Method for controlling output of multiple energy storage system

Abstract

The present disclosure relates to a method for controlling multiple ESS outputs. A method according to one embodiment of the present disclosure checks the battery status of a plurality of energy storage devices (ESS) individually to check the available battery remaining amount in real time, dynamically sets the battery output distribution ratio according to the battery status, and can determine a charging and discharging schedule according to the battery output distribution ratio.

Description

Technology Field

[0001] The present invention relates to a multi-ESS output control method. Background Technology

[0002] Currently, battery types include lithium-ion (NCM-based) batteries and lead-acid batteries, which have achieved significant commercialization. In addition, numerous batteries utilizing new methods and constituent materials are being developed, such as lithium-sulfur batteries, lithium iron phosphate batteries, and lithium titanium oxide batteries, which improve stability and output compared to conventional lithium-ion batteries, as well as nickel-hydrogen batteries and redox flow batteries.

[0003] As various types of batteries are developed, energy storage devices can be configured using multiple types of batteries, and in this case, control methods that maximize the characteristics of each battery are required.

[0004] Furthermore, for the operation of the power system on a ship, energy storage devices must generally be charged using available power—excluding essential loads based on the grid's supply capacity—and supplied by discharging from the storage devices if power is insufficient. Since there are spatial and weight limitations when installing energy storage devices on ships compared to onshore installations, selecting the appropriate battery type for vessels subject to rapid load fluctuations is crucial. Battery selection must consider factors such as energy density, output, and cost, and multiple types of batteries can be applied. Consequently, an output control system capable of maximizing battery lifespan and efficiency is required.

[0005] Measures for the efficient and stable utilization of energy storage devices are required in overall fields that utilize batteries, such as terrestrial energy storage systems or electric vehicles. The problem to be solved

[0006] According to one embodiment of the present invention, a multi-ESS output control method is provided that enables stable power supply to the power grid through output control of an energy storage device composed of various types of batteries. means of solving the problem

[0007] To solve the problem of the present invention described above, a multi-ESS output control method according to one embodiment of the present invention may provide a method comprising: a step of individually checking the battery status of a plurality of energy storage devices to check the available battery remaining amount in real time; a step of dynamically setting the output distribution ratio of the battery according to the battery status; and a step of determining a charging and discharging schedule according to the output distribution ratio of the battery.

[0008] Additionally, the step of dynamically setting the output distribution ratio may include: a step of calculating the expected lifespan of each of a plurality of energy storage devices; and a step of setting the output distribution ratio higher in order of the energy storage devices with the higher calculated expected lifespans.

[0009] Additionally, the setting step may include the step of calculating the installation capacity of each of the plurality of energy storage devices.

[0010] Additionally, the setting step may include: a step of calculating the maximum output of each of a plurality of energy storage devices; and a step of setting the output distribution ratio higher in order of the energy storage devices with the larger calculated maximum output.

[0011] Additionally, the setting step may include: a step of calculating the time required to charge each of a plurality of energy storage devices; and a step of setting the output distribution ratio higher in order of the energy storage devices with the shorter calculated charging time.

[0012] Additionally, the setting step may include: a step of calculating the time required for discharge of each of a plurality of energy storage devices; and a step of setting the output distribution ratio higher in order of the energy storage devices with the longer calculated time required for discharge.

[0013] Additionally, the setting step may include: a step of calculating the discharge amount of each of a plurality of energy storage devices; and a step of setting the output distribution ratio higher in order of the energy storage devices with the smaller calculated discharge amount.

[0014] In addition, a method may be provided that further includes the step of proceeding with a charging and discharging schedule so that charging and discharging of the energy storage device are performed according to a set output distribution ratio.

[0015] Other aspects, features, and advantages other than those described above will become clear from the following drawings, scope of patent application, and detailed description of the invention. Effects of the invention

[0016] According to one embodiment of the present invention, an efficient grid configuration is possible through the configuration of an energy storage device according to various types of batteries, and by mixing batteries of various prices, both economic efficiency and control stability can be improved.

[0017] In addition, output distribution that takes into account the output characteristics of various types of batteries has the effect of allowing for the maximum lifespan of the energy storage device.

[0018] In addition, according to one embodiment of the present invention, it is possible to operate an energy storage device capable of responding to rapid load fluctuations, and by linking or integrating with a power management system (PMS) on board a ship, it is possible to prevent overload and blackout, thereby enabling stable power system operation. Brief explanation of the drawing

[0019] FIG. 1 is an exemplary drawing for explaining a power system connected with various types of energy storage devices according to one embodiment. FIG. 2 is an exemplary diagram illustrating an output control system linked with multiple energy storage devices. Figure 3 is an exemplary diagram illustrating the distribution of output according to load fluctuations when multiple energy storage devices are connected. Specific details for implementing the invention

[0020] The advantages and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments presented below, but can be implemented in various different forms and should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. The embodiments presented below are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In describing the present invention, detailed descriptions of related known technologies are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0021] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0022] Some embodiments of the present disclosure may be represented by functional block configurations and various processing steps. Some or all of these functional blocks may be implemented by various numbers of hardware and / or software configurations that execute specific functions. For example, the functional blocks of the present disclosure may be implemented by one or more microprocessors or by circuit configurations for a specific function. Additionally, for example, the functional blocks of the present disclosure may be implemented in various programming or scripting languages. The functional blocks may be implemented as algorithms executed on one or more processors. Furthermore, the present disclosure may employ prior art for electronic configuration, signal processing, and / or data processing, etc. Terms such as “mechanism,” “element,” “means,” and “configuration,” etc., may be used broadly and are not limited to mechanical and physical configurations.

[0023] Furthermore, the connecting lines or connecting members between the components depicted in the drawings are merely illustrative of functional connections and / or physical or circuit connections. In the actual device, connections between components may be represented by various alternative or added functional connections, physical connections, or circuit connections.

[0024] FIG. 1 is an exemplary drawing for explaining a power system connected with various types of energy storage devices according to one embodiment.

[0025] Referring to FIG. 1, a power system connected to various types of energy storage devices may include a Power Conversion System (PCS) (110) and a Battery Management System (BMS) (120) for each type of battery (100).

[0026] In one embodiment, the battery management system (120) includes a battery control unit and a switching unit and manages the battery unit. The battery control unit receives information about the battery unit and performs calculations. The battery management system may receive information directly or through a measuring unit. The information includes the time at which a turn-off command is received and the open circuit voltage (OCV), and may further include the level of the output current, the state of charge (SOC) of each battery (one of B1 to Bn), etc.

[0027] The battery control unit can transmit signals to the outside indicating whether the battery unit is capable of charging or discharging, or if there are any abnormalities, based on the received information. The battery control unit is turned on for a predetermined period by the turn-on current (Ito) from the interface unit, and receives a control current (Ict) by turning on the first transistor during the turned-on period. Additionally, after receiving a turn-off command from the outside, if preset conditions are satisfied, the switching unit can be turned off to cut off the control current (Ict). The turn-off command may be received from the outside through the interface unit to the battery management system, or it may be received through a separate path not shown in FIG. 1. However, the battery control unit determines whether preset conditions are satisfied based on the received information of the battery unit. The switching unit is turned off only when preset conditions are satisfied. The preset conditions may include whether a preset time has elapsed after receiving a turn-off command, or whether the difference between the maximum and minimum values ​​of the open circuit voltage during a certain period is smaller than a preset size.

[0028] A switching unit is positioned between a battery unit and a battery control unit and includes a first transistor and a regulator. The first transistor is positioned between the battery unit and the regulator, and the gate electrode of the first transistor is electrically connected to the battery control unit. The battery control unit controls the level of the control current by changing the voltage level supplied to the gate electrode of the first transistor. In response to a turn-off command from the outside, the switching unit is turned off when a preset condition is satisfied, and the control current (Ict) is cut off due to the turn-off of the first transistor in the switching unit. The regulator removes ripple from the current from the battery unit.

[0029] Types of batteries may include lithium-ion batteries, lead-acid batteries, lithium-sulfur batteries, lithium iron phosphate batteries, lithium titanium oxide batteries, nickel-hydrogen batteries, and redox flow batteries.

[0030] FIG. 2 is an exemplary diagram illustrating an output control system linked with multiple energy storage devices.

[0031] Referring to FIG. 2, each of the different types of Energy Storage Systems (ESS) (210) may have a Local EMS (220) for each output control system, and a Master EMS (230) for controlling each output control system (220) may be configured at the upper level.

[0032] The battery state of each type of energy storage device (ESS) (210) may include different characteristics that the battery may have, such as energy density, price, lifespan, thermal runaway temperature, discharge depth, efficiency, charging and discharging speed, fire and explosion risk, operating temperature, heat generation, lifespan, and installed capacity and maximum output.

[0033] The master output control system (230) is an external control system that performs monitoring and control by being connected to the output control system (220) of a plurality of energy storage devices (210) via a communication line. It is linked or integrated with the onboard power management system (PMS) that operates the power system based on the difference between the load consumption and the power generation amount within the grid, and shares battery characteristics and information such as power generation capacity, charge amount, load amount, expected lifespan, and time required for charging and discharging. Based on this, it can transmit control signals between the onboard power management system (PMS) and the output control system (220) of the plurality of energy storage devices (210).

[0034] The master output control system (230) may include the steps of individually checking the battery status and characteristics for a plurality of energy storage devices and checking the remaining battery capacity in real time. Additionally, it may include the step of dynamically setting the output distribution ratio of the battery according to the battery status and characteristics. Additionally, it may include the step of determining a charging and discharging schedule according to the output distribution ratio of the battery.

[0035] The step of dynamically setting the output distribution in the master output control system (230) may include the step of calculating the expected lifespan of each of the plurality of energy storage devices, and may further include the step of setting the output distribution ratio higher in order of the energy storage devices with the higher expected lifespans calculated.

[0036] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include the step of calculating the installation capacity of each of the plurality of energy storage devices, and may further include the step of setting the output distribution ratio higher in order of the energy storage devices with the larger calculated installation capacity.

[0037] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include the step of calculating the maximum output of each of the plurality of energy storage devices, and may further include the step of setting the output distribution ratio higher in order of the energy storage devices with the larger calculated maximum output.

[0038] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include a step of calculating the time required for charging each of a plurality of energy storage devices, and may further include a step of setting the output distribution ratio higher in order of the energy storage devices with the shorter calculated charging time.

[0039] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include the step of calculating the time required for discharge of each of the plurality of energy storage devices, and may further include the step of setting the output distribution ratio higher in order of the energy storage devices with the longer calculated time required for discharge.

[0040] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include a step of calculating the load amount of each of the plurality of energy storage devices, and may further include a step of setting the output distribution ratio higher in order of the energy storage devices with the higher calculated load amount.

[0041] Additionally, the step of dynamically setting the output distribution in the master output control system (230) may include a step of calculating the discharge amount of each of the plurality of energy storage devices, and may further include a step of setting the output distribution ratio higher in order of the energy storage devices with the smaller calculated discharge amount.

[0042] Additionally, the master output control system (230) may further include a step of performing a charging and discharging schedule so that charging and discharging are performed first in order of energy storage devices with a higher output distribution ratio.

[0043] The output distribution ratio of the battery may be flexibly set according to each of the battery's state and characteristics, or may be flexibly set according to multiple states and characteristics.

[0044] For example, energy storage devices with the longest remaining expected lifespan can be prioritized for charging and discharging to ensure uniform lifespan management for installed batteries. Additionally, by considering both charging and discharging speeds and the State of Charge (SOC), the output allocation ratio of energy storage devices with a large remaining charge and faster charging speeds can be increased to handle a greater load. Furthermore, by considering both the C-rate and maximum output, the output allocation ratio of energy storage devices with higher C-rates and higher maximum outputs can be increased to handle a greater load. Moreover, by considering the installed capacity, Depth of Discharge (DOD), and remaining expected lifespan, the output allocation ratio of energy storage devices with large installed capacity, low discharge rates, and long remaining expected lifespans can be increased to handle a greater load.

[0045] In other words, one may select and consider one of the battery's states and characteristics, or one may select multiple states and characteristics and consider them in various combinations.

[0046] While battery states and characteristics may be considered in equal proportions, a flexible output distribution ratio can be established by assigning priorities among them, giving higher priority to those states and characteristics at a higher proportion. Alternatively, if the output distribution ratios are equal, the system may be configured so that the energy storage device with a higher output distribution ratio for higher priority battery states and characteristics takes priority in handling the load.

[0047] For example, if price is set as the highest priority, the system can be configured so that the energy storage device with the lowest price takes priority in handling the load when the output distribution ratio is the same.

[0048] The output distribution ratio can be flexibly set by category by grouping states and characteristics with similar properties.

[0049] For example, battery charge status, charge amount, and discharge amount can be included in a single category. Additionally, thermal runaway temperature, operating temperature, and the risk of fire and explosion can be included in a single category and considered together when dynamically setting the output distribution ratio. Furthermore, a dynamic output distribution ratio can be set by considering both of the aforementioned categories.

[0050] In addition, by assigning priorities to grouped categories, the output distribution ratio can be flexibly set by giving higher priority categories a greater proportion. If the output distribution ratios are equal, the system can be configured so that the energy storage device with the higher output distribution ratio of the higher priority category takes priority in handling the load.

[0051] The above items can be applied during both charging and discharging.

[0052] Figure 3 is an exemplary diagram illustrating the distribution of output according to load fluctuations when multiple energy storage devices are connected.

[0053] Referring to FIG. 3, in the case of a battery type with low output and a large decrease in lifespan due to charging and discharging cycles, it can be controlled to handle an output where the change in charging and discharging amount is not large (310).

[0054] In the case of a battery type capable of high output and long charging and discharging cycles, it can be controlled to handle output that responds to rapid load fluctuations (330).

[0055] According to one embodiment, the master output control system can select one of a plurality of energy storage devices to control charging and discharging, and can select a plurality to control charging and discharging.

[0056] According to one embodiment, various embodiments of the present disclosure may have characteristics of a power source different from existing power generation systems (rotating machine-based power sources) by adding a fuel cell to an energy storage device, which is an essential component of the present invention. Even though the characteristics of the power source have changed, the Master Energy Management System (Master EMS) can analyze the amount of power generated by the power source and perform control to operate each energy storage device (ESS) in an optimal state.

[0057] The scope of the present embodiment is not limited by the aforementioned embodiment and the attached drawings, but is defined by the claims set forth below, and should be interpreted to include all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents. Explanation of the symbols

[0058] 100 : Battery type 110: Power converter 120: Battery Management System 210: Energy storage device 220: Output control system 230: Master Output Control System

Claims

Claim 1 A method for configuring an ESS output control system that reflects the characteristics of each of a plurality of energy storage devices of different battery types, comprising: a step of individually checking the battery status of the plurality of energy storage devices to check the available battery remaining amount in real time; a step of dynamically setting an output distribution ratio for the plurality of energy storage devices of different battery types based on a priority set for each of the plurality of battery characteristics according to the plurality of battery characteristics included in the battery status; and a step of determining a charging and discharging schedule according to the set output distribution ratio of the batteries. Claim 2 A multi-ESS output control method according to claim 1, wherein the plurality of battery characteristics include the expected lifespan of an energy storage device, and the setting step includes the step of setting the output distribution ratio higher as the expected lifespan increases. Claim 3 A method for controlling multiple ESS outputs according to claim 1, wherein the plurality of battery characteristics include the installed capacity of an energy storage device. Claim 4 A method for controlling multiple ESS outputs according to claim 1, wherein the plurality of battery characteristics include the maximum output of an energy storage device, and the setting step includes the step of setting the output distribution ratio higher as the maximum output increases. Claim 5 A method for controlling multiple ESS outputs according to claim 1, wherein a plurality of battery characteristics include a time required for charging an energy storage device, and the setting step includes a step of setting an output distribution ratio higher as the time required for charging becomes shorter. Claim 6 A method for controlling multiple ESS outputs according to claim 1, wherein the plurality of battery characteristics include the time required for discharging an energy storage device, and the setting step includes the step of setting the output distribution ratio higher as the time required for discharge increases. Claim 7 A multi-ESS output control method according to claim 1, wherein the plurality of battery characteristics include a load amount of an energy storage device, and the setting step includes a step of setting a higher output distribution ratio in order of energy storage devices as the load amount increases. Claim 8 A multi-ESS output control method according to claim 1, further comprising the step of performing a charging and discharging schedule so that charging and discharging of an energy storage device are performed according to a set output distribution ratio.

Images