KR20240032473A - Energy Storage System - Google Patents

Abstract

An energy storage device according to embodiments of the present disclosure includes: battery packs each including battery cells; a power converter for converting electrical energy stored in the battery packs and supplying the converted electrical energy to a system; battery switches for connecting the battery packs in series in a default state and switching a connection state when a fault occurs in at least one of the battery packs; a booster converter for boosting output voltages of the battery packs switched in the connection state and supplying the boosted output voltages to the power converter when a fault occurs in at least one of the battery packs; and a booster switch for supplying the output voltages of the battery packs switched in the connection state to the boost converter when a fault occurs in at least one of the battery packs.

Description

Energy storage system {Energy Storage System}

The present disclosure relates to energy storage devices, and more specifically, to battery-based energy storage devices and methods of operating the same.

An energy storage device is a device that stores or charges external power and then outputs or discharges the externally stored power. For this purpose, the energy storage device is equipped with a battery, and a power converter is used to supply power to the battery or output power from the battery.

To increase overall battery capacity, battery cells can be connected. The overall battery capacity is determined by the series/parallel connection structure of the battery cells. Battery cells may differ in chemical and physical properties, and there may be differences in capacity accordingly. Additionally, when using an energy storage device, a problem may occur in a specific battery pack.

Korean Patent Publication No. 10-2006-0059680 discloses an overvoltage protection circuit for short-circuit and series-connected battery packs, and Korean Patent Publication No. 10-2018-0044750 discloses a voltage imbalance of multiple battery packs connected in parallel. and is launching a battery system that solves problems such as circulating current.

The problem that the present disclosure aims to solve is to provide an energy storage device that can stably manage battery output.

Another task of the present disclosure is to provide an energy storage device that can operate continuously by avoiding a defective battery pack even when a problem occurs in a specific battery pack.

Another task of the present disclosure is to provide an energy storage device that can improve the overall efficiency of the system, battery life, charge/discharge speed, and efficiency by more stably controlling the temperature of the system according to operating conditions. will be.

The tasks of the present disclosure are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above problem, the energy storage device according to embodiments of the present disclosure includes switches that can change the series connection state of the battery pack and a boost converter that can boost the output voltage, and output the battery pack. can be managed stably.

In order to achieve the above task, the energy storage device according to embodiments of the present disclosure arranges battery cooling plates for each battery pack and controls the flow rate and direction of coolant supplied to the battery cooling plates, thereby lowering the temperature of the battery packs. Can be managed effectively.

In order to achieve the above task, the energy storage device according to embodiments of the present disclosure includes battery packs each including battery cells, a power converter that converts the electrical energy stored in the battery packs and supplies it to the system, and a default ), battery switches that connect the battery packs in series and switch the connection state when a fault occurs in at least one of the battery packs, and when a fault occurs in at least one of the battery packs, the connection A booster converter that boosts the output voltage of the battery packs of which the state has been switched and supplies the output voltage to the power converter, and, when a fault occurs in at least one of the battery packs, the output voltage of the battery packs of which the connection state has been switched. It includes a booster switch that supplies power to the boost converter.

The boost converter may boost the output voltage of the battery packs whose connection state has been switched to the output voltage of the battery packs connected in series in the default state.

If a problem occurs in three or more of the battery packs, an emergency stop may occur.

When the battery packs are being charged, the boost converter may be turned off.

A diode that prevents reverse current may be connected to the negative terminal of the battery packs.

The battery switches can change the connection state so that the remaining battery packs, excluding the faulty battery pack, are connected in series.

It may further include a battery manager that controls the battery switches and the booster switch.

The battery manager is disposed in each of the battery packs, and is connected to battery pack circuit boards for acquiring status information of battery cells included in each battery pack and the battery pack circuit boards through a communication line, and the battery pack circuit It may include a main circuit board that receives status information obtained from each battery pack from the boards.

The power converter can control the battery switches and the booster switch.

The booster switch may be disposed between one of the battery packs, the booster converter, and the power converter.

The battery switches and the booster switch may be 3-way switches.

The battery switches have a pole connected to the boost converter, one contact point connected to the positive terminal of the first battery pack among the battery packs, and the other contact point connected to the negative terminal of the first battery pack. A first battery switch, a pole is connected to the negative terminal of the first battery pack and the first battery switch, one contact point is connected to the positive terminal of a second battery pack among the battery packs, and the other contact point is connected to the positive terminal of the second battery pack among the battery packs. A second battery switch connected to the negative terminal of the battery pack, a pole connected to the negative terminal of the second battery pack and the second battery switch, and one contact point connected to the positive terminal of a third battery pack among the battery packs. A third battery switch has another contact point connected to the negative terminal of the third battery pack, and a pole is connected to the negative terminal of the third battery pack and the third battery switch, and one contact point is connected to the negative terminal of the third battery pack. Among them, it may include a fourth battery switch connected to the positive terminal of the fourth battery pack, and the other contact point is connected to the negative terminal of the fourth battery pack.

The booster switch may have a pole connected to the negative terminal of the fourth battery pack and the fourth battery switch, one contact point may be connected to the booster converter, and the other contact point may be connected to the power converter.

An energy storage device according to an embodiment of the present disclosure includes a plurality of battery cooling plates disposed corresponding to each battery pack; And, a cooling module including a pump that flows coolant to the plurality of battery cooling plates, and a heat exchanger that exchanges heat with air and the coolant flowing by the pump.

According to at least one of the embodiments of the present disclosure, battery output can be stably managed.

Additionally, according to at least one of the embodiments of the present disclosure, even when a problem occurs in a specific battery pack, continuous operation can be performed by avoiding the defective battery pack.

Additionally, according to at least one of the embodiments of the present disclosure, the overall efficiency of the system, battery life, charge/discharge speed, and efficiency can be improved by controlling the temperature of the system more stably according to operating conditions.

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

1A and 1B are conceptual diagrams of an energy supply system including an energy storage device according to an embodiment of the present disclosure.
Figure 2 is a conceptual diagram of a home energy service system including an energy storage device according to an embodiment of the present disclosure.
Figure 3 is an exploded perspective view of an energy storage device including battery packs according to an embodiment of the present disclosure.
Figure 4 is a diagram illustrating a battery connection configuration in a normal state.
Figures 5 to 7 are diagrams referenced in the explanation of changing the battery connection state when a problem occurs in the battery.
Figure 8 is a flowchart of a method of operating an energy storage device according to an embodiment of the present disclosure.

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

In the drawings, parts not related to the description are omitted in order to clearly and briefly explain the present disclosure, and identical or extremely similar parts are denoted by the same drawing reference numerals throughout the specification.

Meanwhile, the suffixes “module” and “part” for components used in the following description are simply given in consideration of the ease of writing this specification, and do not give any particularly important meaning or role in and of themselves. Accordingly, the terms “module” and “unit” may be used interchangeably.

Additionally, 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.

The top (U), bottom (D), left (Le), right (Ri), front (F), and back (R) used in the drawings are used to describe the battery pack and the energy storage device including the battery pack. This can be set differently depending on the standard.

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

Referring to FIGS. 1A and 1B, the energy supply system includes an energy storage device 1 based on a battery 35 in which electrical energy is stored, a load 7 as a power demand source, and a system provided as an external power supply source ( 9) may be included.

The energy storage device 1 includes a battery 35 that stores (charges) electrical energy received from the system 9, etc. in direct current (DC) form or outputs (discharges) the stored electrical energy to the system 9, etc.; A power converter 32 (PCS: Power Conditioning System) that converts electrical characteristics (e.g., AC/DC interconversion, frequency, voltage) to charge or discharge the battery 35, and the current of the battery 35 , includes a battery manager 34 (BMS: Battery Management System) that monitors and manages information such as voltage and temperature.

The system 9 may include power generation facilities and transmission lines that produce power. The load 7 is a consumer that consumes power and may include home appliances such as refrigerators, washing machines, air conditioners, TVs, robot vacuum cleaners, robots, and mobile electronic devices such as vehicles and drones.

The energy storage device 1 can store power from the outside in the battery 35 and then output the power to the outside. For example, the energy storage device 1 can receive direct current or alternating current power from the outside, store it in the battery 35, and then output direct current or alternating current power to the outside.

Meanwhile, since the battery 35 mainly stores direct current power, the energy storage device 1 receives direct current power or converts the received alternating current power into direct current power and stores it in the battery 35. The stored direct current power can be converted into alternating current power and supplied to the system 9 or load 7.

At this time, the power converter 32 in the energy storage device 1 performs power conversion and voltage charges the battery 35, or transfers direct current power stored in the battery 35 to the system 9 or the load 7. can be supplied.

The energy storage device 1 can charge the battery 35 based on power supplied from the system and discharge the battery 35 when necessary. For example, in emergency situations such as a power outage, or during times, days, or seasons when the price of electric energy supplied from the system 9 is high, the electric energy stored in the battery 35 can be supplied to the load 7.

The energy storage device 1 has the advantage of being able to improve the safety and convenience of renewable energy generation by storing electrical energy generated from renewable energy sources such as solar energy, and can be used as an emergency power source. In addition, by using the energy storage device 1, it is possible to level loads with large fluctuations depending on time of day and season, and save energy consumption and costs.

The battery manager 34 can measure the temperature, current, voltage, charge amount, etc. of the battery 35 and monitor the state of the battery 35. Additionally, the battery manager 34 can control and manage the operating environment of the battery 35 to optimize it based on the status information of the battery 35.

Meanwhile, the energy storage device 1 may include a power manager 31a (PMS: Power Management System) that controls the power converter 32.

The power manager 31a may perform the function of monitoring and controlling the status of the battery 35 and the power converter 32. The power manager 31a may be a controller that controls the overall operation of the energy storage device 1.

The power converter 32 can control power distribution of the battery 35 according to control commands from the power manager 31a. The power converter 32 can convert power according to the connection status of the system 9, the power generation means such as solar power, the battery 35, and the load 7.

Meanwhile, the power manager 31a can receive status information of the battery 35 from the battery manager 34. Control commands can be transmitted to the power converter 32 and the battery manager 34.

The power manager 31a may include communication means such as a Wi-Fi communication module and memory. Various information necessary for the operation of the energy storage device 1 may be stored in the memory. Depending on the embodiment, the power manager 31a may include a plurality of switches and control the power supply path.

The power manager 31a and/or the battery manager 34 may use various known SOC methods such as a current integration method and a state of charge (SOC) calculation method based on open circuit voltage (OCV). The SOC of the battery 35 can be calculated using a calculation technique. If the charge amount of the battery 35 exceeds the maximum charge amount, the battery may overheat and operate irreversibly. Likewise, if the charge amount is below the minimum charge amount, the battery may deteriorate and become unrecoverable. The power manager 31a and/or the battery manager 34 can control the optimal use area and maximum input/output power by monitoring the internal temperature and charge amount of the battery 35 in real time.

The power manager 31a may operate under the control of the energy manager 31b (EMS: Energy Management System), which is a higher-level controller. The power manager 31a can control the energy storage device 1 by receiving commands from the energy manager 31b, and can transmit the status of the energy storage device 1 to the energy manager 31b. The energy manager 31b may be provided in the energy storage device 1 or in a higher-level system of the energy storage device 1.

The energy manager 31b can receive information such as rate information, power usage, and environmental information, and control the energy storage device 1 according to the user's energy production, storage, and consumption patterns. The energy manager 31b may be provided as an operating system for monitoring and controlling the power manager 31a.

The controller that controls the overall operation of the energy storage device 1 may include the power manager 31a and/or the energy manager 31b. Depending on the embodiment, either the power manager 31a or the energy manager 31b may perform the other function. Additionally, the power manager 31a and the energy manager 31b may be integrated into one controller and provided as one unit.

Meanwhile, the installed capacity of the energy storage device 1 varies depending on the customer's installation conditions, and can be expanded to the required capacity by connecting a plurality of power converters 32 and batteries 35.

The energy storage device 1 may be connected to at least one power generation device (see 3 in FIG. 2) separately from the system 9. The power generation device 3 is a wind power generator that outputs direct current power, a hydroelectric power generator that outputs direct current power using water power, a tidal power generator that outputs direct current power using tidal power, or a power generator that uses heat such as geothermal heat. It may include a thermal power generation device that outputs direct current power. Hereinafter, for convenience of explanation, the description will focus on the solar power generation device as the power generation device 3.

Figure 2 is a conceptual diagram of a home energy service system including an energy storage device according to an embodiment of the present disclosure.

Referring to FIG. 2, the energy storage device 1 may be connected to a system 9 such as a power plant 5, a power generation device such as a solar power generator 3, and a plurality of loads 7x1 and 7y1.

Electrical energy generated by the solar generator 3 can be converted in the PV inverter 4 and supplied to the system 9, the energy storage device 1, and the loads 7x1 and 7y1. As explained with reference to FIG. 3, depending on the installation type, the electrical energy generated by the solar generator 3 is converted in the energy storage device 1 and distributed to the system 9, the energy storage device 1, and the loads (7x1). , 7y1) may also be supplied.

Meanwhile, the energy storage device 1 is equipped with one or more wireless communication modules and can communicate with the terminal 6. The user can monitor and control the status of the energy storage device 1 and the home energy service system through the terminal 6. Additionally, the home energy service system can provide cloud (5)-based services. The user can monitor and control the status of the home energy service system by communicating with the cloud (5) through the terminal (6) regardless of location.

According to an embodiment of the present disclosure, the above-described battery 35, battery manager 34, and power converter 32 may be disposed inside one casing 12. The battery 35, battery manager 34, and power converter 32, which are integrated into one casing 12, can store and convert power and can be called an all-in-one energy storage device 1a. .

In addition, separate enclosures (1b) outside the casing (12) include components for power distribution such as a power manager (31a), an automatic transfer switch (ATS), a smart meter, and switches, and terminals (6). ), a communication module for communication with the cloud 5, etc. may be deployed. A configuration in which components related to power distribution and management are integrated into one enclosure (1) may be named a smart energy box (1b).

The above-described power manager 31a can be accommodated in the smart energy box 1b. A controller that controls the overall power supply connection of the energy storage device 1 may be placed in the smart energy box 1b. The controller may be the power manager 31a described above.

In addition, switches are accommodated in the smart energy box (1b), connected to the grid power * (5, 9), a solar generator (3), a battery (35) of the all-in-one energy storage device (1a), and loads (7x1, You can control the connection status of 7y1). Loads 7x1 and 7y1 may be connected to the smart energy box 1b through load panels 7x2 and 7y2.

Meanwhile, the smart energy box (1b) is connected to the grid power sources (5, 9) and the solar generator (3). In addition, when a power outage occurs in the systems 5 and 9, an automatic transfer switch (ATS) is switched so that the electric energy produced by the solar generator 3 or stored in the battery 35 is supplied to a predetermined load 7y1. ) can be placed in the smart energy box (1b).

Alternatively, the power manager 31a may perform the automatic transfer switch (ATS) function. For example, when a power outage occurs in the systems 5 and 9, the power manager 31a is configured to transfer the electrical energy produced by the solar generator 3 or stored in the battery 35 to a predetermined load (7y1). ), you can control switches such as relays to supply power.

Meanwhile, current sensors, smart meters, etc. may be placed in each current supply path. The electricity produced through the energy storage device (1) and the solar generator (3) can be measured and managed through a smart meter (at least a current sensor).

The energy storage device 1 according to an embodiment of the present disclosure includes at least an all-in-one energy storage device 1a. In addition, the energy storage device 1 according to an embodiment of the present disclosure includes an all-in-one energy storage device 1a and a smart energy box 1b, thereby enabling simple and efficient storage, supply, distribution, communication, and control of power. We can provide integrated services that can be performed through .

Meanwhile, the energy storage device 1 according to an embodiment of the present disclosure may operate in multiple operation modes. In the PV self-consumption mode, solar power generation power is first used in the load, and the remaining power is stored in the energy storage device (1). For example, if the solar generator 3 generates more power than the usage of the loads 7x1 and 7y1 during the day, the battery 35 is charged.

In the rate-based charge/discharge mode, four time zones can be set and input, and the battery 35 can be discharged during times when electricity rates are high and the battery 35 can be charged during times when electricity rates are low. The energy storage device 1 can help users save on electricity bills through a rate-based charge/discharge mode.

Backup-only mode is a mode to prepare for emergency situations such as power outages. When a typhoon is predicted in the weather forecast or there is a possibility of other power outages, the battery (35) is charged to the maximum and supplied as an essential load (7y1) in an emergency. It can operate with the highest priority.

Figure 3 is an exploded perspective view of an energy storage device including battery packs according to an embodiment of the present disclosure.

Referring to FIG. 3, the energy storage device 1 according to an embodiment of the present disclosure includes battery packs 10 arranged in a vertical direction, and a casing 12 forming a space where the battery packs 10 are arranged. ), includes a door 28 that opens and closes the front of the casing 12.

The casing 12 may have a front opening. The casing 12 includes a casing rear wall 14 covering the rear, a pair of casing side walls 20 extending forward from both ends of the casing rear wall 14, and a pair of casing side walls 20 extending forward from the top of the casing rear wall 14. It may include a casing top wall 24 extending forward, and a casing base 26 extending forward from the bottom of the casing rear wall 14. The casing rear wall 14 includes a pack fastening portion 16 formed to be fastened to the battery pack 10.

Switches 22a and 22b that turn on/off the power of the energy storage device 1 may be disposed on one of the pair of casing side walls 20. In one embodiment of the present disclosure, the first switch 22a and the second switch 22b are disposed, and the power is turned on only by the switching combination of the first and second switches 22a and 22b, so that the energy storage device 1 is turned on. Safety can be strengthened.

Inside the casing 12, a power converter 32 (PCS: Power Conditioning System), which converts the characteristics of electricity for charging or discharging the battery, is included in the battery pack 10 and/or the battery pack 10. A battery management system (BMS) that monitors information such as current, voltage, and temperature of battery cells may be deployed.

The power converter 32 includes a circuit board 33 and a switching element 33a (for example, an insulated gate bipolar transistor; IGBT) may be included.

The battery manager 34 is disposed inside the battery pack circuit board (not shown) and the casing 12 disposed in each of the plurality of battery packs 10a, 10b, 10c, and 10d, and includes the plurality of battery pack circuit boards and communication lines ( It may include a main circuit board (34a) connected to (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 the power line 198 extending from the battery pack 10.

A plurality of battery packs 10a, 10b, 10c, and 10d are disposed inside the casing 12. A plurality of battery packs 10a, 10b, 10c, and 10d may be arranged in a 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 portion 16 disposed on the rear casing wall 14.

Each battery pack 10 may include at least one battery module (not shown) including a plurality of battery cells connected in series or parallel. For example, the battery pack 10 may include a battery module assembly (not shown) consisting of two battery modules (not shown) that are electrically connected to each other and physically fixed. The battery module assembly may include a first battery module and a second battery module arranged to face each other. The first and second battery modules each include a sensing board (not shown) that senses information about a plurality of battery cells, and the battery pack circuit board collects sensing information of the first and second battery modules from the sensing board. It can be transmitted to the battery manager 34.

The energy storage device 1 according to an embodiment of the present disclosure includes internal components such as a battery 35 capable of storing electricity, a power converter 32 responsible for the input and output of the battery 35, and the battery 35. Includes a thermal management system to regulate temperature.

The ESS thermal management system according to an embodiment of the present disclosure recovers waste heat generated from the battery 35, power converter 32, reactor, etc. when the system is driven, and discharges the recovered waste heat to the outside to heat the battery 35, It is a water-cooled temperature control system to improve system efficiency by reducing the temperature of the power converter 32. When using an existing air-cooled thermal management system, heat recovery efficiency is low, so the temperature of each component in the system may be high. When the temperature of the battery is kept stable within a certain temperature range when charging and discharging the battery, the charging and discharging speed within the battery increases, which has the advantage of increasing battery use efficiency.

According to the present disclosure, as a thermal management system, the energy storage device 1 includes a cooling module 40 that cools internal components such as the battery pack 10 and the PCS board 33. According to an embodiment of the present disclosure, the cooling module 40 can cool the battery pack 10, the PCS board 33, etc. using a water cooling method.

For example, a battery cooling plate 50 is disposed in response to each battery pack 10, and coolant circulates between the cooling module 40 and the battery cooling plate 50 along the coolant flow path 60 to cool the battery pack. (10) can be cooled. The coolant flow path 60 includes an inlet flow path 60b through which coolant flows from the cooling module 40 into the battery cooling plate 50, and an outlet flow path through which coolant is discharged from the battery cooling plate 50 to the cooling module 40 ( 60a) may be included.

Considering the problems of coolant supply and leakage, a coolant with insulation performance is applied, and a coolant that can be used even at low temperatures is more preferable.

The cooling module 40 includes a pump for circulating coolant, a heat exchanger for discharging waste heat recovered during system operation through heat exchange with the air, and the coolant heated according to waste heat recovery is cooled to the minimum ambient temperature and circulated. You can do it.

The cooling module 40 is supported by a plate 41 and can be in contact with a PCS board, etc. 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, etc. to cool each part other than the cooling module 40.

The battery-side water blocks are configured to increase proportionally according to the number of battery modules applied, and are configured so that the normal coolant flow rate is supplied equally to each water block.

The water block, which is composed of each heating element part, has coolant flowing inside it and is configured to recover waste heat through surface contact with the heating element. In order to efficiently operate the thermal management system, a temperature sensor is placed at the rear end of the water block for each component to detect the outlet water temperature.

In addition, the thermal management system applies a valve to switch the coolant flow path as needed, and the flow rate of the fluid supplied to each heating unit is variable, thereby controlling the temperature of the heating unit to maintain the temperature within the target temperature range. can do.

The power manager 31a or the battery manager 34 may be a controller that also controls the thermal management system. Alternatively, the thermal management system may have a separate controller. Sensing information such as temperature sensors is transmitted to the controller, and the controller can control the operation mode of the thermal management system and the operation (opening/closing, opening degree control) of the pump, fan, and valve.

If the condition is to preheat the parts in the system, some power is consumed by controlling the reactive power of the PCS without using the heat exchanger by controlling the open/close valve (ex, 1-way valve) placed on the coolant inlet side of the heat exchanger. Heat is generated, and the waste heat generated at this time is recovered to preheat the battery. The battery preheated through this control increases the battery charge capacity and charging speed, allowing the ESS system to be operated more efficiently. In this way, the ESS thermal management system can expand the operating range of the system by improving the battery operating range and charging speed through cooling in high temperature conditions and preheating in low temperature conditions.

In the case of household ESS products, four operating modes can be configured depending on operating conditions.

The first operating mode is PCS and battery cooling mode. PCS and battery cooling mode is when heat is generated from the PCS, battery, and reactor due to the use of ESS batteries. The waste heat generated from each heating part can be recovered and released into the atmosphere through a heat exchanger.

The second operation mode is a low outdoor temperature operation and standby mode, and is a PCS cooling and battery heating mode to cool the battery with coolant heated through heat generation from the PCS. The heat exchanger is not used in PCS cooling and battery heating modes.

The third operation mode is a battery-only cooling mode to improve battery efficiency by cooling the battery module when only the PCS is cooled after the end of normal operation. The battery exclusive cooling mode is an operation mode for additional battery cooling when only the PCS with a small thermal mass is cooled early at the end of system operation.

The fourth operation mode is PCS exclusive cooling mode. The PCS exclusive cooling mode is an operation mode mainly used to cool the PCS when the operation time is short or the output is low, so the battery generates little heat, but only the PCS generates high heat.

FIG. 4 is a diagram illustrating a battery connection configuration in a normal state, and FIGS. 5 to 7 are diagrams referred to in an explanation of a change in the battery connection state when an abnormality occurs in the battery.

Referring to FIGS. 4 to 7, the energy storage device 1 includes battery packs 10 each including battery cells, and when discharging, converts the electrical energy stored in the battery packs 10 to the system ( It includes a power converter (32) that supplies power to 9).

When charging, the power converter 32 can convert electrical energy supplied from the system 9 or a distributed power source such as solar power, and store it in the battery packs 10.

Additionally, the energy storage device 1 includes switches 420 and 415 that determine the connection status of the battery packs 10.

Battery switches 420 connect all of the battery packs 10 in series in the default state. Therefore, in the default state, which is a normal condition, all of the battery packs 10 are connected in series, and the total voltage of the battery packs 10 becomes the output voltage of the energy storage device 1. For example, when four battery packs (10a, 10b, 10c, 10d) each having an output voltage of 100V are connected in series, 400V can be output.

In an abnormal state in which a fault occurs in at least one of the battery packs 10, the battery switches 420 change the connection state to exclude the faulty battery pack. That is, the switching states of some of the battery switches 420 are switched so that only the remaining battery packs in normal conditions are connected in series, excluding the faulty battery pack.

On the other hand, when the connection state is changed to connect in series only the remaining battery packs in normal conditions, excluding the faulty battery pack, the output voltage is lowered. For example, if a problem occurs in any one of the four battery packs (10a, 10b, 10c, 10d) with an output voltage of 100V and the series connection is reconfigured with three battery packs, 300V is output and two of them have a problem. If this occurs and the series connection is reconfigured with two battery packs, 200V will be output. Therefore, the energy storage device 1 further includes a booster converter 410 that boosts the input voltage and supplies it to the power converter 32 in order to maintain stable output during discharge.

The booster converter 410 may boost the output voltage of the battery packs whose connection state has been switched to the output voltage of the battery packs connected in series in the default state. Additionally, when the battery packs are being charged, the boost converter 410 is turned off. When the booster converter 410 is turned off, the booster converter 410 can output voltage without boosting.

That is, the booster converter 410 is turned off during charging, so it does not affect the input voltage, and when discharging, it can boost the input voltage and output it in response to the voltage drop caused by the defective battery pack. there is. For example, when discharging, when the boost converter 410 is turned on, the boost converter 410 can boost the voltage of 300V DC or 200V to 400V DC.

Meanwhile, the booster switch 415, when a fault occurs in at least one of the battery packs 10 during discharge, switches the output voltage of the battery packs 10 whose connection states have been switched to the booster converter. It is switched to supply to (410). The booster switch 415 is disposed between one of the battery packs 10, the booster converter 410, and the power converter 32, and switches the output of the battery packs 10 to the booster converter ( 410) or can be transmitted to the power converter 32.

According to an embodiment of the present disclosure, if a failure situation occurs during normal operation or there is a battery pack that is expected to fail, the system generates an error, but continuous operation is possible. Although the charging and discharging amount of energy is reduced due to a broken battery, users can use the ESS by using the remaining normal batteries until the broken battery is repaired or replaced.

If a problem occurs in three or more of the battery packs 10, an emergency stop may occur. According to an embodiment of the present disclosure, continuous operation is possible by avoiding abnormal conditions in which the entire system must be stopped due to an abnormal state of one or two battery packs. By operating the system stably and continuously, excluding broken batteries, the inconvenience caused by the user's use of the ESS can be reduced. Additionally, if there are many broken batteries, safety accidents can be prevented by stopping the system.

Meanwhile, a diode (D) that prevents reverse current may be connected to the negative terminal (T2) of the battery packs (10).

The battery manager 34 described above can control the battery switches 420 and the booster switch 415. The battery manager 34 can monitor status information of the battery 35 and control the connection structure of the battery 35. The battery manager 34 can control the battery switches 420 and the booster switch 415 based on the battery packs 10.

The battery manager 34 includes battery pack circuit boards (not shown) disposed in each of the battery packs 10 and acquiring status information of a plurality of battery cells included in each battery pack 10, and , and includes a main circuit board 34a connected to the battery pack circuit boards through a communication line and receiving status information obtained from each battery pack 10 from the battery pack circuit boards.

According to an embodiment of the present disclosure, the control circuit 34a, which includes a configuration for managing the battery 35 (particularly a configuration for safety control), and the battery cell sensing circuit (battery pack circuit board) are designed separately, The main functions of the battery manager 34 can be performed and the control circuit 34a, which manages the plurality of battery packs 10, can be protected.

In another embodiment, the power converter 32 may control the battery switches 420 and the booster switch 415.

Meanwhile, the battery switches 420 and the booster switch 415 may be 3-way switches. The three-way switch is also called a Single Pole Double Throw (SPDT) switch and may include one pole and two contact points.

The battery switches 420 may be configured to correspond to battery packs 10a, 10b, 10c, and 10d, respectively. For example, the battery switches 420 include first to fourth battery switches 421, 422, 423, and 424 corresponding to the first to fourth battery packs 10a, 10b, 10c, and 10d, respectively. It can be included.

The first battery switch 421 has a pole (b1) connected to the boost converter 410, and one contact point (a11) connected to the positive terminal (T1) of the first battery pack (10a) among the battery packs (10). ), and the other contact point (a12) may be connected to the negative terminal (T2) of the first battery pack (10a).

The second battery switch 422 has a pole (b2) connected to the negative terminal (T2) of the first battery pack (10a) and the first battery switch 421, and one contact point (a21) connected to the battery pack. Among the contact points 10, the contact point a22 may be connected to the positive terminal T1 of the second battery pack 10b, and the other contact point a22 may be connected to the negative terminal T2 of the second battery pack 10b.

The third battery switch 423 has a pole (b3) connected to the negative terminal (T2) of the second battery pack (10b) and the second battery switch (422), and one contact point (a31) connected to the battery pack. Among the contact points 10, the contact point a32 may be connected to the positive terminal T1 of the third battery pack 10c, and the other contact point a32 may be connected to the negative terminal T2 of the third battery pack 10c.

The fourth battery switch 424 has a pole (b4) connected to the negative terminal (T2) of the third battery pack (10c) and the third battery switch 423, and one contact point (a41) connected to the battery pack. Among the contact points 10, the contact point a42 may be connected to the positive terminal T1 of the fourth battery pack 10d, and the other contact point a42 may be connected to the negative terminal T2 of the fourth battery pack 10d.

In addition, the booster switch 415 has a pole (d) connected to the negative terminal (T2) of the fourth battery pack (10d) and the fourth battery switch 424, and one contact point (c11) connects the power. It is connected to the converter 32, and another contact point c12 may be connected to the booster converter 410.

Referring to FIG. 4, under normal conditions, the pole (b1) of the first battery switch 421 is connected to the contact point (a11), and the pole (b2) of the second battery switch 422 is connected to the contact point (a21). The third battery switch 423 has a pole (b3) connected to the contact point (a31), and the fourth battery switch 424 has a pole (b4) connected to the contact point (a41). Additionally, in the booster switch 415, the pole (d) is connected to the contact point (c11).

Accordingly, the first to fourth battery packs (10a, 10b, 10c, and 10d) are all connected in series, and the total voltage of the first to fourth battery packs (10a, 10b, 10c, and 10d) is the power converter. It is supplied to (32). For example, if the first to fourth battery packs 10a, 10b, 10c, and 10d each have 100V, 400V is supplied to the power converter 32.

Figure 5 illustrates a case where a fault occurs in the first battery pack 10a. Referring to FIG. 5, when a fault occurs in the first battery pack 10a, the first battery switch 421 is switched so that the pole b1 is connected to the contact point a12. In addition, as in normal conditions, the pole (b2) of the second battery switch 422 is connected to the contact point (a21), and the pole (b3) of the third battery switch 423 is connected to the contact point (a31). In the fourth battery switch 424, the pole (b4) is connected to the contact point (a41). Accordingly, the first battery pack 10a is excluded from the series connection, and the second to fourth battery packs 10b, 10c, and 10d reconfigure the series connection.

Additionally, the booster switch 415 has a pole (d) connected to a contact point (c12). Accordingly, the total voltage of 300V of the second to fourth battery packs 10b, 10c, and 10d is input to the booster converter 410, and the booster converter 410 boosts the voltage to 400V to the power converter 32. Can be printed.

Figure 6 illustrates a case where a fault occurs in the third battery pack 10c. Referring to FIG. 6, when a fault occurs in the third battery pack 10c, the third battery switch 423 is switched so that the pole b3 is connected to the contact point a32. In addition, as in normal conditions, the pole (b1) of the first battery switch 421 is connected to the contact point (a11), and the pole (b2) of the second battery switch 422 is connected to the contact point (a21). In the fourth battery switch 424, the pole (b4) is connected to the contact point (a41). Accordingly, the third battery pack 10c is excluded from the serial connection, and the first battery pack 10a, the second battery pack 10b, and the fourth battery pack 10d reconfigure the serial connection.

Additionally, the booster switch 415 has a pole (d) connected to a contact point (c12). Accordingly, the total voltage of 300V of the first battery pack (10a), the second battery pack (10b), and the fourth battery pack (10d) is input to the booster converter 410, and the booster converter 410 converts the voltage to 400V. Boosting can be performed and output to the power converter 32.

Figure 7 illustrates a case where a fault occurs in the second battery pack 10b and the third battery pack 10c. Referring to FIG. 7, when a fault occurs in the second battery pack 10b and the third battery pack 10c, the pole b2 of the second battery switch 422 is connected to the contact point a22. , the third battery switch 423 is switched so that the pole (b3) is connected to the contact point (a32). In addition, as in normal conditions, the pole (b1) of the first battery switch 421 is connected to the contact point (a11), and the pole (b4) of the fourth battery switch 424 is connected to the contact point (a41). do. Accordingly, the second battery pack (10b) and the third battery pack (10c) are excluded from the serial connection, and the first battery pack (10a) and the fourth battery pack (10d) reconfigure the serial connection. .

Additionally, in the booster switch 415, the pole (d) is connected to the contact point (c12). Accordingly, the total voltage of 200V of the first battery pack (10a) and the fourth battery pack (10d) is input to the booster converter 410, and the booster converter 410 boosts the voltage to 400V and the power converter It can be output at (32).

Figure 8 is a flowchart of a method of operating an energy storage device according to an embodiment of the present disclosure.

Referring to FIG. 8, when the energy storage device 1 is turned on (S805), the energy storage device 1 checks the operating conditions and starts operation (S810).

The battery manager 34 monitors the status of the battery 35 and determines whether a fault has occurred for each of the battery packs 10a, 10b, 10c, and 10d included in the battery 35 (S815).

If there is no problem with the battery 35 (S820), the energy storage device 1 operates under normal conditions (S825). Under normal conditions, the battery packs 10a, 10b, 10c, and 10d are connected in series, and the boost converter 410 does not operate.

Meanwhile, if an abnormality occurs in the battery 35 (S820), the energy storage device 1 generates an error (S830). Additionally, the battery manager 34 can identify the battery packs 10a, 10b, 10c, and 10d in which a fault has occurred.

If the number of faulty battery packs 10a, 10b, 10c, and 10d is more than three, the energy storage device 1 stops operating (S845). If the number of faulty battery packs 10a, 10b, 10c, and 10d is two or less, the energy storage device 1 enters emergency operation control (S850).

As emergency operation control is entered (S850), the switches 420 and 415 are controlled to avoid a faulty battery pack (S855). The battery manager 34 or power manager 32 can control the switches 420 and 415.

Additionally, according to the battery control mode such as charge/discharge (S860), the operation of the boost converter 410 is controlled (S865, S870). If in charging mode (S860), the boost converter 410 is turned on (S865), and if in discharging mode (S860), the boost converter 410 is turned off (S870).

As described with reference to FIG. 5, when a fault occurs in the first battery pack (10a) during discharging, the series connection is reconfigured so that the first battery pack (10a) is excluded from the series connection, and the second to fourth batteries The switches 420 and 415 operate so that the outputs of the packs 10b, 10c, and 10d are supplied to the boost converter 410 (S855). Additionally, the boost converter 410 boosts the voltage and outputs it to the power converter 32 (S865).

As described with reference to FIG. 6, when a fault occurs in the third battery pack (10c), the series connection is reconfigured so that the third battery pack (10c) is excluded from the series connection, and the first battery pack (10a) and the third battery pack (10a) are connected to each other. The switches 420 and 415 operate so that the outputs of the second battery pack 10b and the fourth battery pack 10d are supplied to the boost converter 410 (S855). Additionally, the boost converter 410 boosts the voltage and outputs it to the power converter 32 (S865).

As explained with reference to FIG. 7, when a fault occurs in the second battery pack (10b) and the third battery pack (10c), the second battery pack (10b) and the third battery pack (10c) are excluded from the series connection. The series connection is reconfigured as much as possible, and the switches 420 and 415 are operated so that the outputs of the first battery pack 10a and the fourth battery pack 10d are supplied to the boost converter 410 (S855). Additionally, the boost converter 410 boosts the voltage and outputs it to the power converter 32 (S865).

According to the present disclosure, the switches 420 and 415 are controlled to use a normal battery rather than a broken battery during driving. The battery manager 34 can diagnose the state of each battery pack 10, determine which battery is broken, and selectively control the relays of the switches 420 and 415 to avoid the broken battery. Accordingly, even if a problem occurs in a specific battery pack, continuous operation can be performed by avoiding the defective battery pack.

In addition, according to the present disclosure, the boost converter 410 is configured to be selectively used in response to the problem of insufficient DC voltage in the event of a battery failure. Accordingly, battery output can be managed stably.

In the above, preferred embodiments of the present invention have been shown and described, but the present invention is not limited to the specific embodiments described above, and can be used in the technical field to which the invention pertains without departing from the gist of the present invention as claimed in the patent claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be understood individually from the technical idea or perspective of the present invention.

1: Energy storage device
10: Battery pack
12: Casing
32: Power converter
34: Battery manager

Claims (14)

Battery packs each including battery cells;
A power converter that converts the electrical energy stored in the battery packs and supplies it to the system;
Battery switches that connect the battery packs in series in a default state and switch the connection state when a fault occurs in at least one of the battery packs;
When a fault occurs in at least one of the battery packs, a booster converter boosts the output voltage of the battery packs whose connection states have been switched and supplies the output voltage to the power converter; and,
When a fault occurs in at least one of the battery packs, a booster switch supplies the output voltage of the battery packs whose connection states have been switched to the boost converter. According to paragraph 1,
The boost converter is,
An energy storage device that boosts the output voltage of the battery packs whose connection state has been switched to the output voltage of the battery packs connected in series in the default state. According to paragraph 1,
An energy storage device that performs an emergency stop when a problem occurs in three or more of the battery packs. According to paragraph 1,
When the battery packs are being charged, the boost converter is turned off. According to paragraph 1,
An energy storage device in which a diode to prevent reverse current is connected to the negative terminal of the battery packs. According to paragraph 1,
The battery switches are an energy storage device that switches the connection state so that the remaining battery packs are connected in series, excluding the battery pack in which a fault occurred. According to paragraph 1,
An energy storage device further comprising a battery manager that controls the battery switches and the booster switch. In clause 7,
The battery manager,
Battery pack circuit boards disposed in each of the battery packs and acquiring status information of battery cells included in each battery pack,
An energy storage device comprising a main circuit board connected to the battery pack circuit boards through a communication line and receiving status information obtained from each battery pack from the battery pack circuit boards. According to paragraph 1,
The power converter is an energy storage device that controls the battery switches and the booster switch. According to paragraph 1,
The booster switch is,
An energy storage device disposed between one of the battery packs, the booster converter, and the power converter. According to paragraph 1,
The battery switches and the booster switch are energy storage devices that are 3-way switches. According to clause 11,
The battery switches are,
A first battery switch whose pole is connected to the boost converter, one contact point is connected to the positive terminal of a first battery pack among the battery packs, and the other contact point is connected to the negative terminal of the first battery pack,
A pole is connected to the negative terminal of the first battery pack and the first battery switch, one contact point is connected to the positive terminal of the second battery pack among the battery packs, and the other contact point is connected to the negative terminal of the second battery pack. A second battery switch connected to,
A pole is connected to the negative terminal of the second battery pack and the second battery switch, one contact point is connected to the positive terminal of the third battery pack among the battery packs, and the other contact point is connected to the negative terminal of the third battery pack. A third battery switch connected to, and
A pole is connected to the negative terminal of the third battery pack and the third battery switch, one contact point is connected to the positive terminal of the fourth battery pack among the battery packs, and the other contact point is connected to the negative terminal of the fourth battery pack. An energy storage device including a fourth battery switch connected to. According to clause 12,
The booster switch is,
An energy storage device in which a pole is connected to the negative terminal of the fourth battery pack and the fourth battery switch, one contact point is connected to the booster converter, and the other contact point is connected to the power converter. According to paragraph 1,
A plurality of battery cooling plates arranged in correspondence with each battery pack; and,
An energy storage device further comprising a cooling module including a pump that flows coolant to the plurality of battery cooling plates, and a heat exchanger that exchanges heat with air and the coolant flowing by the pump.

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