WO2024076014A1

WO2024076014A1 - Energy storage system

Info

Publication number: WO2024076014A1
Application number: PCT/KR2023/013486
Authority: WO
Inventors: Heejoong JANG; Dongkeun Yang; Hyoungsuk Woo
Original assignee: Lg Electronics Inc.
Priority date: 2022-10-07
Filing date: 2023-09-08
Publication date: 2024-04-11
Also published as: KR20240048675A

Abstract

An energy storage system according to an embodiment of the present disclosure includes: a battery pack including a first battery module and a second battery module that are disposed to face each other; a battery cooling plate disposed to correspond to the first and second battery modules and through which a coolant flows; a first Peltier module having one surface disposed toward the first battery module; a second Peltier module having one surface disposed toward the second battery module; a cooling fan disposed on one side of the battery pack to supply air to an air channel formed between another surface of the first Peltier module and another surface of the second Peltier module; and a damper disposed on another side of the battery pack to open and close the battery pack.

Description

ENERGY STORAGE SYSTEM

The present disclosure relates to an energy storage system, and more particularly, to a battery-based energy storage system and an operating method thereof.

An energy storage system is a system that stores or charges external power and then externally outputs or discharges stored power. To this end, the energy storage system includes a battery, and a power conditioning system is used for supply of power to the battery or output of power from the battery.

Higher the temperature of the battery, the greater the possibility of explosion or ignition. When the battery is used continuously in a state where the temperature of the battery is high, it leads to a reduction in the lifespan of the battery. In addition, when the battery is used in a state where the temperature of the battery is low, internal resistance is increased, which results in low efficiency and difficulty in achieving high output. Therefore, in terms of efficiency and safety, the temperature of the battery should be controlled at an appropriate level.

U.S. Patent Application No. 8557414, published on Feb. 25, 2011, (hereinafter referred to as Prior Literature 1), which is hereby incorporated by reference, discloses an air-cooling type for cooling a battery. The air-cooling type of Prior Literature 1 requires a configuration for utilizing compressed air, such as a compressor to compress air and a tank to store the same, which is not suitable for evenly recovering waste heat in the battery.

Korean Patent Application No. 10-1588572, published on Jan. 20, 2016, (hereinafter referred to as Prior Literature 2), which is hereby incorporated by reference, discloses a hermetic battery pack based on air cooling. The battery pack includes a battery module assembly (BMA) including a plurality of battery cells, a first sealing housing which includes an upper object and a lower object in a cube-like shape with an open top so as to primarily seal the plurality of battery cells in contact with a first heat sink and a second cold sink, a second sealing housing which has a cube-like shape with an open upper surface surrounding an outer circumferential surface of the first sealing housing with upper and lower objects so as to secondarily seal the plurality of battery cells in contact with the first heat sink and the second cold sink, and a Peltier element that is inserted into an insertion groove in a cooling fin housing having a first cooling fin on a lower surface thereof, is in contact with the second cold sink through a cold block for cooling concentration, and is formed in a structure sealed by the second sealing housing and the cooling fin hosing.

In the case of the cooling structure of Prior Literature 2, a heat sink is provided on a heating surface of the cooling plate for air heat dissipation, which is disadvantageous in that preheating of the battery pack is not available and achieving a compact size is difficult due to the heat sink and the like.

It is an objective of the present disclosure to provide an energy storage system that can effectively control the temperature of a battery by controlling the temperature of both the outside and inside of a battery pack.

It is another objective of the present disclosure to provide an energy storage system that can additionally adjust the temperature in a battery pack according to circumstances, while stably controlling the temperature of the entire system using water cooling.

It is yet another objective of the present disclosure to provide an energy storage system equipped with a temperature management means capable of cooling/preheating a battery while achieving a compact structure.

It is yet another objective of the present disclosure to provide an energy storage system that can more stably control the temperature of the system according to operating conditions, thereby increasing the overall efficiency of the system, the lifespan of a battery, charging/discharging speed and efficiency of the battery, etc.

The objectives of the present disclosure are not limited to the objectives described above, and other objectives not stated herein will be clearly understood by those skilled in the art from the following description.

To accomplish the aforementioned objectives, in an energy storage system according to the embodiments of the present disclosure, a battery cooling plate outside a battery pack and a Peltier module inside the battery pack are used, thereby effectively controlling the temperature inside and outside the battery pack.

To accomplish the aforementioned objectives, in the energy storage system according to the embodiments of the present disclosure, the temperature may be additionally adjusted by operating the Peltier module and a fan of the battery pack depending on circumstances, while stably controlling the temperature of an entire system using water cooling.

When a first voltage is applied to the first and second Peltier modules, the one surface of each of the first and second Peltier modules may undergo an endothermic reaction, and the another surface, on an opposite side, of each of the first and second Peltier modules may undergo an exothermic reaction. When a second voltage is applied to the first and second Peltier modules, the one surface of each of the first and second Peltier modules may undergo an exothermic reaction, and the another surface, on an opposite side, of each of the first and second Peltier modules may undergo an endothermic reaction.

The battery cooling fan may be turned on when the one surface of each of the first and second Peltier modules undergoes an endothermic reaction, and the another surface, on the opposite side, of each of the first and second Peltier modules undergoes an exothermic reaction.

In response to the battery cooling fan being turned on, the damper may open an outlet of the air channel.

The first voltage may be applied to the first and second Peltier modules in a cooling mode for battery cooling, and the second voltage may be applied to the first and second Peltier modules in a preheating mode for battery preheating.

The energy storage system may further include a temperature sensor to sense a temperature of the coolant. The first and second Peltier modules may be controlled to be on or off based on the temperature of the coolant sensed by the temperature sensor.

When the temperature of the coolant is greater than or equal to a predetermined temperature, the first voltage may be applied to the first and second Peltier modules.

The energy storage system may further include: a pump to cause the coolant to flow into the battery cooling plate; a heat exchanger for heat exchange of the coolant flowing by the pump with air; and a cooling module including a heat dissipation fan to supply external air to the heat exchanger.

When the temperature of the coolant is below a first reference temperature, the first and second Peltier modules and the battery cooling fan may be controlled to be off, and the heat dissipation fan may be controlled to be on.

When the temperature of the coolant is greater than or equal to the first reference temperature, the first and second Peltier modules may be controlled to be off, and the heat dissipation fan and the battery cooling fan may be controlled to be on.

When the temperature of the coolant is greater than or equal to a second reference temperature, which is higher than the first reference temperature, the first and second Peltier modules, the heat dissipation fan, and the battery cooling fan may be controlled to be on.

The heat dissipation fan may have a rotational speed that varies in response to the temperature of the coolant.

The energy storage system may further include: a first coolant circulation path through which the coolant is supplied from the pump; a second coolant circulation path branched from the first coolant circulation path so as to supply the coolant to a power conditioning system (PCS) water block; a third coolant circulation path branched from the first coolant circulation path so as to supply the coolant to the battery cooling plate; a fourth coolant circulation path through which the coolant discharged from the PCS water block flows; a fifth coolant circulation path branched from the fourth coolant circulation path so as to supply the coolant to the battery cooling plate; a bypass flow path branched from the fourth coolant circulation path so as to supply the coolant to the heat exchanger; a sixth coolant circulation path connected to the battery cooling plate and the bypass flow path; a first heat exchanger flow path connected to an inlet of the heat exchanger and the sixth coolant circulation path; a second heat exchanger flow path connected to an outlet of the heat exchanger; a seventh coolant circulation path connected to the first heat exchanger flow path and the second heat exchanger flow path; and an eighth coolant circulation path connected to the second heat exchanger flow path and the seventh coolant circulation flow path to allow the coolant to flow into the pump.

The energy storage system may further include: a first three-way valve to distribute the coolant in the first coolant circulation flow path to the second coolant circulation path and the third coolant circulation path; a second three-way valve configured such that the coolant in the fourth coolant circulation path is selectively supplied to the fifth coolant circulation path or the bypass flow path; and a third three-way valve configured such that the coolant in the sixth coolant circulation path is selectively supplied to the heat exchanger or the seventh coolant circulation path.

In a preheating mode, the third three-way valve may operate such that the coolant in the sixth coolant circulation path is supplied to the seventh coolant circulation path.

In the preheating mode, the first and the second Peltier modules may be controlled to be on, and the heat dissipation fan and the battery cooling fan may be controlled to be off.

In the preheating mode, the second voltage may be applied to the first and second Peltier modules.

The energy storage system may further include: a first temperature sensor disposed at the eighth coolant circulation path; and a second temperature sensor disposed at the sixth coolant circulation path.

The battery cooling plate may include a front cooling plate and a rear cooling plate disposed on a front surface and a rear surface of the battery pack, respectively.

The battery pack may be provided in plurality, and each of the plurality of battery packs may be provided with the battery cooling plate, the first and second Peltier modules, the battery cooling fan, and the damper.

According to at least one of the embodiments of the present disclosure, the temperature of a battery can be effectively controlled by controlling the temperature of both the outside and inside of a battery pack.

According to at least one of the embodiments of the present disclosure, the temperature can be additionally adjusted in a battery pack according to circumstances, while stably controlling the temperature of an entire system using water cooling.

According to at least one of the embodiments of the present disclosure, as cooling and preheating of a battery are available, the temperature of the battery can be effectively managed within an appropriate temperature range.

According to at least one of the embodiments of the present disclosure, a temperature management means capable of cooling/preheating a battery can be implemented with a compact structure.

According to at least one of the embodiments of the present disclosure, as the temperature of a system is more stably controlled according to operating conditions, the overall efficiency of the system, the lifespan of a battery, charging/discharging speed and efficiency of the battery, and the like can be increased.

Various other effects will be disclosed directly or implicitly in the detailed description according to the embodiments of the present disclosure which will be described later.

FIGS. 1A and 1B are conceptual views of an energy supply system including an energy storage system according to an embodiment of the present disclosure.

FIG. 2 is a conceptual view of a home energy service system including an energy storage system according to an embodiment of the present disclosure.

FIG. 3 is an exploded perspective view of an energy storage system including a plurality of battery packs according to an embodiment of the present disclosure.

FIG. 4 is a conceptual view of a battery pack cooling and preheating system according to an embodiment of the present disclosure.

FIGS. 5A and 5B are views referenced in the description of a battery pack cooling and preheating system according to an embodiment of the present disclosure.

FIGS. 6 and 7 are views for explaining a first cooling mode of an energy storage system according to an embodiment of the present disclosure.

FIGS. 8 and 9 are views for explaining a second cooling mode of an energy storage system according to an embodiment of the present disclosure.

FIGS. 10 and 11 are views for explaining a third cooling mode of an energy storage system according to an embodiment of the present disclosure.

FIGS. 12 and 13 are views for explaining a preheating mode of an energy storage system according to an embodiment of the present disclosure.

FIGS. 14 is a flowchart illustrating a method of operating an energy storage system according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments and may be modified in various forms.

In the drawings, for the sake of clear and brief description, illustration of parts irrelevant to the description is omitted, and the same reference numerals are used for the same or extremely similar parts throughout the specification.

In the following description, a suffix such as "module" and "unit" may be used to refer to elements or components. Use of such a suffix herein is merely intended to facilitate description of the specification, and the suffix itself is not intended to give any special meaning or function. Therefore, the terms "module" and "unit" may be used interchangeably.

Further, in this specification, terms such as "first" and "second" may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another.

"Up (U)" "down (D)" "left (Le)" "right (Ri)" "front (F)" and "rear (R)" used in the drawings are for describing a battery pack and an energy storage system including the battery pack, which may be set differently depending on standards.

Referring to FIGS. 1A and 1B, the energy supply system may include an energy storage system 1 based on a battery 35 in which electric energy is stored, a load 7 that is a power demander, and a grid 9 provided as an external power supply source.

The energy storage system 1 includes the battery 35 that stores (charges) electric energy received from the grid 9 or the like in the form of direct current (DC) or outputs (discharges) the stored electric energy to the grid 9 or the like, a power conditioning system (PCS) 32 for converting electrical characteristics (e.g., AC/DC interconversion, frequency, and voltage) to charge or discharge the battery 35, and a battery management system (BMS) 34 for monitoring and managing information such as the current, voltage and temperature of the battery 35.

The grid 9 may include a power generation facility for generating electric power, a transmission line, and the like. The load 7, which is a demander that consumes power, may include home appliances, such as refrigerators, washing machines, air conditioners, TVs, robot cleaners, and robots, and mobile electronic devices such as vehicles and drones.

The energy storage system 1 may store external power in the battery 35 and then output power to the outside. For example, the energy storage system 1 may receive DC power or AC power from the outside, store the same in the battery 35, and then output the DC power or AC power to the outside.

Since the battery 35 mainly stores DC power, the energy storage system 1 may receive DC power or convert received AC power into DC power, store the DC power in the battery 35, convert the stored DC power into AC power, and supply the AC power to the grid 9 or the load 7.

Here, the PCS 32 in the energy storage system 1 may perform power conversion and charge a voltage in the battery 35 or supply DC power stored in the battery 35 to the grid 9 or the load 7.

The energy storage system 1 may charge the battery 35 based on power supplied from the grid 9, and may discharge the battery 35 when necessary. For example, the electric energy stored in the battery 35 may be supplied to the load 7 in an emergency such as a power outage, or at a time, date, or season when the electric energy supplied from the grid 9 is expensive.

The energy storage system 1 has the advantage of being able to improve the safety and convenience of new and renewable energy generation by storing electric energy generated from a renewable energy source, such as sunlight, and be used as an emergency power source. In addition, when the energy storage system 1 is used, it is possible to achieve load leveling for a load having large fluctuations in time and season, and to reduce energy consumption and cost.

The BMS 34 may measure the temperature, current, voltage, charge amount, and the like of the battery 35 to monitor the state of the battery 35. Further, the BMS 34 may control and manage the operation environment of the battery 35 such that it is optimized based on state information of the battery 35.

Meanwhile, the energy storage system 1 may include a power management system (PMS) 31a that controls the PCS 32.

The PMS 31a may execute a function of monitoring and controlling the states of the battery 35 and the PCS 32. The PMS 31a may be a controller that controls the overall operation of the energy storage system 1.

The PCS 32 may control power distribution of the battery 35 according to a control command of the PMS 31a. The PCS 32 may convert power according to the connection state of the grid 9, a power generation means, such as sunlight, the battery 35, and the load 7.

The PMS 31a may receive state information of the battery 35 from the BMS 34. The PMS 31a may transmit a control command to the PCS 32 and the BMS 34.

The PMS 31a may include a communication means, such as a Wi-Fi communication module, and a memory. Various types of information necessary for the operation of the energy storage system 1 may be stored in the memory. According to an embodiment, the PMS 31a may include a plurality of switches to control a power supply path.

The PMS 31a and/or the BMS 34 may use various well-known state of charge (SOC) calculation methods, such as integrated charge current integration and SOC calculation based on an open circuit voltage (OCV), to calculate the SOC of the battery 35. The battery 35 may overheat and irreversibly operate when the SOC exceeds a maximum SOC. Similarly, when the SOC is less than or equal to a minimum SOC, the battery 35 may deteriorate and become irreversible. The PMS 31a and/or the BMS 34 may monitor the internal temperature and SOC of the battery 35 in real time to control an optimal usage area and maximum input/output power.

The PMS 31a may operate under the control of an energy management system (EMS) 31b, which is a higher-level controller. The PMS 31a may control the energy storage system 1 by receiving a command from the EMS 31b, and may transmit the state of the energy storage system 1 to the EMS 31b. The EMS 31b may be provided in the energy storage system 1 or may be provided in a higher system of the energy storage system 1.

The EMS 31b may receive information such as charge information, power usage, and environmental information, and may control the energy storage system 1 according to energy production, storage, and consumption patterns of a user. The EMS 31b may be provided as an operating system for monitoring and controlling the PMS 31a.

A controller for controlling the overall operation of the energy storage system 1 may include the PMS 31a and/or the EMS 31b. According to an embodiment, one of the PMS 31a and the EMS 31b may also perform the function of the other. In addition, the PMS 31a and the EMS 31b may be integrated into one controller and integrally provided.

Meanwhile, the installation capacity of the energy storage system 1 varies according to customer's installation conditions, and a plurality of PCSs 32 and a plurality of batteries 35 may be connected to expand the installation capacity to a required capacity.

The energy storage system 1 may be connected to at least one power generator (refer to 3 in FIG. 2) separately from the grid 9. A power generator 3 may include a wind power generator that outputs DC power, a hydraulic power generator that outputs DC power using hydraulic power, a tidal power generator that outputs DC power using tidal power, a thermal power generator that outputs DC power using heat geothermal heat, or the like. Hereinafter, for convenience of description, a photovoltaic power generator will be mainly described as the power generator 3.

Referring to FIG. 2, the energy storage system 1 may be connected to the grid 9, such as a power plant 8, a power generator, such as a photovoltaic power generator 3, and a plurality of loads 7x1 and 7y1.

Electric energy generated by the photovoltaic power generator 3 may be converted by a PV inverter 4 to be supplied to the grid 9, the energy storage system 1, and the loads 7x1 and 7y1. According to the type of installation, the electric energy generated by the photovoltaic power generator 3 may be converted in the energy storage system 1 to be supplied to the grid 9, the energy storage system 1, and the loads 7x1 and 7y1.

The energy storage system 1 may include one or more wireless communication modules to communicate with a terminal 6. A user may use the terminal 6 to monitor and control the state of the energy storage system 1 and the home energy service system. In addition, the home energy service system may provide services based on a cloud 5. The user may communicate with the cloud 5 through the terminal 6 regardless of location to thereby monitor and control the state of the home energy service system.

According to an embodiment of the present disclosure, the battery 35, the BMS 34, and the PCS 32, which are described above, may be disposed in one casing 12. The battery 35, the BMS 34, and the PCS 32 that are integrated in one casing 12 can store and convert power and thus can be referred to as an all-in-one energy storage system 1a.

In addition, a separate enclosure 1b outside the casing 12 may be provided with a configuration for power distribution, such as the PMS 31a, an automatic transfer switch (ATS), a smart meter, and a switch, and a communication module for communication with the terminal 6, the cloud 5, and the like. A configuration in which the components related to power distribution and management are integrated in one enclosure 1b may be referred to as a smart energy box 1b.

The above-described PMS 31a may be accommodated in the smart energy box 1b. A controller for controlling the overall power supply connection of the energy storage system 1 may be disposed in the smart energy box 1b. The controller may be the aforementioned PMS 31a.

In addition, switches are accommodated in the smart energy box 1b, so that connection states of the connected grid power sources 5 and 9, the photovoltaic power generator 3, the battery 35 of the all-in-one energy storage system 1a, and the loads 7x1 and 7y1 can be controlled. The loads 7x1 and 7y1 may be connected to the smart energy box 1b through load panels 7x2 and 7y2.

The smart energy box 1b is connected to the grid power sources 5 and 9 and the photovoltaic power generator 3. In addition, the automatic transfer switch (ATS) that is switched such that electric energy generated by the photovoltaic power generator 3 or stored in the battery 35 is supplied to a predetermined load 7y1 when a power outage occurs in the grids 5 and 9 may be disposed in the smart energy box 1b.

Alternatively, the PMS 31a may perform the ATS function. For example, when a power outage occurs in the grids 5 and 9, the PMS 31a may control a switch such as a relay to allow electric energy generated by the photovoltaic power generator 3 or stored in the battery 35 to be supplied to a predetermined load 7y1.

Meanwhile, a current sensor, a smart meter, or the like may be disposed on each current supply path. Electric energy generated through the energy storage system 1 and the photovoltaic power generator 3 may be measured and managed by the smart meter (at least a current sensor).

The energy storage system 1 according to an embodiment of the present disclosure includes at least the all-in-one energy storage system 1a. In addition, the energy storage system 1 according to an embodiment of the present disclosure may include the all-in-one energy storage system 1a and the smart energy box 1b, thereby providing integrated services for performing storage, supply, distribution, communication, and control of electric power in a simple and efficient manner.

The energy storage system 1 according to an embodiment of the present disclosure may operate in a plurality of operation modes. In a PV self-consumption mode, solar power is first used in a load and the remaining power is stored in the energy storage system 1. For example, when the photovoltaic power generator 3 generates more power than the amount of power used by the loads 7x1 and 7y1 during the daytime, the battery 35 is charged.

In a charge/discharge mode based on a rate plan, four time periods may be set and input, so that the battery 35 may be discharged during a time period when electricity rates are high, and the battery 35 may be charged during a time period when electricity rates are low. The energy storage system 1 may allow a user to save the electricity charges in the charge/discharge mode based on a rate plan.

A backup-only mode is the mode for emergency situations such as a power outage, in which the battery 35 is charged to the maximum and power is supplied to the essential load 7y1 with highest priority in an emergency when a typhoon is expected in weather forecast or there is a possibility of another power outage.

Referring to FIG. 3, the energy storage system 1 according to an embodiment of the present disclosure includes a plurality of battery packs 10 arranged in an up-and-down or vertical direction, a casing 12 defining a space in which the plurality of battery packs 10 are disposed, and a door 28 for opening and closing the front of the casing 12.

The casing 12 may have an open front side. The casing 12 includes a casing rear wall 14 covering the rear, a pair of casing sidewalls 20 extending forward from opposite ends of the casing rear wall 14, a casing top wall 24 extending forward from an upper end of the casing rear wall 14, and a casing base 26 extending forward from a lower end of the casing top wall 24. The casing rear wall 14 includes pack fastening parts 16 to fasten the battery packs 10.

A switch (22a, 22b) for turning on/off the power of the energy storage system 1 may be disposed on one of the pair of casing sidewalls 20. In an embodiment of the present disclosure, a first switch 22a and a second switch 22b may be provided, and the power is turned on only by a switching combination of the first and

second switches

22a and 22b to thereby enhance the safety of the energy storage system 1.

The PCS 32 for converting the characteristics of electricity for charging or discharging the battery, and the BMS for monitoring information such as the current, voltage and temperature of the battery packs 10 and/or battery cells included in the battery packs 10 may be disposed inside the casing 12.

The PCS 32 may include a circuit board 33 and a switching device 33a (e.g., an insulated gate bipolar transistor (IGBT)) that is disposed on one side of the circuit board 33 (hereinafter referred to as a "PCS board") and performs power conversion.

The BMS 34 may include battery pack circuit boards (not shown) disposed in the

respective battery packs

10a, 10b, 10c and 10d, and a main circuit board 34a connected to the plurality of battery pack circuit boards through communication lines (not shown).

The main circuit board 34a may be connected to the battery pack circuit board 220 disposed in each of the plurality of

battery packs

10a, 10b, 10c, and 10d through a communication line. The main circuit board 34a may be connected to a power line 198 extending from the battery pack 10.

The plurality of

battery packs

10a, 10b, 10c, and 10d are disposed in the casing 12. The battery packs 10a, 10b, 10c, and 10d may be disposed in the vertical direction. Each of the plurality of battery packs 10 is fixedly disposed in the casing 12. Each of the plurality of

battery packs

10a, 10b, 10c, and 10d is fastened to the pack fastening part 16 provided on the casing rear wall 14.

Each battery pack 10 may include at least one battery module (100a, 100b) including a plurality of battery cells 101 connected in series and parallel. For example, the battery pack 10 may include a battery module assembly 100 including two

battery modules

100a and 100b electrically connected to each other and physically fixed. The battery module assembly 100 may include a first battery module 100a and a second battery module 100b disposed to face each other. Each of the first and

second battery modules

100a and 100b may include a sensing substrate (not shown) for sensing information of a plurality of battery cells 101, and the battery pack circuit boards may collect sensing information of the first and

second battery modules

100a and 100b from the sensing substrate and transmit the same to the BMS 34.

The energy storage system 1 according to an embodiment of the present disclosure includes the battery 35 capable of storing electricity, the PCS 32 in charge of input/output of the battery 35, and a thermal management system for controlling the temperatures of internal components such as the battery 35.

The ESS thermal management system according to an embodiment of the present disclosure is a water-cooled temperature control system for recovering waste heat generated from the battery 35, the PCS 32, a reactor, and the like when the system is driven and discharging the recovered waste heat to the outside to reduce the temperatures of the battery 35 and the PCS, thereby improving the system efficiency. In the case of the conventional air-cooled thermal management system, the temperature of each component in the system may be high due to its low heat recovery efficiency. When the temperature of the battery is stably maintained within a certain temperature range during charging and discharging of the battery, the speed of charging and discharging the battery is increased to thereby enhance the battery usage efficiency.

The energy storage system 1, as a thermal management system, includes a cooling module 40 for cooling the internal components such as the battery packs 10 and the PCS board 33. According to an embodiment of the present disclosure, the cooling module 40 may cool the battery packs 10, the PCS board 33, and the like using a water cooling method.

For example, a battery cooling plate 50 may be disposed corresponding to each battery pack 10, and a coolant may circulate between the cooling module 40 and the battery cooling plate 50 along a coolant flow path 60 to cool the battery packs 10. The coolant flow path 60 may include an inlet flow path 60b through which the coolant is introduced into the battery cooling plate 50 from the cooling module 40, and an outlet flow path 60a through which the coolant is discharged to the cooling module 40 from the battery cooling plate 50.

In consideration of problems of coolant supply and leakage, a coolant having insulating performance is applied, and a coolant that can be used even at low temperatures is more preferable.

The cooling module 40 may include a pump for circulating the coolant, and a heat exchanger and a fan for discharging waste heat recovered during system operation through heat exchange with air, so that the coolant heated according to waste heat recovery may be cooled to the lowest atmospheric temperature to be circulated.

The cooling module 40 may be supported by a plate 41, and may be in contact with the PCS board or the like through the plate 41.

The thermal management system includes a battery-side water block (battery cooling plate 50), a PCS-side water block, a reactor-side water block, and the like to cool parts other than the cooling module 40.

The battery-side water block is configured such that the number of battery-side water blocks increases in proportion to the number of battery modules applied, and the flow rate of the coolant is normally uniformly provided to each water block.

The water block provided for each heating element is configured to allow the coolant to flow inside and to recover waste heat through surface contact with the heating element. In order to efficiently operate the thermal management system, a temperature sensor is disposed at the rear end of the water block for each part to detect the temperature of discharged water.

In addition, the thermal management system may be provided with a valve for switching flow paths of the coolant as needed, and may vary the flow rate of a fluid supplied to each heating part and thus can control the temperature of the heating part to be maintained within a target temperature range.

The PMS 31a or the BMS 34 may be a controller that also controls the thermal management system. Alternatively, the thermal management system may include a separate controller. Sensing information of a temperature sensor or the like is transmitted to the controller, so that the controller can control the operation mode of the thermal management system and the operations of the pump, the fan, and the valve (opening/closing and adjustment of an opening degree).

In the case of conditions for preheating components in the system, heat is generated by consuming some power through reactive power control of the PCS without using a heat exchanger by controlling an on/off valve (e.g., 1-way valve) provided on the coolant inlet side of the heat exchanger, and the generated waste heat is recovered to preheat the battery. The preheated battery through this control can operate the ESS system more efficiently since the battery chargeable capacity and charging speed are increased. In this manner, according to the ESS thermal management system, the operating range and charging speed of the battery can be improved through cooling in high temperature conditions and preheating in low temperature conditions to thereby expand the operating range of the system.

In the case of home ESS products, four operation modes may be configured according to operating conditions.

The first operation mode is a PCS and battery cooling mode. In the PCS and battery cooling mode, heat is generated in the PCS, the battery, and the reactor due to the use of an ESS battery. Waste heat generated in each heating part may be recovered and then be emitted to the atmosphere through a heat exchanger.

The second operation mode is a PCS cooling and battery preheating mode for cooling the battery with the coolant heated through heating of the PCS in a low outdoor temperature operation and standby state. A heat exchanger is not used in the PCS cooling and battery preheating mode.

The third operation mode is a battery-only cooling mode for improving battery efficiency by cooling the battery module when only the PCS is cooled after completion of normal operation. The battery-only cooling mode is an operation mode for additionally cooling the battery when only the PCS with a small thermal mass is cooled early at the time of end of the system operation.

The fourth operation mode is a PCS-only cooling mode. The PCS-only cooling mode is an operation mode for cooling the PCS mainly when the operation time is short or output is low and thus there is little heat from the battery but only the PCS generates high heat.

Hereinafter, the thermal management system will be described in detail with reference to the drawings.

FIG. 4 is a conceptual view of a battery pack cooling and preheating system according to an embodiment of the present disclosure, which is a top view of the battery pack showing an auxiliary temperature control system to which a Peltier module is applied.

The ESS thermal management system according to the present disclosure includes a water-cooled main temperature control system using a coolant circulating therein and an auxiliary temperature control system for controlling the internal temperature of the battery pack 10 through the Seebeck effect of a Peltier element.

As the Peltier element is employed in the battery pack 10, cooling and preheating of the battery 35 can be more efficiently controlled. Thus, the internal temperature of the battery pack 10 can be more stably controlled, and the efficiency and lifespan of the battery 35 can be increased.

Referring to FIG. 4, one or more battery module assemblies 100 are disposed in the battery pack 10. The battery module assembly 100 includes a first battery module 100a and a second battery module 100b that are disposed to face each other. The first and

second battery modules

100a and 100b, each including a plurality of battery cells 101, are electrically connected to each other.

A battery cooling plate 50 is disposed to correspond to each battery pack 10, and the coolant in the main temperature control system flows into the battery cooling plate 50. The first and

second battery modules

100a and 100b may be cooled or preheated according to the temperature of the coolant flowing into the battery cooling plate 50.

An inlet flow path 91 may be connected to an inlet of the battery cooling plate 50, and an outlet flow path 92 may be connected to an outlet of the battery cooling plate 50. The coolant is introduced into the battery cooling plate 50 through the inlet flow path 91 to exchange heat with the first and

second battery modules

100a and 100b. Then, the coolant is discharged out of the battery cooling plate 50 through the outlet flow path 92.

The battery cooling plate 50 is disposed to correspond to the first and

second battery modules

100a and 100b. The battery cooling plate 50 may include a front cooling plate 50f and a rear cooling plate 50b disposed on a front side and a rear side of the battery pack 10, respectively. The front cooling plate 50f may be disposed on the first battery module 100a side, and the rear cooling plate 50b may be disposed on the second battery module 100b side.

Meanwhile, the battery pack 10 is provided therein with a Peltier module 410 including Peltier elements arranged in the longitudinal direction of the first and

second battery modules

100a and 100b.

The Peltier module 410 includes a first Peltier module 410f having one surface disposed toward the first battery module 100a and a second Peltier module 410b having one surface disposed toward the second battery module 100b. In addition, the first and

second Peltier modules

410f and 410b are disposed to face each other with some spacing therebetween. Accordingly, a space (hereinafter referred to as an "air channel") 420 may be formed between the first and

second Peltier modules

410f and 410b to allow air to flow therethrough. In other words, the air channel 420 is formed between the other surface of the first Peltier module 410f and the other surface of the second Peltier module 410b.

The Peltier element is configured such that one surface absorbs heat or generates heat while another surface on the opposite side conversely generates heat or absorbs heat, according to a voltage applied. For example, when a forward voltage is applied to the Peltier element, one surface thereof undergoes an endothermic reaction while the other surface thereof on the opposite side undergoes an exothermic reaction. In addition, when a reverse voltage in a direction opposite to that of the forward voltage is applied to the Peltier element, one surface thereof undergoes an exothermic reaction while the other surface thereof on the opposite side undergoes an endothermic reaction.

The first and

second Peltier modules

410f and 410b each include a Peltier element, and one surfaces of the Peltier elements are disposed toward the first and

second battery modules

100a and 100b, respectively, and the other surfaces of the Peltier elements are spaced to face each other.

When a forward voltage (first voltage) is applied to the first and

second Peltier modules

410f and 410b, one surface of each of the first and

second Peltier modules

410f and 410b undergoes an endothermic reaction while the other surface, opposite to the one surface, of each of the first and

second Peltier modules

410f and 410b undergoes an exothermic reaction.

Conversely, when a reverse voltage (second voltage) is applied to the first and

second Peltier modules

410f and 410b, the one surface of the first and

second Peltier modules

410f and 410b undergoes an exothermic reaction while the other surface, opposite to the one surface, of each of the first and

second Peltier modules

410f and 410b undergoes an endothermic reaction.

In a cooling mode for battery cooling, the first voltage may be applied to the first and

second Peltier modules

410f and 410b, and in a preheating mode for battery preheating, the second voltage may be applied to the first and

second Peltier modules

410f and 410b.

Meanwhile, a battery cooling fan 430 is disposed on one side of the battery pack 10, and a damper 440 is disposed on the other side opposite to the one side. In other words, the battery cooling fan 430 is disposed on one side of each of the first and

second battery modules

100a and 100b, and the damper 440 is disposed on the other side of each of the first and

second battery modules

100a and 100b.

The battery cooling fan 430 and the damper 440 may be fixed to the battery pack 10 by

respective support members

435 and 445. The

support members

435 and 445 are disposed in an inclined manner so as to facilitate the flow of air. In addition, the first and

second battery modules

100a and 100b may be physically fixed inside the battery pack 10 by a fixing member such as a bracket (not shown).

Since the first and

second battery modules

100a and 100b are disposed to be spaced apart from each other, air may flow into a space between the first and

second battery modules

100a and 100b by the operation of the battery cooling fan 430.

In addition, the first and

second Peltier modules

410f and 410b are disposed to face each other with some spacing therebetween so as to correspond to the first and

second battery modules

100a and 100b. Also, the battery cooling fan 430 may be disposed at an inlet 421 of the air channel 420 between the other surface of the first Peltier module 410f and the other surface of the second Peltier module 410b. Accordingly, when the battery cooling fan 430 is turned on, air may flow into the air channel 420.

The damper 440 is configured to open and close an outlet 422 of the air channel 420. The damper 440 may automatically open the outlet 422 of the air channel 420 in response to the battery cooling fan 430 being turned on. The damper 440 may be opened by the flow of air due to the operation of the battery cooling fan 430. When the damper 440 is opened, the air in the air channel 420 may be discharged out of the battery pack 10. When the battery cooling fan 430 is not operating, the damper 440 is closed to thereby prevent water at the outside from being introduced into the battery pack 10.

FIGS. 5A and 5B are views referenced in the description of a battery pack cooling and preheating system according to an embodiment of the present disclosure. FIG. 5A illustrates an example of the operation in a cooling mode, and FIG. 5B illustrates an example of the operation in a preheating mode.

Referring to FIG. 5A, in the cooling mode, one surface of each of the first and

second Peltier modules

410f and 410b undergoes an exothermic reaction. Due to the endothermic reaction of the first and

second Peltier modules

410f and 410b, heat of the first and

second battery modules

100a and 100b is absorbed and cooled.

However, the internal temperature of the battery pack 10 may be increased due to the exothermic reaction occurred on the other surface of each of the first and

second Peltier modules

410f and 410b. Thus, in the cooling mode, the battery cooling fan 430 is turned on, and the damper 440 is opened in response to the operation of the battery cooling fan 430. Consequently, air outside the battery pack 10 may be introduced, pass through the air channel 420, and then be discharged, thereby preventing the temperature rise due to the exothermic reaction of the first and

second Peltier modules

410f and 410b.

Referring to FIG. 5B, in the preheating mode, one surface of each of the first and

second Peltier modules

410f and 410b undergoes an endothermic reaction. Due to the exothermic reaction of the first and

second Peltier modules

410f and 410b, the first and

second battery modules

100a and 100b may be preheated to an appropriate temperature more quickly.

Referring to FIGS. 4, 5A, and 5B, a water-cooled battery cooling plate 50 may be disposed on each of two outer surfaces of the battery pack 10, and the coolant may cool or preheat the battery pack 10 while passing through the battery cooling plate 50 according to the environment of the energy storage system 1, coolant temperature conditions, and the like.

In addition, a

Peltier module

410f, 410b is disposed in the battery pack 10. One battery pack 10 includes a plurality of

battery modules

100a and 100b. For example, two first battery modules 100a disposed at the front side and two second battery modules 100b disposed at the rear side may be provided in the battery pack 10. Each of the

battery modules

100a and 100b may include a plurality of cell arrays electrically connected to each other. The plurality of cell arrays may include a first cell array (not shown) in which a plurality of battery cells are arranged on a straight line, and a second cell array (not shown) in which a plurality of battery cells are arranged in rows and columns.

The inner surface of the two first battery modules 100a and the inner surface of the two second battery modules 100b may be provided with a first Peltier module 410f and a second Peltier module 410b, respectively. The air channel 420 through which air in the middle between the first and

second Peltier modules

410f and 410b flows may be formed.

In addition, the battery cooling fan 430 for supplying air to the inside is disposed on a lateral side of the battery pack 10, so that high-temperature heat may be discharged out of the battery pack 10 when operating the first and

second Peltier modules

410f and 410b in the battery pack 10. The battery cooling fan 430 may be used for air cooling even when the first and

second Peltier modules

410f and 410b are not operating.

Meanwhile, the damper 440 is opened by the operation of the battery cooling fan 430 to allow heated air to be discharged to the outside. The damper 440 is adjacent to an outer surface of an enclosure of the battery pack 10, and is automatically closed when the battery cooling fan 430 is not operating.

Meanwhile, the energy storage system 1 may include a plurality of battery packs 10, and each battery pack 10 may have the battery cooling plate 50, the first and

second Peltier modules

410f and 410b, the battery cooling fan 430, and the damper 440.

A duct 429 (see 429 of FIG. 6, etc.) is connected to surfaces of the plurality of battery packs 10 in contact with the respective battery cooling fans 430, and the duct 429 is connected to an inlet 421 of the air channel 420 of each battery pack 10. Meanwhile, an air inlet of the duct 429 is formed on a bottom surface of the casing 12, so that external air may be introduced from the bottom of the casing 12 to be supplied to the inside of each battery pack 10 through the duct 429. Due to this compact structure, a thermal management means capable of cooling/preheating the battery can be achieved.

According to an embodiment of the present disclosure, the temperature of the battery can be effectively managed by controlling the temperature of the outside and inside of the battery pack 10 together. In addition, the first and

second Peltier modules

410f and 410b may be operated based on the operating condition and state of the energy storage system 1.

FIGS. 6 and 7 are views referenced in the description of a first cooling mode of an energy storage system according to an embodiment of the present disclosure. FIG. 6 is a side view showing four

battery packs

10a, 10b, 10c, and 10d disposed at a lower portion of the casing 12, the circuit board 33 disposed at an upper portion of the casing 12, the cooling module 40, and the like, and FIG. 7 illustrates an overall conceptual view of the thermal management system in the first cooling mode.

Referring to FIGS. 3 to 7, the overall thermal management system and the first cooling mode will be described in detail.

The energy storage system 1 includes a plurality of battery packs 10 arranged in the vertical direction, a plurality of battery cooling plates 50 disposed corresponding to each battery pack 10, and the cooling module 40.

The casing 12 defines a space in which various components are disposed. The battery pack 10, the battery cooling plate 50, and the cooling module 40 are disposed in the casing 12.

The energy storage system 1 according to an embodiment of the present disclosure includes a coolant temperature control system. The cooling module 40 includes a pump 42 to cause the coolant to flow. In addition, the cooling module 40 may include a heat exchanger 43 for heat exchange of the coolant flowing by the pump 42 with air, and a heat dissipation fan 44 to supply external air to the heat exchanger 43. According to an embodiment, the heat dissipation fan 44 may include a first heat dissipation fan 44a and a second heat dissipation fan 44b. In addition, the rotational speed of the heat dissipation fan 44 may vary in response to the temperature of the coolant.

For a better understanding of the embodiments, main components of the cooling module 40, such as the heat exchanger 43, the heat dissipation fan 44, and the pump 42, are separately illustrated in FIG. 6, etc.

Meanwhile, the casing 12 may be provided therein with a heat dissipation fan 44 for the purpose of heat dissipation of the heat exchanger 43, and a flow path duct 45 to guide air that has passed through the heat dissipation fan 44 and the heat exchanger 43 to the outside. The heat exchanger 43 and the heat dissipation fan 44 may be disposed at a duct 45 through which external air passes.

The energy storage system 1 according to an embodiment of the present disclosure is a water-cooled type, which uses a coolant to prevent overheating of the battery pack 10 and the like. According to the operation of the pump 42, the coolant may be supplied to the water block such as the battery cooling plate 50. The coolant flows into the battery cooling plate 50 by the operation of the pump 42 along the inlet flow path 91 and absorbs heat generated from the battery pack 10. The coolant that has passed through the battery cooling plate 50 exchanges heat in the heat exchanger 43, and the heat is released into the atmosphere.

The controller controls the pump 42 to operate, as necessary, so as to circulate the coolant. Heat is released in such a manner that heat generated in the battery pack 10 is absorbed by heat exchange with the coolant and heat of the coolant is exchanged with air using the heat exchanger 43 and the heat dissipation fan 44.

The plurality of

battery packs

10a, 10b, 10c, and 10d may be arranged in the vertical direction, and each of the battery packs 10a, 10b, 10c, and 10d may be provided with one or more battery cooling plates 50. The battery cooling plate 50 receives the coolant through the inlet flow path 91 and discharges the coolant through the outlet flow path 92. Each of the battery packs 10a, 10b, 10c, and 10d may include a front cooling plate 50f and a rear cooling plate 50b disposed at the front and the rear, respectively.

Each

battery pack

10a, 10b, 10c, 10d may include the above-described first Peltier module (410f1, 410f2, 410f3, 410f4) and the above-described second Peltier module (410b1, 410b2, 410b3, 410b4). In addition, each

battery pack

10a, 10b, 10c, 10d may include the above-described battery cooling fan (430a, 430b, 430c, 430d) and the above-described damper (440a, 440b, 440c, 440d).

The duct 429 may be connected to a side surface of the

battery pack

10a, 10b, 10c, 10d on which the

battery cooling fan

430a, 430b, 430c, 430d is disposed. Air may be supplied to an

inlet

421a, 421b, 421c, 421d of each battery pack 10 through the duct 429.

Air introduced into the

battery pack

10a, 10b, 10c, 10d by the operation of the

battery cooling fan

430a, 430b, 430c, 430d passes through the air channel 420. When the

damper

440a, 440b, 440c, 440d is opened in response to the flow of air, the air that has passed through the air channel 420 may be discharged through an

outlet

422a, 422b, 422c, 422d.

Referring to FIGS. 6 and 7, according to the operation of the pump 42, the coolant may be supplied through a first coolant circulation path 501, and may be distributed to second

coolant circulation paths

552 and 553 and a third coolant circulation path 551 that are branched from the first coolant circulation path 501.

The second

coolant circulation paths

552 and 553, which are paths through which the coolant is supplied to the PCS 32 side, are connected to a water block 520 on the PCS 32 side. The coolant discharged from the pump 43 may be supplied to the water block 520 on the PCS 32 side through the first coolant circulation path 501 and the second

coolant circulation paths

552 and 553. Meanwhile, the coolant discharged from the water block 520 on the PCS 32 side flows to a PCS flow path 563.

The third coolant circulation path 551 is a path through which the coolant is supplied to the battery pack 10 side. More specifically, the coolant may be supplied to the battery cooling plate 50, which is a water block on the battery side.

Meanwhile, the energy storage system 1 may include one or

more reactors

531 and 532 for voltage/current stabilization. For example, the energy storage system 1 includes a first reactor 531 to stabilize a sudden change in current applied from an AC power source, and a second reactor 532 to stabilize a sudden change in current applied from the battery pack 10.

Further, the energy storage system 1 may include reactor water blocks 541 and 542 to cool the

reactors

531 and 532. The

reactor water block

541, 542 may come into contact with the

reactor

531, 532 to cool the

reactor

531, 532 using the coolant supplied from the cooling module 40. The coolant of the reactor water blocks 541 and 542 may be discharged to

reactor flow paths

565 and 564.

A T-type connector 571 may be disposed in the second

coolant circulation paths

552 and 553 to distribute the coolant to the second coolant circulation path 553 and a flow path 544 on the

reactor water block

541, 542 side.

When the energy storage system 1 includes the first reactor 531 and the second reactor 532, the energy storage system 1 may further include a T-type connector 572 to evenly distribute the coolant back to the first reactor 531 and the second reactor 532.

Meanwhile, T-

type connectors

591 and 592 may be respectively disposed in the PCS flow path 563 and the

reactor flow paths

565 and 564, and the PCS flow path 563 and the

reactor flow paths

565 and 564 may be combined into a fourth coolant circulation path 555. Accordingly, the coolant discharged from the PCS water block 520 and the reactor water blocks 541 and 542 flows to the fourth coolant circulation path 555.

Meanwhile, the fourth coolant circulation path 555 is branched into a fifth coolant circulation path 556 and a bypass flow path 557. The fifth coolant circulation path 556 is a path through which the coolant is supplied to the battery cooling plate 50 on the battery pack 10 side, and the bypass flow path 557 is a path through which the coolant flows to the heat exchanger 43 side without passing through the battery pack 10 side.

A T-type connector 573 may be disposed at a place or point where the third coolant circulation path 551 and the fifth coolant circulation path 556 meet.

A first three-way valve 511 is disposed in the first coolant circulation path 501. The first three-way valve 511 may be disposed at a point where the first to third

coolant circulation paths

501, 553, and 551 meet, and may distribute the coolant in the first coolant circulation path 501 to the second coolant circulation path 553 and the third coolant circulation path 551.

A second three-way valve 513 is disposed in the fourth coolant circulation path 555. The second three-way valve 513 is disposed at a point where the fourth coolant circulation path 555, the fifth coolant circulation path 556, and the bypass flow path 557 meet, and is configured such that the coolant in the fourth coolant circulation path 555 is selectively supplied to the fifth coolant circulation path 556 or the bypass flow path 557.

Meanwhile, the battery cooling plate 50 receives the coolant through the inlet flow path 91 and discharges the coolant through the outlet flow path 92. A T-type connector 574 is disposed at a point where the outlet flow path 92 of the battery cooling plate 50 and the bypass flow path 557 meet, and a sixth coolant circulation path 558 is connected to the outlet flow path 92 of the battery cooling plate 50 and the bypass flow path 557. The outlet flow path 92 and the bypass flow path 557 are combined into the sixth coolant circulation path 558.

A first heat exchanger flow path 561 is connected to the inlet of the heat exchanger 43, and a second heat exchanger flow path 562 is connected to the outlet of the heat exchanger 43. In addition, the first heat exchanger flow path 561 may be connected to the sixth coolant circulation flow path 558.

A seventh coolant circulation path 503 is connected to the first heat exchanger flow path 561 and the second heat exchanger flow path 562, and may function as a bypass flow path that allows the coolant to bypass the heat exchanger 43. A third three-way valve 594 may be disposed at a point where the first heat exchanger flow path 561, the sixth coolant circulation path 558, and the seventh coolant circulation path 503 meet.

The third three-way valve 594 may be configured such that the coolant in the sixth coolant circulation path 558 is selectively supplied to the heat exchanger 43 or the seventh coolant circulation path 503. In the preheating mode, the third three-way valve 594 may operate such that the coolant does not pass through the heat exchanger 43.

An eighth coolant circulation path 559 may be connected to the second heat exchanger flow path 562 and the seventh coolant circulation path 503 so as to circulate the coolant to the pump 42.

Meanwhile, a T-type connector 575 may be disposed at a point where the second heat exchanger flow path 562, the seventh coolant circulation path 503, and the eighth coolant circulation path 559 meet. The seventh coolant circulation path 503 and the second heat exchanger flow path 562 may be combined into the eighth coolant circulation path 559 through which the coolant is circulated to the pump 42 via the T-type connector 575.

The energy storage system 1 may further include

temperature sensors

581 and 582 to sense the coolant temperature, and may determine the cooling mode based on the coolant temperature sensed by the

temperature sensors

581 and 582. Also, based on the coolant temperature sensed by the

temperature sensors

581 and 582, the first and second Peltier modules 410a and 410b may be controlled to be on or off. For example, when the coolant temperature is greater than or equal to a predetermined temperature, the first voltage may be applied to the first and second Peltier modules 410a and 410b.

Meanwhile, the controller may control the thermal management system based on the coolant temperature sensed by the

temperature sensors

581 and 582. For example, the eighth coolant circulation path 559 may be provided with a first temperature sensor 581, and the sixth coolant circulation path 558 may be provided with a second temperature sensor 582, so as to sense the coolant temperature. The controller may control the thermal management system based on the coolant temperature sensed by the first temperature sensor 581 and/or the second temperature sensor 582. Also, the controller may control the thermal management system based on a difference between the coolant temperatures sensed by the first temperature sensor 581 and the second temperature sensor 582.

As the thermal management system according to an embodiment of the present disclosure is provided with the water-cooled main means and the auxiliary cooling means 410 and 430, the overall system and battery thermal management can be controlled appropriately for various situations.

The first cooling mode is an operation mode selected, while the thermal management system is operating normally, when the temperature control of the PCS 32 & reactors 531 and 532 (PCS & Reactor), and the battery pack 10 can be stably controlled only by the operation of the water-cooled main means. In the first cooling mode, the temperature should be stably controlled without using the Peltier module 410.

When the coolant temperature sensed by the first temperature sensor 581 and/or the second temperature sensor 582 is low, the thermal management system may operate in the first cooling mode.

Referring to FIGS. 6 and 7, when the coolant temperature is less than a first reference temperature, the first and second Peltier modules 410a and 410b and the battery cooling fan 430 are controlled to be off, and the heat dissipation fan 44 is controlled to be on.

Referring to FIGS. 6 and 7, the pump 42 operates, and the coolant is supplied to the first coolant circulation path 501. In the cooling mode, the first three-way valve 511 may distribute the coolant supplied from the pump 42 to the second

coolant circulation paths

552 and 553 and the third coolant circulation path 551.

Meanwhile, the second three-way valve 513 supplies the coolant in the fourth coolant circulation path 555 to the bypass flow path 557. Accordingly, a relatively low-temperature coolant passes through the battery cooling plate 50.

When the coolant temperature is not high, such as during the initial operation of the energy storage system 1, the first cooling mode (Low) is entered. In the first cooling mode, a low-temperature coolant supplied by the pump 42 is heated through the battery pack 10 and the PCS 32 & the

reactors

531 and 532, and the heated coolant releases waste heat recovered through the heat exchanger 43 into the atmosphere.

The first cooling mode (Low) is a control mode initially selected when the system enters the normal operation while the temperature of the battery pack 10 and the PCS 32 &

reactors

531 and 532 are stable. The corresponding operation mode is the initial state of the ESS system when entered the charging and discharging operation, and, at this time, the amount of waste heat recovered from the battery pack 10 and the PCS 32 &

reactors

531 and 532 is not large, waste heat is recovered only with the coolant, and the recovered waste heat is released into the atmosphere through the heat exchanger 43 and the heat dissipation fan 44, without the operation of the first and second Peltier modules 410a and 410b.

Meanwhile, when the coolant temperature is greater than or equal to the first reference temperature, the thermal management system may operate in a second cooling mode.

FIGS. 8 and 9 are views referenced in the description of a second cooling mode of an energy storage system according to an embodiment of the present disclosure.

Referring to FIGS. 8 and 9, the pump 42 operates, and the coolant is supplied to the first coolant circulation path 501. In the second cooling mode, the first three-way valve 511 may distribute the coolant supplied from the pump 42 to the second

coolant circulation paths

552 and 553 and the third coolant circulation path 551. The second three-way valve 513 supplies the coolant in the fourth coolant circulation path 555 to the bypass flow path 557.

When the coolant temperature is greater than or equal to the first reference temperature, the first and second Peltier modules 410a and 410b are controlled to be off, and the heat dissipation fan 44 and the battery cooling fan 430 are controlled to be on. When the coolant temperature rises above the first reference temperature during the operation of the energy storage system 1, the first cooling mode is switched into the second cooling mode. The energy storage system 1 is driven in the same manner as in the previous operation state, and the cooling performance is improved by additionally operating the battery cooling fan 430.

That is, at this time, additional cooling is performed only using the battery cooling fan 430 without the operation of the first and second Peltier modules 410a and 410b in the battery module.

Meanwhile, when the coolant temperature is greater than or equal to a second reference temperature, which is higher than the first reference temperature, the thermal management system may operate in a third cooling mode.

FIGS. 10 and 11 are views referenced in the description of a third cooling mode of an energy storage system according to an embodiment of the present disclosure.

When the temperature of the coolant rises above the second reference temperature set higher than the first reference temperature while the energy storage system 1 is operating, the second cooling mode is switched into the third cooling mode.

Referring to FIGS. 10 and 11, when the coolant temperature is greater than or equal to the second reference temperature, which is higher than the first reference temperature, the first and second Peltier modules 410a and 410b, the heat dissipation fan 44, and the battery cooling fan 430 are controlled to be on. The energy storage system 1 is driven in the same manner as in the previous operation state (second cooling mode), and a forward voltage (first voltage) is applied to the first and second Peltier modules 410a and 410b, thereby additionally cooling the first and

second batteries

100a and 100b.

When the coolant temperature is greater than or equal to the second reference temperature, which is higher than the first reference temperature, the coolant is supplied to the heat exchanger 43, and the heat dissipation fan 44 operates. In addition, the first and second Peltier modules 410a and 410b are operated in the cooling mode. Since it is high-temperature conditions, the heat dissipation fan 44 is also operated, so that water cooling is performed by the heat exchanger 43 and the heat dissipation fan 44, and a surface adjacent to the battery pack 10 is cooled by the first and second Peltier modules 410a and 410b.

Air in the air channel 420 at the middle is heated by the operation of the first and second Peltier modules 410a and 410b. Here, the air heated in the air channel 420 according to the operation of the battery cooling fan 430 is discharged out of the battery pack 10 through the damper 440. In the third cooling mode, the temperature of each cell in the battery module can be stably controlled by cooling through the main water-cooling system and by cooling through the Peltier module.

FIGS. 12 and 13 are views referenced in the description of a preheating mode of an energy storage system according to an embodiment of the present disclosure.

When the coolant temperature is less than or equal to a predetermined temperature, normal operation of the battery pack 10 may be impossible or adverse effects in terms of the life span and efficiency of the battery may be caused, and thus the operation mode is controlled to be a mode for preheating the battery pack 10.

In the preheating mode, the first and second Peltier modules 410a and 410b are controlled to be on, and the heat dissipation fan 44 and the battery cooling fan 430 are controlled to be off. Here, a second voltage (reverse voltage) is applied to the first and second Peltier modules 410a and 410b.

Referring to FIGS. 12 and 13, in the preheating mode, the pump 42 may operate, and the first three-way valve 511 may operate such that the coolant supplied to the first coolant circulation path 501 is supplied to the second

coolant circulation paths

552 and 553. That is, all of the coolant supplied through the pump 42 is supplied to the PCS 32 &

reactors

531 and 532 through the first three-way valve 511.

The second three-way valve 513 operates such that the coolant in the fourth coolant circulation path 555 is supplied to the fifth coolant circulation path 556. In the preheating mode, the coolant flowing by the operation of the pump 42 is discharged at a low temperature through the battery cooling plate 50. The low-temperature coolant is bypassed to the seventh coolant circulation path 503 through the third three-way valve 594, without being supplied to the heat exchanger 43. This is because when the coolant is supplied to the heat exchanger 43, the temperature of the coolant is further reduced due to the low outdoor air temperature.

In addition, in the preheating mode, a reverse voltage (second voltage) is applied to the first and second Peltier modules 410a and 410b to additionally preheat the first and

second battery modules

100a and 100b. The coolant that has bypassed the heat exchanger 43 is supplied to the pump 42.

The first and second Peltier modules 410a and 410b are configured such that an exothermic reaction occurs on the surface adjacent to the battery pack 10 and an endotherm reaction occurs on the air channel 420 at the middle. Through this operation control, the battery can be preheated more quickly, and the system can be controlled to quickly enter the normal operation. Also, by stably maintaining the battery at a temperature higher than a predetermined temperature, a reduction in the lifespan of the battery can be prevented.

According to an embodiment of the present disclosure, the battery cooling plate 50 is disposed on one side of each of the first and

second battery modules

100a and 100b, and the first and second Peltier modules 410a and 410b are disposed on the other side of each of the first and

second battery modules

100a and 100b. As heat can be transferred in both directions between the first and

second battery modules

100a and 100b, the battery temperature can be managed more effectively. In addition, according to the embodiment of the present disclosure, the temperature of the battery module can be more efficiently controlled by adjusting the temperature of both the inner and outer surfaces of the battery.

FIGS. 14 is a flowchart of a method of operating an energy storage system according to an embodiment of the present disclosure.

In a state where the energy storage system 1 is powered on (S1405), the controller checks operating conditions (S1410 to S1435) and analyzes the coolant temperature detected by the temperature sensors 581 and 582 (S1440).

Various logics and conditions may be applied as operating conditions of the energy storage system 1 by the manufacturer and the user. For example, the controller may analyze the storage capacity of the battery 35 (S1410) to enter a power demand management mode based on the storage capacity of the battery 35 and a load (S1415). The power demand management mode, which is the above-described charge/discharge mode based on a rate plan, may be selectively controlled as an operation mode with time (S1420). In the late-night time period when electricity rates are low, the operation may be controlled in an energy storage mode in which the battery 35 is charged with the power supplied from the grid 9 (S1425). During the daytime when electricity rates are high and the load is high, the operation may be controlled in an energy supply mode in which the battery 35 is discharged. (S1430).

The controller may enter a thermal management system operation mode based on the operating conditions of the energy storage system 1 (S1435), and may analyze the coolant temperature detected by the temperature sensor 581, 582 (S1440). The controller may select a thermal management system operation mode based on the coolant temperature (S1445).

The thermal management system may also operate in a preheating mode for preheating the battery 35 (S1450).

In the preheating mode (S1450), as described with reference to FIGS. 12 and 13, the pump 42 may be turned on, and a radiator that includes the

valves

511, 513, and 594, the heat exchanger 43, and the heat dissipation fan 44 may be controlled.

In a state where the thermal management system operates in the preheating mode, the PCS 32 &

reactors

531 and 532 may generate heat through reactive power control in the case of the preheating mode operation, the coolant may circulate, and the battery 35 may be preheated (S1450).

In the preheating mode (S1450), a reverse voltage (second voltage) is applied to the first and second Peltier modules 410a and 410b to additionally preheat the first and

second battery modules

100a and 100b. Here, the battery cooling fan 430 may be controlled to be off.

When cooling is required, the controller may control the thermal management system to operate in a cooling mode (S1455, S1460, S1465). In the cooling mode (S1455, S1460, S1465), the temperature of the entire system can be stably managed by water cooling, and the temperature can be additionally adjusted in the battery pack 10 according to circumstances.

In the cooling mode (S1455, S1460, S1465), as described with reference to FIGS. 6 to 13, the

valves

511, 513, and 594 are controlled such that the coolant is supplied to the battery cooling plate 50.

When the coolant temperature sensed by the

temperature sensor

581, 582 is below a first reference temperature, which is the mid-low temperature reference value, the thermal management system may operate in a first cooling mode (S1455). When the coolant temperature is greater than or equal to the first reference temperature, the thermal management system may operate in a second cooling mode (S1460).

In the first cooling mode (S1455), as described with reference to FIGS. 6 and 7, the first and second Peltier modules 410a and 410b, and the battery cooling fan 430 are controlled to be off, and the heat dissipation fan 44 is controlled to be on. Thus, cooling through the radiator is only performed.

In the second cooling mode (S1460), as described with reference to FIGS. 8 and 9, the first and second Peltier modules 410a and 410b are controlled to be off, and the heat dissipation fan 44 and the battery cooling fan 430 are controlled to be on. Accordingly, cooling through the radiator and the battery cooling fan 430 is performed.

Meanwhile, when the coolant temperature is greater than or equal to a second reference temperature, which is the high temperature reference value, the thermal management system may operate in a third cooling mode (S1465). In the third cooling mode (S1465), as described with reference to FIGS. 10 and 11, the heat exchanger 43 and the heat dissipation fan 44 are operated, and a water tank three-way valve 441 and a water tank three-way valve 450 are controlled such that the coolant passes through a water tank 400. In the third cooling mode (S1465), a forward voltage (first voltage) is also applied to the first and second Peltier modules 410a and 410b to perform additional cooling.

In addition, the rotational speed of the heat dissipation fan 44 may be controlled according to the coolant temperature (S1470). For example, the higher the coolant temperature, the faster the heat dissipation fan 44 rotates.

While the present disclosure has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made herein without departing from the spirit and scope of the present disclosure as defined by the following claims and such modifications and variations should not be understood individually from the technical idea or aspect of the present disclosure.

Claims

An energy storage system comprising:

a battery pack comprising a first battery module and a second battery module that are disposed to face each other;

a battery cooling plate disposed to correspond to the first and second battery modules and through which a coolant flows;

a first Peltier module having one surface disposed toward the first battery module;

a second Peltier module having one surface disposed toward the second battery module;

a cooling fan disposed on one side of the battery pack to supply air to an air channel formed between another surface of the first Peltier module and another surface of the second Peltier module; and

a damper disposed on another side of the battery pack to open and close the battery pack.
The energy storage system of claim 1, wherein, when a first voltage is applied to the first and second Peltier modules, the one surface of each of the first and second Peltier modules undergoes an endothermic reaction, and the another surface, on an opposite side, of each of the first and second Peltier modules undergoes an exothermic reaction, and

wherein, when a second voltage is applied to the first and second Peltier modules, the one surface of each of the first and second Peltier modules undergoes an exothermic reaction, and the another surface, on an opposite side, of each of the first and second Peltier modules undergoes an endothermic reaction.
The energy storage system of claim 2, wherein the battery cooling fan is turned on when the one surface of each of the first and second Peltier modules undergoes an endothermic reaction, and the another surface, on the opposite side, of each of the first and second Peltier modules undergoes an exothermic reaction.
The energy storage system of claim 3, wherein, in response to the battery cooling fan being turned on, the damper opens an outlet of the air channel.
The energy storage system of claim 2, wherein the first voltage is applied to the first and second Peltier modules in a cooling mode for battery cooling, and

wherein the second voltage is applied to the first and second Peltier modules in a preheating mode for battery preheating.
The energy storage system of claim 1, further comprising a temperature sensor to sense a temperature of the coolant,

wherein the first and second Peltier modules are controlled to be on or off based on the temperature of the coolant sensed by the temperature sensor.
The energy storage system of claim 6, wherein, when the temperature of the coolant is greater than or equal to a predetermined temperature, the first voltage is applied to the first and second Peltier modules.
The air storage system of claim 6, further comprising:

a pump to cause the coolant to flow into the battery cooling plate;

a heat exchanger for heat exchange of the coolant flowing by the pump with air; and

a cooling module comprising a heat dissipation fan to supply external air to the heat exchanger.
The energy storage system of claim 8, wherein, when the temperature of the coolant is below a first reference temperature, the first and second Peltier modules and the battery cooling fan are controlled to be off, and the heat dissipation fan is controlled to be on.
The energy storage system of claim 9, wherein, when the temperature of the coolant is greater than or equal to the first reference temperature, the first and second Peltier modules are controlled to be off, and the heat dissipation fan and the battery cooling fan are controlled to be on.
The energy storage system of claim 10, wherein, when the temperature of the coolant is greater than or equal to a second reference temperature, which is higher than the first reference temperature, the first and second Peltier modules, the heat dissipation fan, and the battery cooling fan are controlled to be on.
The energy storage system of claim 8, wherein the heat dissipation fan has a rotational speed that varies in response to the temperature of the coolant.
The energy storage system of claim 8, further comprising:

a first coolant circulation path through which the coolant is supplied from the pump;

a second coolant circulation path branched from the first coolant circulation path so as to supply the coolant to a power conditioning system (PCS) water block;

a third coolant circulation path branched from the first coolant circulation path so as to supply the coolant to the battery cooling plate;

a fourth coolant circulation path through which the coolant discharged from the PCS water block flows;

a fifth coolant circulation path branched from the fourth coolant circulation path so as to supply the coolant to the battery cooling plate;

a bypass flow path branched from the fourth coolant circulation path so as to supply the coolant to the heat exchanger;

a sixth coolant circulation path connected to the battery cooling plate and the bypass flow path;

a first heat exchanger flow path connected to an inlet of the heat exchanger and the sixth coolant circulation path;

a second heat exchanger flow path connected to an outlet of the heat exchanger;

a seventh coolant circulation path connected to the first heat exchanger flow path and the second heat exchanger flow path; and

an eighth coolant circulation path connected to the second heat exchanger flow path and the seventh coolant circulation flow path to allow the coolant to flow into the pump.
The energy storage system of claim 13, further comprising:

a first three-way valve to distribute the coolant in the first coolant circulation flow path to the second coolant circulation path and the third coolant circulation path;

a second three-way valve configured such that the coolant in the fourth coolant circulation path is selectively supplied to the fifth coolant circulation path or the bypass flow path; and

a third three-way valve configured such that the coolant in the sixth coolant circulation path is selectively supplied to the heat exchanger or the seventh coolant circulation path.
The energy storage system of claim 14, wherein, in a preheating mode, the third three-way valve operates such that the coolant in the sixth coolant circulation path is supplied to the seventh coolant circulation path.
The energy storage system of claim 15, wherein, in the preheating mode, the first and the second Peltier modules are controlled to be on, and the heat dissipation fan and the battery cooling fan are controlled to be off.
The energy storage system of claim 16, wherein, in the preheating mode, the second voltage is applied to the first and second Peltier modules.
The energy storage system of claim 13, further comprising:

a first temperature sensor disposed at the eighth coolant circulation path; and

a second temperature sensor disposed at the sixth coolant circulation path.
The energy storage system of claim 1, wherein the battery cooling plate comprises a front cooling plate and a rear cooling plate disposed on a front surface and a rear surface of the battery pack, respectively.
The energy storage system of claim 1, wherein the battery pack is provided in plurality, and

wherein each of the plurality of battery packs is provided with the battery cooling plate, the first and second Peltier modules, the battery cooling fan, and the damper.