KR102140713B1 - Control system and Control method of Uninterruptible Power Supply using Lithium-ion Battery - Google Patents

Abstract

The present invention relates to a control system for an uninterruptible power supply device using a lithium ion battery, and in particular, to supply the AC energy supplied from the AC power supply to the load at a constant voltage through an uninterruptible power supply device provided between the AC power supply and the load. In the control system of the uninterruptible power supply device to be connected to the first node between the AC power supply and the load, the energy reservoir consisting of a lithium ion battery to provide a voltage to the load and the first node and the energy It is provided between the reservoir, the control system of the uninterruptible power supply using a lithium ion battery including a switching unit for controlling the voltage provided from the AC power source to the energy reservoir and the voltage provided from the energy reservoir to the load. It is about.

Description

Control system and control method of uninterruptible power supply using lithium ion battery {Control system and Control method of Uninterruptible Power Supply using Lithium-ion Battery}

The present invention relates to a control system and a control method of an uninterruptible power supply using a lithium ion battery, and more specifically, to efficiently connect a lithium ion battery as an energy reservoir to an uninterruptible power supply that immediately supplies power in an emergency, lithium According to the state of charge (SOC) of the ion battery, it is to enable stable power supply to the load while effectively preventing overcharge and overdischarge of the energy reservoir.

Power sources for communication, broadcasting, hospitals, and facilities require a high degree of stability and reliability, and in most cases, even short-term power outages are not allowed. To respond to this, power is backed up using an uninterruptible power supply (UPS). In other words, an uninterruptible power supply device is a device that supplies stable power to a load when power is unstable, such as a power outage or an instantaneous power supply. A typical example used as an energy reservoir for an uninterruptible power supply is a secondary lead acid battery.

This secondary lead acid battery has the advantage of having a high energy density of 20 to 120 Wh/kg, but has a drawback of having a low power density of 50 to 250 W/kg and a low cycle life characteristic of 500 times. For this reason, an uninterruptible power supply using a secondary lead acid battery has excellent characteristics for long-time power supply due to its high energy density, but has a problem of regular maintenance and repair costs due to its low lifespan characteristics.

Accordingly, in recent years, lithium ion batteries are being used as energy storage devices for uninterruptible power supplies.

However, since lithium ion batteries have different characteristics from secondary lead acid batteries, there is a disadvantage in that the risk of explosion by overcharging or overdischarging is high when connected to lithium ion batteries without changing the structure of a conventional uninterruptible power supply.

The present invention focuses on the difficulty of providing a lithium ion battery as an energy reservoir without changing the structure of the uninterruptible power supply due to the risk of explosion due to overcharging or overdischarging.

European Patent No. 0739075 (“Power supply system”, hereinafter referred to as prior art 1) discloses an uninterruptible power supply having an overcurrent protection function, and prior art 1 uses an accumulator as an energy reservoir, due to the use of the accumulator. There is no mention of any way to overcome the low lifespan that occurs.

European registered patent 0739075 (Registration date 1999.03.03.)

The present invention has been devised to improve the prior art as described above, and efficiently connects a lithium ion battery other than a conventional lead acid battery to an uninterruptible power supply that immediately supplies power in an emergency, and the state of charge of the lithium ion battery (SOC , State Of charge), efficiently prevents overcharge and over-discharge of energy storage and at the same time efficiently reduces the volume of the uninterruptible power supply, saves large capacity, and enables uninterruptible power supply to stably supply power to the load. It is to provide a control system.

In order to achieve the above object and to solve the problems of the prior art, the control system of the uninterruptible power supply using a lithium ion battery according to the present invention is supplied from the AC power through the uninterruptible power supply provided between the AC power supply and the load In the control system of the uninterruptible power supply to supply the AC energy to the load at a constant voltage, the energy is composed of a lithium ion battery connected to the first node between the AC power and the load, providing a voltage to the load It is preferably provided between the reservoir and the first node and the energy reservoir, and includes a switching unit that controls a voltage provided from the AC power source to the energy reservoir and a voltage provided from the energy reservoir to the load. Do.

The switching unit is composed of a first switch, a second switch, a third switch, a resistor and a diode connected between the first node and both ends (+) of the energy reservoir, and the first switch is the energy storage The second node, which is the both ends of the ruler, is connected in series with the first node, the resistor is provided between the first switch and the first node, and the second switch is the second node, which is both ends of the energy reservoir. Connected in parallel with the first node, the diode is connected in parallel with the third node and the first node at both ends of the energy reservoir to prevent reverse current from the load to the energy reservoir, and the third switch It is preferable that a connection is provided between the diode and the first node.

When the energy storage unit is first connected to the uninterruptible power supply using the lithium ion battery, the switching unit closes the first switch for a predetermined time and opens the second switch and the third switch to open the It is desirable to match the voltage between the energy reservoir and the inverter of the uninterruptible power supply.

According to the state of charge (SOC) of the energy storage unit, the switching unit closes the third switch and opens the first switch and the second switch when the charging state is full. ) To supply the voltage to the load through the energy reservoir.

According to the state of charge (SOC) of the energy storage unit, the switching unit closes the second switch and opens the first switch and the third switch when the charging state is overdischarge. It is preferable to charge the energy reservoir while providing a voltage from the AC power supply to the load.

In the control method of an uninterruptible power supply using a lithium ion battery according to the present invention, AC energy supplied from AC power is supplied to a load at a constant voltage through control of a switching unit composed of a first switch, a second switch, and a third switch. In the control method of the uninterruptible power supply using a lithium ion battery, the first switch is connected (close), the second switch and the third switch open (open) to provide a voltage to the load An initial connection step of matching the voltage between the energy reservoir, which is a lithium ion battery, and the inverter of the uninterruptible power supply; A first determining step of determining whether the state of charge (SOC) of the energy storage person is equal to or greater than a first preset value; A second determining step of determining whether the state of charge of the energy reservoir is equal to or less than a preset second set value when the state of charge of the energy reservoir is not equal to or greater than the first set value according to the determination result of the first determination step; A third determining step of determining whether a voltage is supplied to the load through the energy reservoir when the state of charge of the energy reservoir is less than or equal to the second set value according to the determination result of the second judgment step; A fourth determining step of determining whether the state of charge of the energy reservoir is equal to or less than a preset third set value when supplying a voltage to the load through the energy reservoir according to the determination result of the third judgment step; According to the determination result of the fourth determination step, when the state of charge of the energy reservoir is less than or equal to the third set value, the second switch is closed and the first switch and the third switch are opened. Over-discharge preventing step of charging the energy reservoir while providing a voltage from the AC power supply to the load; It is preferably made of.

According to the determination result of the first determination step, when the state of charge of the energy reservoir is equal to or greater than the first set value, the third switch is closed and the first switch and the second switch are opened. Therefore, it is preferable to include an overcharge prevention step of supplying a voltage to the load through the energy reservoir.

According to the determination result of the second determination step, when the state of charge of the energy reservoir is not equal to or less than the second set value, the second switch is closed and the first switch and the third switch are opened ( It is preferable to consist of an over-discharge preventing step of charging the energy reservoir while providing a voltage from the AC power supply to the load.

According to the determination result of the third determination step, when the voltage is not supplied to the load through the energy reservoir, the second switch is closed and the first switch and the third switch are opened. Therefore, it is preferable to include an over-discharge prevention step of charging the energy reservoir while providing a voltage from the AC power supply to the load.

According to the determination result of the fourth judging step, when the state of charge of the energy reservoir is not equal to or less than the third set value, the third switch is closed and the first switch and the second switch are opened ( It is preferable to consist of an overcharge prevention step of supplying a voltage to the load through the energy reservoir by opening).

According to a control system and a control method of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention, it is provided between an AC power source and a load, and is an energy storage device for an uninterruptible power supply device that immediately supplies power in an emergency It has an effect of efficiently reducing the volume of the uninterruptible power supply by connecting a lithium ion battery rather than a secondary lead acid battery.

In addition, depending on the state of charge (SOC) of the lithium ion battery, there is an effect of stably supplying power to a load by storing a large amount of power while effectively preventing overcharge and overdischarge of an energy reservoir.

In addition, when configuring a plurality of energy reservoirs, there is an effect that can easily control its own cell balancing and charging state.

1 is a view briefly showing a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.
2 is a view showing in detail the switching unit of the control system of the uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.
3 is a first exemplary view of an operation of a switching unit of a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.
4 is a second exemplary view of an operation of a switching unit of a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.
5 is a third exemplary view of an operation of a switching unit of a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.
6 is a flowchart illustrating a method of controlling an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention.

Hereinafter, a control system and method for controlling the uninterruptible power supply using the lithium ion battery of the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. In addition, the same reference numerals throughout the specification indicate the same components.

At this time, unless there are other definitions in the technical terms and scientific terms to be used, it has the meanings commonly understood by those of ordinary skill in the art to which this invention belongs, and the gist of the present invention in the following description and the accompanying drawings. Descriptions of well-known functions and configurations that may be obscured are omitted.

In addition, a system refers to a set of components, including devices, mechanisms and means, organized and regularly interacted to perform the necessary functions.

The uninterruptible power supply normally supplies AC power to a load from a commercial AC power supply through a power conversion device, a distortion correction circuit, and the like, and also operates by connecting an energy storage device to the output of the rectifying device, thereby saving the energy storage device It is possible to supply power to the load without interruption through the inverter.

That is, the control system of the uninterruptible power supply device using a lithium ion battery according to an embodiment of the present invention and a control method thereof, in the event of a voltage accident in the AC power supply 10, is capable of supplying a constant voltage to the load 20 It is a control system and a control method that enables an energy storage device composed of a lithium ion battery to be safely connected to an uninterruptible power supply (UPS).

1 is a view briefly showing the configuration of a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention. The configuration of a control system of an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention will be described in detail with reference to FIG. 1.

The control system of the uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention includes a switching unit 40 in the uninterruptible power supply provided between the AC power supply 10 and the load 20, thereby alternating current Switching unit so that the AC energy supplied from the power source 10 is stably supplied to the load 20 at a constant voltage, and at the same time, the overcharge and overdischarge of the energy reservoir 30 composed of the lithium ion battery can be quickly managed. 40 can be controlled.

As shown in Figure 1, the control system of the uninterruptible power supply using a lithium ion battery includes an AC power supply 10, a load 20, a converter 1, an inverter 2, a fixed switch 3, and an energy reservoir 30 and the switching unit 40.

To learn more about each configuration,

The converter 1 is connected to the AC power supply 10 and converts AC energy supplied from the AC power into DC power to transmit the DC power converted to the inverter 2 or the energy reservoir 30.

The inverter 2 is connected to the converter 1, converts the received DC power into constant voltage, constant frequency AC power, and transmits it to the load 20,

The fixed switch 3 may transfer the load 20 so that power is supplied from the energy reservoir 30 in order to prevent malfunction and stop operation of the load 20 in the event of an accident of the inverter 2.

The energy reservoir 30 is connected to the first node 50 between the AC power supply 10 and the load 20, and when the voltage provided from the AC power supply 10 to the load 20 is outside the allowable voltage range That is, as described above, the power supply from the AC power supply 10 to the load 20 is not smoothly performed due to any emergency, or AC power supply with constant voltage and constant frequency is generated due to an accident of the inverter 2 If this is not done smoothly, a voltage can be provided to the load 20.

At this time, the energy reservoir 30 of the present invention may be composed of a lithium ion battery.

Lithium ion batteries are more expensive than conventional secondary lead acid batteries, but have a high volume utilization because they are 4 to 5 times smaller in volume, have less temperature sensitivity than secondary lead acid batteries, and have a large storage capacity.

Accordingly, when considering the operation cycle of the uninterruptible power supply, there is a superior effect in terms of economy and performance compared to a secondary lead acid battery.

However, since the lithium ion battery has a high possibility of explosion when overcharged and is very dangerous when an explosion occurs, a new linkage structure for limiting overcharge in order to link the lithium ion battery to the uninterruptible power supply connected to the conventional secondary lead acid battery There is a problem that requires

This can be solved by providing the switching unit 40 in the present invention.

To learn more,

The switching unit 40 is provided between the first node 50 and the energy reservoir 30, and the voltage provided from the AC power source 10 to the energy reservoir 30 and the load from the energy reservoir 30 The voltage provided by (20) can be controlled.

As shown in FIG. 2, the switching unit 40 includes a first switch 41 and a second switch 42 provided between the first node 50 and both ends (+) of the energy reservoir 30. , It may be made of a third switch 43, a diode 44 and a resistor (45).

The first switch 41 is connected in series with the second node 60 and the first node 50, which are both ends of the energy reservoir 30,

The resistor 45 is provided between the first switch 41 and the first node 50,

In the second switch 42, both ends of the energy reservoir 30 are connected in parallel with the second node 60 and the first node 50,

The diode 44 is connected in parallel with the third node 70 and the first node 50, which are both ends of the energy reservoir 30, to prevent reverse current from the load 20 to the energy reservoir 30,

The third switch 43 may be provided between the diode 44 and the first node 50.

As described above, the control system of the uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention facilitates overcharging of the energy reservoir 30 composed of a lithium ion battery using the switching unit 40 as described above. It can be limited, and even if a plurality of energy storage elements are provided, self-balancing of the cell or the state of charge of the energy reservoir can be easily controlled by itself.

In addition, by connecting the diode 44 in parallel with the first node 50, there is an advantage in that a potential difference can be made and the turn-on speed of the diode 44 is increased when a voltage accident occurs.

The switching unit 40, as shown in Figure 3, when the energy reservoir 30 is first connected to the uninterruptible power supply, or when connected again after maintenance,

The first switch 41 is closed for a predetermined period of time, and the second switch 42 and the third switch 43 are opened to open the energy reservoir 30 and the inverter 2 of the uninterruptible power supply. The voltages can be matched.

At this time, the predetermined time means a time of 1 second to 10 seconds, and after the voltage matching of the energy storage device 30 is completed, it overlaps with the next operation to continue the operation.

In addition, the control of the switching unit 40 may be performed in a battery management system (BMS).

Thereafter, the state of charge (SOC) of the lithium ion battery that is the energy storage device 30 is received from the battery management system,

In order to prevent overcharging of the energy reservoir 30, a voltage may be provided to the load 20 through the energy reservoir 30,

In addition, in order to prevent over-discharge of the energy reservoir 30, a voltage may be simultaneously supplied to the load 20 and the energy reservoir 30 from the AC power supply 10.

To learn more,

The switching unit 40, as shown in Figure 4, when the charge state of the energy storage device 30 received from the battery management system is a fully charged state,

The third switch 43 is connected, and the first switch 41 and the second switch 42 are opened to supply a voltage to the load 20 through the energy reservoir 30. Can. Through this, it is possible to prevent the danger caused by overcharging of the energy reservoir 30 in advance.

At this time, in order to prevent the overcharge of the energy reservoir 30, the operation of connecting the third switch 43 of the switching unit 40 and opening the first switch 41 and the second switch 42, In order to match the voltage between the energy reservoir 30 and the inverter 2, the first switch 41 may be connected for a predetermined time and overlapped with the operation of opening the second switch and the third switch, and may be made in a continuous operation. have.

In addition, as described above, control of the switching unit 40 may be performed in a battery management system (BMS).

In addition, the switching unit 40, as shown in Figure 5, when the charge state of the energy reservoir 30 received from the battery management system is an over-discharge state,

The second switch 42 is connected (closed) and the first switch 41 and the third switch 43 are opened (open) to provide a voltage from the AC power supply 10 to the load 20, while saving energy. Allow 30 to be charged. Through this, it is possible to quickly prevent over-discharge of the energy reservoir 30.

At this time, in order to prevent over-discharge of the energy reservoir 30, the operation of connecting the second switch 42 of the switching unit 40 and opening the first switch 41 and the third switch 43 is In order to match the voltage between the energy reservoir 30 and the inverter 2, the operation of connecting the first switch 41 for a predetermined time and opening the second switch and the third switch, or the energy reservoir ( In order to prevent overcharging of 30), the third switch 43 of the switching unit 40 is connected, and the operation of opening the first switch 41 and the second switch 42 overlaps with the operation, and thus may be performed in a continuous operation. .

In addition, as described above, control of the switching unit 40 may be performed in a battery management system (BMS).

6 is a flowchart illustrating steps of a method of controlling an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention. A method of controlling an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention will be described in detail with reference to FIG. 6.

A method of controlling an uninterruptible power supply using a lithium ion battery according to an embodiment of the present invention includes a switching unit 40 in an uninterruptible power supply provided between an AC power supply 10 and a load 20, thereby alternating current Switching unit so that the AC energy supplied from the power source 10 is stably supplied to the load 20 at a constant voltage, and at the same time, the overcharge and overdischarge of the energy reservoir 30 composed of the lithium ion battery can be quickly managed. 40 can be controlled.

As shown in Figure 6, the control method of the uninterruptible power supply using a lithium ion battery is the first connection step (S100), the first judgment step (S200), the second judgment step (S300), the third judgment step (S400) , The fourth determination step (S500), over-discharge prevention step (S600) and overcharge prevention step (S700).

To learn more about each step,

In the initial connection step (S100), when the energy reservoir 30 is first connected to the uninterruptible power supply, or when it is reconnected after maintenance,

The first switch 41 is closed for a predetermined period of time, and the second switch 42 and the third switch 43 are opened to open the energy reservoir 30 and the inverter 2 of the uninterruptible power supply. The voltages can be matched.

The first determining step S200 may determine whether the state of charge (SOC) of the energy storage device 30 is greater than or equal to a first preset value in the battery management system.

At this time, the first set value means a charge value such that the state of charge of the energy reservoir 30 can be supplied to the load 20 because the state of charge is close to the buffer state or the buffer state.

According to the determination result of the first determination step S200, when the state of charge of the energy reservoir 30 is greater than or equal to the first set value, an overcharge prevention step S700 may be performed.

The overcharge prevention step (S700) is a third switch (43) (close) and the first switch (41) and the second switch (42) to open (open) through the lithium ion battery that is the energy storage (30) The voltage is supplied to the load 20.

Through this, it is possible to prevent overcharging of the energy reservoir 30 and to simultaneously supply a constant voltage to the load 20.

In the second determination step S300, according to the determination result of the first determination step S200, when the state of charge of the energy reservoir 30 is not equal to or greater than the first set value, that is, less than the first set value,

It may be determined once again whether the state of charge of the energy reservoir 30 is equal to or less than a second preset value.

At this time, the second set value means an unstable intermediate state in which the state of charge of the energy reservoir 30 is neither a buffer state nor a discharge state.

That is, according to an additional determination, since the voltage is supplied to the load 20 or refers to a charging state in which charging may be performed by the AC power source 10, the second set value can be arbitrarily operated by the user.

In the third determination step (S400 ), according to the determination result of the second determination step (S300 ), when the state of charge of the energy reservoir 30 is less than or equal to the second set value,

Currently, it may be determined whether the voltage is being supplied to the load 20 through the energy reservoir 30.

In addition, according to the determination result of the second determination step (S300), when the state of charge of the energy reservoir 30 is not less than the second set value, that is, when the second set value is exceeded, the over-discharge prevention step ( S600).

The over-discharge prevention step (S600) connects the second switch 42 and closes the first switch 41 and the third switch 43 to open the AC power supply 10 to load 20. At the same time as providing the voltage, the energy reservoir 30 can be charged.

Through this, it is possible to prevent over-discharge of the energy reservoir 30.

In the fourth determination step S500, when a voltage is supplied to the load 20 through the energy reservoir 30 according to the determination result of the third determination step S400,

Currently, it may be determined whether the state of charge of the energy reservoir 30 is equal to or less than a preset third set value.

At this time, the third set value is a state in which the charging state of the energy reservoir 30 is close to the discharge, and means a charging value in which voltage supply to the load 20 is no longer dangerous.

In addition, according to the determination result of the third determination step (S400 ), when the voltage is not supplied to the load 20 through the energy reservoir 30, the energy reservoir 30 applies a voltage to the current load 20. Although not being supplied, since the state of charge is less than or equal to the second set value, there is a risk of overdischarge, and to prevent this, an overdischarge prevention step (S600) is performed.

That is, the second switch 42 is connected (close) and the first switch 41 and the third switch 43 are opened, thereby providing a voltage from the AC power supply 10 to the load 20, and energy The reservoir 30 is charged.

In addition, according to the determination result of the fourth determination step S500, when the state of charge of the energy reservoir 30 is less than or equal to the third set value, that is, the state of charge of the current energy reservoir 30 is close to discharge. In the case, by directly performing the over-discharge prevention step (S600), the lithium ion battery is protected from over-discharge.

On the contrary, if the state of charge of the energy reservoir 30 is not equal to or less than the third set value, that is, exceeds the third set value, according to the determination result of the fourth determination step S500, the overcharge prevention step ( S700) is continuously performed.

In other words, the state of charge of the energy reservoir 30 is not fully charged, but the voltage is continuously supplied to the load 20, and the current state is not close to the discharge, until the current state is maintained and immediately before the discharge, That is, the voltage can be supplied to the load 20 just before reaching the third set value.

In other words, in other words, the control system of the uninterruptible power supply using the lithium ion battery of the present invention and the control method thereof are in an uninterruptible power supply device in which the energy storage device 30 is composed of a lithium ion battery, the uninterruptible power supply device and the energy storage device 30 ) As well as constructing a new linkage structure, and controlling the switching unit 40 to control the state of charge (SOC) of the lithium ion battery, which is an energy reservoir 30 composed of the lithium ion battery. Accordingly, it is possible to efficiently control overcharge and overdischarge of the energy reservoir 30.

As described above, in the present invention, it has been described by specific matters such as specific components, etc. and limited embodiment drawings, which are provided to help a more comprehensive understanding of the present invention, and the present invention is limited to the above-described one embodiment. No, those of ordinary skill in the art to which the present invention pertains are capable of various modifications and variations from these descriptions.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and should not be determined, and all claims that are equivalent or equivalent to the scope of the present invention as well as the scope of the claims described below will be said to belong to the scope of the spirit of the invention. .

1: converter
2: Inverter
3: Fixed switch
10: AC power
20: load
30: energy store
40: switching unit
41: first switch 42: second switch
43: third switch 44: diode
45: resistor
50: first node
60: second node
70: 3rd node

Claims (10)

In the control system of the uninterruptible power supply unit to supply the AC energy supplied from the AC power supply to the load at a constant voltage through the uninterruptible power supply device provided between the AC power supply and the load,
An energy reservoir connected to a first node between the AC power supply and the load, and configured of a lithium ion battery providing a voltage to the load; And
Switching is provided between the first node and the energy reservoir, and controls the voltage provided from the AC power source to the energy reservoir and the voltage provided from the energy reservoir to the load according to the state of charge of the energy reservoir. part;
It includes,
The switching unit
It is composed of a first switch, a second switch, a third switch, a resistor and a diode connected between both ends (+) of the first node and the energy reservoir,
The first switch is connected in series with the first node and a second node at both ends of the energy reservoir, the resistor is provided between the first switch and the first node, and the second switch is the energy The second node, which is the both ends of the reservoir, is connected in parallel with the first node, and the third switch is provided between the diode and the first node, wherein the diode is the third node and the third node that are both ends of the energy reservoir. It is connected in parallel with one node to prevent reverse current from the load to the energy reservoir and to generate a potential difference to improve turn-on speed,
When the energy reservoir is first connected to the uninterruptible power supply using the lithium ion battery or reconnected after maintenance,
Control of the uninterruptible power supply using a lithium ion battery that matches the voltage between the energy reservoir and the inverter of the uninterruptible power supply by connecting the first switch for a predetermined time and opening the second switch and the third switch. system.
delete delete According to claim 1,
The switching unit
When the energy reservoir is fully charged,
A control system for an uninterruptible power supply using a lithium ion battery, characterized in that the third switch is connected and the first switch and the second switch are opened to supply a voltage to the load through the energy reservoir.
According to claim 1,
The switching unit
When the energy reservoir is over-discharged,
Connecting the second switch and opening the first switch and the third switch to provide a voltage from the AC power supply to the load, while charging the energy reservoir, an uninterruptible power supply using a lithium ion battery. Control system.
Controlling the voltage provided from the AC power source to the energy reservoir and the voltage provided from the energy reservoir to the load according to the state of charge of the energy reservoir through the control of the switching unit consisting of the first switch, the second switch, the third switch and the diode In the control method of the uninterruptible power supply using a lithium ion battery,
An initial connection step of connecting the first switch, opening the second switch and the third switch to match the voltage between the energy reservoir, which is a lithium ion battery providing voltage to the load, and the inverter of the uninterruptible power supply;
A first determining step of determining whether the state of charge of the energy reservoir is equal to or greater than a first preset value;
According to the determination result of the first determination step, when the state of charge of the energy reservoir is greater than or equal to the first set value,
Connecting the third switch and opening the first switch and the second switch to supply a voltage to the load through the energy reservoir, but the first switch for a predetermined time to match the voltage between the energy reservoir and the inverter. An overcharge prevention step of overlapping with the operation of connecting and opening the second switch and the third switch to perform a continuous operation;
According to the determination result of the first determination step, when the state of charge of the energy reservoir is not equal to or greater than the first set value,
A second determination step of determining whether the state of charge of the energy reservoir is equal to or less than a preset second set value;
According to the determination result of the second determination step, when the state of charge of the energy reservoir is less than or equal to the second set value,
A third determining step of determining whether a voltage is supplied to the load through the energy reservoir;
When supplying a voltage to the load through the energy reservoir according to the determination result of the third determination step,
A fourth determining step of determining whether the state of charge of the energy reservoir is equal to or less than a preset third set value;
According to the determination result of the fourth determination step, when the state of charge of the energy reservoir is less than or equal to the third set value,
An over-discharge preventing step of closing the second switch and opening the first switch and the third switch to charge the energy reservoir while providing a voltage from the AC power to the load;
It consists of,
The diode is connected in parallel with both ends (+) of the energy storage element, the control method of the uninterruptible power supply using a lithium ion battery, characterized in that to prevent a reverse current from the load to the energy storage element.
delete The method of claim 6,
According to the determination result of the second determination step, when the state of charge of the energy reservoir is not less than the second set value,
An over-discharge preventing step of connecting the second switch and opening the first switch and the third switch to charge the energy reservoir while providing a voltage from the AC power to the load;
Control method of the uninterruptible power supply using a lithium ion battery, characterized in that consisting of.
The method of claim 6,
When the voltage is not supplied to the load through the energy reservoir according to the determination result of the third determination step,
An over-discharge preventing step of connecting the second switch and opening the first switch and the third switch to charge the energy reservoir while providing a voltage from the AC power to the load;
Control method of the uninterruptible power supply using a lithium ion battery, characterized in that consisting of.
The method of claim 6,
According to the determination result of the fourth determination step, when the state of charge of the energy reservoir is not less than the third set value,
An overcharge prevention step of connecting the third switch and opening the first switch and the second switch to supply a voltage to the load through the energy reservoir;
Control method of the uninterruptible power supply using a lithium ion battery, characterized in that consisting of.

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