KR102251476B1 - Method for estimating the capacity of an energy storage system associated with renewable energy and apparatus therefor - Google Patents

Abstract

The present invention relates to a method and an apparatus for calculating the capacity of an energy storage system linked to renewable energy, and specifically, to design or operate an energy storage system used to compensate for the unstable output of renewable energy. The present invention relates to a method for calculating the capacity of the energy storage system and an apparatus therefor.

Description

A method for estimating the capacity of an energy storage system associated with renewable energy and apparatus therefor.

The present invention relates to a method and an apparatus for calculating the capacity of an energy storage system linked to renewable energy, and specifically, to design or operate an energy storage system used to compensate for the unstable output of renewable energy. The present invention relates to a method for calculating the capacity of the energy storage system and an apparatus therefor.

Renewable energy refers to energy used by recycling existing fossil fuels or converting renewable energy, and has been suggested as an alternative in response to the increasing demand for fossil fuels as the population increases and the development of industry. will be. Wind energy, solar energy, bio energy, algae energy, geothermal energy, etc. are present in these types of renewable energy, and unlike fossil fuels, these renewable energy are renewable, so there is no fear of depletion. However, it has advantages in that it is eco-friendly because it emits less carbon dioxide, but it is highly influenced by the natural environment when installing structures (power plants) to produce new and renewable energy, and the investment cost is high in the early stages of development and the economy is low. There are also disadvantages such as points.

On the other hand, in addition to the interest in technology related to the production of renewable energy as an energy source, technological interest is constantly increasing in facilities that provide generated power. In particular, the demand for electricity is continuously increasing with the development of the industry. On the other hand, resources for generating electricity are gradually reaching their limits. Recently, systems for efficiently managing the supply and demand of electricity are being studied in various ways. The Energy Storage System was proposed as part of an effort to solve the above problems.In particular, energy is used to eliminate energy waste and consumer discomfort due to an imbalance between the supply and demand of power within the system. In order to provide an environment that can be produced and consumed intentionally, research on energy storage systems has been actively conducted in recent years.

The energy storage system basically refers to a system that stores power generated from an energy source and then utilizes it when necessary.In particular, supply fluctuations, instability, and imbalance are inevitable at the time when energy source conversion to renewable energy is inevitable. Interest in energy storage systems is increasing in order to efficiently utilize new and renewable energy having characteristics of the sex.

In particular, among the shortcomings of the renewable energy source, the instability of the output may cause great damage to the system, and an energy storage system for mitigating the instability of the output is essential. On the other hand, in order to design an energy storage system suitable for the existence of any renewable energy source, it is very important to first determine how much capacity to design an energy storage system that can cover. It will be said that it is important to confirm whether the energy storage system to be operated can operate with a degree of reliability.

The present invention has been proposed in light of this point, and relates to a method and an apparatus capable of calculating the capacity of an energy storage system linked to a renewable energy source and further providing the reliability thereof numerically.

Registered Patent No. 10-1834061 (announced on March 02, 2018)

An object of the present invention is to provide a method and apparatus capable of calculating the capacity of the energy storage system when designing or operating an energy storage system linked to a renewable energy source.

In particular, the present invention uses the predicted information that was predicted in the past for the generation amount (or output) of the renewable energy source, and the actual generation amount information of the corresponding new and renewable energy source, and further, the error rate obtained from the above information. The purpose is to provide a predicted range of power generation amount plus reliability for the power generation amount of a renewable energy source predicted at the time point, and the purpose of allowing the capacity of the energy storage system to be calculated according to the power generation amount forecast range above.

In addition, it is an object of the present invention to provide an energy storage system suitable for a corresponding renewable energy source based on a reliable capacity calculation result when designing an energy storage system linked to a renewable energy source through this.

In addition, according to the present invention, since it is possible to know the predicted range of reliable generation amount for any renewable energy source, it is possible to determine a reference to be output to the load end based on this reference, and based on this reference, the energy storage system Its purpose is to enable operation to control the charging and discharging of the battery.

In addition, it is intended to further increase the operational stability of the energy storage system by utilizing both a long-period battery and a short-period battery when controlling charging and discharging of the energy storage system.

In order to solve the above problem, the method of calculating the capacity of the energy storage system according to the present invention includes: (a) predicted generation amount prediction information of a renewable energy source predicted for a plurality of past time points and production at the past time points. Obtaining an error rate by comparing the actual generation amount information of the new and renewable energy source that has been used; (b) obtaining generation amount prediction information that predicts the generation amount of the renewable energy source for a plurality of future points in time; And (c) generating a generation amount prediction range for the future time points by applying an error range calculated from the error rate to the generation amount prediction information for the future time points.

In addition, in the method of calculating the capacity of the energy storage system, the generation amount prediction information in the step (a) is a set of predicted values of the generation amount of the renewable energy source at the past time points, and the The actual power generation information in step (a) may be a set of actual power generation values of the renewable energy source at the past time points.

In this case, step (c) may include applying an error range calculated from the error rate to the predicted value of the generation amount of the renewable energy source at the future time points.

In addition, in the method of calculating the capacity of the energy storage system, the generation amount prediction range for the future time points in the step (c) is a prediction value and an error range of the generation amount of the renewable energy source at the future time points. It may be characterized in that it is a set of.

In this case, the step (c) may include calculating an average of the error rates from the plurality of error rates obtained for the past time points; Calculating a standard deviation from the average of the error rates and the plurality of error rates; It may include; calculating a range of an error rate according to a predetermined reliability.

Furthermore, in step (c), after the step of calculating the range of the error rate, the upper limit of the range of the calculated error rate is applied to the predicted power generation value at the future time points, so that the power generation amount predicted value and the error range at each future time point are determined. It may also be characterized by acquiring.

In addition, the method of calculating the capacity of the energy storage system may further include (d) determining the capacity of the energy storage system based on the predicted range of the generation amount for the second period after the step (c). I can.

In addition, the method of calculating the capacity of the energy storage system includes (e) defining a reference for charging/discharging operation of the energy storage system for each unit time based on the predicted range of the generation amount after the step (c). It may contain more.

In this case, after the step (e), charging or discharging the short-cycle battery and the long-cycle battery provided in the energy storage system according to the reference; may further include.

On the other hand, the device for calculating the capacity of an energy storage system according to another embodiment of the present invention includes prediction information on a generation amount of a renewable energy source predicted for a plurality of past time points, and the new and renewable energy produced at the past time points. An information collection unit that collects information on the actual amount of power generation of the energy source and information on the amount of power generation predicted by predicting the amount of power generation of the renewable energy source for a plurality of future time points; An error rate is obtained by comparing the predicted generation amount information of the renewable energy source predicted for the plurality of past times with the actual generation amount information of the renewable energy source produced at the past time points, and the amount of power generation for the future time points An operation unit that applies an error range calculated from the error rate to prediction information to generate a power generation amount prediction range for the future time points; And a storage unit for storing the information collected by the information collecting unit and a predicted range of power generation generated by the calculating unit.

According to the present invention, there is an effect of reliably calculating the capacity of an energy storage system.

In addition, according to the present invention, since it is possible to determine the capacity of the energy storage system with relatively high reliability, it is possible to design an energy storage system most suitable for the renewable energy source in terms of cost and efficiency.

In addition, according to the present invention, it is possible to know the predicted range of reliable generation amount, and based on this, the output reference to the load terminal can be determined. There is an effect that can be increased.

In addition, according to the present invention, since two or more batteries having different charge/discharge cycles are mixed, there is an effect of further increasing the stability of the energy storage system.

1 shows a schematic configuration of an energy storage system that is an object of capacity calculation.
FIG. 2 is a schematic diagram of an apparatus capable of performing a capacity estimation method proposed by the present invention, and FIG. 3 is a sequence diagram illustrating a capacity estimation method.
4 shows a state in which the amount of power generation of a renewable energy source is predicted.
FIG. 5 shows the state of the generation amount prediction range obtained by applying an error range to the generation amount prediction information of FIG. 4.
6 shows a state in which an output reference of a renewable energy source is determined based on a predicted range of power generation.
7 and 8 illustrate a state in which the energy storage system is charged and discharged according to the output reference when an output reference is determined.

Details of the objects and technical configurations of the present invention, as well as operational effects thereof, will be more clearly understood by the following detailed description based on the accompanying drawings in the specification of the present invention. An embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

The embodiments disclosed herein should not be construed or used as limiting the scope of the present invention. It is natural for those skilled in the art that the description including the embodiments of the present specification has various applications. Accordingly, any of the embodiments described in the detailed description of the present invention are exemplary for better describing the present invention, and it is not intended that the scope of the present invention be limited to the embodiments.

The functional blocks shown in the drawings and described below are only examples of possible implementations. In other implementations, other functional blocks may be used without departing from the spirit and scope of the detailed description. Further, although one or more functional blocks of the present invention are represented as individual blocks, one or more of the functional blocks of the present invention may be a combination of various hardware and software configurations that perform the same function.

In addition, the expression that includes certain elements is an expression of “open type” and simply refers to the existence of the corresponding elements, and should not be understood as excluding additional elements.

Furthermore, when a component is referred to as being “connected” or “connected” to another component, it should be understood that it may be directly connected or connected to the other component, but other components may exist in the middle. do.

Prior to a full description of the present invention, first, a basic configuration of the technical field to which the present invention pertains will be described with reference to FIG. 1. 1 is a view for understanding the technical field to which the present invention pertains, and is a diagram for schematically explaining an energy storage system subject to capacity calculation in the present invention, and configurations around the energy storage system.

1, the energy storage system 10 is connected to the renewable energy source 30 and the grid 20 at the same time, and basically, the energy storage system receives and stores power generated from the renewable energy source. Or supply it back to the grid side.

The term renewable energy source referred to in this detailed description may be understood to mean facilities capable of producing energy, that is, power by using renewable energy more specifically, including wind power plants, geothermal power plants, May include solar power plants, bioenergy power plants, tidal power plants, etc. For reference, in this detailed description, a wind power plant will be described as a representative example of a renewable energy source to aid understanding of the invention.

On the other hand, the grid 20 refers to a power grid that delivers electricity produced in a power plant to a consumer, and this may include components necessary to supply power to individual loads such as transmission lines and substations.

The energy storage system 10 may include an energy management unit 11, a battery unit 13, and a power conversion unit 12 as a basic configuration as shown in FIG. 1, and in addition to this, the battery management unit 14 May be further included.

First, the energy management unit (11, Energy Management System) analyzes the energy use pattern in the system and allows the supply of energy to be adjusted based on the analyzed use pattern.It collects information on the entire power supply system and load frequency at all times. It refers to a configuration that optimally controls the operation of power generation facilities linked to the system through monitoring, and performs economic power supply through efficient management of the power system. The energy management unit collects information such as power consumption demand and current power situation of users in the system, and analyzes the power consumption pattern from the past to the latest. Also, based on the analyzed power consumption pattern, the future Another function is to predict the power consumption and adjust the charge/discharge schedule in the energy storage system accordingly. In addition, the energy management unit may monitor the amount of power produced from the renewable energy source at all times, and accordingly, may control charging and discharging of the batteries by controlling the battery unit and the power conversion unit.

Next, the power conversion unit (12, Power Conditioning System) is an intermediate-stage system that basically connects the power produced from the energy source to the power system, and performs conversion between AC and DC, voltage/current/frequency conversion, etc. do. For example, energy supplied from a renewable energy source may be charged to the battery unit through a power conversion system, or energy discharged from the battery unit may be supplied to the system through the power conversion unit. In addition, the power conversion unit may be driven under the control of the energy management unit, and in particular, may control charging and discharging of the batteries included in the battery unit by referring to data received from the energy management unit. In this case, the data that the power converter can refer to may include a real-time amount of power of the power supplied from the renewable energy source, a real-time variation value of the supplied power frequency, and the like.

Next, the battery unit 13 basically includes batteries capable of charging or discharging for mitigating unstable power supplied from the aforementioned renewable energy source, and at this time, the batteries provided in the battery unit are charged differently. It may be two or more batteries having a discharge period. Preferably, the two or more batteries may include a short-cycle battery 13a and a long-cycle battery 13b, that is, one having a relatively short period of charge and discharge, and the other having a relatively long period of charge and discharge. . In addition, the batteries mentioned in this detailed description may include various things such as a flow battery and a secondary battery, and for example, a flywheel, a NAS, an all-solid-state battery, and the like may be included. For reference, in this detailed description, a lithium ion battery will be referred to as a representative example of a short-cycle battery, and a vanadium redox flow battery as a representative example of a long-cycle battery. It will be said that there is no limitation on the type as long as it is not limited to the embodiment and can be defined by a relative difference in charge/discharge cycles.

Finally, the energy storage system may further include a battery management system 14. The battery management unit senses the voltage, current, and temperature of the battery and controls the charge/discharge amount of the battery to an appropriate level. It also performs cell balancing of the battery and monitors the remaining capacity of the battery. In addition, the battery management unit protects the battery by performing an emergency operation when a dangerous situation occurs. This battery management unit performs a separate function from the power conversion unit described above, but has a common point in that each has control rights for the battery.Depending on the design, the power conversion unit and the battery management unit may be implemented as a single server. I can.

In the above, the basic configuration of an energy storage system subject to capacity calculation in the present invention has been described.

FIG. 2 is a schematic diagram of an apparatus for executing a method according to the present invention, that is, a method of calculating a capacity of an energy storage system, and FIG. 3 is a sequence listing a method of calculating a capacity of an energy storage system.

For reference, in this detailed description, a device for capacity calculation will be shown and described as if it is a separate and independent device, but as a device capable of performing the capacity calculation method according to the present invention, a central processing unit (CPU) and a memory are provided. All types of devices may be understood to be included in the'device for calculating the capacity of an energy storage system (hereinafter referred to as a device for calculating the capacity)' that the present invention claims. In particular, it is understood that the device for calculating the capacity according to the present invention may be understood to be the same as a part constituting the energy storage system described in FIG. 1, for example, an energy management unit (EMS) or a power management unit (PCS). .

Hereinafter, an apparatus and a method for calculating capacity according to the present invention will be described in detail with reference to FIGS. 2 and 3.

According to FIG. 2, the apparatus 100 for calculating the capacity of the energy storage system may largely include an information collection unit 101, an operation unit 103, and a storage unit 105.

First of all, the information collection unit 101 collects information that predicted the amount of generation of new and renewable energy sources in the past, that is, information about the amount of generation of generation of new and renewable energy sources, and further collects information about the amount of actual generation of new and renewable energy sources in the past. Refers to the composition. The generation amount prediction information, the actual generation amount information, and the like collected by the information collection unit may be received from a separate server existing outside. In addition, the prediction information of the generation amount of the renewable energy source is not limited to the prediction method (a prediction method based on weather information, a prediction method using artificial intelligence, etc.). The information collected by the information collecting unit includes, for example, the wind power plant during past preset times or periods (April 25, 2018 13:00-13:30), assuming that there is a wind power plant. 'Generation amount prediction information' may be included as to how much power generation (output) will be produced, and'actual power generation information', which is the amount of power actually produced by the wind power plant during the same time periods or periods as above, may be included. have. On the other hand, this is only one embodiment, and the information collection unit is the predicted generation amount predicted information for the renewable energy source at past times or periods, and the corresponding renewable energy source actually outputs during the same times or periods. It is possible to collect information on the actual generation amount, which is the amount of electricity.

On the other hand, the generation amount prediction information that the information collection unit can collect may include not only the past but also future time points based on the present time point. That is, the above information collection unit can collect predicted information on the amount of power generation of the corresponding renewable energy source regardless of the past or future time point, and the actual power generation information of the corresponding renewable energy source can be collected on the past.

Next, the calculation unit 103 is the most central configuration in the apparatus for calculating the capacity according to the present invention, and after performing a series of calculations based on the information collected by the information collection unit, finally, the new reproduction It can be understood as a configuration that generates a predicted range of power generation for future points in time for an energy source. One of the most important objectives of the present invention is to provide the generation amount of a new and renewable energy source in a'range', if the generation amount prediction information predicted for the conventional renewable energy sources was prediction information consisting of only one value at each time point. , In the present invention, by further providing an expected range of the output value of the renewable energy source based on a predicted value, it is possible to calculate the capacity based on reliable data when designing an energy storage system. I did it.

Among the steps performed by the operation unit 103 to calculate the capacity, the error rate is calculated by comparing the predicted generation amount prediction information in the past and the actual generation amount information in the same period (time points). A step may be included, and a step of generating a generation amount prediction range by applying the error range calculated from the above error rate to the generation amount prediction information for a future period (time points) may be included. Each of the steps performed by the operation unit to calculate the capacity will be described in detail in the detailed description with reference to the accompanying drawings.

Finally, the storage unit 105 is included in the device for calculating the capacity. The storage unit 105 is a configuration capable of storing information such as the information previously collected by the information collecting unit 101 and a result of the calculation unit 103, such as a power generation amount prediction range. The storage above is ROM (Read Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), Flash memory, SRAM (Static RAM), HDD (Hard Disk Drive), SSD (Solid State Drive) may be implemented.

FIG. 3 is a sequence diagram of a method for calculating a capacity of an energy storage system by an apparatus for calculating capacity.

With reference to this, the method comprises a step of collecting, by the information collection unit, information on predicting the generation amount of a new renewable energy source predicted for a plurality of past time points among the configurations of the device for capacity calculation (S101), and the past time points. It may be started from the step (S102) of collecting the actual power generation information of the corresponding renewable energy source at the same time points. Renewable energy sources have unstable output due to their nature, so the expected amount of power generation, that is, the amount of output, is calculated based on past data, and this predicted amount of power is used as a reference for determining the charge/discharge schedule of the energy storage system (ESS) in the future. It is used as data. For example, in the case of a wind power plant, the amount of output fluctuates depending on the weather, and such wind power generation amount prediction information may be generated by referring to weather information that can be obtained from the outside and information on the amount of past power generation in the same time period.

On the other hand, after steps S101 and S102, among the configurations of the device for calculating the capacity, the calculating unit may compare the previously collected generation amount prediction information with the actual generation amount information to obtain an error rate (S103). In this case, the error rate represents an index of how much the difference between the predicted power generation amount and the actual power generation amount is, for example, the error rate can be calculated by the following equation.

At this time, the power generation amount predicted value refers to the power generation amount value predicted at a certain point in the past among the power generation amount prediction information, and the actual power generation amount value refers to the power amount value actually generated at that time point. In other words, the error rate refers to the calculated value of how much difference between the predicted value and the actual value, as can be guessed from the meaning of this term.

On the other hand, after calculating and obtaining the error rate, the information collection unit in the configuration of the apparatus for calculating the capacity according to the present invention obtains the generation amount prediction information that predicts the generation amount of the new and renewable energy source for the future point(s). (S104) The generation amount prediction information for future time points acquired in this step may also be a result calculated by various methodologies (weather information-based, artificial intelligence-based) like the power generation amount prediction information for past time points.

For reference, FIG. 4 shows an example of the generation amount prediction information obtained in step S104, and the graph shown in FIG. 4 shows the generation amount prediction information for an arbitrary period in the future, but the generation amount prediction information for a past arbitrary period Again, it is understood that only the shape of the graph is different and can be illustrated in this way. 4, the graph shows generation amount prediction information for a wind power plant. The horizontal axis of the graph represents time, and the vertical axis represents the amount of power generation. The unit time in the time axis may be arbitrarily set according to the user's intention, and for example, the unit time may be set in various ways such as 1 minute, 10 minutes, 1 hour, and 1 day. In addition, although the above generation amount prediction information is macroscopically shown as a single connected graph line, it is understood through the enlarged drawing that the _{corresponding generation amount prediction information is actually a set of generation amount prediction values (P GEN) at a plurality of past points in time.} I can. That is, the dotted rectangle in FIG. 4 is an enlarged view of the corresponding area, and it can be seen that generation values corresponding to a plurality of viewpoints exist in the enlarged area, and the connection of these generation values becomes the generation amount prediction information. . For example, each point marked in the enlarged area may be predicted values of the amount of power generated by the wind power plant predicted at 10-minute intervals.

On the other hand, after obtaining the generation amount prediction information for the future arbitrary points in step S104, the calculation unit of the configuration of the device for capacity calculation applies the error range calculated from the error rate to the previously acquired generation amount prediction information (in the future). Generate a prediction range (S105). That is, in step S105, even though the generation amount prediction information has already been obtained for the future random times, the error range calculated from the past data is overlaid on the generation amount prediction information. It can be understood as a step of providing a range that can reliably inform whether or not to have.

5 shows an example of a predicted range of power generation, which is an output generated by an operation unit. Looking at this, it can be seen that the generation amount prediction range is that an arbitrary gray area is overlaid above and below the graph of the generation amount prediction information shown in FIG. 4. Recalling that the generation amount prediction information is a set of values predicted for a plurality of time points, the power generation amount prediction range may be understood as a set of a plurality of error ranges calculated from error rates for a plurality of time points. When looking at the enlarged area of FIG. 5, it can be seen that a predicted power generation value exists at a certain point in time, and an error range of error rates Da and Db above and below this power generation value is applied to form one line segment. have. The power generation prediction range in FIG. 5 can be understood as information formed by a collection of a plurality of power generation prediction values and error ranges at each of these time points, and a region formed by a set of a plurality of line segments corresponding to each time point visually. I can.

On the other hand, if we relate to the meaning of the power generation amount prediction range of FIG. 5, it means that the amount of power that the wind power plant can produce at any future time point, that is, the predicted value of the amount of power generation, may exist within the error range, for example. When the predicted power generation value at 13:00 on June 10, 2019 is 5kW, and the error rate calculated from past data is ±5%, the wind power generation value at that time is ±5 based on 5kW. It can be interpreted as being within the error range of %.

Meanwhile, in the step S105, various methods may exist in a method in which the calculation unit applies an error range to the generation amount prediction information for the future time points.

For example, the calculation unit can calculate a plurality of error rates based on the predicted generation value and actual generation value for 13:00 for the past week, and calculate the generation amount predicted value corresponding to 13:00 of the next day. As a reference, after calculating an upper limit value and a lower limit value according to the average value of the error rates, the upper limit value and the lower limit value may be generated as one error range. In addition, by repeating this process for other points in time, the operation unit may generate a single generation amount prediction range consisting of a plurality of error ranges.

As another example, the operation unit may statistically use error rate values obtained from past data to further increase the reliability of the error range. For example, as a result of calculating the error rate for the same time period for n days, if the average of the error rate is D _M and the standard deviation is σ _{1 , the error rate value (D m} ) in the 95% confidence interval according to n observations The range can be calculated as the following equation.

에 대응되는 A값과

에 대응되는 B값의 사이에 존재할 수 있으며, 위 식으로부터는 오차율이 매우 높은 확률로 A값과 B값 사이에 존재할 것임을 의미함을 알 수 있으므로, 연산부로서는 더 큰 값인 B를 발전량 예측값에 적용시킴으로써 해당 시점에서의 오차범위를 연산할 수 있다. That is, the error rate value (D _m ) is

A value corresponding to and

It can exist between the B values corresponding to, and from the above equation, it can be seen that the error rate will exist between the A and B values with a very high probability. You can calculate the error range at that point in time.

As such, the calculation unit obtains an error rate by comparing the generation amount prediction information obtained by the information collecting unit and the actual generation amount information, and applies the error range calculated from the error rate to the generation amount prediction information for the'future' time points. You can create a prediction range.

On the other hand, unlike the above embodiment, the calculation unit in the present invention can statistically calculate the generation amount prediction range by using only the actual generation amount values for a plurality of points in the past without calculating the error rate. . In this case, the information collection department will say that it is not necessary to collect the generation amount prediction information for the past time points, and only the actual generation amount information must be collected.

For example, as a result of analyzing the actual power generation values for the same time period for n days, when the average of the actual power generation values is G _M and the standard deviation is σ2, the power generation value predicted in the 95% reliability interval according to n observations ( The range of G _m ) can be calculated as the following equation.

과

사이에 존재할 수 있으며, 연산부는 위 범위를 곧 오차범위로 삼아 최종적으로 발전량 예측범위를 산출할 수도 있다. 이처럼 본 발명에서의 연산부는 오차율이 아닌 실제 발전량 정보만을 가지고도 미래 시점들에 대한 발전량 예측범위를 생성할 수도 있다.In other words, the predicted power generation value (G _m ) at a future point in time is

and

It may exist between, and the calculation unit may use the above range as an error range and finally calculate the generation amount prediction range. As described above, the calculation unit in the present invention may generate the generation amount prediction range for future time points only with the actual generation amount information, not the error rate.

Meanwhile, after the generation amount prediction range is generated in step S105, the capacity of the energy storage system may be determined based on this (S106). In this case, the capacity of the energy storage system may be a standard value within the error range of the predicted power generation value that can be checked in the predicted power generation amount generated previously.

So far, an apparatus and a method for calculating the capacity of an energy storage system have been described with reference to FIGS. 2 to 5.

Hereinafter, a method of operating an energy storage system will be described with reference to FIGS. 6 to 8, based on the predicted range of the generated power generation amount. For reference, FIGS. 6 to 8 assume a state in which the device for capacity calculation described above is provided in the energy storage system. As already mentioned in the previous description, the device for capacity calculation is an energy management unit (Energy Management). System) or the power conversion unit (Power Conditioning System) and at least the same or at least the capacity calculation device can perform all the functions performed by the energy management unit or the power conversion unit is premised.

6 is a diagram illustrating a state in which a reference (horizontal line) is defined for each arbitrary section when the generation amount prediction range is generated by the operation unit. The above reference is defined based on the amount of power generated by a renewable energy source (wind power plant) at future points in time. For example, the reference may be defined as an average value of the predicted range of power generation amount predicted for each section. . Meanwhile, as will be described later, the defined reference may serve as a reference for the operation of the energy storage system, more precisely, the operation of the battery unit.

The graph of FIG. 7 is an easy-to-understand view of charging or discharging of the battery unit according to the actual power generation amount of the wind power plant in a state in which a reference is defined. The dotted rectangle in FIG. 7 represents a section in which the reference K is already defined based on the predicted range of power generation, and a graph with different heights within the square represents the amount of power actually output from the wind power plant. In accordance with this, the operation of the battery unit in the energy storage system is such that charging occurs when the power generation amount of the wind power plant has a higher value than the reference, and discharge occurs when the amount of power generation is less than the reference, so that the amount of power provided to the grid side. It can be seen that it is being performed to enable smoothing.

On the other hand, FIG. 8 shows an embodiment in which the battery unit in the energy storage system operates using two different types of batteries, that is, a short-cycle battery and a long-cycle battery. A short-cycle battery can be charged for a section that exceeds a certain reference line (dotted line), and a long-cycle battery can be charged for a section that does not exceed the baseline (dotted line). The battery may be discharged, and the long-period battery may be discharged for a period that does not exceed the reference line.

As described above, according to the present invention, charging and discharging of the battery unit is performed based on the reference (K), but it is possible to charge and discharge short-cycle batteries and long-cycle batteries according to the level of power generation, thereby extending the life of each battery. In addition, it is possible to reduce the maintenance cost and improve the safety of the entire energy storage system.

As described above, a method for calculating the capacity of an energy storage system linked to renewable energy and an apparatus for the same have been described. The present invention is not limited to the specific embodiments and application examples described above, and various modifications can be implemented by those of ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, these modified implementations should not be understood as being distinguished from the technical idea or perspective of the present invention.

10 energy storage system
11 Energy management unit 12 Power conversion unit 13 Battery unit 14 Battery management unit
13a short cycle battery 13b long cycle battery
20 grid
30 Renewable energy sources
Device for calculating 100 capacity
101 Information Collection Department
103 Operation unit
105 storage

Claims (10)

In the method of calculating the capacity of the energy storage system,
(a) Power generation amount prediction information of the renewable energy source predicted for a plurality of past time points-The power generation amount prediction information is a set of prediction values of the power generation amount of the renewable energy source at the past time points-and the past time points Obtaining an error rate by comparing the actual generation amount information of the new and renewable energy source produced at -the actual generation amount information is a set of actual generation amount values of the new and renewable energy source at the past time points;
(b) obtaining generation amount prediction information that predicts the generation amount of the renewable energy source for a plurality of future points in time; And
(c) generating a generation amount prediction range for the future time points by applying an error range calculated from the error rate to the power generation amount predicted value of the new and renewable energy source at the future time points;
Including,
The predicted range of generation amount for the future time points in step (c) is a set of the predicted value of power generation amount of the renewable energy source and an error range at the future time points,
The step (c),
Calculating an average of the error rates from the plurality of error rates obtained for the past time points;
Calculating a standard deviation from the average of the error rates and the plurality of error rates;
Calculating a range of an error rate according to a predetermined reliability;
Characterized in that it comprises a,
How to estimate the capacity of an energy storage system.
delete delete delete delete The method of claim 1,
The step (c),
After the step of calculating the range of the error rate,
By applying the upper limit of the range of the calculated error rate to the predicted power generation value at the future time points, the power generation amount predicted value and the error range at each future time point are obtained,
How to estimate the capacity of an energy storage system.
The method of claim 1,
After step (c) above,
Step (d) determining the capacity of the energy storage system based on the predicted range of the generation amount generated in step (c);
Further comprising,
How to estimate the capacity of an energy storage system.
The method of claim 1,
After step (c) above,
(E) defining a reference for charging/discharging operation of the energy storage system for each unit time based on the generation amount prediction range;
Further comprising,
How to control the energy storage system.
The method of claim 8,
After step (e),
Charging or discharging a short cycle battery and a long cycle battery provided in the energy storage system according to the reference;
Further comprising,
How to control the energy storage system.
In the device for calculating the capacity of the energy storage system,
Power generation amount prediction information of the renewable energy source predicted for a plurality of past times-The power generation amount prediction information is a set of predicted power generation amount of the renewable energy source at the past time points -, which was produced at the past time points The actual power generation amount information of the new and renewable energy source-The actual power generation amount information is a set of actual power generation amount values of the new and renewable energy source at the past time points-and of the new and renewable energy source for a plurality of future time points. An information collection unit that collects generation amount prediction information that predicts the amount of power generation;
An error rate is obtained by comparing the predicted generation amount information of the renewable energy source predicted for the plurality of past times with the actual generation amount information of the new renewable energy source produced at the past time points, and obtained the error rate at the future time points. An operation unit for generating a predicted range of generation amounts for the future time points by applying an error range calculated from the error rate to a predicted value of the generation amount of a renewable energy source; And
A storage unit for storing information collected by the information collecting unit and a predicted range of generation amount generated by the calculating unit;
Including,
The generation amount prediction range for the future time points is a set of the power generation amount prediction value and the error range of the renewable energy source at the future time points,
The operation unit,
Computing an average of error rates from a plurality of error rates obtained for the past time points, calculating a standard deviation from the average of the error rates and the plurality of error rates, and calculating a range of error rates according to a predetermined reliability Characterized in that to run,
A device for estimating the capacity of an energy storage system.

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