Charge / discharge control system and charge / discharge control method of energy storage system capable of setting charge / discharge output upper limit in accordance with state of charge

Abstract

To provide a system and a method that most efficiently use an ESS in an extent that a problem of battery safety is not induced.SOLUTION: An ESS charge / discharge control system according to the present invention comprises: a data collection unit for collecting ESS operation record data; a data learning unit for generating an OCV-SoC table on the basis of the ESS operation record data; a voltage upper limit calculation unit for calculating a charge / discharge voltage upper limit on the basis of a V-SoC table during charging and a V-SoC table during discharging calculated on the basis of the OCV-SoC table and the ESS operation record data; an output upper limit calculation unit for calculating SoC ranges of charging and discharging in accordance with the calculated voltage upper limit, and calculating an output upper limit in accordance with the calculated SoC ranges of charging and discharging; and an ESS operation unit for executing an ESS charge / discharge command on the basis of the output upper limit in accordance with the SoC ranges of charging and discharging, and the calculated SoC ranges of charging and discharging.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a system and method for charging and discharging an energy storage system, and more particularly to an ESS charging and discharging system and method for setting an upper limit of charging and discharging output according to SoC so that an ESS can be used most efficiently without inducing a battery safety problem such as a fire. [Background technology]

[0002] An Energy Storage System (ESS) is a device that stores generated electricity and then makes it possible to reuse the stored electricity when it is needed. Therefore, the use of ESS has made it possible to use energy more efficiently in the preliminary stages of power generation, transmission, substations, distribution and storage. In addition, the power generated by new renewable energies such as solar and wind power is difficult to predict accurately and has a high output fluctuation rate, so the quality of the power was not uniform when connected to the power grid, but the use of ESS has made it possible to use power of a more uniform quality.

[0003] In order to use such ESS more safely and efficiently, various research and development of safety and efficiency related technologies for batteries is underway. In particular, control technologies such as monitoring various parameters such as the charge state, temperature, voltage, and current of each battery cell, calculating the state of charge (hereinafter referred to as "SoC"), cell balancing that balances the degree of charge and discharge of each battery cell, and protection functions such as preventing overvoltage, overcurrent, and overcharging are being actively researched and developed.

[0004] In particular, the most important ESS charging methods among these ESS control technologies include the constant current method, the constant power method, and the constant voltage method, and among these, the constant power method (hereinafter referred to as "CP") is most widely used due to its ease of control according to the instantaneous power amount.

[0005] CP charging uses a constant power, so the current decreases as the battery voltage rises with the progress of charging. Due to this voltage rise during charging, the ESS reaches the safe operating voltage of the battery cell before the battery is fully charged, causing a failure of the ESS system. Since this ESS failure occurs when the cell goes outside of its safe operating voltage range, appropriate voltage management is essential.

[0006] However, in the past, attempts were made to estimate the battery SoC based on the open circuit voltage (OCV) value and then control the voltage based on this. However, the SoC estimated through the OCV differed from the SoC value calculated based on the voltage during actual battery charging and discharging, and the voltage change patterns according to output and SoC were different, which created problems in using the SoC during ESS operation. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent No. 10-2493221 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, the present invention has been devised to solve the above-mentioned problems, and its object is to provide an ESS charging / discharging system that can use the ESS most efficiently without causing battery safety issues by calculating in advance the maximum output that can be driven by the SoC during the charging / discharging process.

[0009] However, the various problems that the present invention is intended to solve are not limited thereto, and are included in the specific contents described in the detailed description of the present invention. [Means for solving the problem]

[0010] The ESS charge / discharge control system of the present invention may include a data collection unit that collects ESS operation record data; a data learning unit that generates an OCV-SoC table based on the ESS operation record data; a voltage upper limit calculation unit that calculates a charge / discharge voltage upper limit based on the OCV-SoC table, a V-SoC table during charging calculated based on the ESS operation record data, and a V-SoC table during discharging; an output upper limit calculation unit that calculates a charge and discharge SoC range according to the calculated voltage upper limit and calculates an output upper limit according to the calculated charge and discharge SoC range; and an ESS operation unit that executes an ESS charge / discharge command based on the charge and discharge SoC range and the output upper limit according to the calculated charge and discharge SoC range.

[0011] In this case, the voltage upper limit calculation unit can calculate the inflection point and the safe upper and lower limit SoC values ​​of the battery based on the OCV-SoC table.

[0012] In addition, the voltage upper limit calculation unit can calculate a voltage upper limit during charging based on a V-SoC table during charging, an inflection point, and a safe upper limit SoC of the battery.

[0013] In addition, the voltage upper limit calculation unit can calculate a voltage upper limit during discharge based on a V-SoC table during discharge, an inverse point of an inflection point, and a safe lower limit SoC of the battery.

[0014] In addition, the output upper limit calculation unit can cluster power-SoC data based on the ESS operation record data, derive SoC intervals during charging based on the V-SoC table of at least a part of the clustered clusters and the voltage upper limit during charging, and derive output upper limits for each SoC interval during charging.

[0015] In addition, the output upper limit calculation unit may derive an SoC range during discharging based on an inverse point of an SoC that is a range maximum value of an SoC range during charging, and derive an output upper limit for each SoC range during discharging.

[0016] Meanwhile, the ESS charge / discharge control system further includes a charge / discharge planning unit, and the ESS operation unit may transmit a control command to the ESS according to a planned charge / discharge amount and charge / discharge time to perform charging / discharging.

[0017] In addition, the ESS operation unit may ignore the charge / discharge plan and interrupt charging / discharging if the current instantaneous voltage value falls outside the safe operating voltage range of the ESS.

[0018] In addition, when the current power amount collected through the data collection unit becomes lower than the minimum base power, the ESS operation unit ignores the charge / discharge plan, executes a discharge command to make the current power amount equal to the minimum base power, and can stop charging / discharging if there is no remaining battery power.

[0019] In addition, the ESS charge / discharge control system further includes an SoC estimation unit, and the ESS operation unit transmits a charge / discharge command to the ESS according to the charge / discharge plan set by the charge / discharge plan unit, and can interrupt charging / discharging when the remaining battery level is insufficient or the battery is fully charged according to the SoC estimated by the SoC estimation unit.

[0020] In addition, the ESS operation unit can transmit a charge / discharge command to the ESS according to the charge / discharge plan set by the charge / discharge planning unit, and generate a control command for the ESS based on the output upper limit for each SoC section calculated by the output upper limit calculation unit. Effect of the Invention

[0021] Therefore, according to the present invention, an ESS charging / discharging system can be obtained that can use the ESS most efficiently within a range that does not induce battery safety issues by calculating in advance the maximum output that can be driven by the SoC during the charging / discharging process.

[0022] The effects of the present invention are not limited to the above-mentioned examples, and various other effects are included in the present specification. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a block diagram showing an ESS charge / discharge control system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart for explaining the charge and discharge operation of the ESS charge and discharge control system according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a flowchart illustrating a step of calculating an upper limit of an ESS charge / discharge voltage according to an embodiment of the present invention. [Figure 4] FIG. 4 is a graph showing an OCV-SoC according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a graph showing V-SoC during charging operation according to an embodiment of the present invention. [Figure 6] FIG. 6 is a graph showing V-SoC during discharging operation according to an embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart illustrating a step of calculating an upper limit of an ESS charge / discharge output according to an embodiment of the present invention. [Figure 8] FIG. 8 is a graph showing power-SoC versus past charging data in charging and discharging an ESS according to an embodiment of the present invention. [Figure 9] FIG. 9 is a V-SoC graph during CP charging operation at a specific power according to an embodiment of the present invention. [Figure 10] FIG. 10 is a V-SoC graph during CP charging operation at a specific power according to an embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing a charge / discharge power control period based on SoC data according to an embodiment of the present invention. [Figure 12] FIG. 12 is a diagram showing a charge / discharge power control period based on SoC data according to an embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing a charge / discharge power control period based on SoC data according to an embodiment of the present invention. [Figure 14] FIG. 14 is a graph showing a charge / discharge operation plan and an actual operation during an ESS charge / discharge operation as a conventional technique. [Figure 15]FIG. 15 is a graph showing a charge / discharge operation plan and an actual operation during the ESS charge / discharge operation according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. The following embodiments are provided to fully disclose the present invention and to allow those skilled in the art to fully understand the scope of the invention. Also, the dimensions of components in the drawings may be exaggerated or reduced for ease of explanation.

[0025] However, the following embodiments are provided to enable a person having ordinary skill in the art to fully understand the present invention, and the present invention can be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0026] On the other hand, throughout the specification, when a part is said to "include" a certain element, this does not exclude other elements, unless specifically stated to the contrary, but means that the part may further include other elements.

[0027] The above-mentioned objects and features will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, which will enable those skilled in the art to which the present invention pertains to easily implement the technical ideas of the invention.

[0028] Next, an ESS charge / discharge control system according to an embodiment of the present invention will be described in detail with reference to FIG.

[0029] Referring to FIG. 1, an ESS charge / discharge control system 1000 according to an embodiment of the present invention may include an analysis unit 100 and an ESS 200.

[0030] The analysis unit 100 can set an output upper limit for each SoC, a bank operation range, and upper and lower limits of a cell voltage operation range, and can perform possible operation output by checking the possible output range before executing an operation plan. In addition, the analysis unit 100 can recalculate the output at one-minute intervals in order to sensitively respond to voltage changes. In the present embodiment, the analysis unit 100 can be embodied as a server, for example, but can also be embodied as various devices such as a personal computer, a notebook PC, or a tablet PC that can perform a computing function and machine learning.

[0031] More specifically, the analysis unit 100 according to an embodiment of the present invention may include an analysis control unit 110, a data collection unit 120 that collects ESS operation records, a data learning unit 130 that derives an OCV-SoC table based on the ESS operation records, a voltage upper limit calculation unit 140 that calculates a step-by-step charge / discharge voltage upper limit by analyzing the OCV-SoC table, an output upper limit calculation unit 150 that calculates an output upper limit for each charge / discharge SoC range according to the calculated voltage upper limit, and an ESS operation unit 160 that executes an ESS charge / discharge command according to a determined SoC range, output / voltage range, and operation plan. A detailed configuration of the analysis unit 100 will be described in more detail later in the operation description section referring to FIG. 2.

[0032] The analysis unit 100 may further include a charge / discharge planner 170 and an SoC estimator 180 for an ESS charge / discharge command. The charge / discharge operation plan of the charge / discharge planner 170 and the SoC estimation operation of the SoC estimator 180 may utilize the charge / discharge operation method of the AI-based predictive ESS charge / discharge operation device and method (Korean Patent No. 10-2232513) and the ESS optimal operation system and method using adaptive SoC estimation (Korean Patent No. 10-2493221). The Korean Patent Nos. 10-2232513 and 10-2493221 are incorporated herein by reference.

[0033] Meanwhile, the ESS 200 may include an ESS control unit 210, a PCS 220, a BMS 230, and a battery 240. In this case, the ESS control unit 210 may control the PCS 220 based on operation plan data or a control command received from the analysis unit 100, and may provide voltage, current, and power data related to the ESS operation to the analysis unit 100 or other databases.

[0034] The PCS (Power Conditioning System) 220 is a component for converting DC power into AC power or DC power to charge and discharge the battery 240, and the PCS 220 has safe operating voltage information of the battery 240 constituting the ESS 200, or can be provided via the analysis unit 100 and the ESS control unit 210. At this time, the safe operating voltage information can be the capacity of the PCS 220 (half that of a normal battery) and the maximum charging output associated therewith. In addition, the ESS control unit 210 can set the upper and lower limits of the SoC to 10% to 90% or a range equivalent thereto for the safety of the battery.

[0035] Meanwhile, the BMS (Battery Management System) 230 is configured to manage each battery 240, and can control a situation where only some of the battery cells among the plurality of battery cells are overcharged or not charged by controlling charging and discharging of each battery cell in the battery 240. The BMS 230 can also store an ESS operation record at a minimum interval of one minute. In this case, the stored ESS operation record can include, for example, the instantaneous current (A), instantaneous voltage (V), SoC (%), and output (kWh). Here, the ESS operation record can further include power demand (kWh). The ESS operation record is also collected together with a timestamp so that time information indicating the time when each data of the instantaneous current (A), instantaneous voltage (V), SoC (%), output (kWh), and power demand (kWh) of the battery can be confirmed. The ESS operational record is created by the BMS 230 by collecting data including battery instantaneous current (A), instantaneous voltage (V), SoC (%), output (kWh) and power demand (kWh) for a given period of time, along with time information identifying the time the data was collected.

[0036] 2 to 13, a detailed configuration and operation of the analysis unit 100 that can set an operation plan for the ESS 200 by setting the range of SoC and determining the output power / voltage upper limit for each SoC range will be described. In this case, the analysis control unit 110, data collection unit 120, data learning unit 130, voltage upper limit calculation unit 140, output upper limit calculation unit 150, and ESS operation unit 160, which are detailed configurations of the analysis unit 100, may be software, a software module, hardware, a hardware module, or a combination of software and hardware.

[0037] The analysis control unit 110 may be implemented, for example, by a processor or software executed on a processor. In this case, the analysis control unit 110 may control the data collection unit 120, the data learning unit 130, the voltage upper limit calculation unit 140, the output upper limit calculation unit 150, and the ESS operation unit 160, and manage the overall operation of the analysis unit 100.

[0038] The overall operation of the analysis section 100 is as shown in FIG.

[0039] First, the data collector 120 queries, receives, and transmits the past operation details for a given period from the ESS operation records stored in the BMS 230 or a separate database in response to a request from the data learner 130 (S100).

[0040] In this case, data can be collected from the BMS 230 or database either by directly connecting to the database or via a RestAPI of an Energy Management System (EMS). In this case, the data collector 120 collects the instantaneous current (A), instantaneous voltage (V), SoC (%), and output (kWh) of the battery 240 stored in the BMS 230 together with a time stamp.

[0041] Next, the data learning unit 130 generates an OCV-SoC table based on the collected ESS operation record data (S200). In this case, the OCV-SoC table can be derived, for example, as described in Korean Patent Registration No. 10-2493221, which is incorporated herein by reference.

[0042] The voltage upper limit calculation unit 140 can calculate the charge / discharge voltage upper limit using the OCV-SoC table, the V-SoC curve during maximum output charging, and the V-SoC table during discharging (S300).

[0043] Specifically, referring to Figures 3 and 4, first, the voltage upper limit calculation unit 140 may determine the inflection point SoC1 where the slope of the OCV-SoC curve increases sharply and the voltages corresponding to the battery's safe upper and lower limits of SoC (S310). For example, the battery's safe upper and lower limits of SoC may be 90% and 10%, respectively.

[0044] The voltage upper limit calculation unit 140 calculates a V-SoC table (relationship between voltage and SoC) during maximum output charging of the ESS 200 based on the ESS operation record data, and then calculates the upper voltage limits (V1 to V4) during charging based on the V-SoC table during maximum output charging, the inflection point, and the SoC of the battery safety upper limit (S320). At this time, the OCV-SoC curve is a value estimated based on an open circuit voltage value, and may be different from the actual V-SoC curve when the ESS 200 is charged at maximum output.

[0045] 5, the upper voltage limit calculation unit 140 can derive a voltage V1 corresponding to the inflection point SoC1 in the V-SoC curve during maximum output charging, and can calculate a voltage V4 corresponding to V1 and the battery safety upper limit SoC.

[0046] After calculating V1 and V4, the voltage upper limit calculation unit 140 can calculate, for example, the midpoint between V1 and the battery safe upper limit SoC voltage (for example, the voltage (V) when the SoC is 90% on the OCV-SoC curve) as V2, and the midpoint between V2 and V4 as V3.

[0047] In this case, the voltage upper limit calculation unit 140 can generate V1 to V4 calculated as described above as the voltage upper limits (V1 to V4) during charging.

[0048] Meanwhile, the voltage upper limit calculation unit 140 calculates the upper voltage limit (V a ~V d ) can be calculated (S330).

[0049] More specifically, referring to FIG. 6, the voltage upper limit calculation unit 140 calculates a voltage V aHere, the inverse point means the difference between 100% and the point SoC. For example, the inverse point of the inflection point SoC1 described above means the SoC corresponding to 100-SoC1.

[0050] In addition, the voltage upper limit calculation unit 140 calculates a voltage V corresponding to the lower safe limit SoC of the battery in the OCV-SoC. d (For example, the voltage when the SoC is 10% in OCV-SoC) and again, V in the V-SoC curve during maximum output discharge a and V d The upper limit of the discharge voltage can be calculated based on the above. For example, V a and V d Divide into thirds and choose the larger of the three points as V b , the smaller of the three equal points is V c After setting the discharge voltage upper limit (V a , V b , V c , V d ) can be calculated.

[0051] 2, after the charge / discharge voltage upper limit is calculated, the output upper limit calculation unit 150 can calculate and set the charge / discharge output upper limit based on the charge voltage upper limit and the discharge voltage upper limit (S400).

[0052] 7, first, the output upper limit calculation unit 150 can cluster the power-SoC data based on the past ESS operation record data (S410). Referring to Fig. 8, the output upper limit calculation unit 150 separates the power-SoC data during charging based on the past ESS operation record data into five clusters (differentiated by color) based on, for example, the average power value.

[0053] In this case, the cluster with the highest power value (orange) among the clusters is the power-SoC data when charging at maximum output power, which corresponds to the V-SoC curve when charging at maximum output obtained earlier. Since this is a case where charging is performed at maximum output, there is no need to obtain a separate output upper limit.

[0054] Meanwhile, the output upper limit calculation unit 150 can derive the SoC ranges (SoC1 to SoC4) based on the V-SoC of each cluster and the upper voltage limit during charging (S420).

[0055] Specifically, the output upper limit calculation unit 150 can calculate a V-SoC table as shown in FIG. 9 by using data corresponding to the cluster (purple) with the second highest power value among the clusters. At this time, the SoC (SoC2) corresponding to the charging power upper limit (V2) can be obtained. In addition, the output upper limit calculation unit 150 can calculate a V-SoC as shown in FIG. 10 by using data corresponding to the cluster (red) with the third highest power value among the clusters, and can obtain an SoC (SoC3) corresponding to the charging power upper limit (V3) at this time. The output upper limit calculation unit 150 can calculate a V-SoC by using data corresponding to the fourth highest cluster (green) in the same manner, and then obtain an SoC (SoC4) corresponding to V4. That is, the maximum SoC (SoC2 to SoC4) that does not exceed V2, V3, and V4 can be calculated based on the V-SoC curves at the top three outputs excluding the maximum power. In this manner, for example, an SoC section during charging as shown in FIG. 11 can be derived.

[0056] Then, the output upper limit calculation unit 150 derives an output upper limit for each SoC section during charging (S430).

[0057] More specifically, the ESS 200 during charging has a maximum output with an output upper limit in a section (1) having an SoC smaller than SoC1. In a section (2) between SoC1 and SoC2, the output upper limit is set to a power value corresponding to the cluster with the second highest power value (e.g., 80 kWh in FIG. 6). In a section between SoC2 and SoC3, the output upper limit can be set to a power value corresponding to the cluster with the second highest power value (e.g., 60 kWh in FIG. 6).

[0058] However, if the SoC is equal to or higher than a reference value, for example, 80% or higher, the output upper limit can be set to an output value determined for the safety of the battery. For example, for an SoC of 80% or higher, the output upper limit can be fixed to (maximum power) / 5 in the 80%-85% range, and to maximum power / 10 in the 85%-90% range, for the safety of the battery.

[0059] On the other hand, if the SoC value (SoC4) that is the reference for the last section among the above-mentioned sections does not reach 80%, the output upper limit calculation unit 150 can determine an output value determined from the SoC value (SoC4) that is the reference for the last section as the output upper limit. For example, in Fig. 11, control can be performed to (maximum power) / 5 in section (4) that exceeds 80%, but in the example of Fig. 12, since SoC4 does not exceed 80%, control can be performed to charge from SoC4 to (maximum power) / 5.

[0060] Therefore, the output upper limit calculation unit 150 can generate the maximum SoC value (SoC1 to SoC4) for each interval and the charging output upper limit value corresponding to each interval.

[0061] During discharging, an output upper limit for each SoC section is derived based on the inverse point of the maximum SoC value for each section during charging (S440).

[0062] In the discharging process, the same method as in the charging process (i.e., clustering based on power-SoC data) cannot be applied for the following reasons.

[0063] 1) The charging process must proceed quickly during light load times, but the discharging process is generally calculated based on electricity rates.

[0064] 2) Price variables are values ​​that fluctuate arbitrarily, making it difficult to clearly estimate and apply output upper limits based on existing ESS operation data.

[0065] Therefore, when charging, the lower limit of the discharge SoC is derived based on the inverse point of the maximum SoC value (SoC1 to SoC4) of each section, and then the possible upper limit of the output is calculated. At this time, the output upper limit calculation unit 150 calculates the upper limit of the voltage (V a ~V d ) can be used to determine the output upper limit.

[0066] First, the output upper limit calculation unit 150 sets the discharge output upper limit at maximum power in the section (6) up to the inverse point (100-SoC1) of SoC1, as opposed to charging. At this time, the inverse point (100-SoC4 to 100-SoC1) of the maximum SoC value (SoC1 to SoC4) in each section during charging obtained in the above-mentioned charging process is obtained, and the discharge SoC section can be set as shown in FIG.

[0067] In this case, the output upper limit calculation unit 150 calculates the voltage range (V a ~V d For example, during discharge, the SoC sections (7), (8), and (9) are set to V b , V c , V d More specifically, among the discharge data corresponding to the SoC section (7), the maximum output that does not exceed V b The upper limit of the discharge output can be set to the maximum output among the data that does not exceed V. c The upper limit of the discharge output can be set to the maximum output among the data that does not exceed V. d The data not exceeding the above value can be selected, and the maximum output among them can be selected as the upper limit of the discharge output.

[0068] In the above-described manner, the output upper limit calculation unit 150 can generate the upper limit of the charging output and the upper limit of the discharging output.

[0069] Finally, the ESS operation unit 160 can perform charging / discharging by transmitting a control command to the PCS 220 via the ESS control unit 210 according to the charge / discharge amount and charge / discharge time planned by the charge / discharge planning unit 170 (S500).

[0070] However, the ESS operation unit 160 according to an embodiment of the present invention basically generates a control command to operate the ESS according to the charge / discharge operation plan of the charge / discharge planning unit 170, and operates the ESS with the following priorities in consideration of maintaining a safe operating voltage and minimum base power of the ESS.

[0071] Priority 1: If the current instantaneous voltage value is outside the safe operating voltage range of the ESS, ignore the charging / discharging plan and interrupt charging / discharging.

[0072] Priority 2: If the current power amount collected through the data collector 120 becomes lower than the minimum base power, ignore the charge / discharge plan, execute a discharge command to make it equal to the minimum base power, and stop charging / discharging if there is no remaining battery power.

[0073] Priority 3: Execute a charge / discharge command according to the charge / discharge plan set by the charge / discharge plan unit 170, and interrupt charge / discharge if the remaining battery power is insufficient or full according to the SoC estimated by the SoC estimation unit 180.

[0074] Priority 4: The ESS operation unit 160 generates an operation output control command based on the SoC-specific output upper limit calculated by the output upper limit calculation unit 150 during ESS operation.

[0075] When the ESS was operated by setting an output upper limit for each SoC according to the present invention, the failure rate was reduced and the operation rate of the ESS increased by more than 20%p compared to the existing operation method. When the ESS was operated according to the present invention, the operation rate of the existing operation method was 76.8% over the same period, while the operation rate after applying the method of the present invention was 98.2%, and the ESS could be used more efficiently by operating according to an optimized schedule.

[0076] In addition, excluding the variation caused by the difference between the predicted solar radiation amount and the actual solar radiation amount, the ESS was able to be used very efficiently almost as planned. Referring to Figure 14, it can be seen that before the application of the method of the present invention, the output upper limit was not properly set, and it was not possible to operate as planned.

[0077] In particular, in section 1200, there is a very large difference between the purple blocks in Figure 14, which is the operation plan, and the yellow line, which is the actual operation data. This is thought to be because the output upper limit has not been properly set, making it impossible to operate as planned.

[0078] However, referring to Fig. 15, it can be seen that the ESS is operated to be more similar to the ESS operation plan after applying the method according to the embodiment of the present invention. Specifically, in section 1300 in Fig. 15, which corresponds to section 1200, it can be seen that there is very little difference between the purple blocks of the operation plan and the yellow line which is the actual operation data, and that the difference occurs only in the section where there is a variation caused by the difference between the predicted solar radiation value and the actual solar radiation amount.

[0079] Therefore, according to the present invention, an ESS charging / discharging system can be provided that can use the ESS most efficiently within a range that does not cause a safety issue for the battery by pre-calculating the maximum output that can be driven by the SoC during the charging / discharging process.

[0080] Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made within the scope of the technical idea of ​​the present invention. Therefore, the embodiments disclosed in the present invention are merely for the purpose of explanation, and are not intended to limit the technical idea of ​​the present invention. Therefore, the above-described embodiments should be understood as illustrative and not restrictive in all respects. The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0081] 100 Analysis section 110 Analysis control section 120 Data collection section 130 Data learning section 140 Voltage upper limit calculation section 150 Output upper limit calculation section 160 ESS operation unit 170 Charge / discharge planning unit 180 SoC estimation section 200 ESS

Claims

1. a data collection unit that collects ESS operation record data; A data learning unit that generates an OCV-SoC table based on ESS operation record data; a voltage upper limit calculation unit that calculates a charge / discharge voltage upper limit based on the OCV-SoC table, a V-SoC table during charging calculated based on ESS operation record data, and a V-SoC table during discharging; an output upper limit calculation unit that calculates a range of the SoC for charging and discharging according to the calculated upper voltage limit, and calculates an output upper limit according to the calculated range of the SoC for charging and discharging; an ESS operation unit that performs an ESS charge / discharge command based on the charge / discharge SoC range and an output upper limit according to the calculated charge / discharge SoC range; An ESS charge and discharge control system.

2. The ESS charge / discharge control system of claim 1 , wherein the upper voltage limit calculation unit calculates an inflection point and upper and lower safe SoC values ​​of a battery based on an OCV-SoC table.

3. 3. The ESS charge / discharge control system according to claim 2, wherein the voltage upper limit calculation unit calculates the upper limit voltage during charging based on a V-SoC table during charging, an inflection point, and a battery safety upper limit SoC.

4. 4. The ESS charge / discharge control system according to claim 3, wherein the voltage upper limit calculation unit calculates the upper voltage limit during discharge based on a V-SoC table during discharge, an inverse point of an inflection point, and a battery safe lower limit SoC.

5. 5. The ESS charge / discharge control system of claim 4, wherein the output upper limit calculation unit clusters power-SoC data based on ESS operation record data, derives SoC ranges during charging based on a V-SoC table of at least a portion of the clustered clusters and a voltage upper limit during charging, and derives output upper limits for each SoC range during charging.

6. The ESS charge / discharge control system of claim 5 , wherein the output upper limit calculation unit derives the SoC range during discharge based on an inverse SoC point that is a maximum value of the SoC range during charging, and derives an output upper limit for each SoC range during discharge.

7. Further including a charge / discharge planning unit, The ESS charge / discharge control system according to claim 1 , wherein the ESS operation unit transmits a control command to the ESS according to a planned charge / discharge amount and charge / discharge time to perform charging / discharging.

8. a data collection component collecting ESS operational record data; A data learning unit generates an OCV-SoC table based on ESS operation record data; a voltage upper limit calculation unit calculating a charge / discharge voltage upper limit based on an OCV-SoC table, a V-SoC table during charging calculated based on ESS operation record data, and a V-SoC table during discharging; an output upper limit calculation unit calculating a range of SoC for charging and discharging according to an upper limit of a charging and discharging voltage, and calculating an output upper limit according to the calculated range of SoC for charging and discharging; generating an ESS charge / discharge command based on the charge / discharge SoC range and an output upper limit according to the calculated charge / discharge SoC range; An ESS charge / discharge control method comprising:

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