy storage system, thereby preventing a reduction in a customer base load that is a basis for bidding for power demand response. Background Art

[0002] In modern society, electric power is used as an important means to improve the quality of life, and therefore, various measures are established and supplemented for the production and consumption of electric power.

[0003] One of them is power demand response, which is a system in which when the power exchange requests a reduction in power to cope with power shortages or instability, users (consumers) such as factories and facilities (participating customers) save electricity as agreed and receive settlement.

[0004] This system regulates the maximum demand for electricity, thereby resolving the problem of insufficient supply during peak hours of electricity usage, and provides the same effect at a lower cost than building new power plants.

[0005] In this regard, Figure 1 As shown, in the power demand response system, based on the power demand response bid, the customer baseline load (CBL) is calculated using the Max (4 / 5) calculation method based on the time point of the application for the required reduction request.

[0006] Furthermore, since the amount of electricity usage that can be reduced is determined based on the customer base load, in order to calculate a higher reduction amount, it is necessary to prevent the customer base load that serves as a reference from decreasing, but no corresponding solution has been provided yet.

[0007] Prior art literature

[0008] Patent Literature

[0009] (Patent Document 1) Korean Patent Publication No. 10-2014-0119342

[0010] (Patent Document 2) Korean Patent Publication No. 10-2013-0063949 Summary of the invention

[0011] Problems to be solved by the invention

[0012] The present invention is proposed to solve the above-mentioned problems and aims to provide an ESS charge and discharge process management device that minimizes the average discharge amount in the maximum load time period while maintaining the charge and discharge efficiency of the energy storage device, thereby preventing the customer's benchmark load, which is the basis for power demand response bidding, from decreasing.

[0013] Solutions for solving problems

[0014] To this end, the ESS charge and discharge process management device according to the present invention is characterized in that it includes: a load data storage unit that provides information on maximum load, medium load and light load by statistical data on the user's power usage by season and time period; a power control unit that controls the charging and discharging of the energy storage device (ESS) according to each time period of the maximum load, medium load and light load; a DR participation amount calculation unit that calculates the power demand response (DR) participation capacity in the total discharge capacity of the above-mentioned energy storage device; a scheduler that manages a calculation period of a customer baseline load (CBL) including the power usage during the last five working days from the power demand response participation bid date; and a CBL management unit that determines the discharge amount of the above-mentioned energy storage device in a manner of dividing the power demand response participation capacity at different times on each working day of a week managed by the above-mentioned scheduler and discharging.

[0015] At this time, preferably, the DR participation amount calculation unit calculates an equalized discharge amount that evenly distributes the discharge amount discharged from the energy storage device to the power load according to time periods, and calculates the remaining capacity of the total discharge capacity of the energy storage device other than the equalized discharge amount as the power demand response participation capacity.

[0016] Furthermore, preferably, the scheduler transmits a charge / discharge command signal to the power control unit in such a manner that the energy storage device is charged during the light load period and the energy storage device is discharged during the maximum load period.

[0017] And, preferably, it also includes: a load monitoring unit, which monitors the power usage of the power load, and the load monitoring unit calculates the power usage used in the power load, compares the power usage with the benchmark usage judged as an abnormal working day, thereby determining whether the day is an abnormal working day.

[0018] Furthermore, preferably, in the above-mentioned dispatcher, when the electricity usage of the above-mentioned power load is maintained above the benchmark usage on the above-mentioned abnormal working day, the above-mentioned power demand response bidding is carried out, and when the electricity usage of the above-mentioned power load is less than the benchmark usage on the above-mentioned abnormal working day, the above-mentioned power demand response participation capacity is recalculated.

[0019] Furthermore, in the above-mentioned dispatcher, while waiting for registration and reduction tests or waiting for participation in peak demand power demand response, if no power supply instruction is received until the power demand response trading time period of that day, then in summer and spring and autumn, the above-mentioned energy storage device is discharged in the initial medium load time period after the above-mentioned power demand response trading time period, and in winter, the above-mentioned energy storage device is discharged in the initial maximum load time period after the above-mentioned power demand response trading time period.

[0020] Furthermore, the CBL management unit causes the power demand response to participate in capacity discharge during the maximum load period, and discharges at a later time each day starting from the first working day when discharge is started according to a discharge plan of the power demand response.

[0021] Furthermore, the entire time period of the above-mentioned maximum load is composed of a plurality of unit times with one hour as a unit. When the number of unit times (one hour) constituting the time period of the above-mentioned maximum load is greater than the number of working days in the above-mentioned week, the above-mentioned CBL management unit specifies a split discharge week with a number of days (days) equivalent to the difference between the number of the above-mentioned unit times and the number of working days in a week, and in the above-mentioned split discharge week, the above-mentioned power demand response participation amount is equally divided in different time periods and discharged.

[0022] It also includes: a template database (DB), which provides the document templates required for the above-mentioned electricity demand response bidding; and a bid generation unit, which receives the document templates from the above-mentioned template DB and records the application matters required for the above-mentioned electricity demand response bidding, and the above-mentioned scheduler transmits the bid in the form of an electronic document generated by the above-mentioned bid generation unit to the bidding agency server via the network.

[0023] Effects of the Invention

[0024] In the present invention as described above, the energy storage device is charged when the load is light, and discharged when the load is maximum, and at this time, the discharge is evenly divided, so that the charging and discharging efficiency of the energy storage device is maintained.

[0025] In particular, in the present invention, the average discharge amount in the time period of the maximum load on weekdays is minimized to prevent a decrease in the customer standard load that is a standard for bidding for power demand response, thereby maintaining the reduction amount of power demand response. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a conceptual diagram showing customer benchmark load.

[0027] Figure 2 1 is a diagram showing the structure of an ESS charge and discharge progress management device according to the present invention.

[0028] Figure 3 This is a classification table of maximum load, medium load and light load applicable to the present invention.

[0029] Figure 4 It is a diagram showing the charge and discharge status of the energy storage device according to time periods in summer and spring and autumn.

[0030] Figure 5 It is a diagram showing the charge and discharge status of the energy storage device by time period in winter. DETAILED DESCRIPTION

[0031] Hereinafter, an ESS charging and discharging process management device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0032] like Figure 2 As shown, the ESS charge and discharge process management device 10 according to the present invention relates to an ESS operation method for optimal participation in power demand response, which maintains the charge and discharge efficiency of the energy storage device. In particular, the average discharge amount in the maximum load time period is minimized, thereby preventing the customer's base load, which is the basis for bidding for power demand response, from decreasing.

[0033] At this time, Demand Response (DR) is also called "power demand response", which means that when the power exchange requests to reduce power in response to power shortage or instability, the power demand response customer saves (reduces) power according to the preset agreement and obtains settlement. In other words, it is a system that is compensated by reducing the amount of power used.

[0034] Electricity demand response customers include various electricity users such as factories, buildings and large supermarkets. The customer baseline load (CBL) is a predicted value of the normal electricity usage used by participating customers when the electricity load is not reduced. This refers to the load that serves as the basis for reducing electricity demand in the corresponding time period.

[0035] To this end, the ESS charging and discharging process management device 10 according to the present invention includes a load data storage unit 11, a power control unit 12, a DR participation amount calculation unit 13, a scheduler 14, and a CBL management unit 15. Furthermore, in other embodiments, it may also include a load monitoring unit 16, a template DB 17, and a bid generation unit 18.

[0036] The technical structure of the present invention as described above can be realized by a computing device including a server PC with a CPU, a program memory, a database, and a network communication module, etc., and some structures can also be set in an external third terminal to be linked to each other.

[0037] The load data storage unit 11 collects or refers to statistical data on power usage by season and time period of users, stores information on time periods of maximum load, medium load and light load, and provides it to the power control unit 12 and the like.

[0038] Electricity usage varies from country to country. Figure 3 As shown, when Korea is used as a reference, statistical samples for calculation of maximum load, medium load, and light load are obtained from average values ​​of all users managed by the power exchange.

[0039] Furthermore, first, the power load according to the season is divided into summer and spring / autumn, and the other seasons are winter, and then the power load according to the season classified as described above is classified according to the time period, thereby dividing it into maximum load, medium load and light load according to the season and time period.

[0040] The power control unit 12 is also called a power control system (PCS), and controls the charging and discharging of an energy storage system (ESS). To this end, the power control unit 12 receives power in the ESS system to charge a battery (storage battery).

[0041] The power control unit 12 is a system that converts the characteristics of electricity (eg, frequency, voltage, and AC / DC) to achieve system release (discharge). Due to the limitations imposed thereby, the maximum discharge amount per hour is, for example, 30% of the ESS capacity.

[0042] In particular, the power control unit 12 controls charging or discharging in each time period of maximum load, medium load and light load. That is, the necessity and efficiency of charging or discharging will change according to the power load of the season and time period, so the scheduler 14 performs control.

[0043] The DR participation amount calculation unit 13 calculates the power demand response participation capacity of the total discharge capacity (total battery capacity) of the energy storage device, wherein the power demand response participation capacity refers to the remaining capacity of the total capacity except for the equal discharge amount for equal discharge to the power load.

[0044] To this end, the DR participation amount calculation unit 13 first calculates an average discharge amount that evenly distributes the discharge amount from the energy storage device to the power load in each time period, and then calculates the remaining capacity of the total discharge capacity of the energy storage device excluding the above average discharge amount as the power demand response participation capacity.

[0045] like Figure 4 and Figure 5 As shown, assuming that the total capacity of the energy storage device is 10M, the maximum charging capacity is 10M, and correspondingly, the maximum discharging capacity is also 10M. The maximum discharging capacity per hour is 30% of the ESS capacity, so the maximum discharging capacity per hour is 3M.

[0046] In addition, the average discharge amount is the amount of electricity discharged by the energy storage device during the maximum load time when electricity is expensive in the power exchange. As an example, the average discharge amount is 1.4M in each time period, and the remaining 1.6M (10M-6H×1.4M) is equivalent to the above-mentioned power demand response participating capacity.

[0047] The scheduler 14 manages the discharge schedule of the energy storage device, and in particular, manages the calculation period of the customer base load. The calculation period of the customer base load is the latest five working days from the day of the power demand response participation bidding.

[0048] Specifically, the customer base load calculation method uses the Max (4 / 5) method, by which the average value of four working days other than the working day with the largest power usage among the last five working days is calculated, wherein the calculation is performed for each time period.

[0049] Therefore, when the scheduler 14 receives a request for participation in a power demand response bid, it manages the calculation period for each time period within five working days before that, and provides the progress to the CBL management unit 15 described later.

[0050] However, preferably, the scheduler 14 transmits a charge / discharge command signal to the power control unit 12 in such a manner that the energy storage device is charged during a light load period and the energy storage device is discharged during a maximum load period.

[0051] The time period of light load is a time period of low electricity rate, and the energy storage device is charged during this time period. On the contrary, the electricity rate during the time period of maximum load is high, so the difference can be obtained by discharging the energy storage device.

[0052] Furthermore, in the scheduler 14, while waiting for registration and reduction test or waiting for participation in peak demand power demand response, if no power supply instruction is received until the power demand response trading time period of the day (for example: 10:00-20:00), discharge is performed in the following manner.

[0053] For example, in summer and spring and autumn, the energy storage device is discharged during the first medium load period after the power demand response trading period, and in winter, the energy storage device is discharged during the first maximum load period after the power demand response trading period.

[0054] In summer and spring / autumn, there is no peak load period with the most expensive electricity after 20:00, which is the end of the trading period. Therefore, discharge is performed during the medium load period instead. In winter, there is a peak load period after 20:00. Therefore, discharge is performed during this period to maximize the discharge benefit.

[0055] The CBL management unit 15 prevents a decrease in the customer standard load, which is a reference for determining the reduction amount of the power demand response participating customer, and determines the discharge amount of the energy storage device on each weekday of the week managed by the dispatcher 14 .

[0056] In particular, in the present invention, as described above, the customer base load calculation method applies the Max (4 / 5) method, and therefore the CBL management unit 15 determines the discharge amount of the energy storage device by discharging the participating capacity in response to power demand at different times during the working day.

[0057] As shown in the following <Mathematical formula>, the supply-side power usage measured by a meter such as Korea Electric Power TM is defined as a value obtained by subtracting the discharge amount of the energy storage device from the user's load-side power usage.

[0058] <Mathematical formula> Supply-side power usage = Load-side power usage - ESS discharge

[0059] At this time, the power usage (power consumption) used as the basis for calculating the customer benchmark load refers to the power usage on the supply side. Therefore, the greater the discharge of the energy storage device, the smaller the power usage on the supply side, and the smaller the customer benchmark load. That is, if the average discharge of the energy storage device increases, the customer benchmark load decreases.

[0060] Therefore, as in the present invention, if the power demand response participating capacity is divided and discharged at different times on weekdays during the calculation period of the customer benchmark load, the average discharge value of the energy storage device in each time period of four days out of five days except for the day with the largest discharge amount will become smaller, and conversely, the customer benchmark load will become larger, thereby preventing it from decreasing.

[0061] Figure 4 and Figure 5 The timetable for applying the customer base load calculation method is shown in . Figure 4 The figure shows the ESS charging and discharging status by time period in summer and spring / autumn. Figure 5FIG. 5 shows the charge and discharge status of the ESS by time period in winter.

[0062] As shown in the figure, the present invention corresponds to the Max (4 / 5) method of calculating the customer base load, and controls the energy storage device in a manner of dividing the power demand response participating in the capacity and discharging at different times during the working days of the week.

[0063] For example, the CBL management unit 15 causes the power demand response to participate in capacity discharge during the peak load period, and discharges at later times each day starting from the first working day when discharge starts, according to the discharge plan of the power demand response.

[0064] That is, discharge is performed only during the time period of maximum load when electricity is expensive, so Figure 4 In the process, discharge is performed in steps such as 10 o'clock, 11 o'clock, 13 o'clock, 14 o'clock, 15 o'clock, etc. Figure 5 In the process, discharge is performed in steps such as 10 o'clock, 11 o'clock, 17 o'clock, 18 o'clock, 19 o'clock, and 20 o'clock.

[0065] Different from what is shown, if the power demand response participates in capacity discharge at 10 o'clock on Monday and Tuesday (both days) on weekdays, it will be 2.2M (1.4+0.8) on Monday, 3.0M (1.4+1.6) on Tuesday, and 1.4M on Wednesday, Thursday and Friday respectively.

[0066] Therefore, when calculating the average of Monday, Wednesday, Thursday, and Friday (four days) except Tuesday when the discharge amount is the largest, the average value is 1.6M ((2.2+1.4+1.4+1.4) / 4), and the average discharge value of the energy storage device becomes larger compared with the case where the discharge amount is divided at different times (1.4M).

[0067] The increase in the average discharge value of the energy storage device means that the energy storage device is used instead of the power supplied by Korea Electric Power and the like. Therefore, the power usage on the supply side is reduced, and the CBL, which is the customer base load, is reduced.

[0068] It can be seen from this that controlling the energy storage device in such a manner as to divide the power demand response participating capacity and discharge it at different times during the working days of the week, as in the present invention, is beneficial to the customer base load.

[0069] However, the entire time period of the maximum load is composed of multiple unit times in units of one hour (1H). Figure 4 and Figure 5In the example, although the time periods are slightly different, the maximum load in both summer and winter is six hours (six unit times). Therefore, it may happen that the five days including Monday, Tuesday, Wednesday, Thursday, and Friday (which are working days of the week) cannot be dispersed and allocated to six unit times.

[0070] In this way, when the number of unit times (one hour) constituting the time period of the maximum load is greater than the number of working days in a week, the CBL management unit 15 specifies a split discharge week with a number of days equivalent to the difference between the number of unit times and the number of working days in a week. And, in the specified split discharge week, the power demand response participation amount is evenly divided in different time periods and discharged.

[0071] For example, Figure 4 and Figure 5 As shown, on Monday, 1.6M is divided into two 0.8M and discharged at 10 o'clock and 16 o'clock respectively, thereby preventing repeated discharge in the same time period while discharging only during the maximum load time period.

[0072] On the other hand, the load monitoring unit 16 monitors the power usage of the power load that obtains power from the energy storage device, calculates the power usage used by the power load, and compares the power usage with the reference usage for determining an abnormal working day, thereby determining whether the day is an abnormal working day.

[0073] An abnormal working day refers to a day when the value of the average power usage during the reduction period corresponding to the required reduction request for the maximum reference day (10 days or 20 days) is less than 75% of the average power usage, and this day is excluded from the calculation of the reference day.

[0074] That is, if electricity usage is reduced by more than 75% compared to usual times, this day is equivalent to an abnormal working day, not a weekday or weekend (weekends are excluded), and is therefore excluded when calculating CBL as the customer base load.

[0075] Therefore, when the power usage of the power load is maintained above the benchmark usage on an abnormal working day, the dispatcher 14 conducts a power demand response bid, and if the bid is successful, the dispatcher 14 can obtain an additional reduction in the settlement amount according to the content of the successful bid. Even if the bid is unsuccessful, the existing CBL economic operation for preventing the customer's benchmark load from decreasing can be maintained.

[0076] Conversely, when the power usage of the power load is less than the baseline usage on an abnormal working day, the day is an abnormal working day and is therefore excluded from the calculation of the customer baseline load, so the power demand response participating capacity can be freely recalculated and applied.

[0077] At this time, preferably, the discharge is performed at two times in one day, and the discharge is performed at the time when the power demand response is planned according to the schedule of the previous day (an abnormal working day).

[0078] For example, when Tuesday is an abnormal working day, power demand response is participated in on Wednesday, and additionally, bidding may be conducted again at 11 o'clock which is the power demand response participation time on the previous day (Tuesday).

[0079] Of course, when Tuesday is an abnormal working day, it is not necessary to discharge only on Wednesday (the day after Tuesday) in two times, and discharge can also be performed on Thursday or Friday or even on Monday of the following week.

[0080] On the other hand, the template DB 17 and the bid generating unit 18 (not described) are provided as needed. The template DB 17 provides document templates required for bidding for power demand response. The bid generating unit receives the document templates from the template DB 17 and records application items required for bidding for power demand response.

[0081] Therefore, the scheduler 14 transmits the bid generated by the bid generating unit 18 in the form of an electronic file to a bidding agency server such as Korea Electric Power or a power intermediary through the network, so that the power demand response bidding can be automatically performed according to a predetermined process.

[0082] The specific embodiments of the present invention are described above. However, those skilled in the art will appreciate that the concept and scope of the present invention are not limited to the specific embodiments described above, and that various modifications and variations are possible without changing the gist of the present invention.

[0083] Therefore, the embodiments described above are provided to fully inform those skilled in the art of the scope of the present invention, and it should be understood that the embodiments described above are illustrative rather than restrictive in all aspects, and the present invention is defined only according to the scope of the claims.

[0084] Description of reference numerals:

[0085] 11: Load data storage unit

[0086] 12: Power control unit

[0087] 13: DR participation calculation department

[0088] 14: Scheduler

[0089] 15: CBL Management Department

[0090] 16: Load monitoring unit

[0091] 17: Template DB

[0092] 18: Bid generation department.

Claims

1. A device for managing the charging and discharging process of an energy storage device, characterized in that: include: A load data storage unit (11) provides information on maximum load, medium load and light load by collecting statistical data on the user's power usage by season and time period; A power control unit (12) controls the charging and discharging of the energy storage device according to each time period of the maximum load, medium load and light load; A power demand response participation amount calculation unit (13) for calculating the power demand response participation capacity in the total discharge capacity of the energy storage device; A dispatcher (14) that manages a calculation period of a customer base load including power usage during the five working days most recent from the power demand response participation bidding date; as well as A customer reference load management unit (15) determines the discharge amount of the energy storage device by dividing the power demand response participating capacity and discharging it at different times on each weekday managed by the scheduler (14). The customer reference load management unit (15) causes the power demand response to participate in capacity discharge during the maximum load period, and discharges at a later time each day starting from the first working day when discharge starts according to the discharge plan of the power demand response.

2. The energy storage device charging and discharging process management device according to claim 1, characterized in that: The power demand response participating amount calculation unit (13) calculates an average discharge amount that evenly distributes the discharge amount discharged from the energy storage device to the power load in time periods, and calculates the remaining capacity of the total discharge capacity of the energy storage device excluding the average discharge amount as the power demand response participating capacity.

3. The energy storage device charging and discharging process management device according to claim 1, characterized in that: The scheduler (14) transmits a charge / discharge command signal to the power control unit (12) in such a manner that the energy storage device is charged during the light load period and the energy storage device is discharged during the maximum load period.

4. The energy storage device charging and discharging process management device according to claim 1, characterized in that: Also includes: A load monitoring unit (16) monitors the power usage of the power load, The load monitoring unit (16) calculates the amount of electric power used in the electric power load, compares the amount of electric power used with a reference amount of power used to determine an abnormal working day, and thereby determines whether the current day is an abnormal working day.

5. The energy storage device charging and discharging process management device according to claim 4, characterized in that: In the scheduler (14), When the power usage of the power load is maintained at or above the reference usage on the abnormal working day, the power demand response bidding is performed, When the power usage of the power load is less than the benchmark usage on the abnormal working day, the power demand response participation capacity is recalculated.

6. The energy storage device charging and discharging process management device according to claim 1, characterized in that: In the scheduler (14), While waiting for registration and reduction tests or waiting for participation in peak demand power demand response, if no power supply instruction is received until the power demand response trading time period on the bidding day, the energy storage device is discharged during the initial medium load time period after the power demand response trading time period in summer and spring and autumn, and is discharged during the initial maximum load time period after the power demand response trading time period in winter.

7. The energy storage device charging and discharging process management device according to claim 1, characterized in that: The entire time period of the maximum load is composed of a plurality of unit times in units of one hour. The customer reference load management unit (15) specifies a split discharge week by a number of days corresponding to the difference between the number of unit times and the number of working days in a week when the number of unit times constituting the maximum load time period is greater than the number of working days in a week, Furthermore, in the split discharge week, the power demand response participating amount is equally split and discharged in different time periods.

8. The energy storage device charge and discharge process management device according to any one of claims 1 to 7, characterized in that: Also includes: A template DB (17) which provides a document template required for the power demand response bidding; as well as A bid document generating unit (18) receives the document template from the template DB (17) and records application items required for the power demand response bid. The scheduler (14) transmits the bid in the form of an electronic file generated by the bid generating unit (18) to a bidding organization server via a network.

Images