KR102386233B1 - Apparatus for storing emergency power using recycled batteries - Google Patents

Abstract

A system for storing energy using recycled batteries of the present invention is a system for storing power generated by various power generation devices and supplying the stored power to a load. The system includes: a battery module for storing power; and a power conversion device for converting AC power produced by a generator into DC power to store the DC power in the battery module, and converting the DC power stored in the battery module into AC power to transfer the AC power to the load, wherein the battery module includes: at least one recycled battery; and voltage optimizers having input terminals connected to the at least one recycled battery, respectively, to output by bypassing or boosting the DC voltage (Va) input from the corresponding recycled battery, and output terminals connected in parallel to output the same equalized voltage (Veq) as other adjacent recycled batteries. Therefore, the stable energy is generated by utilizing batteries with low efficiency compared to the initial capacity, so that the utilization of waste batteries is increased, and as a result, environmental problems caused by the discharge of waste batteries are minimized.

Description

Energy storage system using recycled batteries {APPARATUS FOR STORING EMERGENCY POWER USING RECYCLED BATTERIES}

The present invention relates to an energy storage system using a recycled battery.

Due to recent environmental problems, the global demand for electric vehicles is increasing.

An electric vehicle is a vehicle that generates driving power by supplying electric energy from a high-voltage battery to an electric motor. is attracting attention.

However, the life cycle of an electric vehicle battery, which is a key component of such electric vehicles, is usually 7 to 10 years, and when it is below 70% of the initial capacity, the mileage decreases and the charging speed decreases, so replacement is necessary. According to the Ministry of Environment, the annual discharge of waste batteries in 2030 is expected to reach about 110,000, and the total accumulated number will reach about 420,000.

Electric vehicle batteries are composed of metals such as nickel, lithium, cobalt, and manganese and polymer electrolytes, so if they are buried together with general waste, they may contaminate soil and groundwater, and if incinerated, they may explode or release harmful gases. there is.

Accordingly, there is a growing interest in the use of EV batteries that have reached the end of their lifespan.

As a conventional technology for battery recycling, Korean Patent Application Laid-Open No. 10-2020-0048913 discloses a waste battery-based energy storage system that provides an energy storage service using a plurality of waste batteries with a built-in BMS (Battery Management System). a master BMS for recognizing and registering the BMS of each of the waste batteries as a slave BMS, and monitoring a battery state of each of the waste batteries through each of the slave BMSs; a battery control unit that adjusts a battery charging sequence according to the battery state of each of the waste batteries, sequentially charges the waste batteries one by one according to the battery charging sequence when the batteries are charged, and discharges all of the waste batteries at once when the batteries are discharged; an inverter for generating and providing load power based on the power generated by the renewable energy system and the charging power of each of the waste batteries; and an energy management unit configured to monitor and analyze the power generation power of the renewable energy system and power consumption of a load to control the inverter MPPT and simultaneously determine and adjust the operation mode of the battery control unit. This is disclosed.

According to the above patent, by enabling the recycling of large-capacity waste batteries used in electric vehicles, etc., the cost of implementing an independent home energy storage system used for home use can be dramatically reduced, and battery misuse through recycling of large-capacity waste batteries It has the effect of minimizing the environmental damage caused by it.

However, as described above, the conventional energy storage system using waste batteries does not solve the problem of circulating current caused by the difference in output voltages when a plurality of waste batteries are connected in parallel, so there is a problem that the waste batteries cannot be effectively used. .

Korean Patent Publication No. 10-2020-0048913

Therefore, the present invention provides an energy storage system using a recycled battery that generates stable energy by using batteries with low efficiency compared to the initial capacity, thereby increasing the utilization of the waste battery, and thereby minimizing environmental problems caused by the discharge of the waste battery. would like to provide

In addition, the present invention solves the problem of temperature rise in the energy storage system due to the circulation current by solving the problem of circulating current caused by the difference in output voltage when connecting a plurality of recycled batteries in parallel, and furthermore, fire To provide an energy storage system using recycled batteries that can prevent

In addition, the present invention does not pre-classify recycled batteries with different degrees of performance degradation depending on the manufacturer, the age of use, the usage environment, the number of charge/discharge, etc., but utilizes them as they are, so that an energy storage system can be conveniently implemented We aim to provide an energy storage system using recycled batteries.

In order to achieve the above object, the energy storage system provided by the present invention is an energy storage system for storing electric power produced by various power generation devices and supplying the stored electric power to a load side, the energy storage system comprising: a battery module for storing the electric power; and a power conversion device that converts the AC power produced by the power generator into DC power and stores it in the battery module, converts the DC power stored in the battery module into AC power and transmits it to the load side, wherein the battery The module comprises at least one recycled battery; and an input terminal connected to each of the one or more recycled batteries to bypass or boost the DC voltage Va input from the corresponding recycled battery, and output the same voltage as that of other adjacent recycled batteries ( It is characterized in that it includes voltage optimization units that output Veq).

Preferably, the voltage optimizer includes: a first backflow prevention diode installed between the input terminal and the output terminal; a first booster part installed between the input terminal and the first backflow prevention diode to bypass or boost the DC voltage Va; a first switch for turning on/off the first booster unit; a comparator for comparing the DC voltage (Va) with a voltage (Veq) of an output terminal of the first backflow prevention diode to turn on/off the first switch; Comparing the output voltage (Vb) of the first booster unit and the voltage (Veq) of the first backflow prevention diode output terminal, based on the result, a first outputting control signal for determining the boosting voltage of the first booster unit control unit; and an oscillator that generates a PWM pulse based on the control signal and outputs the PWM pulse to the first booster through the first switch.

As described above, the energy storage system using the recycled battery of the present invention generates stable energy by utilizing the batteries with lower efficiency compared to the initial capacity, thereby increasing the utilization of the waste battery, thereby minimizing the environmental problem caused by the discharge of the waste battery. There are advantages to being able to do that.

In addition, the present invention solves the problem of circulating current caused by the difference in output voltage when connecting a plurality of recycled batteries in parallel, thereby solving the problem of temperature rise in the energy storage system due to the circulating current, and furthermore, fire has the advantage of preventing

In addition, the present invention does not pre-classify recycled batteries having different degrees of performance degradation depending on the manufacturer, the age of use, the operating environment, the number of times of charging/discharging, etc. There is an advantage to

1 is a block diagram illustrating a schematic configuration of an energy storage system according to an embodiment of the present invention.
2 is a block diagram illustrating a configuration of a battery module applied to an energy storage system according to an embodiment of the present invention.
3 is a block diagram illustrating a configuration of a voltage optimization unit according to a first embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings, but it will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily practice the present invention. However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. On the other hand, in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification. In addition, even if the detailed description is omitted, descriptions of parts that can be easily understood by those skilled in the art are omitted.

Throughout the specification and claims, when a part includes a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

1 is a block diagram illustrating a schematic configuration of an energy storage system according to an embodiment of the present invention. Referring to FIG. 1 , an energy storage system (ESS, Energy Storage System) 10 according to an embodiment of the present invention stores power produced and delivered by various power generation devices (eg, power generation source 20), A device for transmitting the stored power to the load side (eg, the transmission/distribution device 30 , the consumer 40 , etc.) in response to a request from the load side, the battery module 100 , the BMS 11 , the PCS 13 ), and the EMS 15 .

The battery module 100 is a device for storing the power, and may include at least one recycled battery.

The BMS (Battery Management System) 11 is a device for monitoring and controlling the state of the battery module 100 , and suppresses problems that may occur in each of at least one battery included in the battery module 100 . In order to do this, the charging/discharging state of each of the batteries, the remaining amount of the battery, etc. are monitored and controlled.

The PCS (Power Conditioning System) 13 converts electrical characteristics (eg, frequency, voltage, AC/DC, etc.) to store input power in a battery or discharge pre-stored power to the system. In particular, the PCS 13 converts AC power to DC power, or DC power to AC power, but converts AC power produced by the power generation device (eg, power source 20 ) into DC power to convert the battery module 100 .

The EMS (Energy Management System) 15 controls and monitors all operations of the ESS 10 . For example, the EMS 15 controls the energy flow to store or consume energy produced from various types of energy sources, and collects/manages information such as the ESS 10 status to use optimal energy. can support

2 is a block diagram illustrating a configuration of a battery module applied to an energy storage system according to an embodiment of the present invention. Referring to FIG. 2 , the battery module 100 applied to the ESS 10 according to an embodiment of the present invention includes at least one recycled battery (a first recycled battery 111 , a second recycled battery 112 , and The third recycled battery 113) 110, and at least one voltage optimizer (the first voltage optimizer 121, the second voltage optimizer 122, and the nth voltage optimizer 123) 120 ) is included.

At this time, each of the at least one recycled battery 110 (ie, the first recycled battery 111 , the second recycled battery 112 , and the n-th recycled battery 113 ) exceeds a predetermined service life in an electric vehicle or the like. It may be a battery whose performance has been degraded because it has been used for a long time or exceeded the allowable number of charge/discharge cycles. Accordingly, each of the recycled batteries 110 (that is, the first recycled battery 111, the second recycled battery 112, and the n-th recycled battery 113) is a battery with different performance, manufacturers, etc., and the The outputs may not all be identical.

When batteries with different outputs are connected in parallel and used in this way, there is a risk of fire due to generation of circulating current.

Accordingly, the battery module 100 of the present invention optimizes the voltage at the rear end of each of the recycled batteries 110 (ie, the first recycled battery 111 , the second recycled battery 112 , and the n-th recycled battery 113 ). The units (ie, the first voltage optimization unit 121 , the second voltage optimization unit 122 , and the n-th voltage optimization unit 123 ) 120 are connected, and different batteries (ie, the first recycled battery) are connected. (111), the second recycled battery 112, and the nth recycled battery 113) equalize the respective outputs Va1, Va2, ..., Van to output the same equalized voltage Veq.

To this end, each of the at least one voltage optimizer has an input terminal connected to each of the one or more recycled batteries, and bypasses or boosts the DC voltage Va input from the corresponding recycled battery and outputs the output terminal in parallel. It is connected to output the same uniform voltage (Veq) as other adjacent recycled batteries.

That is, the voltages output from each of the voltage optimization units (ie, the first voltage optimizer 121 , the second voltage optimizer 122 , and the nth voltage optimizer 123 ) 120 are illustrated in FIG. 2 . As described above, by being connected in parallel to one bus and delivered to the PCS 13, the voltage optimization units (ie, the first voltage optimization unit 121, the second voltage optimization unit 122, and the n-th voltage optimization unit ( 123)) (120) Each output voltage is equally matched to the largest value among the respective output voltages.

3 is a block diagram illustrating a configuration of a voltage optimization unit according to a first embodiment of the present invention. Referring to FIG. 3 , the voltage optimization unit 50 according to the first embodiment of the present invention includes a reverse flow prevention diode 51 , a booster unit 52 , a switch 53 , a comparison unit 54 , and a control unit 55 . , and an oscillator 56 .

The backflow prevention diode 51 is connected between the input terminal and the output terminal of the voltage optimization unit 50 . At this time, the voltage Va1 input from the corresponding recycled battery (eg, the first recycled battery 111 illustrated in FIG. 2 ) is input to the input terminal (ie, the input terminal of the voltage optimization unit 50), An equalization voltage Veq determined by equalization with neighboring recycled batteries is applied to the output terminal (ie, the output terminal of the voltage optimization unit 50 ).

When the voltage Va1 input to the voltage optimization unit 50 is lower than the equalization voltage Veq, the backflow prevention diode 51 prevents the equalization voltage Veq from flowing backward into the voltage optimization unit 50 . do.

The booster 52 is installed between the input terminal (ie, the input terminal of the voltage optimization unit 50 ) and the reverse flow prevention diode 51 to bypass or boost the input voltage Va1 and output it. To this end, the on/off of the booster unit 52 is controlled by the duty ratio of the PWM pulse supplied from the inductor (not shown) connected to the input terminal and the oscillator 56 to be described later, and the current flowing through the inductor (not shown). It may include a switch unit (not shown) for controlling the amount of.

Accordingly, the booster unit 52 boosts and outputs the input voltage Va1 by the amount of current flowing through the inductor (not shown). An equal voltage (Veq) equal to the value can be output.

The switch 53 turns on/off the booster unit 52 , and transmits the PWM pulse oscillated by the oscillator 56 to the booster unit 52 . In this case, the switch 53 may be implemented as a power switching device such as an FET, an IGBT, or an SCR.

The comparator 54 compares the input voltage Va1 with the voltage Veq at the output terminal of the backflow prevention diode 51 to turn on/off the switch 53 . That is, the comparator 54 turns off the switch 53 to bypass the input voltage Va1 when the input voltage Va1 is higher than the voltage Veq at the output terminal of the backflow prevention diode 51 , and the input voltage When (Va1) is lower than the voltage (Veq) of the output terminal of the reverse flow prevention diode, the switch 53 is turned on to control to boost the input voltage (Va1).

The control unit 55 compares the output voltage Vb of the booster unit 52 with the voltage Veq at the output terminal of the backflow prevention diode 51, and determines the boosting voltage of the booster unit 52 based on the result. Outputs a control signal. At this time, the control unit 55 compares the output voltage Vb of the booster unit 52 and the voltage Veq at the output terminal of the reverse flow prevention diode 51, and the output voltage Vb of the booster unit 52 prevents the reverse flow. The boosting voltage may be determined to be equal to the voltage Veq of the output terminal of the diode 51 . That is, the control unit 55 may determine the voltage to boost by the difference between the output voltage Vb of the booster unit 52 and the voltage Veq at the output terminal of the backflow prevention diode 51 . To this end, the control unit 55 generates a control signal for determining the duty ratio of the PWM pulses generated by the oscillator 56 and transmits it to the oscillator 56 .

At this time, the control unit 55 compares the output voltage Vb of the booster unit 52 with the voltage Veq at the output terminal of the reverse flow prevention diode 51, and the output voltage Vb of the booster unit 52 prevents the reverse flow. The duty ratio of the PWM pulse may be gradually changed until it becomes equal to the voltage Veq of the output terminal of the diode 51 .

The oscillator 56 generates a PWM pulse based on the control signal output from the controller 55 , and then transmits it to the booster 52 . At this time, the oscillation unit 56 generates a PWM pulse with a duty ratio determined by the control signal transmitted from the control unit 55 , and transmits the PWM pulse to the booster unit 52 through the switch 53 .

Then, the booster unit 52 may boost the input voltage Va1 by controlling on/off of an internal switch unit (not shown) based on the duty ratio of the PWM pulse.

According to the example, a voltage of 300V, which is the highest output, is output from the second recycled battery 112 among the plurality of recycled batteries 110 illustrated in FIG. 2 , and a voltage of 200V is output from the first recycled battery 111 . In this case, as illustrated in FIG. 2 , a voltage of 300V is applied to the output terminals of each of the plurality of voltage optimization units 120 connected in parallel, and at this time, the voltage optimization unit 50 illustrated in FIG. 3 is shown in FIG. If it is an internal block of the first voltage optimization unit 121 among the plurality of voltage optimization units 120 illustrated in , a voltage of 300V is applied to the output terminal of the first voltage optimization unit 121, and the first voltage optimization unit 121 A voltage of 200V is applied to the input terminal of

Then, the comparator 54 compares the input voltage 200V with the voltage 300V at the output terminal of the backflow prevention diode 51, and the input voltage 200V is lower than the voltage 300V at the output terminal of the backflow prevention diode 51, so the switch 53 is Control to boost the input voltage 200V by turning it on.

In addition, the control unit 55 compares the output voltage Vb of the booster unit 52 with the voltage 300V at the output terminal of the backflow prevention diode 51 , and the output voltage Vb of the booster unit 52 determines the output voltage Vb of the backflow prevention diode 51 . ) Determine the boosting voltage to be equal to the output voltage of 300V. Alternatively, the control unit 55 compares the output voltage Vb of the booster unit 52 with the voltage 300V at the output terminal of the backflow prevention diode 51 until the output voltage Vb of the booster unit 52 becomes 300V. , it is also possible to gradually change the duty ratio of the PWM pulses.

On the other hand, if the voltage optimization unit 50 illustrated in FIG. 3 is an internal block of the second voltage optimization unit 122 among the plurality of voltage optimization units 120 illustrated in FIG. 2 , the highest in the second recycled battery 112 . Since the output voltage of 300V is output, a voltage of 300V is applied to both the output terminal and the input terminal of the second voltage optimization unit 122 .

Then, the comparator 54 compares the input voltage 300V with the voltage 300V at the output terminal of the backflow prevention diode 51, and the input voltage 300V is not lower than the voltage 300V at the output terminal of the backflow prevention diode 51, so the switch 53 is Control to bypass the input voltage 230V by turning it off.

On the other hand, when the switch 53 is off, the control unit 55 may turn off the oscillator 56 so as not to generate a PWM pulse.

In this way, the present invention has an advantage in that it is possible to generate stable energy by utilizing batteries having lower efficiency compared to the initial capacity, thereby increasing the utilization of the waste battery, and thereby minimizing environmental problems due to the discharge of the waste battery.

In addition, the present invention solves the problem of temperature rise in the energy storage system due to the circulation current by solving the problem of circulating current caused by the difference in output voltage when connecting a plurality of recycled batteries in parallel, and furthermore, fire has the advantage of preventing

In addition, the present invention does not pre-classify recycled batteries having different degrees of performance degradation depending on the manufacturer, the age of use, the operating environment, the number of times of charging/discharging, etc. There is an advantage to

In the above, embodiments of the present invention have been described, but the scope of the present invention is not limited thereto, and the present invention is easily changed from the embodiments by those of ordinary skill in the art to which the present invention pertains and recognized as equivalent. including all changes and modifications to the scope of

10: ESS 11: BMS
13: PCS 15: EMS
20: power source 30: transmission/distribution
40: consumer 50: voltage optimization unit
51: reverse flow prevention diode 52: booster unit
53: switch 54: comparison unit
55: control unit 56: oscillation unit
100: battery module 110: batteries
120: voltage optimization units

Claims (4)

In the energy storage system for storing power produced by various power generation devices and supplying the stored power to a load side,
a battery module for storing the power; and
A power conversion device that converts the AC power produced by the power generator into DC power and stores it in the battery module, converts the DC power stored in the battery module into AC power and transmits it to the load side,
The battery module is
at least one recycled battery; and
An input terminal is connected to each of the at least one recycled battery to bypass or boost a DC voltage Va input from a corresponding recycled battery, and output it, but the output terminal is connected in parallel to the same equivalent voltage (Veq) as that of other adjacent recycled batteries ) including voltage optimization units that output
The voltage optimizer
a first backflow prevention diode installed between the input terminal and the output terminal;
a first booster part installed between the input terminal and the first backflow prevention diode to bypass or boost the DC voltage Va;
a first switch for turning on/off the first booster unit;
a comparator for comparing the DC voltage (Va) with a voltage (Veq) of an output terminal of the first backflow prevention diode to turn on/off the first switch;
Comparing the output voltage (Vb) of the first booster unit and the voltage (Veq) of the first backflow prevention diode output terminal, based on the result, a first outputting control signal for determining the boosting voltage of the first booster unit control unit; and
and an oscillator that generates a PWM pulse based on the control signal and outputs the PWM pulse to the first booster through the first switch. delete According to claim 1, wherein the first booster unit
an inductor connected to the input terminal; and
and a second switch for controlling the amount of current flowing through the inductor by controlling on/off according to the duty ratio of the PWM pulses supplied from the oscillator;
An energy storage system using a recycled battery, characterized in that it boosts and outputs the DC voltage (Va) input from the recycled battery by the amount of current flowing through the inductor. The method of claim 1, wherein the comparator
When the DC voltage Va is higher than the voltage Veq of the output terminal of the first backflow prevention diode, the first switch is turned off to bypass the DC voltage Va,
When the DC voltage Va is lower than the voltage Veq of the output terminal of the first backflow prevention diode, the first switch is turned on to control to boost the DC voltage Va. Energy storage using a recycled battery system.

Images