KR100830351B1 - IGVIS UPS System - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IGBT UPS (Insulated Gate Bipolar Transistor Uninterruptible Power Supply) system, and more particularly, having a microprocessor to monitor whether input power is smoothly output to the load side, The power is charged to the built-in battery through the burr, and when an unstable power input is detected, the input power is cut off and the charged DC voltage is converted into an AC voltage through a DC / AC converting means, thereby making the output power unstable. I) to protect the data in operation and to ensure that the system connected to the load side can be reliably shut down. The present invention also relates to an ISI UPS system forcibly terminating a system connected to a load side through a microprocessor and an output interrupting means when input power is unstable or power failure is maintained even after supplying stable power for a certain time.

Description

Insulated gate bipolar transistor uninterruptible power supply system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IGBT UPS (Insulated Gate Bipolar Transistor Uninterruptible Power Supply) system, and more particularly, having a microprocessor to monitor whether input power is smoothly output to the load side, The power is charged to the built-in battery through the burr, and when an unstable power input is detected, the input power is cut off and the charged DC voltage is converted into an AC voltage through a DC / AC converting means, thereby making the output power unstable. I) to protect the data in operation and to ensure that the system connected to the load side can be reliably shut down. The present invention also relates to an ISI UPS system forcibly terminating a system connected to a load side through a microprocessor and an output interrupting means when input power is unstable or power failure is maintained even after supplying stable power for a certain time.

In the case of medium and large information processing devices, when the power supply is interrupted, such as a power failure, the data of the uninterrupted power supply (hereinafter referred to as a UPS) is supplied so that data in operation in an emergency such as a power failure is lost. I am preparing for a problem.

To this end, in a computer system that performs important tasks such as a large computer, an uninterruptible power supply (UPS) is installed so that the computer can be continuously supplied with power even when the power supply from the power company is interrupted.

On the other hand, even in a personal computer (PC), the need for a UPS to cope with unforeseen accidents due to power outages during the operation is the same, but the existing UPS is expensive and bulky and requires a separate installation space is not easily used to be. However, in recent years, due to the rapid spread of personal computers, the necessity and utilization of the above-mentioned UPS are increasing in offices and homes.

In addition, the AVR (Automatic Voltage Regulator) is a device that constantly outputs irregular voltage caused by the change of the input voltage. It is mainly used with the UPS, and thus the power failure compensation function and the voltage regulation function are used simultaneously. Various products having the functions of the UPS and the AVR are being developed.

1 and 2 is a block diagram of a UPS / AVR combined power supply according to the prior art.

As shown in FIG. 1, the conventional UPS / AVR composite power supply device includes an A / D converter 4 for converting commercial AC power into DC, and converting the DC power into AC power to supply the load. A D / A inverter (7), a charger (5) for converting the commercial power into direct current to charge a battery (BATT), a DC-DC converter (6) for maintaining a constant voltage, and the D / A inverter ( 7) In case of abnormality or overload, use synchronous transfer switch unit 8 and input power to selectively apply AC power of commercial AC power or D / A inverter 7 as output AC power. The CPU 1 monitors and controls the operation of the synchronous transfer switch unit 8. In the drawing, reference numeral 2 denotes a front panel for indicating a charging state and a power supply state of the battery Batt, 3 and 9 are noise filters, and D is a diode.

Hereinafter, the operation of the conventional UPS / AVR combined power supply device will be described.

First, the commercial AC power input via the input terminal is converted from the A / D converter 4 to the DC power in normal operation, which charges a plurality of batteries BATT included in the charger 5. In addition, the DC power of the A / D converter 4 is converted into the AC power in the D / A inverter 7 and applied to the external system through the synchronous transfer switch unit 8 and the plurality of output terminals. At this time, the DC-DC converter 6 adjusts the low voltage and the overvoltage step by step to uniformly output the irregular voltage caused by the change of the input voltage.

When commercial AC power is interrupted in the above state, the DC power of the battery BAT charged with the predetermined voltage passes through the DC-DC converter 6 and the diode D, and then in the D / A inverter 7. By being converted into AC power and applied to an external system through the synchronous transfer switch section 8, the external system can operate stably despite a power failure.

If the commercial AC power is applied again during this operation, the charger 5 again charges the battery BATT.

In addition, when an abnormality occurs in the D / A inverter 7, the CPU 1 detects this and bypasses the commercial AC power supply directly to an external system by the switching operation of the synchronous transfer switch unit 8. In this case, the user may recognize that an abnormality occurs by looking at the battery state on the front panel 2.

According to the prior art having the above-described configuration, there is a computer main body, a monitor, a printer, a digitizer, a hub, a plotter, an external modem, and the like even in one computer system. On the other hand, there is a weak equipment in the irregular power supply, because the UPS and the AVR function is used together, there is an advantage that you do not have to pay expensive costs because you do not purchase the UPS and AVR separately.

However, in the conventional uninterruptible power supply device, the uninterruptible power supply device causes a lot of deterioration in the reliability of the power supply line, such as deterioration of efficiency of the commercial line, generation of harmonic noise, and power factor distortion. In particular, due to the recent increase in capacitive loads, there are disturbances in power plants due to harmonic currents, and the problem of peak power is so severe that there is a need for countermeasures caused by the uninterruptible power supply itself.

In addition, from the load side, the output distortion of the uninterruptible power supply device in a non-linear load adversely affects the neighboring devices, thereby hindering the supply of high-quality used power, which necessitates the need for fundamental improvement.

In order to improve such a problem, the UPS has been disclosed to prevent the disconnection of the output voltage and to be strong in the electrical external environment. Hereinafter, another UPS device will be described with reference to FIG. 2.

As shown in FIG. 2, the UPS / AVR composite power supply according to the related art outputs the input power input through the input switch 511 to the load side through the primary coil, and controls the output for the input to control the load side. A filter circuit 514 for controlling the load-side output to the input of the first transformer 513 by controlling the voltage / current of the first transformer 513 and the secondary coil of the first transformer 513. ), A first inverter 515 for controlling the voltage and current of the filter circuit 514, a battery 516 for supplying uninterruptible power, and converting the battery 516 power to AC power in case of power failure A second inverter 517, the second inverter 517, and the first inverter for charging the battery 516 by converting the input power into a direct current power source by receiving the input power from the load side during normal operation. Output of transformer 513 A second transformer 518 connected between the load sides and outputting the load side output power to the second inverter 517 side during normal power supply and the output of the second inverter 517 to the load side power source in case of power failure; and the input switch An input voltage (Vi) and an input current (iS) are detected at a rear stage, an output voltage (VO) and an output current (iP) are detected at the load side connection terminal, and a DC voltage (Vd) is detected at the battery 516, respectively. However, the high speed detector 80 detects the signals detected using CT and PT at high speed without delay time, and the input / output voltage, current, and DC voltage detected by the high speed detector 80. Microprocessor 90 for controlling uninterruptible control, automatic voltage control (AVR) function, various monitoring, display and protection functions by receiving various inputs and setting various functions by key input, and PWM of the microprocessor 90 Image based on control signal A gate driver 70 for outputting a signal for PWM control of the first inverter 515 and the second inverter 517, and a keypad for allowing a driver to operate the controller for various function setting, monitoring control, and set value control. And an LCD 110 for displaying menus and setting value indicators when setting functions, as well as displaying various statuses.

However, in the composite power supply having the above-described configuration, the overcurrent is controlled by connecting one SCR 512 to the input switch 511 and the load line.

Accordingly, the SCR 512 has a disadvantage in that it is impossible to control overcurrent and abnormality generation in the UPS system due to disconnection and malfunction, and there is a disadvantage in that the SCR 512 cannot detect an overcurrent flowing in the UPS system even in normal operation.

An object of the present invention for solving the above problems of the prior art is as follows.

First, using the main controller as a microprocessor, all functions, including inverter PWM generation and bypass power semiconductor switching pulse signal generation, are software-programmed so that various parameters related to the system can be set and memorized by the keypad. To provide.

Secondly, the LCD control for keypad input signal processing and monitoring is to provide a UPS that can be processed in a communication with the main controller using the 8-BIT PIC micro-controller to be strong and separate operation in the electrical external environment.

Thirdly, through the fast sensing technology of the line voltage, it is possible to provide an on-line PUS that is output so that the output voltage is not disconnected in connection with the line voltage and the transfer time is ignored.

Fourthly, under normal line voltage, energy is supplied to the load through the line with high efficiency, and the inverter generates a voltage almost equal to the line voltage to provide a UPS to cope with abnormal voltage while charging.

Fifth, it is to control overcurrent and abnormal occurrence of the UPS system due to SCR disconnection and malfunction, and to detect an overcurrent flowing in the UPS system even in normal operation.

The UPS according to the present invention is connected to a KEPCO power source or a battery, and is connected in series with the first and second input blocking means for applying AC or DC input power, and the output of the first input blocking means. Input switching means composed of bidirectional SCR and the input power input through the input switching means to control the output to the load side through the primary coil, the output by passing the primary coil by the input of the input switching means A first transformer for controlling the output to the load side, and a filter circuit for controlling the output of the input of the first transformer by controlling the voltage / current of the secondary coil of the first transformer; It is connected to the output part of the filter circuit to control voltage, current and frequency, and to supply stable power to the load side by IGBT pulse width modulation (PWM) control according to the load protection and the circuit protection from abnormal occurrence of overload, short circuit and ground fault. A first inverter; A battery connected to the first b input blocking means for supplying uninterruptible power; A second inverter for converting the battery power into an AC power and outputting it to a load side during power failure, or receiving the input power from the load side in normal operation, converting the battery power into a DC power, and charging the battery; Connected between the second inverter and the 1b output switching means for outputting the load side output power to the second inverter side during normal power supply, and outputting the output of the second inverter to the load side power through the first b output switching means during power failure. A second transformer; First and second output switching means for controlling an overcurrent of an AC output power flowing to the load side by connecting a bidirectional SCR to an output of the second transformer or the first a input blocking means; First a output blocking means connected in series with an output of said first switching output means and outputting an AC output power flowing to said load side; Maintenance bypass switch (MBS) is connected in parallel to the input portion of the input blocking means 1a and the output of the output blocking means 1a to prevent the power supply from being applied at all, thereby avoiding the operation of the U.S. troubleshooting or emergency operation. 1b output blocking means for; An input voltage Vi and an input current iS are detected at the rear end of the input switching means, an output voltage VO and an output current iP are respectively detected at the load side connection terminal, and a DC voltage Vd is detected at the battery. A high speed detection unit for detecting a signal detected using a current transformer (CT) and a potential transformer (PT) at high speed without a delay time by a resistance circuit; Receiving input / output voltage and current and DC voltage detected by the high speed detector, and setting various functions by key input to control uninterruptible control, automatic voltage control (AVR) function, and various monitoring, display and protection functions. A microprocessor for; A gate driver configured to output a pulse width modulation (PWM) control signal of the first inverter and the second inverter based on a pulse width modulation (PWM) control signal of the microprocessor; A keypad for operating by a driver for various function setting and monitoring control and set value control; And a display (LCD) for displaying menus and setting values at the time of function setting, as well as displaying various statuses, using an 8-bit microcontroller that shares key input processing and display control functions as an input controller and an output controller. The keypad and display (LCD) are configured as independent controllers by communicating with a microprocessor.

The microprocessor may further include: an output voltage controller for controlling an output voltage by controlling the first inverter through a filter circuit to control the first inverter for an automatic voltage control (AVR) function; Battery charging control unit for controlling charging voltage and charging current, line voltage monitoring unit for monitoring and displaying input and output voltages and alarm control, and mode-specific mode for storing and managing setting values for various modes. Note for controlling the setting unit, the output voltage control unit, the battery charging control unit, the line voltage monitoring unit and the setting unit for each mode, the selection of system operating conditions, alarm control, various protection functions and bypass. A control unit, the output voltage control unit, the battery charging control unit, and the line voltage monitoring unit The pulse width modulation PWM generating a pulse width modulation (PWM) signal for controlling the gate of the first inverter and the second inverter under the control of the main controller according to the control function of the mode setting unit, and outputting the pulse width modulation (PWM) signal to the gate driver. It is characterized by consisting of a signal generator.

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The first b output switching means may be configured to detect, measure, and control an output power flowing to the load side by connecting a bidirectional switch in parallel with an output of the first a input blocking means and an output of the first a output switching means. It features.

In addition, the 1a, 1b output switching means, the bidirectional SCR to supply the power stably to the load side when the UPS function does not operate normally due to the failure of the transformer, switch, blocking device, rectifier device or charging device and inverter It is characterized in that for controlling the overcurrent by configuring.

The present invention having the above-mentioned means for solving the problem, as an IGP UPS system, can combine the AVR function in order to maximize the efficiency at the line voltage, the inverter functions as an uninterruptible power supply, all the function control software high efficiency, It has the effect of providing high power factor, high performance PU system.

In addition, there is an advantage that the output power flowing to the load side in the UPS function can be detected and measured or output control to be a smooth output power.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a block diagram of a UPS system showing an embodiment according to the present invention, FIG. 4 is an internal functional block diagram of the microprocessor of FIG. 3, and FIG. 5 is a simplified diagram of an uninterruptible power supply system of a UPS system according to the present invention. 6A to 6F are explanatory diagrams showing power flow paths of respective operation modes of the UPS system according to the present invention, and FIG. 7 is a diagram illustrating a control panel of a keypad and an LCD of the UPS system according to the present invention. .

As shown in FIGS. 3 to 5, the iGIS UPS system according to the present invention is connected to a KEPCO (not shown) power source through a first input blocking means 211 to apply an AC input power, and the first bb of FIG. It is connected to the battery 40 through the input blocking means 212 receives a DC input power. In this case, the first b input blocking means 212 may charge the battery 40 with power input from the load side during normal operation, and switch switching to output the battery 40 power to the load side during power failure. Or connect.

Here, the input switching means 12 is connected in series to the output of the first input blocking means 211, and the first transformer 10 is connected in series to the input water switching means 12. At this time, the input switching means 12 is preferably configured to control the over-current of the input power by configuring a bi-directional SCR.

The first transformer 10 outputs the input power input through the input switching means 12 to the load side through the primary coil, and passes the primary coil by the input of the input switching means 12. Control output and output to load side.

In addition, by connecting the filter circuit 20 to the secondary coil of the first transformer 10 to control the output by controlling the voltage / current to the input of the first transformer (10).

In addition, voltage, current, and frequency are controlled by the first inverter 30 connected to the filter circuit 20, and the IGBT pulse width modulation (PWM) according to the load protection and the circuit protection from abnormal occurrence of overload, short circuit, and ground fault. The control supplies stable power to the load side.

The battery 40 is connected to the first b input blocking means 212 to supply an uninterruptible power supply. In the normal state, the power input from the load side is charged in the battery 40, and when the power failure occurs, the battery 40 power can be output to the load side.

The second inverter 50 connected in series with the first inverter 30 converts the battery 40 power into AC power at the time of power failure and outputs the power to the load side, or receives the input power from the load side at the normal time and receives DC power. Is converted to charge to the battery.

In addition, a second transformer 60 is connected in series between the second inverter 50 and the first b output switching means 311. In this case, the second transformer 60 outputs the load-side output power to the second inverter 50 when the power is normally supplied, and outputs the output of the second inverter 50 to the first b output switching means 311 in case of power failure. It is preferable to be able to output to the load-side power supply through.

The first transformer output switch 311 or the first output switch means 312 is connected to an output of the second transformer 60 or the first a input blocking means 211 by a bidirectional SCR. At this time, the first a, 1b output switching means (311, 312) controls the overcurrent of the AC output power flowing to the load side. In addition, the first b output switching means 312 is connected to an output of the first a input blocking means 211 and an output of the first a output switching means 311 in parallel to the output flowing to the load side Detect, measure, and control power.

In addition, the 1a, 1b output switching means (311, 312), if the failure of the transformer, switch, blocking device, rectifier device, charging device and inverter due to failure of the normal operation of the UPS function, the power supply to the load side stably It is desirable to configure bidirectional SCR to provide overcurrent control.

Here, the first a output blocking means 213 connected in series with the output of the first a output switching means 311 outputs an AC output power flowing to the load side.

At this time, a maintenance bypass switch (MBS) is connected in parallel to an input portion of the first a input blocking means 211 and an output portion of the first a output blocking means 213 so that no power is applied to the UE failure. It is preferable to be configured to avoid the operation of the UE in the case of repair or emergency.

In addition, the input voltage Vi and the input current iS at the output of the first a input blocking means 211, the output voltage VO and the output current iP at the load side connection terminal, and the battery 40. ) Is detected by the high speed detector 80 and the high speed detector 80 to detect signals detected by CT and PT at high speed without delay time. Microprocessor 90 for receiving input / output voltage, current and DC voltage, and setting various functions by key input to control uninterruptible control, automatic voltage control (AVR) function, various monitoring, display and protection functions; And a gate driver 70 outputting a signal for PWM control of the first inverter 30 and the second inverter 50 based on the PWM control signal of the microprocessor 90, and various function setting and monitoring control. The operator can control the And a keypad 100 that allows, is configured to display the various states as well as including the LCD (110) for the menu and the set value display in the feature set.

Here, in the drawing, a transformer (PT), a current transformer (CT), and the like for detecting the voltage and current of the input and output terminals are not shown in the drawings, but such detection in a UPS system circuit can be easily understood by those skilled in the art. Since it is a matter, it is omitted for the sake of simplicity of the drawings.

In addition, the SCR of the input switching means 12 is installed on the other power line of the two power lines in parallel with the first transformer 10 so as to control the emergency shutoff by the microprocessor 90.

Meanwhile, the microprocessor 90 controls core functions of the present invention by a program, and the functions are shown in FIG.

The microprocessor 90 controls the first inverter 30 for the AVR function to control the secondary coil of the first transformer 10 through the filter circuit 20 to control the output voltage. The control unit 92, the battery charge control unit 94 for controlling the charging voltage and the charging current of the battery 40, and the line voltage monitoring unit for monitoring the input and output voltage, display control and alarm control thereof 95, a mode setting unit 96 for storing and managing setting values for various modes, control of each unit, and selection of system operation conditions, test operation, alarm control, various protection functions and bypasses. The main control unit 93 for controlling and the PWM signal for the gate control of the first inverter 30 and the second inverter 50 by the control of the main control unit 93 according to the control function of each unit Raised phase The PWM driver 91 outputs the gate driver 70. Each unit refers to the output voltage control unit, the battery charging control unit, the line voltage monitoring unit, and the mode setting unit.

As shown in FIG. 5, when the keypad and the LCDs 100 and 110 are configured as independent controllers, the microprocessor using an 8-bit microcontroller as an input / output controller 120 as shown in FIG. 3. Communication with (90) allows for independent configuration and can be configured to share the microprocessor's key input processing and display control functions.

Referring to the operation and effects of the present invention configured as described above are as follows.

The present invention simultaneously performs the function as an uninterruptible power supply and an AVR function, and operates as a highly efficient high-function online UPS through software main control. In order to maximize the efficiency at the available line voltage, the inverter performs an AVR function that controls the output voltage by the electrostatic voltage while controlling the buffer voltage between the output and the input so that the output power is supplied from the line. The various parameters related to the system are stored in the keypad.

First, the basic flow will be described with reference to the circuits of FIGS. 3 and 5, and the input power source Vi is input through the first a input blocking means 211 and the input switching means 12 to provide the first transformer 10. It is output to the load side through the primary coil. At this time, the voltage and current of the secondary coil of the first transformer 10 are controlled by the filter circuit 20 to control the output voltage Vo to perform the AVR function.

The filter circuit 20 is controlled by the first inverter 30, the first inverter 30 is PWM controlled by the control of the microprocessor 90. At this time, voltage, current, and frequency are controlled by the first inverter 30, and a stable power is supplied to the load side by changing the phase angle of the SCR according to circuit protection and load variation from an abnormal occurrence such as an overload, short circuit, or ground fault. do.

 In this case, only the converted DC voltage passes through the first b input blocking means 212 to charge the battery 40. In this case, the battery 40 is connected to the first b input blocking means 212 to supply an uninterruptible power supply.

That is, when the input power is out of power, the second inverter 50 is controlled by the control of the microprocessor 90 so that the DC power of the battery 40 is converted into AC power, and the second transformer 60 and the first transformer are controlled. It is supplied to the output load side through the 1a output switching means and the 1a output blocking means to operate as an uninterruptible power supply.

The PWM control of the present invention is used for the inverter sinusoidal voltage control, but more complicated in the control method than the conventional bipolar PWM method, but uses a unipolar (unipolar) PWM method that can reduce the ripple voltage by about 2 times, It is controlled by the PWM generator 91 on the internal program of the microprocessor 90 of 4. The sine wave frequency output from the inverter may be set by the keypad 100 and may be operated differently from the line frequency. That is, when the high speed detector 80 detects the input voltage Vi, the frequency is detected by zero crossing of the voltage, and when the input frequency and the output frequency are different, the PWM is controlled according to the set output frequency to automatically output the output frequency. You can tune to the set frequency.

The output voltage control unit 92 controls the function of the automatic voltage regulator (AVR) that matches the measured output voltage with the reference output voltage. The voltage control and output is performed to obtain responsiveness and stability to the load. Perform a current compensation control function, and detects an input voltage and an input current, an output voltage and an output current through the high-speed detector 80 to calculate and match the set output voltage and output current to the first inverter 30. PWM control, and accordingly the voltage and current of the secondary coil of the first transformer 10 is controlled through the filter circuit 20 to compensate for the output voltage and output current to perform the AVR function. .

The battery charging control unit 94 performs floating charging to charge up to a general floating charging voltage and equal charging to charge up to a maximum charging voltage at the time of initial installation or charging after being discharged to a battery low voltage. Limited to the maximum charging current. If the charging current reaches 10% or less of the maximum charging current value during even charging, it enters the floating charging.

The charging current control calculates the effective current based on the difference between the input current and the output current to detect the battery charging current.When charging by limiting to the maximum charging current value and reaching full charge, the charging current is reduced by the constant voltage control function. Charge current responsiveness is determined by the charge control gain. In the temperature compensation of the even charging voltage, if the temperature drops below room temperature, the charging voltage is increased. Temperature compensation at temperatures above room temperature uses positive temperature compensation, and compensation at low temperatures uses negative temperature compensation.

The line voltage monitoring unit 95 determines whether the line voltage is normal or abnormal as a voltage difference from the normal voltage, and when the value is larger than the specified value, the inverters are operated. This is to monitor and control the input voltage, and it is possible to eliminate frequent changes between the line operation and the inverter operation through the hysteresis voltage at the boundary of the line voltage drop when detecting the line voltage.

In detecting whether the line voltage is abnormal, the sensitivity of the line voltage can be desensitized by using the detection time constant of the line voltage. If the frequency of the line voltage is out of the allowable range from the specified value, the inverter is operated without operating the line. The output is sent in voltage.

In other words, voltage monitoring applies the system hysteresis voltage, reduces the frequent change by using the system voltage time constant, and operates only the inverter without operating with the line voltage when it is out of the system abnormal frequency or the system abnormal voltage. Operating only the inverter without operating at the line voltage cuts off the SCR 12 under the control of the microprocessor 90 to block the line voltage, that is, the input voltage from being output to the output load, and to turn off the second inverter 50. This means that it converts the charging power of the battery 40 to AC power to output to the load side output voltage Vo.

The setting unit 96 for each mode is for setting various setting values, and sets and stores various setting values by menu selection of the keypad 100. Then, as a selection function, it is possible to select whether the operating frequency of the system is 60Hz or 50Hz, select whether to operate the system automatically when all the batteries are discharged by the inverter operation and the line voltage is input. Select the operating method of contact terminals (a contact and b contact). In addition, if the gain is not correct when accepting or outputting numerical values from analog data for fine calibration, an error will occur in the processor. Therefore, the gain needs to be readjusted.

This can be adjusted in the fine calibration parameter, where the battery voltage gain is the measurement gain of the battery voltage, the output voltage gain is the measurement gain of the output voltage, the output current gain is the measurement gain of the output current, and the charge current gain is the charge current. The measured gain of the input voltage gain adjusts the measured gain of the input voltage. These variables are displayed on the LCD 120 using the rated output current. As the output voltage gain increases, the value displayed on the LCD increases in line mode and decreases in constant voltage control in inverter mode.

The main controller 93 controls the respective units and controls the PWM generator 91 according to the control function of each unit to execute the main control of the actual UPS system.

In the alarm function, the buzzer does not sound at normal line voltage, and the buzzer sounds when the inverter is operated at abnormal line voltage. The buzzer sounds differently by distinguishing inverter operation, abnormality caused by protection function, and battery low status.

When the inverter is operating, the buzzer sounds, and when the alarm silent switch of the keypad 100 is pressed, the buzzer does not sound without pressing the switch again. In case of an abnormal state, the buzzer will sound continuously. If the overload is not abnormal, the buzzer will sound continuously and if the overload is released, the buzzer will not sound. The buzzer also sounds when the UPS system is stopped.

The protection function controls the battery undervoltage condition, overcurrent, overload, battery fault, and bypass overcurrent as a protection function.

The battery undervoltage generates a battery undervoltage signal if the battery voltage is discharged to 85% of its rated voltage and fails to maintain the output voltage to an acceptable level. At this time, the inverter operates for 30 seconds at maximum. When the line voltage is restored from the battery low voltage, the inverter returns to normal operation.

The over current stops the system in order to protect the inverter when the overcurrent is continuously generated by 300% or more because the output current exceeds the load state in the inverter operation.

Overload is to protect the inverter from overload. If the output current exceeds the accumulated amount up to 1 minute due to the overload set when the rated current is over the rated current, it is recognized as overload.

The battery abnormality generates an abnormal signal and stops the inverter when the battery voltage is discharged to 85% of the rated voltage in the inverter operation. If the input power is applied, the battery will be alarmed even when the battery is open. In this case, the inverter will continue to run and will return to normal when the battery is connected.

Bypass overcurrent causes an output short or fault when operating at line voltage to turn off the bypass switch to protect the bypass switch. The reference value of the abnormal current is an overcurrent value.

Initialization functions include fault initialization, parameter initialization, and system initialization. Fault initialization removes past fault records and prepares them for readiness. Parameter initialization sets all variables or selection functions to their default values. In system initialization, restart the system.

Meanwhile, when the keypad and the LCD are configured as independent controllers, an input / output controller 120 which is an 8-bit microcontroller communicating with the microprocessor 90 may be further configured as shown in FIG. 3. Independently configured keypad and LCD control panel has a state diagram showing the flow of the system at the top as shown in FIG. "Inverter" to indicate the presence of a signal, "Bypass" to supply the input power to the output, "Fault" to indicate that the system is abnormal, and "Overload".

In the LCD 110 configuration, the first line represents the overall situation of the UPS, and the second line represents various internal variables of the UPS. Displays the battery voltage capacity, battery voltage, battery current, output voltage, output current, input voltage, input current, output frequency, temperature, status display and the number of power failures, date and time, and the display selection up and down of the keypad 100 Use keys to read the value.

The "Mode" of the keypad 100 enters or exits a menu and controls the movement of a variable, and the up and down keys change the type and display variables of a variable value and an alarm. To change the off state, "O", "I" means that the menu is selected or the parameter is set, the system is stopped and operated, and the system is restarted in the event of a fault.

In the UPS system of the present invention operated by a microprocessor performing the above functions, line operation, inverter operation, and bypass control are performed, and the state thereof is as shown in FIGS. 6A to 6F.

The normal operation is a line operation mode, in which input power is output to the load side as shown in FIG. 6A, and the secondary coil of the first transformer 10 is controlled by the first inverter 30 through the filter circuit 20. Only the AVR function is controlled, and the normal operation is performed in which the battery 40 is charged by the function of the second inverter 50.

As illustrated in FIG. 6B, the power failure operation is operated as an inverter mode in which the power of the battery 40 is output to the load side by controlling the second inverter 50 when a power failure of the input power is detected.

In the power failure return, as shown in FIG. 6C, the input is output to the load side, and the power fed back from the output is operated as the charging mode to the battery 40 through the second inverter, and the first inverter 30 and the filter circuit are performed. The secondary side of the first transformer 10 is controlled via 20 to return to normal operation with the AVR function.

Bypass, as shown in Fig. 6D, does not control the inverter, that is, the UPS does not operate and controls the bypass function in which the input power is transferred to the load side as it is.

Emergency bypass is a maintenance bypass switch (MBS) is provided in parallel with the UPS system of the present invention, as shown in Figure 6e is to transmit the input power to the load side through the emergency switch, and cut off the SCR It is to prevent the operation of the PS in case of troubleshooting or other emergency.

6F, the input power is automatically output to the load side by the bypass path by not operating the inverter as shown in FIG. 6F, and is operated when it cannot be handled within the system.

Although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the claims to be described below by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents.

1 is a block diagram of a UPS / AVR combined power supply according to the prior art.

2 is a simplified circuit diagram of yet another conventional UPS / AVR combined power supply.

Figure 3 is a configuration of a UPS system showing an embodiment according to the present invention.

4 is an internal functional block diagram of the microprocessor of FIG.

5 is a simplified circuit diagram of an uninterruptible power supply system of a UPS system according to the present invention.

6A to 6F are explanatory diagrams showing power flow paths for respective operation modes of the UPS system according to the present invention;

Figure 7 is an exemplary control panel of the keypad and LCD of the UPS system according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: first transformer 12: input switching means

20: filter circuit 30: first inverter

40: battery 50: second inverter

60: second transformer 70: gate driver

80: high speed detection unit 90: microprocessor

91: PWM generator 92: Output voltage controller

93: main controller 94: battery charge control unit

95: line voltage monitoring unit 96: mode setting unit

100: keypad 110: LCD

120: input / output controller 211: 1a input blocking means

212: 1b input blocking means 213: 1a output blocking means

214: first b output blocking means 311: first a output switching means

312: 1b output switching means

Claims (5)

First and second input blocking means connected to the KEPCO power supply or the battery to apply AC or DC input power; Input switching means configured to be connected in series with an output of the first blocking input means, the bidirectional SCR configured to control an overcurrent of the input power; A first transformer outputting the input power input through the input switching means to the load side through the primary coil, and controlling the output by passing the primary coil by the input of the input switching means to output to the load side; A filter circuit for controlling the output to the input of the first transformer by controlling the voltage / current of the secondary coil of the first transformer; It is connected to the output part of the filter circuit to control voltage, current and frequency, and to supply stable power to the load side by IGBT pulse width modulation (PWM) control according to the load protection and the circuit protection from abnormal occurrence of overload, short circuit and ground fault. A first inverter; A battery connected to the first b input blocking means for supplying uninterruptible power; A second inverter for converting the battery power into an AC power and outputting it to a load side during power failure, or receiving the input power from the load side in normal operation, converting the battery power into a DC power, and charging the battery; Connected between the second inverter and the 1b output switching means for outputting the load side output power to the second inverter side during normal power supply, and outputting the output of the second inverter to the load side power through the first b output switching means during power failure. A second transformer; First and second output switching means for controlling an overcurrent of an AC output power flowing to the load side by connecting a bidirectional SCR to an output of the second transformer or the first a input blocking means; First a output blocking means connected in series with an output of said first switching output means and outputting an AC output power flowing to said load side; Maintenance bypass switch (MBS) is connected in parallel to the input portion of the input blocking means 1a and the output of the output blocking means 1a to prevent the power supply from being applied at all, thereby avoiding the operation of the U.S. troubleshooting or emergency operation. 1b output blocking means for; An input voltage Vi and an input current iS are detected at the rear end of the input switching means, an output voltage VO and an output current iP are respectively detected at the load side connection terminal, and a DC voltage Vd is detected at the battery. A high speed detection unit for detecting a signal detected using a current transformer (CT) and a potential transformer (PT) at high speed without a delay time by a resistance circuit; Receiving input / output voltage and current and DC voltage detected by the high speed detector, and setting various functions by key input to control uninterruptible control, automatic voltage control (AVR) function, and various monitoring, display and protection functions. A microprocessor for; A gate driver configured to output a pulse width modulation (PWM) control signal of the first inverter and the second inverter based on a pulse width modulation (PWM) control signal of the microprocessor; A keypad for operating by a driver for various function setting and monitoring control and set value control; And Micro-controllers that share key input processing and display control functions as input controllers and output controllers, including a display (LCD) for displaying various statuses and displaying menus and setting values at the time of function setting. And communicate with a processor, wherein the keypad and display (LCD) are configured as independent controllers. The method of claim 1, The microprocessor, An output voltage controller for controlling the output voltage by controlling the first inverter for controlling an automatic voltage control (AVR) function and controlling the secondary side of the first transformer through a filter circuit; A battery charging control unit controlling a charging voltage and a charging current of the battery; A line voltage monitoring unit configured to monitor input and output voltages and display and control alarms thereof; A mode setting unit for storing and managing various mode setting values; A main control unit for controlling the output voltage control unit, the battery charging control unit, the line voltage monitoring unit and the mode setting unit, as well as selecting a system operation condition, an alarm control, various protection functions, and bypass; And Pulse width modulation for gate control of the first inverter and the second inverter by control of the main controller according to a control function of the output voltage controller, the battery charging controller, the line voltage monitoring unit and the mode setting unit. And a pulse width modulation (PWM) signal generation unit for generating a (PWM) signal and outputting the signal to the gate driver. delete The method of claim 1, The 1b output switching means detects, measures, and controls output power flowing to the load side by connecting a bidirectional switch in parallel to an output of the first a input blocking means and an output of the first a output switching means. Igity UPS system. The method of claim 1, The 1a, 1b output switching means is composed of a bidirectional SCR to stably supply power to the load side when the UPS function does not operate normally due to a failure of a transformer, a switch, a blocking device, a rectifying device, a charging device, and an inverter. IGBS system, characterized in that for controlling the over-current.

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