KR101643705B1 - Apparatus and method for controlling ups - Google Patents

Apparatus and method for controlling ups Download PDF

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Publication number
KR101643705B1
KR101643705B1 KR1020150129070A KR20150129070A KR101643705B1 KR 101643705 B1 KR101643705 B1 KR 101643705B1 KR 1020150129070 A KR1020150129070 A KR 1020150129070A KR 20150129070 A KR20150129070 A KR 20150129070A KR 101643705 B1 KR101643705 B1 KR 101643705B1
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South Korea
Prior art keywords
battery
unit
power
switching unit
link
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KR1020150129070A
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Korean (ko)
Inventor
이인환
구태근
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성신전기공업(주)
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/002—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which a reserve is maintained in an energy source by disconnecting non-critical loads, e.g. maintaining a reserve of charge in a vehicle battery for starting an engine
    • H02J7/022—
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems

Abstract

The present invention discloses an apparatus and a method for controlling an uninterrupted power supply device. According to a specific embodiment of the present invention, the apparatus: is interlocked with an input switching unit transmitting AC power supply to a rectifying unit to be driven; installs a battery switching unit discharging battery power of rated capacity at a battery output end; and additionally has a charging unit charging a battery with the AC power supply. Therefore, a DC/DC converter performing an existing battery charging and discharging function is removed, which reduces a manufacturing process and a manufacturing cost of the uninterrupted power supply device, and lightens and reduces the uninterrupted power supply device. The apparatus can stabilize a DC link voltage by switching the battery switching unit to transfer a DC link voltage, raised in an overvoltage change of the raised DC link voltage.

Description

[0001] APPARATUS AND METHOD FOR CONTROLLING UPS [0002]

The present invention relates to an apparatus and method for controlling an uninterruptible power supply, and more particularly, to an apparatus and method for controlling an uninterruptible power supply, and more particularly, to a battery switching unit The present invention relates to a technique for eliminating a DC / DC converter performing a conventional charge / discharge function of a battery and controlling a boosted DC link voltage by further configuring a charging unit performing a battery charging function.

Power conversion devices such as uninterruptible power supply (UPS) are constantly evolving with the development of passive components in the field of power electronics, semiconductor switching devices, and high-speed controllers. However, the basic circuit configuration has several configurations depending on the capacity, but in general, it is a half-bridge or full-bridge circuit in medium and large capacity, and a circuit configuration is configured at two levels and three levels according to the configuration of the semiconductor switching element.

As is well known, the uninterruptible power supply unit is composed of a rectifier, an inverter, and a DC / DC converter as shown in FIG. 1. The rectifier normally converts AC power to DC power and stores the converted DC power through a DC / DC converter Or the DC power is supplied to the inverter, and the inverter converts the converted DC power into AC power to supply power to the load. In case of power failure or input AC power failure, DC power is continuously supplied to the inverter through the DC / DC converter to supply the AC power to the load stably.

Typically, in an uninterruptible power supply, the rectifier must boost the DC link voltage to 700V to 800V to generate input power factor control and inverter output voltage. The number of cells of the battery is 30 to 40 cells and the nominal voltage is 360V to 480V. A DC / DC converter boost circuit configuration is required to control the low voltage of the battery to DC link voltage in case of power failure.

Generally, the battery charge time is based on 10 hours, and the battery charging DC / DC converter is designed to be about 10% of the rated capacity of the rectifier, so that the proportion of the battery charger is low in the entire system. However, the DC / DC converter for battery discharge must be designed equal to the rated capacity. That is, since the DC / DC converter is designed based on 100% of the rated capacity of the rectifier, there is a problem that the ripple of the battery charging power source becomes large due to low inductance.

Accordingly, the present invention further includes a charging unit for charging the AC power source with a battery by providing a battery switching unit, which is driven in conjunction with the input switching unit for transmitting the AC power to the rectifying unit and discharging the battery power of the rated capacity, at the battery output terminal, It is possible to eliminate the DC / DC converter which performs the charge / discharge function of the existing battery and to propose a method of controlling the overvoltage of the boosted DC link power source.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a battery switching unit driven in conjunction with an input switching unit for transmitting AC power to a rectifying unit, And DC / DC converters performing the conventional battery charging and discharging function are removed, so that the manufacturing process and manufacturing cost of the uninterruptible power supply can be lowered, and the manufacturing cost of the uninterruptible power supply can be reduced And to provide an apparatus and method for controlling an uninterruptible power supply apparatus capable of reducing the size of the apparatus.

It is another object of the present invention to provide an apparatus and method for controlling an uninterruptible power supply apparatus capable of stabilizing a DC link voltage as a step-up DC link voltage is stepped down by a battery in an overvoltage fluctuation of a DC link voltage during a power interruption .

According to a first aspect of the present invention, there is provided an apparatus for controlling an uninterruptible power supply system,

An input switching unit which is switched according to a control signal supplied from the control unit to pass the AC power ; A rectifier for converting the AC power passed through the input switching unit into a DC power; A DC link portion linking the rectifying portion; An inverter for converting a DC link voltage of the DC link unit into an AC power and delivering the DC link voltage to a load; And a control unit for generating and transmitting a control signal for controlling the input switching unit, the rectifying unit, and the inverter. The switching unit switches in conjunction with the input switching unit, boosts the discharge voltage of the battery during a power failure, To a load via an inverter; And a charging unit that receives AC power and charges the battery.

Preferably, the input switching unit may be provided as a bi-directional switch element which is switched to an on state according to a control signal provided from the control unit and transmits an AC power to the rectifying unit during normal operation, A bidirectional switching device for transmitting an anode power source to the battery through the DC link unit and the rectifying unit and a cathode power source for the battery during the DC link overvoltage to the battery through the rectifying unit, .

Preferably, the battery switching unit may be configured to switch to an on state when a predetermined reference time elapses after the input switching unit is switched to the off state at the time of a power failure, And to switch to the on state when the current of the input AC power source after switching to the add-off state is equal to or lower than the hold current of the SCR element.

Preferably, the battery switching unit switches the positive polarity power of the battery to be transmitted to the battery after the positive polarity power of the battery is boosted via the rectifying unit in the reactor charging mode, and the positive polarity power of the battery is transmitted to the battery via the DC link unit and the rectifying unit in the DC link charging mode To switch the boosted DC link voltage to the inverter.

Preferably, the battery switching unit may be provided such that when the overvoltage of the boosted DC link voltage fluctuates, the battery cathode power is transmitted to the battery via the rectifying unit so that the DC link overvoltage is reduced by the battery. The negative electrode power source is switched to be transmitted to the battery via the rectifying unit and the DC link unit and the negative electrode power source of the battery is switched to be transmitted to the battery via the rectifying unit in the reflux mode.

Meanwhile, the control method of the uninterruptible power supply system of the present invention based on the above-

(A) passing the AC power having passed through the input switching unit to the load through the rectifying unit and the inverter; The battery switching unit is operated when the predetermined reference time elapses after the input switching unit is interrupted during the power failure and when the current of the input AC power source is equal to or less than the holding current of the input switching unit and the positive polarity power of the battery is boosted by the rectifying unit And (b) executing boost control to transfer the boosted DC link voltage to the inverter.

Preferably, the step (c) further comprises the step (c) of performing the step-down control by applying the DC link voltage to the battery when the step-up DC link voltage is an overvoltage after step (b).

As described above, according to the apparatus and method for controlling the uninterruptible power supply according to the present invention, the battery switching unit driven in conjunction with the input switching unit for transmitting the AC power to the rectifying unit and discharging the battery power of the rated capacity is connected to the battery output terminal The DC / DC converter performing the existing charge / discharge function of the battery is removed to reduce the manufacturing cost and manufacturing cost of the uninterruptible power supply, and furthermore, the uninterruptible power supply It is possible to reduce the size of the apparatus.

According to the present invention, the DC link voltage can be stabilized by switching the battery switching unit to transfer the boosted DC link voltage to the battery in the overvoltage fluctuation of the boosted DC link voltage.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further understand the technical idea of the invention. And should not be construed as limiting.
1 is a diagram showing a configuration of a general UPS device
2 is a diagram showing a configuration of a control apparatus for an uninterruptible power supply apparatus according to the present invention.
FIG. 3 is a diagram showing a detailed configuration of a control apparatus for an uninterruptible power supply apparatus according to the present invention.
4 is a waveform diagram showing a control signal of a control unit supplied to the controller of the uninterruptible power supply apparatus of the present invention.
FIG. 5 is a graph showing a current flow in a negative section half period and a positive section half period of the input AC power source of the uninterruptible power supply apparatus of the present invention.
FIG. 6 is a graph showing a current flow in each mode when the battery discharge power source voltage is increased in the controller of the uninterruptible power supply apparatus of the present invention.
FIG. 7 is a graph showing a current flow in each mode when the DC link voltage depressurization is performed in the controller of the uninterruptible power supply apparatus of the present invention.
FIG. 8 is a flowchart illustrating a process of controlling an uninterruptible power supply according to another embodiment of the present invention.

For a better understanding of the present invention and its operational advantages and the objects attained by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the preferred embodiments of the present invention with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

The specific structure or functional description presented in the embodiment of the present invention is merely illustrative for the purpose of illustrating an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention can be implemented in various forms. And should not be construed as limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Meanwhile, in the present invention, the terms first and / or second etc. may be used to describe various components, but the components are not limited to the terms. The terms may be referred to as a second element only for the purpose of distinguishing one element from another, for example, to the extent that it does not depart from the scope of the invention in accordance with the concept of the present invention, Similarly, the second component may also be referred to as the first component.

Whenever an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but it should be understood that other elements may be present in between something to do. On the other hand, when it is mentioned that an element is "directly connected" or "directly contacted" to another element, it should be understood that there are no other elements in between. Other expressions for describing the relationship between components, such as "between" and "between" or "adjacent to" and "directly adjacent to" should also be interpreted.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It will be further understood that the terms " comprises ", or "having ", and the like in the specification are intended to specify the presence of stated features, integers, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

For convenience of explanation in the embodiment of the present invention, the three-phase three-level uninterruptible power supply will be described as an example, but the present invention is not limited thereto.

FIG. 2 is a diagram illustrating the configuration of a control apparatus for an uninterruptible power supply apparatus according to an embodiment of the present invention, and FIG. 3 is a diagram illustrating a detailed configuration of a control apparatus for the uninterruptible power supply apparatus shown in FIG. 2 and 3, the controller of the uninterruptible power supply according to the embodiment of the present invention includes a battery switching unit that is driven in conjunction with an input switching unit for transmitting AC power to a rectifying unit and discharges battery power of a rated capacity A rectifying unit 200 and a charging unit 250, a DC link unit 300, and a charging unit, which are installed at a battery output terminal and have AC charging function, An inverter 400, a battery 500, a battery switching unit 600, and a control unit 700.

Here, the input switching unit 100 is connected to the output terminal of the AC power source AC at one end and connected to the input reactor L at the other end thereof to receive the AC power AC. That is, the input switching unit 100 is switched to the ON state according to the control signal of the controller 700 in the normal mode, passes through the inputted AC power source AC, and transmits the input AC power to the rectifier 200 through the input reactor L Respectively. 3, the input switching unit 100 is provided as a three-phase bidirectional switching device that switches according to a control signal of the controller 700, and is provided with SCR elements T1, T2, and T3.

One end of the rectifying unit 200 is connected to the output ends of the input reactors L1, L2 and L3 provided as three-phase coils and the other end is connected to the DC link unit 300 to pass the input reactor L One AC power source is input. The rectifying unit 200 may include one or more switching devices 201 for converting AC power into DC power and a free wheeling diode 202 provided at both ends of the switching device 201.

One or more switching elements 201 are connected between a positive terminal of the DC link unit 300 and an output terminal of the input reactor and a negative terminal of the DC link unit 300 and an output terminal of the input reactor. The lower switching element 205 can be classified as a lower switching element. Here, the number of the at least one switching element 201 is three.

The rectifying part 200 includes a switching element 211 connected between the upper switching element 203 and the lower switching element 205 to allow the AC power of the at least one switching element 201 to pass therethrough, And a free wheeling diode 213 provided at both ends of the free wheeling. The at least one switching element 211 is connected to the output terminal of the upper switching element 203 at one end and connected to the DC link unit 300 at the other end thereof to receive the AC power converted by the at least one switching element 201 . That is, only the partial waveform of the AC power is selected by the upper switching element 203, the lower switching element 205, and the switching element 211, which are switched in accordance with the control signal generated from the controller 700, The AC power source is converted into a DC power source subdivided into three levels according to the phase control

The DC link unit 300 includes capacitors C1 and C2. The DC link unit 300 receives the boosted DC power from the rectifier 200 during normal operation and receives the discharge power of the battery 500 during a power failure. And the DC link voltage of the DC link unit 300 is transmitted to the inverter 500. [

The inverter 400 is connected to the DC link unit 300 to which the DC power of the rectifying unit 200 is applied and is provided with a plurality of switching devices S7-S12, S7'-S12 'and freewheeling diodes, Level inverter, the DC link voltage is supplied to the three-level PWM control signal, and the DC link voltage is converted into AC power and transferred to the load. The operation of the three-level inverter according to the embodiment of the present invention is similar to that of a conventional three- It is the same or similar to a series of processes

The battery switching unit 600 is connected between the battery 500 and the input switching unit 100 and is provided with bidirectional switching elements T4, T5 and T6 (T4 ', T5' and T6 ') of SCR .

The battery switching unit 600 is interlocked with the input switching unit 100 and when the input switching unit 100 is switched to the on state during normal operation, the battery switching unit 600 is switched to the turn off state, When the switching unit 100 is switched to the turn-off state, the predetermined reference time (8.33 ms) is switched to the turn-on state after the elapse.

Hereinafter, a series of processes in which the input switching unit 100 is cut off and the battery switching unit 600 is operated will be described in detail with reference to FIGS. 4 and 5. FIG.

4, a control signal generated from the control unit 700 supplied to the input switching unit 100 and the battery switching unit 600 is shown. Referring to FIG. 4, When the control signal of the switching unit 100 is stopped, a time point when a reverse voltage is applied to the a-phase input switching unit 100 is a time point d, and a time point when a reverse voltage is applied to the b-phase input switching unit 100 is f , and the time point when a reverse voltage is applied to the c-phase input switching unit 100 is h.

On the other hand, the maximum time that the control signal supplied to the input switching unit 100 of each phase is stopped and the SCR of the actual input switching unit 100 is cut off is half of the AC input voltage of the control signal, , The determination reference time is about 8.33 ms, and when 50 Hz AC power is input, it is 10 ms.

5 (a) shows a short-circuit current flowing when the input switching unit 100 and the battery switching unit 600 operate simultaneously. For example, when the input switching unit 100 operates, When the bi-directional switching element T4 of the battery switching part 600 is in the cutoff state and the bi-directional switching element T4 'is operated at a time when the half cycle has not elapsed, the input AC is bi- It can be seen that a short-circuit current is generated by a short-circuit voltage of Va + Vbat-Vc1 during the period when the switching element T1 and the bi-directional switching element T4 'of the battery switching unit 600 simultaneously conduct.

At this time, since the input switching unit 100 is switched to the turn-off state and the supply of the AC power is cut off, the rectifier unit 200 does not connect any energy source during the reference time, so that the capacitors C1 and C2 of the DC link unit 300 ), The only energy source is discharged by the load, and the discharge time is derived from the following equations (1) and (2).

Figure 112015088630195-pat00001
.. Equation 1

Figure 112015088630195-pat00002
... Equation 2

Here, the capacity of the capacitors C1 and C2 installed in the DC link unit 300 in the uninterruptible power supply unit of 100 kVA capacity is

Figure 112015088630195-pat00003
And as the rated capacity increases, the capacity of the capacitor also increases proportionally. For a 100 kVA capacity, applying a power factor of 0.8 and an efficiency of 95% will yield approximately 84 kW, where the equivalent load resistance is approximately
Figure 112015088630195-pat00004
.

If the capacitor capacity and the equivalent load resistance are substituted into Equation 1, the DC link voltage is about 719 V until the elapse of the determination reference time (8.33 ms) after the input switching unit 100 is turned off, and the capacitor capacity And the equivalent load resistance, the discharge time, which has elapsed up to 650 V, which is the minimum voltage required for the inverter to generate a normal AC output voltage, is 29 ms.

Therefore, it can be seen that the capacitor voltage of the DC link unit 300 is sufficient for supplying power to the load even if the capacitor is discharged for the determination reference time (8.33 ms) by the derived discharge time (29 ms).

That is, after the elapse of the determination reference time (8.33 ms) after the input switching unit 100 is turned off, the battery switching unit 600 has a margin of about 20 ms, and the battery discharge voltage for about 20 ms It can be seen that it is sufficient time to supply.

As a result, even if the battery switching unit 600 is operated after the determination reference time (8.33 ms) elapses, no circulating current is generated between the input AC power source AC and the battery 500, and the inverter 400 supplies power to the load It is understood that the energy required for the DC link voltage is sufficiently secured.

5B, since the bidirectional switching device T4 of the battery switching unit 600 is cut off in the negative half period of the input voltage, the short-circuit voltage and the current are not generated in the negative period I can see that no.

As shown in FIG. 5 (a), due to short-circuit current during the time when the input AC voltage is concurrently conducted between the input switching part T1 and the battery switch T4 'within a positive half period, the damage of the uninterruptible power supply The bidirectional switching device T4 'of the battery switching part 600 must be switched to the on-state after a predetermined determination time (8.33 ms) after the input switching part 100 is switched to the turn-off state . The controller 700 may include a gate driver or a micro control unit (MCU) and may control the input switching unit 100, the rectifier 200, and the inverter 400.

In the embodiment of the present invention, for convenience of explanation, the control unit 700 sets the determination reference time to a predetermined time (8.33 ms) as an example. However, when the battery switching unit 600 May be switched to the turn off state. That is, the bidirectional switching device T4 'of the battery switching unit 600 is turned on when the input switching unit 100 is switched to the turn-off state and the input AC power supply is below the holding current of the SCR device Switching control is performed.

6 (a) and 6 (b) show the flow of current supplied from the battery discharge power supply to the inverter in the uninterruptible power supply apparatus shown in FIG. 2, (C) and (d) illustrate a step-up process of an uninterruptible power supply unit in which a negative terminal of a battery is connected to a negative terminal of a DC link.

6 (a) and 6 (b), in order to allow the positive power supply of the battery to pass through the rectifying unit 200 and the battery switching unit 600 and to be transmitted to the battery 500 in the reactor power storage mode, The bidirectional switching elements T1, T2 and T3 of the battery switching section 600 and the bidirectional switching elements T4, T5 and T6 of the battery switching section 600 are cut off and the bidirectional switching elements T4 'and T5 The anode power source of the battery 500 passes through the DC link unit 300 and the rectifying unit 200 and then is transmitted to the battery through the battery switching unit 600. In this case, Respectively.

Here, the reactor power mode means a state in which the battery is boosted by the rectification part 200 during a power failure, and the DC link charge mode is a state in which the reactor power source and battery power of the boosted rectifier part 200 are charged to the DC link part it means.

That is, referring to (a), the positive (+) power source of the battery 500 in the reactor charging mode is connected to the upper switching element 203 of the rectifier 200 and the bidirectional switching elements T4 ' T5 ', and T6', and is transmitted to the battery 500. FIG. At this time, the upper switching element 203 is turned on, the lower switching element 205 is turned off, and the bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are cut off. At this time, the upper switching element 203 is turned on and the lower switching element 205 is turned off.

The positive (+) power source of the battery 500 is connected to the DC link unit 300 and the lower switching unit 205 of the rectifier unit 200 and then to the battery switching unit (not shown) T4 ', T5', and T6 'of the battery pack 600 to be transmitted to the battery, the positive power source of the boosted battery 500 is charged in the DC link unit 300. [ At this time, the upper switching device 203 is turned off and the lower-stage switching device 205 is turned on.

In the capacitor charging mode, the positive power of the battery is transmitted to the battery 500 through the battery switching unit 600 and the lower switching unit 205 of the rectifying unit 200, The bidirectional switching elements T1, T2 and T3 of the battery switching part 600 and the bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are cut off and the bidirectional switching elements T4 'and T5' , T6 'are operated. At this time, the upper switching element 203 is turned off and the lower switching element 205 is turned on.

the anode power of the battery 500 is transmitted to the DC link unit 300 after passing through the battery switching unit 600 and the upper switching device 203 of the rectifying unit 200 in the DC link charging mode, The bidirectional switching elements T4 ', T5' and T6 'of the battery switching part 600 are operated. At this time, the lower switching element 205 is turned off and the upper switching element 203 is turned on.

Accordingly, the input AC power source AC is turned off when the input switching unit 100 and the battery switching unit 600 are turned off and the bidirectional switching device T4 (T4, T5, T6) of the battery switching unit 600 is turned off The at least one switching device 201 of the rectifier 200 which is operated by the input power factor control and the DC link voltage control during the normal operation of the input AC power supply AC is in the off state And the battery voltage is boosted by the bi-directional switching devices T4 ', T5', and T6 'of the upper switching device 203 and the battery switching unit 600 when the predetermined criterion time elapses And the capacitors C1 and C2 of the DC link unit 300 are charged.

According to an embodiment of the present invention, a charging unit for charging an AC power source is further provided by providing a battery switching unit, which is driven in conjunction with an input switching unit for transmitting AC power to a rectifying unit and discharging battery power of a rated capacity, Accordingly, the manufacturing process and manufacturing cost of the uninterruptible power supply can be reduced by removing the DC / DC converter that performs the conventional charge / discharge function of the battery.

Hereinafter, with reference to FIG. 7, a series of processes for stabilizing the DC link voltage when the DC link voltage changes in an overvoltage will be described.

That is, when the DC link voltage is temporarily raised due to a sudden decrease of the load during operation of the load due to the battery boosted DC link voltage at the rectification part 200 during the power failure, the capacitor of the DC link part 300 driven by the DC link voltage Since one or more switching elements of the inverter 400 are damaged, the DC link voltage must be controlled to a constant voltage or lower.

7 (a) and 7 (b) show the flow of current during the execution of the step-down mode for controlling the DC link voltage raised due to a sudden decrease in load during a power failure, (C) and (d) show a current flow for executing the step-down of the uninterruptible power supply connected to the negative terminal of the DC link unit .

Here, the step-down mode refers to a state in which the DC link voltage is lowered by the battery to control the DC link voltage during the power failure, and the reflux mode in the step-down control means the reflux state of the voltage accumulated in the reactor.

That is, in the step-down mode of (a), the negative electrode power of the battery is transmitted to the battery 500 by the DC link unit 300 after passing through the battery switching unit 600 and the lower stage switching device 203 of the rectifying unit 200 The bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are operated so that the battery negative power is supplied to the battery switching part 600 and the upper switching element 205 of the rectifying part 200 The bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are operated so as to be transmitted to the battery 500 after passing through the battery 500. [ At this time, the bidirectional switching elements T4 ', T5', T6 'of the input switching unit 100 and the battery switching unit 600 are cut off.

The negative electrode power of the battery is transmitted to the battery 500 by the DC link unit 300 after passing through the battery switching unit 600 and the rectifying unit 200. Thus, The DC link voltage of the battery 500 is lowered by the battery 500.

Referring to (b), in the reflux mode, the battery negative electrode power is transmitted to the battery 500 after passing through the battery switching unit 600 and the rectifying unit 200. Thus, the DC link voltage is stabilized to a constant voltage.

(C) shows a state in which the negative power of the battery is passed through the DC link unit 300 and the top switching element 203 of the rectifying unit 200 in the step-down mode, and then transmitted to the battery 500 by the battery switching unit 600 The bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are operated so that the battery negative power is supplied to the battery switching part 600 and the lower switching element 205 of the rectifying part 200 The bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are operated so as to be transmitted to the battery 500 after passing through the battery 500. [ At this time, the bidirectional switching elements T4 ', T5', T6 'of the input switching unit 100 and the battery switching unit 600 are cut off.

The negative electrode power of the battery is transmitted to the battery 500 by the DC link unit 300 after passing through the battery switching unit 600 and the rectifying unit 200. Therefore, The DC link voltage of the battery 500 is lowered by the battery 500.

Referring to (d), in the reflux mode, the battery cathode power is transmitted to the battery 500 after passing through the battery switching unit 600 and the rectifying unit 200. Thus, the DC link voltage is stabilized to a constant voltage.

That is, the bidirectional switching elements T4, T5 and T6 of the battery switching part 600 are operated and the bidirectional switching elements T4 ', T5' and T6 'are closed when the overvoltage of the DC link voltage fluctuates, It can be seen that the overvoltage of the DC link is absorbed by the battery 500 because the DC link 300 is activated in the step-down mode.

Accordingly, the DC link voltage can be stabilized when the DC link voltage that is boosted during the power blackout transients the boosted DC link voltage to the battery in the overvoltage variation, thereby changing the overvoltage of the DC link voltage.

A process of discharging the battery power of the rated capacity, which is driven in conjunction with the input switching unit for transmitting the AC power to the rectifying unit, and a process of controlling the overvoltage of the DC link voltage will be described with reference to FIG.

FIG. 8 is a flowchart illustrating an operation of the controller of the UPS device shown in FIG. 2. Referring to FIG. 8, a process of controlling the UPS device according to another embodiment of the present invention will be described.

 The AC power AC input from the outside under the control of the control unit 700 is transmitted to the load via the input switching unit 100, the rectifying unit 200, the DC link unit 300 and the inverter 400 in the ON state And the load is driven by the AC power source (S1, S2, S3).

 The control unit 700 switches the input switching unit 100 to an off state when a power failure occurs during normal operation of the load, and switches the battery switching unit 600 to an on state when a predetermined determination reference time has elapsed (S4-S7 ).

On the other hand, if it is determined in step S6 that the predetermined reference time has not elapsed, the controller 700 determines whether the current value of the input AC power source has decreased below the holding current of the input switching unit 100, (S8) when the current value of the input switching unit 100 is lower than the holding current of the input switching unit 100 (S7). If the current does not decrease below the holding current of the input switching unit 100 in step S8, the process proceeds to step S5.

Accordingly, the discharge power of the battery is boosted by the rectification unit 200, and the boosted DC link voltage is transmitted to the load through the inverter 400 (S9)

Accordingly, by switching the battery switching unit in conjunction with the input switching unit for charging the AC power source with the battery by the charging unit and delivering the AC power to the rectifying unit, the discharge power of the battery is boosted by the rectifying unit during the power failure, The DC / DC converter performing the charge / discharge function can be removed, thereby reducing the manufacturing cost and manufacturing cost of the uninterruptible power supply, and also enabling the lightning-saving of the uninterruptible power supply.

 Meanwhile, when the DC link voltage is an overvoltage during the execution of step S8, the controller 700 transmits the negative power of the battery to the rectifier 200 via the battery switch 600, which is turned on, (S10, S11).

Thereafter, the controller 700 determines whether the AC power is restored. If the AC power is restored, the controller 700 proceeds to step S2. If the AC power is not restored, the controller 700 proceeds to step S9.

Accordingly, the DC link voltage can be stabilized when the DC link voltage that is boosted during the power failure transfers the boosted DC link voltage to the battery when the overvoltage fluctuates, thereby changing the overvoltage of the DC link voltage.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

And a charging unit for charging the AC power source with a battery, the battery switching unit being driven in conjunction with the input switching unit for transmitting the AC power to the rectifying unit and discharging the battery power of the rated capacity, The DC / DC converter performing the charging / discharging function can be eliminated to reduce the manufacturing process and the manufacturing cost of the uninterruptible power supply unit, and the uninterruptible power supply unit can be made slimmer and thinner, and when the overvoltage of the boosted DC link voltage fluctuates, It is possible to achieve a significant improvement in terms of operation accuracy and reliability as well as performance efficiency in the control apparatus and method of the uninterruptible power supply unit which can stabilize the DC link voltage by switching the battery switching unit to transfer the voltage to the battery , The uninterruptible power supply is likely to be commercially available or operating This is an invention that is industrially applicable because it is practically possible to carry out clearly.

Claims (11)

An input switching unit which is switched according to a control signal supplied from the control unit to pass the AC power;
A rectifying unit for converting an AC power passed through the input switching unit to a DC power;
A DC link portion linking the rectifying portion;
An inverter for converting the DC link voltage of the DC link unit into AC power and delivering the DC link voltage to the load; And
And a controller for generating and transmitting a control signal for controlling the input switching unit, the rectifying unit, and the inverter,
A battery switching unit that is switched in conjunction with the input switching unit to switch the voltage of the battery when the power failure occurs, and to transfer the boosted DC link voltage to the load via the inverter; And
And a charging unit that receives AC power and charges the battery.
The battery switching unit
And a bidirectional switching element for transmitting a negative power of the battery of the battery to the battery through the rectifying part when the DC link overvoltage is temporarily caused by a sudden decrease of the load during operation of the load,
The bidirectional switching element is operated so that the negative electrode power of the battery is transmitted to the battery by the DC link portion after passing through the lower switching element of the battery switching portion and the rectifying portion and the battery negative electrode power is passed through the rectifying portion And the DC link overvoltage is supplied to the battery so that the DC link overvoltage is lowered by the battery. 2. The apparatus of claim 1, wherein the input switching unit
And a bidirectional switch element that is switched to an on state in accordance with a control signal provided from the controller and transmits the AC power to the rectifier during a normal operation of the uninterruptible power supply. delete delete The battery pack of claim 1,
And switches to the on state when the predetermined reference time elapses after the input switching unit is switched to the off state upon power failure. delete The apparatus of claim 1, wherein the battery switching unit
In order to provide the boosted DC link voltage to the inverter in the case of a power failure, the positive power supply of the battery in the reactor charging mode is boosted via the rectifying section and switched to be delivered to the battery,
And switches the positive power supply of the battery to be transmitted to the battery via the DC link part and the rectifying part in the DC link charging mode. delete The battery pack of claim 1,
Wherein the switching unit switches the negative power supply of the battery to be transmitted to the battery via the rectifying unit and the DC link unit in the step-down mode, and switches the negative power supply of the battery that has been reduced in the return mode to be transmitted to the battery via the rectifying unit. controller.
(A) passing the AC power having passed through the input switching unit to the load through the rectifying unit and the inverter;
The battery switching unit is operated when the predetermined reference time elapses after the input switching unit is interrupted during the power failure and when the current of the input AC power source is equal to or less than the holding current of the input switching unit and the positive polarity power of the battery is boosted by the rectifying unit And (b) executing boost control to transfer the boosted DC link voltage to the inverter,
After the step (b)
Further comprising the step of: (c) performing the step-down control by applying the DC link voltage to the battery when the DC link voltage temporarily boosted due to a sudden decrease in load during operation of the load is an overvoltage. Way. delete
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102195370B1 (en) * 2020-04-27 2020-12-28 성신전기공업(주) Apparatus for contrlling ups
KR20220037157A (en) * 2020-09-17 2022-03-24 성실에너지 주식회사 Energy Storage System
WO2023048324A1 (en) * 2021-09-24 2023-03-30 성실에너지 주식회사 Vehicle having power synchronization method using one-cord power plug

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JPH10248246A (en) * 1997-02-28 1998-09-14 Sanken Electric Co Ltd Switching power-supply apparatus
KR100830351B1 (en) * 2007-09-12 2008-05-20 국제통신공업 주식회사 Insulated gate bipolar transistor uninterruptible power supply system
JP2012075274A (en) * 2010-09-29 2012-04-12 Sanken Electric Co Ltd Uninterruptible power supply

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10248246A (en) * 1997-02-28 1998-09-14 Sanken Electric Co Ltd Switching power-supply apparatus
KR100830351B1 (en) * 2007-09-12 2008-05-20 국제통신공업 주식회사 Insulated gate bipolar transistor uninterruptible power supply system
JP2012075274A (en) * 2010-09-29 2012-04-12 Sanken Electric Co Ltd Uninterruptible power supply

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102195370B1 (en) * 2020-04-27 2020-12-28 성신전기공업(주) Apparatus for contrlling ups
KR20220037157A (en) * 2020-09-17 2022-03-24 성실에너지 주식회사 Energy Storage System
WO2022059918A1 (en) * 2020-09-17 2022-03-24 성실에너지 주식회사 Energy storage system
KR102443460B1 (en) 2020-09-17 2022-09-15 성실에너지 주식회사 Energy Storage System
US11824364B2 (en) 2020-09-17 2023-11-21 Sungsilenergy Co., Ltd Energy storage system
WO2023048324A1 (en) * 2021-09-24 2023-03-30 성실에너지 주식회사 Vehicle having power synchronization method using one-cord power plug

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