KR20230006284A - Apparatus for controlling disconnecting switch and uninterruptible power supply including the same - Google Patents

Abstract

According to an embodiment of the present invention, an apparatus for controlling a disconnecting switch, which is an apparatus for controlling a disconnecting switch connected between a battery and an external load, comprises: a microcontroller unit (MCU) keeping the output of a high level signal for a first period and outputting a pulse signal after the first period; a Schmitt Trigger Buffer with a signal level outputted during the first period transitions from a low level to a high level; and a multi vibrator having a first input connected to an output of the MCU and having a second input connected to an output of the Schmitt Trigger Buffer, and disconnecting the disconnecting switch in accordance with the signal applied to the first and second inputs. Therefore, an active operation can be guaranteed.

Description

Disconnector control device and uninterruptible power supply including the same

The present disclosure relates to a disconnector control device and an uninterruptible power supply device including the same.

A rechargeable or secondary battery is different from a primary battery that provides only irreversible conversion of chemical substances into electrical energy in that it can be charged and discharged repeatedly. Low-capacity rechargeable batteries are used as power supplies for small electronic devices such as mobile phones, notebook computers, and camcorders, and high-capacity rechargeable batteries are used in electric vehicles (EVs), hybrid vehicles (HVs), or It is used as a power supply device such as an energy storage system (ESS) or an uninterruptible power supply (UPS) system using a medium- or large-sized battery used for home or industrial use.

In general, an uninterruptible power supply is a system that automatically supplies power without interruption in an instant when normal power is not supplied or power failure occurs. An uninterruptible power supply (UPS) is an essential device for electronic devices including computers during operation that must supply continuous power without interruption. or to prevent loss of control function and malfunction of various control devices.

As an electromechanical switch in a protection system of an uninterruptible power supply, one or more relays controlled by a relay drive circuit and a disconnecting switch (DS) are used. A disconnector is a mechanical earthing switch that opens and closes a circuit to change the connection to the main circuit in an open, no-load condition. The disconnector completely disconnects the UPS from the power supply target in the event of a burst of protection system.

Embodiments are intended to protect the uninterruptible power supply even in the event of a malfunction of the protection system.

Embodiments are for normally operating disconnectors.

Embodiments are intended to prevent tripping of the disconnector upon start-up of the uninterruptible power supply.

A disconnector control device according to an embodiment is a disconnector control device for controlling a disconnector connected between a battery and an external load, maintains the output of a high level signal for a first period, and generates a pulse signal after the first period. A microcontroller unit (MCU) for outputting, a Schmitt trigger buffer in which a signal level output during a first period transitions from a low level to a high level at least once, and a first input is connected to an output of the MCU, and A multivibrator having two inputs connected to the output of the Schmitt trigger buffer and outputting a signal for shorting the disconnector according to signals applied to the first input and the second input.

The multivibrator shorts the disconnector when a pulse signal is input to the first input and a high level signal is applied to the second input and when a high level signal is input to the first input and a pulse signal is input to the second input. signal can be output.

The disconnector control device further comprising a photocoupler for transmitting a signal for shorting the disconnector to the disconnector. The signal level to be output is transitioned.

An uninterruptible power supply device according to an embodiment is an uninterruptible power supply device that is connected to an external grid to receive power and is connected to an external load to supply power, and includes a battery, a disconnector connected between the battery and the external load, and a battery during normal operation. A microcontroller unit (MCU) outputting a pulse signal to the microcontroller unit (MCU), and a disconnector control unit receiving the pulse signal and controlling opening and closing of the disconnector, wherein the disconnector control unit has a signal for shorting the disconnector when operation of the microcontroller unit is started. outputs

The microcontroller unit maintains the output of the high level signal for a first period from the start of operation, and outputs a pulse signal after the first period, and the disconnector control unit outputs a signal level from a low level to a high level during the first period. A Schmitt trigger buffer that transitions at least once to , and a first input is connected to the output of the MCU, a second input is connected to the output of the Schmitt trigger buffer, and a disconnector according to a signal applied to the first input and the second input. It may include a multi-vibrator that outputs a signal for shorting.

The multivibrator shorts the disconnector when a pulse signal is input to the first input and a high level signal is applied to the second input and when a high level signal is input to the first input and a pulse signal is input to the second input. signal can be output.

A photocoupler for transmitting a signal for shorting the disconnector to the disconnector may be further included.

The disconnector opens when a signal for shorting the disconnector is not input during the second period, and the signal level output from the Schmitt trigger buffer transitions within a shorter period than the second period.

According to the embodiments, there is an effect of ensuring smooth operation of the uninterruptible power supply when the operation starts.

According to the embodiments, there is an effect of providing a robust uninterruptible power supply device even when the protection system is abnormally operated.

According to the embodiments, there is an effect of preventing additional accidents caused by the battery.

1 is a diagram schematically illustrating an uninterruptible power supply and peripheral configurations according to an exemplary embodiment.
2 is a block diagram schematically illustrating an uninterruptible power supply according to an embodiment.
3 is a block diagram showing an example of a disconnector control device.
4 shows a function table of the multivibrator of the disconnector control device.
5 is a graph showing input and output signals of the disconnector control device of FIG. 3 .
6 is a block diagram showing a disconnector control device according to an embodiment.
FIG. 7 is a graph showing input/output signals of the disconnector control device of FIG. 6 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, operational effects and implementation methods according to embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, like reference numerals denote like elements, and redundant descriptions are omitted. This invention may, however, be embodied in many different forms and should not be construed as limited only to the embodiments shown herein. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the invention to those skilled in the art.

Accordingly, processes, elements, and techniques may not be described that are not deemed necessary to one skilled in the art for a thorough understanding of the aspects and features of the present invention. In the drawings, the relative sizes of elements, layers, and regions may be exaggerated for clarity.

As used herein, the term "and/or" includes any and all combinations of one or more associated listed items. Also, use of "may" when describing embodiments of the invention means "one or more embodiments of the invention." In the following description of embodiments of the present invention, singular terms may include plural forms unless the context clearly indicates otherwise.

Although the terms "first" and "second" are used to describe various elements, it will be appreciated that these elements should not be limited by these terms. This term is only used to distinguish one element from another. For example, a first element could be termed a second element, and likewise, a second element could be termed a first element without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more related and recited items. An expression such as "at least one" precedes a list of elements and modifies the entire list of elements and not individual elements of the list.

As used herein, the terms "substantially", "about" and similar terms are used as terms of approximation and not terms of degree, and are measured values or calculations that would be recognized by one of ordinary skill in the art. This is to account for the inherent deviation of the measured values. Further, when the term "substantially" is used in combination with a characteristic that can be expressed using a number, the term "substantially" denotes a range of +/-5% of the value centered on that number.

1 is a diagram schematically illustrating an uninterruptible power supply and peripheral configurations according to an exemplary embodiment.

System 30 includes power plants, substations, transmission lines, and the like. Grid 30 allows power to be supplied to load 40 and/or battery 20 of uninterruptible power supply 10 when in normal conditions. When the grid 30 is in an abnormal state, power supply from the grid 30 to the uninterruptible power supply 10 is stopped and power from the battery 20 of the uninterruptible power supply 10 is supplied to the load 40 .

The load 40 consumes power supplied from the system 30 , power stored in the battery 20 , and/or power supplied from the system 30 . A home or a factory may be an example of the load 40 .

The uninterruptible power supply device 10 is a system that automatically supplies power without interruption in an instant when power is not supplied or there is a power outage. The uninterruptible power supply 10 is an essential device for electronic devices including computers during operation that needs to supply continuous power without interruption, and provides stable power even in the event of voltage or frequency fluctuations or momentary power outages to prevent the destruction or erasure of computer data. It can prevent, protect, or prevent loss of control function and malfunction of various control devices.

According to an embodiment, the uninterruptible power supply device 10 may supply power to the load 40 as an energy storage device in normal times even when a problem does not occur in the system 30 . The uninterruptible power supply system uses the battery 20 to supply the load 40 together with the system 30 in consideration of the peak time when the power consumption of the load 40 is large even in normal times or the price of power supplied from the system 30. can supply power to The battery 20 may be charged by receiving power from the system 30 during a time zone when late-night electricity is supplied. However, since the uninterruptible power supply device 10 needs to continuously supply power even when it is difficult to supply power from the system 30, it is necessary to store power over a certain amount of power even if it is normally operated as an energy storage device.

2 is a block diagram schematically illustrating an uninterruptible power supply according to an embodiment.

Referring to FIG. 2 , the uninterruptible power supply 10 includes a battery rack 20a, the uninterruptible power supply 10, and a battery control unit (BCU) 50.

The uninterruptible power supply device 10 is a device that prevents power failures due to voltage fluctuations, frequency fluctuations, instantaneous blackouts, transient voltages, etc. generated from commercial power and always supplies stable power. The uninterruptible power supply 10 is generally composed of an input/output terminal, a rectifier, a filter, an inverter, a converter, a charger, and a switch.

Specifically, the rectifier is a circuit that rectifies the AC voltage of the system 30 and converts it into a DC voltage to output the DC voltage in order to store the power of the system 30 in the battery in the charging mode. The rectifier may include a semiconductor rectifier, an electron tube rectifier, a mechanical rectifier, and the like.

An inverter is connected between the load 40 and the rectifier. The inverter may convert the DC voltage output from the battery into the AC voltage of the grid 30 in the discharge mode. Meanwhile, the inverter may be a bidirectional inverter in which directions of input and output may be changed. The inverter may include a filter for removing harmonics from the AC voltage output to the system 30 . In addition, the inverter may include a phase locked loop (PLL) circuit for synchronizing the phase of the AC voltage output from the inverter with the phase of the AC voltage of the system 30 in order to suppress generation of reactive power. In addition, the inverter may perform functions such as limiting a range of voltage fluctuation, improving power factor, removing a direct current component, and protecting transient phenomena. When not in use, the inverter can also be turned off to minimize power consumption.

The DC link unit is connected between the rectifier and the inverter to keep the DC link voltage constant. The level of the DC link voltage may become unstable due to an instantaneous voltage drop in the grid 30, a peak load occurring in the load 40, and the like. However, the DC link voltage needs to be stabilized in order for the inverter and battery to operate stably. To this end, the DC link unit is connected between the battery, the inverter, and the rectifier, and for example, a large-capacity capacitor may be used.

As such, in the uninterruptible power supply 10, the rectifier converts commercial or emergency power from alternating current to direct current, and the inverter converts it back to alternating current to supply stable power to the load and simultaneously charge the battery, and power failure In this case, the DC power charged in the battery by the rectifier is converted into alternating current by the inverter to supply the AC power to the load. Alternatively, the uninterruptible power supply device 10 may supply commercial power to a load by bypassing the commercial power without passing through a converter or an inverter in normal conditions.

The battery ('20' in FIG. 1) may include at least one battery rack 20a. Battery rack (20a) may include one or more battery modules (200a, 200b, 200n) and a rack management unit (Rack Battery Management System, hereinafter referred to as 'RBMS').

One or more battery modules 200a, 200b, and 200n are parts that store power and may include battery cells as sub-elements thereof. The number of battery cells included in each of the battery modules 200a, 200b, and 200n may be determined according to a required output voltage. Various secondary batteries capable of being charged with such battery cells may be used. For example, secondary batteries used in battery cells include nickel-cadmium batteries, lead-acid batteries, nickel-metal hydride batteries (NiMH), lithium-ion batteries, lithium It may be a lithium polymer battery or the like.

RBMS (210) controls the charging and discharging operation of the batteries in the battery rack (20a). The RBMS 210 monitors the state of charge, voltage, current, etc. of the batteries and transmits the measured data to the BMS 56. The BMS 56 may transmit a control signal to the RBMS 210 based on the data received from the RBMS 210.

The battery control unit (BCU) 50 includes disconnecting switches (D/S) 52a and 52b, a charge control switch 54, a BMS 56, a shunt resistor, and fuses F1 and F2. ) may be included.

The disconnectors 52a and 52b are controlled to be opened or shorted by the signal CS output from the BMS 56. The disconnectors 52a and 52b are in a short-circuit state when the signal CS is normally output from the BMS 56. Disconnectors 52a and 52b can be opened to completely isolate battery 20 from load 30 in case of BMS 56 failure. The disconnectors 52a and 52b are opened when the signal CS is not output from the BMS 56 for a predetermined period of time (eg, 23 ms) (ie, is not normally output).

The charge control switch 54 may control the flow of charging current output from the system 30 connected to the battery under the control of the BMS 56 . When an off signal is received from the BMS 56, it turns off and blocks the inflow of charging current, thereby protecting the battery from overcurrent caused by overcharging. Switch S1 is connected to limit current flow from grid 30 to battery 100. That is, the charging current is blocked by using the switch S1. At this time, a discharge current may flow through the diode D1.

The BMS 56 monitors the states of the system 30, the battery 20, and the load 40, and controls the operation of the inverter, rectifier, and battery according to the monitoring result and a preset algorithm. For example, the BMS 56 may control the charge control switch 54 by sensing an overcurrent through a shunt resistor. The BMS 56 may monitor whether a power failure has occurred in the system 30, the state of charge of the battery 20, the amount of power consumed by the load 40, time, and the like. In addition, when the power to be supplied to the load 40 is not sufficient, such as when a power failure occurs in the system 30, the BMS 56 prioritizes power-using devices included in the load 40 and prioritizes them. It is also possible to control the load 40 to supply power to devices with high power consumption.

When the BMS 56 starts working, the output of the signal CS may be delayed by the booting of the component that outputs the signal CS. Then, there are cases in which the disconnectors 52a and 52b are opened even during normal operation of the BMS 56. This will be described with reference to FIGS. 3 to 5 .

3 is a block diagram showing an example of a disconnector control device, FIG. 4 shows a function table of a multivibrator of the disconnector control device, and FIG. 5 is a graph showing input and output signals of the disconnector control device of FIG. 3 .

Referring to FIG. 3, the BMS 56 includes a multivibrator 100 that receives a pulse signal output from the MCU 110 and outputs a signal CS and a photocoupler that transmits the signal CS to control the disconnector. (photocoupler) 120 is included.

Referring to FIG. 4, the multivibrator 100 outputs a signal (ie, voltage) to an output Q according to voltage levels input to the first input CLR, the second input A, and the third input B. ) can be output. The output Q is adjusted to maintain a high-level signal longer than the on-duty period of the pulse signal transmitted from the MCU 110 composed of pulses of constant frequency with time constant values of R1 and C1. For example, since the high level pulse lasts for 2 seconds and the pulse period of the MCU 110 is 200 ms, the output Q outputs a high level as a DC waveform.

Referring to FIG. 5 , the MCU 110 is booted at t1. During the period P1 between t1 and t2, booting of the MC 110 continues, and at this time, the MCU 110 outputs a signal of a high level (H).

Then, the driving voltage (VD) (that is, a high level signal) is applied to the first input (CLR) of the multivibrator 100, the second input (A) is connected to the ground, and the second input (B) A high level (H) signal is being input.

As can be seen from the function table of FIG. 4, during the period P1, the output Q outputs a low level (L) signal. The low level (L) signal may be output as a low level signal (CS) through the photocoupler 120 . The disconnectors 52a and 52b are opened by the low level (L) signal CS. Here, it has been described that the signal CS of the low level (L) opens the disconnectors 52a and 52b, but the signal level is only an example and the signal CS of the high level (H) is configured differently. The disconnectors 52a and 52b may be opened.

As described above, by the booting time of the MCU 110 outputting the pulse signal to be provided to the multivibrator 100, a high level signal instead of the pulse signal is sent to the third input (B) of the multivibrator 100. is provided on Accordingly, there is a problem in that even when the MCU 110 operates normally, the low-level signal CS is provided to the disconnectors 52a and 52b to open the disconnectors 52a and 52b.

Next, with reference to FIGS. 6 and 7 , a disconnector control device according to an embodiment will be described.

6 is a block diagram showing a disconnector control device according to an embodiment, and FIG. 7 is a graph showing input/output signals of the disconnector control device of FIG. 6 .

Referring to FIG. 6, the BMS 56 includes a multivibrator 100 that receives a pulse signal output from the MCU 110 and outputs a signal CS, and a photocoupler that transmits the signal CS to control the disconnector. 120, and a Schmitt trigger buffer 130 outputting a signal to the first input CLR of the multivibrator 100.

Referring to FIG. 7 , the MCU 110 is booted at t1. During the period P1 between t1 and t2, booting of the MC 110 continues, and at this time, the MCU 110 outputs a signal of a high level (H).

The input signal Vin of the Schmitt trigger buffer 130 rises from the time point t1. When the input signal Vin exceeds a predetermined level (time point ta), the Schmitt trigger buffer 130 outputs a high level signal. Then, at time ta, the output signal of the Schmitt trigger buffer 130 transitioning from the low level (L) to the high level (H) is applied to the first input (CLR) of the multivibrator 100, and the second input (A ) is connected to the ground, and a high level (H) signal is input to the second input (B).

Therefore, the multivibrator 100 outputs a pulse signal, but outputs a high level signal due to the time constant values of R1 and C1.

The period P2 from t1 to ta is shorter than the period during which the disconnectors 52a and 52b are not opened even if the signal CS is not applied (23 ms as an example described above). Accordingly, the disconnectors 52a and 52b maintain a short-circuit state.

Since the multivibrator 100 outputs a signal of a high level (H) for a predetermined period (2 seconds as an example described above) by one pulse signal, the signal CS is at a high level to the disconnectors 52a and 52b. Therefore, during the P1 period (800 ms as an example described above) after the time point ta, the disconnectors 52a and 52b maintain a short-circuit state.

Thereafter, when the booting of the MCU 100 is completed at t2, the output signal of the high level (H) Schmitt trigger buffer 130 is applied to the first input CLR of the multivibrator 100, and the second input ( A) is connected to ground, and a pulse signal is input to the second input (B).

Then, the multivibrator 100 outputs a signal of high level (H), and the disconnectors 52a and 52b maintain a short-circuit state.

Meanwhile, when the MCU 110 is in a failure state, the output signal of the high level (H) Schmitt trigger buffer 130 is applied to the first input (CLR) of the multivibrator 100, and the second input (A ) is connected to the ground, and a low level (L) signal is input to the second input (B). Then, the output Q of the multivibrator 100 outputs a signal of low level (L), and since the low level signal CS is transmitted to the disconnectors 52a and 52b, the disconnectors 52a and 52b can be opened.

As described above, according to the present disclosure, even if a high level signal is provided to the third input (B) of the multivibrator 100 instead of a pulse signal by the booting time of the MCU 110, the Schmitt trigger buffer 130 The high level signal CS is provided to the disconnectors 52a and 52b by using the disconnectors 52a and 52b to maintain the disconnectors 52a and 52b in a shorted state.

In addition, the disconnector control device of the present disclosure, when the MCU 110 enters a fault state, opens the disconnectors 52a and 52b to completely separate the load 30 and the uninterruptible power supply 10.

The disconnector control device according to the present disclosure can be applied to an uninterruptible power supply, and in addition to the uninterruptible power supply, any field to which a secondary battery such as a vehicle or a home or industrial energy storage system (ESS) can be applied can be applied.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also included in the scope of the present invention. that fall within the scope of the right.

Claims (9)

A disconnector control device for controlling a disconnector connected between a battery and an external load,
A microcontroller unit (MCU) that maintains an output of a high level signal during a first period and outputs a pulse signal after the first period;
A Schmitt trigger buffer in which a signal level output during the first period transitions from a low level to a high level at least once, and
A first input is connected to the output of the MCU, a second input is connected to the output of the Schmitt trigger buffer, and a signal for shorting the disconnector is output according to signals applied to the first input and the second input. multivibrator to play
Disconnector control device comprising a. According to claim 1,
When the pulse signal is input to the first input and the high level signal is applied to the second input of the multivibrator, the high level signal is input to the first input, and the pulse signal is input to the second input. Outputting a signal that shorts the disconnector when input,
disconnector control device. According to claim 1,
The disconnector control device further comprises a photocoupler for transmitting a signal for shorting the disconnector to the disconnector. According to claim 1,
The disconnector is opened when a signal for shorting the disconnector is not input during a second period,
In the Schmitt trigger buffer, the output signal level transitions within a period shorter than the second period.
disconnector control device. An uninterruptible power supply that is connected to an external grid to receive power and connected to an external load to supply power,
battery,
A disconnector connected between the battery and the external load,
A microcontroller unit (MCU) that outputs a pulse signal during normal operation; and
The disconnector control unit receives the pulse signal and controls opening and closing of the disconnector.
including,
The disconnector control unit outputs a signal for shorting the disconnector when the operation of the microcontroller unit is started.
Uninterruptible power supply. According to claim 5,
The microcontroller unit maintains an output of a high level signal for a first period from the start of operation and outputs a pulse signal after the first period;
The disconnector control unit,
A Schmitt trigger buffer in which a signal level output during the first period transitions from a low level to a high level at least once, and
A first input is connected to the output of the MCU, a second input is connected to the output of the Schmitt trigger buffer, and a signal for shorting the disconnector is output according to signals applied to the first input and the second input. Including a multivibrator that does,
Uninterruptible power supply. According to claim 6,
When the pulse signal is input to the first input and the high level signal is applied to the second input of the multivibrator, the high level signal is input to the first input, and the pulse signal is input to the second input. Outputting a signal that shorts the disconnector when input,
Uninterruptible power supply. According to claim 6,
The uninterruptible power supply further comprises a photocoupler for transmitting a signal for shorting the disconnector to the disconnector. According to claim 6,
The disconnector is opened when a signal for shorting the disconnector is not input during a second period,
In the Schmitt trigger buffer, the output signal level transitions within a period shorter than the second period.
Uninterruptible power supply.

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