KR101425141B1 - Transformerless uninterruptible power supply including energy stoarge function - Google Patents

Abstract

The present invention relates to a transformerless uninterruptible power supply including an energy storage function including a three-phase rectifier; a three-phase inverter; a DC-DC converter for converting power generated from a solar cell into a stable DC power; a charging/discharging unit to charge/discharge a battery; a mode controller to control an operation for 24 hours a day by changing a mode in an order of a first mode, a second mode, a third mode, and a fourth mode, to provide DC power of the three-phase rectifier to a load side and the battery in the first mode, to provide power of the solar cell and the DC power of the three-phase rectifier to the load side and the battery in the second mode, to provide the power of the solar cell and power of the battery to the load in the third mode, and to provide power of the battery to the load in the fourth mode.

Description

TECHNICAL FIELD [0001] The present invention relates to a transformer-type uninterruptible power supply having an energy storing function,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an uninterruptible power supply (UPS) that does not use a transformer, and to an uninterruptible power supply having an energy storage system (ESS) function.

An uninterruptible power supply (UPS) is an emergency power supply that continuously supplies power to a load in case the power supply to the load is not provided, such as a power outage or an internal electric circuit voltage is cut off. Among these uninterruptible power supply units, the transformer type UPS has advantages of the light load and the rated operation efficiency compared with the transformer type UPS.

Meanwhile, the energy storage system (ESS) is a system that aims to reduce power cost and to use energy efficiently by storing the commercial power in the battery such as lithium ion, nickel, lead accumulator battery, to be.

The uninterruptible power supply and the energy storage system are designed and used independently of each other according to the purpose of use.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transformer-type uninterruptible power supply having an energy storage function that integrates the functions of the uninterruptible power supply and the functions of the energy storage system.

It is another object of the present invention to provide a transformer-type uninterruptible power supply having an energy storage function that maximizes operation efficiency and provides cleaner sinusoidal waves to a load while performing the function of an energy storage system.

According to an aspect of the present invention, there is provided a transformer-type uninterruptible power supply having an energy storage function. The uninterruptible power supply unit is a three-phase rectifier that converts an AC input power supplied from the system to DC power and outputs the DC power to an AC power source to convert the DC power into an AC power and discharges the power to the system. Phase inverter, a DC-DC converter for converting a power generated in the solar cell into a stable DC voltage, an output terminal of the three-phase rectifier, an output terminal of the DC-DC converter, and an input terminal of the three- A charging unit for charging the battery with the DC voltage and discharging the voltage of the battery, a solar radiation amount measuring unit for measuring the solar radiation amount, a battery remaining amount measuring unit for measuring the remaining amount of the battery, The amount of solar radiation provided by the battery remaining amount measuring unit And performs a power supply control for 24 hours a day by individually performing at least one of the second battery charging mode, the first battery discharge mode, and the second battery discharge mode according to the comparison, The DC power of the three-phase rectifier is supplied to the load and the battery in the first battery charging mode, and the DC power of the solar battery and the DC power of the three- The power of the solar cell and the power of the battery are supplied to the load during the first battery discharge mode and the power of the battery is supplied to the load during the second battery discharge mode, And a mode control unit.

Wherein the three-phase three-level rectifier is a three-phase three-level PWM rectifier, and the three-phase three-level PWM rectifier and the three-phase three-level PWM inverter are four- 3-level inverter bridges are configured in parallel to generate 3-phase 4-wire output voltage.

Phase three-phase PWM rectifier, recognizes an error of the DC voltage output from the three-phase three-level PWM rectifier and an input current of each of three phases, A DC voltage and an input power factor controller for providing a PWM signal to the switching elements of the three-phase three-level PWM rectifier using an error of each of the input current and the DC voltage; Phase three-level PWM inverter and an error of the AC voltage output by the three-phase three-level PWM inverter and a DC voltage input to the three-phase three-level PWM inverter, And an output voltage controller for providing the PWM signal to the switching elements of the three-phase three-level PWM inverter.

Wherein the DC voltage and input power factor controller comprises: a phase detector for detecting a phase and phase change of the AC input power source and outputting a sine value; a DC voltage output controller for outputting a DC voltage control command value A DC voltage controller for detecting a first error value and outputting a current command value of each phase corresponding to a first error value, A plurality of phase current controllers for calculating a duty control amount corresponding to a command value, and a plurality of phase rectification circuits for providing a PWM signal to the four switching elements of each phase constituting the three-phase three-level PWM rectifier, And a PWM generator.

Each of the plurality of phase rectification PWM generators includes a three-level pulse width modulator for receiving duty information received from the phase current controller and generating on / off information, which is a duty value corresponding to the duty information, And a switching signal generator for setting a dead time between the switching elements and outputting the PWM signal as an ON or OFF signal to each switching element in accordance with the on or off information based on the set dead time .

Wherein the output voltage controller comprises: a phase detector for detecting a change in phase and phase of the AC input power and outputting a sine value; And the duty information corresponding to the error of the alternating voltage is calculated by comparing the detected value of the direct current voltage and the detected load current value of the corresponding phase with the output voltage control command value on the corresponding phase A plurality of inverter output voltage controllers for receiving and outputting the duty information and setting a dead time between the switching elements, and switching on / off the switching elements according to the duty information on the basis of the set dead time, And a switching signal generator for outputting the PWM signal.

The sine value of the phase detector reflects the first compensation phase due to the delay component of the PLL circuit in the phase detected using the PLL circuit.

According to the present invention, the uninterruptible power supply includes a phase compensator that receives a sine value of the phase detector, corrects a sine value of the phase detector according to the load current, and provides a corrected sine value to the inverter output voltage controller .

In the above, the mode controller sets the first battery charge mode to the first time in the night time zone.

Wherein the mode control unit keeps the first battery charging mode when the current sunshine amount is less than the set amount and the remaining amount of the battery is less than the set value while one mode is set and the current sunshine amount is less than the set amount Sets the second battery charging mode when the remaining amount of the battery is equal to or greater than the set value and sets the second battery charging mode when the current amount of sunshine is equal to or greater than the set amount and the remaining amount of the battery is equal to or less than the set value, And sets the first battery discharge mode when the present amount of sunshine is equal to or greater than the preset amount and the remaining amount of the battery is equal to or greater than the set value.

The mode control unit sets the power failure mode when the AC input power is not applied from the system, and provides at least one of the power of the battery and the power of the solar cell to the load. When an internal failure occurs, an internal failure mode is set Bypasses the AC input power supplied from the system to the load side through the first power supply line and bypasses the load side through the second power supply line when the manual bypass operation mode is set.

According to the embodiment of the present invention, by integrally providing the UPS function and the ESS function by using one transformer-type uninterruptible power supply unit, by separately configuring the two devices, it is possible to reduce the cost incurred and maximize the efficiency Let's do it. Also, according to the embodiment of the present invention, the use of the three-phase three-level rectifier and the three-phase three-level inverter maximizes the operating efficiency and minimizes the filter capacity on the input side and the output side.

1 is a block diagram of a transformer-type uninterruptible power supply according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a main function related configuration of a transformer-type uninterruptible power supply apparatus having an energy storing function according to an embodiment of the present invention.
3 is a circuit diagram of a DC voltage and input power factor controller of an uninterruptible power supply unit having an energy storage function according to an embodiment of the present invention.
4 is a circuit diagram of an output voltage controller of an uninterruptible power supply unit having an energy storage function according to an embodiment of the present invention.
FIG. 5 is a power flow chart of a first battery charging mode of a transformer-type uninterruptible power supply unit having an energy storing function according to an embodiment of the present invention.
6 is a power flow diagram of a second battery charging mode of the transformerless uninterruptible power supply unit having an energy storing function according to the embodiment of the present invention.
FIG. 7 is a power flow diagram of a first battery discharge mode of a transformer-type uninterruptible power supply apparatus having an energy storing function according to an embodiment of the present invention.
FIG. 8 is a power flow diagram of a second battery discharge mode of a transformerless uninterruptible power supply having an energy storage function according to an embodiment of the present invention.
9 is a power flow diagram of an uninterruptible power supply apparatus having an energy storage function according to an embodiment of the present invention.
10 is a power flow diagram of an internal failure mode of a transformerless uninterruptible power supply having an energy storage function according to an embodiment of the present invention.
11 is a power flow diagram of a passive bypass operation mode of a transformer-type uninterruptible power supply having an energy storage function according to an embodiment of the present invention.
12 is a flowchart illustrating an operation of an uninterruptible power supply unit having an energy storage function according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Hereinafter, an uninterruptible power supply using a three-level power converter according to an embodiment of the present invention will be described with reference to the accompanying drawings.

Hereinafter, a transformer-type uninterruptible power supply having an energy storing function according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram of a transformer-type uninterruptible power supply having an energy storage function according to an embodiment of the present invention. 1, a transformer-type uninterruptible power supply apparatus 100 having an energy storing function according to an embodiment of the present invention includes a three-phase rectifier 110, a three-phase inverter 120, a charging unit 130, The first filter 140a, the second filter 140b, the DC voltage and input power factor controller 150, the output voltage controller 160, the DC-DC converter 170, the irradiation amount measuring unit 180a, (180b), and a mode control unit (190).

The uninterruptible power supply unit 100 having the energy storing function according to the embodiment of the present invention includes first to third switches SW1 to SW4 for selectively operating the UPS function and the ESS function.

The first switch SW1 is located between the grid (AC grid) 21 and the first filter unit 140a and the second switch SW2 is located between the PV (Photovoltaic) panel The third switch SW3 is located on the bypass line PATH2 for bypassing the commercial power supply of the system 21. The third switch SW3 is located between the solar cell 22 and the DC-

The three-phase rectifier 110 converts the AC input power (commercial power) input from the system 21 to DC power and outputs the DC power to the inverter 120. If necessary, the DC power supplied from the battery 200 is supplied to the AC power source Transforms the power to the system. The three-phase three-level rectifier 110 may be a three-phase three-level PWM (Pulse Width Modulation) rectifier. In the case of the three-phase three-level PWM rectifier 110, And a switching element, and reduces the harmonic components in the AC side currents (Ia, Ib, Ic).

The three-phase inverter 120 converts the input DC power into AC power and supplies it to the load side, or converts the DC power of the battery 200 provided from the charging unit 130 into AC power and supplies it to the load side. The three-phase inverter 120 may be a three-phase three-level PWM inverter, and includes a plurality of switching elements whose ON and OFF operations are controlled in accordance with a PWM switching operation in the case of a three-phase three-level PWM, The harmonic content is made into a voltage waveform having a low content, that is, a waveform close to a sinusoidal wave.

The charging and discharging unit 130 is coupled to the output terminal of the three-phase rectifier 110, the output terminal of the DC-DC converter 170, and the input terminal of the three-phase inverter 120, The battery 200 is charged or discharged. More specifically, the charging unit 130 is electrically coupled to the system 21 and the solar cell 22 to charge the battery by inputting a DC voltage from at least one of the system 21 and the solar cell 22, So that the voltage of the battery 200 is discharged to be provided to the load side.

The first filter 140a removes the noise included in the voltage waveform input to the three-phase three-level PWM rectifier 110 and the second filter 140b removes noise included in the voltage waveform input to the three- To remove noise such as harmonics included in the signal to provide a clean sine wave to the load. At this time, the AC power generated by the three-phase three-level PWM inverter 120 is an AC voltage waveform having a small harmonic component, so that the capacities of the reactors L4, L5 and L6 included in the second filter 140b can be minimized .

The DC voltage and input power factor controller 150 controls the DC voltage and the input power factor of the three-phase three-level PWM rectifier 110. The DC voltage and input power factor controller 150 detects the phase of three phases (U phase, V phase, W phase) from the commercial voltage inputted to the three-phase three-level PWM rectifier 110, Phase three-level PWM rectifier 110 by using the three-phase phase of the commercial voltage and the error between the input current and the DC voltage, detects the error of the DC voltage output from the three-phase three-phase PWM rectifier 110, And controls the power conversion operation of the three-phase three-level PWM rectifier 110 by providing PWM signals to the plurality of switching elements.

The output voltage controller 160 detects phases of three phases (U-phase, V-phase, W-phase) at a commercial voltage and detects an error of the AC voltage output by the three- Phase three-level PWM inverter (120) by using the three-phase phase of the commercial voltage and the error between the input voltage and the output voltage to provide a PWM signal for the plurality of switching elements constituting the three- 120 in accordance with the control signal.

The DC-DC converter 170 converts a DC voltage provided by a PV (Photovoltaic) panel, that is, the solar cell 22, into a stable DC voltage and outputs the DC voltage. That is, the DC-DC converter 170 boosts or reduces the DC voltage provided by a photovoltaic (PV) panel, that is, the solar cell 22, to provide the battery 200 or the load side.

The solar radiation amount measuring unit 180a measures the amount of sunlight, that is, the solar radiation amount provided from the sun, and provides the solar radiation amount measured to the mode control unit 190. The battery remaining amount measuring unit 180b measures the remaining amount of the battery 200 and provides the measured remaining amount of the battery to the mode control unit 190. [ Here, the remaining amount of the battery is the battery voltage or the state of charge (SOC) of the battery with respect to the full charge.

The mode control unit 190 controls the turn-on / off of the switches SW1 to SW4 and controls charging or discharging of the battery 200 so that the ESS function and the UPS function are performed. At this time, the mode control unit 190 changes the driving mode by using the solar radiation amount measured by the irradiation amount measuring unit 180a and the remaining amount of the battery measured by the battery remaining amount measuring unit 180b at the time of performing the ESS function, And selectively turns on / off each of the switches SW1 to SW4.

FIG. 2 is a circuit diagram of a main function related configuration of a transformer-type uninterruptible power supply apparatus having an energy storing function according to an embodiment of the present invention. 2, the transformer-type uninterruptible power supply apparatus 100 having an energy storage function according to an embodiment of the present invention includes a three-phase three-level PWM rectifier 110 and a three-phase three-level PWM inverter 120, It is used as a converter.

The first filter 140a is located at the input end of the three-phase three-level PWM rectifier 110 and the second filter 140b is located at the output end of the three-phase three-level PWM inverter 120. Each of the first and second filter units 140a and 140b is composed of three LC filters each composed of a reactor and a capacitor and one LC filter is formed on one of three phases (U phase, V phase, W phase) .

Here, the first and second filter units 140a and 140b and the charge / discharge unit 130 are circuits commonly used in an uninterruptible power supply, so a detailed description of the operation will be omitted.

The three-phase three-level PWM rectifier 110 comprises three three-level inverter bridges constituted by T-shaped four IGBT switching elements T11 to T14, T21 to T24 and T31 to T34 in parallel to form a three-phase four- It is a rectifier that can generate voltage output. Specifically, the three-phase three-level PWM rectifier 110 converts the input three-phase currents Ia, Ib, and Ic into a sinusoidal wave, that is, a sinusoidal wave through PWM control, converts the input AC voltage into a DC voltage, do.

At this time, the switching element T11 and the switching element T13 of the U-phase switching elements T11 to T14 complement each other, and the switching element T12 and the switching element T14 complement each other to supply the input U-phase AC voltage to three Level PWM voltage having a voltage level (+ Vdc / 2, 0, -Vdc / 2) (see A in FIG. 3). Here, the complementary operation refers to a switching operation in which when one switching element is turned on, the other switching element is turned off.

The switching element T21 and the switching element T23 of the V-phase switching elements T21 to T24 complement each other and the switching element T22 and the switching element T24 complementarily operate to convert the input V-phase AC voltage into three voltages Level PWM voltage having a level (+ Vdc / 2, 0, -Vdc / 2) (see A in FIG. 3).

The switching element T31 and the switching element T33 of the W-phase switching elements T21 to T24 complement each other, and the switching element T32 and the switching element T34 operate complementary to each other to reduce the input W-phase AC voltage to 3 Level PWM voltage having two voltage levels (+ Vdc / 2, 0, -Vdc / 2) (see A in FIG. 3).

As shown in Table 1, the three-phase three-level PWM rectifier 110 has eight switching modes according to the operation of each switching device. In the switching operation except Table 1, the switching device is damaged, . When three such three-level inverter bridges are arranged in parallel, a three-phase rectifier capable of independently controlling the three-phase four-wire output current is possible. In Table 2, a U-phase switching device as a representative among three phases is described as an example.

Switching
device Switching mode  0 Switching mode  One Switching mode  2 Switching mode  3 Switching mode  4 Switching mode  5 Switching mode  6 Switching mode  7 T ₁₁ OFF ON OFF OFF OFF ON OFF OFF T ₁₂ OFF OFF ON OFF OFF ON ON OFF T ₁₃ OFF OFF OFF ON OFF OFF ON ON T ₁₄ OFF OFF OFF OFF ON OFF OFF ON

Next, the three-phase three-level PWM inverter 120 comprises three three-level inverter bridges constituted by T-shaped four IGBT switching elements (T41 to T44, T51 to T54, and T61 to T64) It is an inverter that can generate line-type output voltage. In the switching elements T41 to T44 for generating the A-phase voltage, the switching element T41 and the switching element T43 complement each other and the switching element T42 and the switching element T44 complement each other to generate three voltage levels + Vdc / 2, 0, -Vdc / 2).

The A-phase 3-level PWM voltage generated by such a switching operation is converted to a sine-wave voltage Va through an A-phase LC filter composed of a reactor L4 and a capacitor C4 and supplied to the load. The B-phase and C-phase PWM voltages are generated by the switching elements T51 to T54 and the switching elements T61 to T64, respectively, and the sinusoidal voltages Va and Vc are generated through the B- and C-phase LC filters L5, L6, Respectively, and supplied to the load.

The three-phase three-level PWM inverter 120 has eight switching modes according to the operation of each switching device as shown in Table 2. In the switching operation except Table 2, the switching device is damaged, . When three such three-level inverter bridges are arranged in parallel, a three-phase inverter configuration capable of independently controlling the three-phase four-wire output voltage is possible. In Table 2, a U-phase switching device as a representative among three phases is described as an example.

Switching
device Switching mode  0 Switching mode  One Switching mode  2 Switching mode  3 Switching mode  4 Switching mode  5 Switching mode  6 Switching mode  7 T ₄₁ OFF ON OFF OFF OFF ON OFF OFF T ₄₂ OFF OFF ON OFF OFF ON ON OFF T ₄₃ OFF OFF OFF ON OFF OFF ON ON T _A44 OFF OFF OFF OFF ON OFF OFF ON

3 is a circuit diagram of a DC voltage and input power factor controller of an uninterruptible power supply unit having an energy storage function according to an embodiment of the present invention. 3, the DC voltage and input power factor controller 150 includes a phase detector 151, a DC voltage controller 152, a plurality of phase current controllers 153, 155, 157, and a plurality of phase rectifier PWMs Generator 154, 156, and 158, respectively.

The phase detector 151 detects the phase and phase change of the input voltage, that is, the commercial voltage. To this end, the phase detector 151 detects the phase or angle (theta) of the commercial voltage through the PLL circuit, compensates the compensation angle considering the time delay of the PLL circuit with the detected angle, and generates a sine value sinwt including the phase information. .

The DC voltage controller 152 controls the DC voltage Vdc and the DC voltage control command value (reference value, Vdc_ref) to maintain the DC voltage Vdc of the three-phase three-level PWM rectifier 110 at a constant DC voltage. And outputs the error values to the three-phase current command values Ia_ref, Ib_ref, and Ic_ref through the PI (proportional integration) controller 152a. The current command value is a current adjustment value to be controlled so that the DC voltage Vdc becomes the DC voltage control command value.

The plurality of phase current controllers 153, 155, and 157 respectively calculate a duty control amount corresponding to the current command value of the corresponding phase. To this end, each of the phase current controllers 153, 155 and 157 receives the current command values (Ia_ref, Ib_ref, Ic_ref) of the phase provided by the DC voltage controller 152 and outputs the received current command values to the input current detection The error value is compared with the values Ia, Ib, and Ic, and the duty command value corresponding to the error value is obtained through the PI controller 153a. Each of the phase current controllers 153, 155, and 157 then calculates a voltage command value by multiplying the duty command value by the phase of the input voltage detected by the phase detector 151, and outputs the voltage command value through the duty calculator 153b And outputs duty information corresponding to the duty ratio. Here, the duty information is provided as a duty control amount, for example, in the form of a sine wave.

Each of the plurality of phase rectification PWM generators 154, 156 and 158 provides ON and OFF signals, that is, PWM signals, to the switching elements (i.e., a plurality of IGBTs) of the respective phases of the three-phase three-level PWM rectifier 110 . To this end, each of the plurality of phase rectification PWM generators 154, 156, 158 includes a three-level pulse width modulator 154a and a switching signal generator 154b. Each of the three-level pulse width modulators 154a receives the duty information received from the phase current controllers 153, 155 and 157 and generates on or off information (e.g., D11 to D14) that is a duty value corresponding to the duty information And provides it to the switching signal generator 154b.

The switching signal generator 154b receives the received on or off information to set an on-time interval (i.e., dead time) between the switching elements, and sets the on- Or a PWM signal which is an OFF signal.

4 is a circuit diagram of an output voltage controller of an uninterruptible power supply unit having an energy storage function according to an embodiment of the present invention. 4, the output voltage controller 160 includes a bypass phase detector 161, a phase compensator 162, a plurality of inverter output voltage controllers 163, 165, 167, a plurality of inverter PWM generators 164, 166, 168).

The phase detector 161 detects an input voltage, that is, a phase and phase change of the commercial voltage. For this purpose, the phase detector 161 detects the phase or angle (theta) of the commercial voltage through the PLL circuit, compensates the compensation angle considering the time delay of the PLL circuit with the detected angle, and generates a sine value sinwt including the phase information. . The phase compensator 162 reflects the current Io on the load side from the phase detector 161 using the phase shifter 161 and outputs the corrected sine value sinwt1.

Most of the computer equipment includes a condenser input type power supply device, and at the same time, a large impulsive shock current flows instantaneously when the power is applied, and the phase compensator 162 compensates for this. The phase compensator 162 detects the load current Io and detects the difference from the overcurrent protection value, and outputs a sine value sinwt1 including the phase information in proportion thereto.

The plurality of inverter output voltage controllers 163, 165, and 167 control the output voltage of the three-phase three-level PWM inverter 120, that is, the three-phase AC voltage to have a predetermined magnitude and phase. For this purpose, each of the plurality of inverter output voltage controllers 163, 165, and 167 detects an error value by comparing the AC output voltage (i.e., detection value) of the corresponding phase with the output voltage control command value on the corresponding phase, (Proportional integration) controller 163a to generate and output voltage command values for each of the three phases. At this time, a limiter 163b for limiting the threshold value is provided at the output terminal of the PI controller 163a so that only the value within the set range of the current command value is outputted.

The voltage command value passed through the limiter 163b is calculated with the output of the phase compensator to calculate the voltage command value to be duty-controlled, and the duty information corresponding to the voltage command value is output through the duty calculator 163c. Here, the duty information is provided in the form of a sine wave, for example.

Each of the plurality of inverter PWM generators 164, 166 and 168 provides ON and OFF signals, that is, PWM signals, to the switching elements of the inverters of the respective phases constituting the three-phase three-level PWM rectifier 110. To this end, each of the plurality of inverter PWM generators 164, 166, 168 includes a three-level pulse width modulator 164a and a switching signal generator 164b. Each of the three-level pulse width modulators 164a receives the duty information received from the inverter output voltage controllers 163, 165 and 167 and outputs on / off information (e.g., D41 to D44) as duty values corresponding to the duty information And provides it to the switching signal generator 154b.

The switching signal generator 164b receives the received duty information and sets an ON time interval (i.e., dead time) between the switching elements. Based on the set dead time, the switching signal generator 164b turns ON or OFF And outputs a PWM signal as a signal.

Hereinafter, a method of operating an ESS according to an embodiment of the present invention will be described with reference to FIGS. 5 to 12.

The mode control unit 190 sets the first battery charging mode when entering the night time electricity time zone (S1201). Domestic daylight hours are from 10:00 am to 8:00 pm (sometimes from 11:00 am to 9:00 pm). Therefore, the mode controller 190 sets the first battery charging mode to PM 10:00 (or PM 11:00).

When the first battery charging mode is set, the mode controller 190 performs a power control operation according to the first battery charging mode as shown in FIG. 5 (S1202).

The mode control unit 190 turns off the second switch SW2 to shut off the power supply to the solar cell 22 and then turns on the first switch SW1 So that the commercial power source of the system 21 is supplied to the load and the charging and discharging unit 130 through the three-phase rectifier 110. Accordingly, the DC power source of the three-phase rectifier 110 partially charges the battery 200 through the charging unit 130 and a part of the DC power is supplied to the load.

When the mode control unit 190 sets the first battery charging mode, the mode control unit 190 receives the solar radiation amount from the irradiation amount measurement unit 180a and receives the remaining battery amount from the remaining battery amount measurement unit 180b to grasp the current solar radiation amount and the remaining amount of the battery S1203), the current solar radiation amount is compared with a set amount set in S1204, and it is determined whether the remaining amount of the battery is equal to or larger than a set value (S1217).

The mode control unit 190 continues to maintain the first battery charging mode when the current solar irradiation amount is smaller than the set amount and the remaining battery amount is smaller than the set value and releases the first battery charging mode when the current solar irradiation amount is larger than the set amount , The second battery charging mode is set (S1205).

When the second battery charging mode is set, the mode control unit 190 performs a power control operation according to the second battery charging mode as shown in FIG. 6 (S1206).

The mode control unit 190 maintains the first switch SW1 in a turned-on state so that the commercial power of the system 21 is supplied to the load through the three-phase rectifier 110, And the second switch SW2 is turned on to charge the battery 200 with the power of the solar cell 22.

Then, the mode control unit 190 sets the second battery charging mode and determines the remaining battery level and the current solar radiation amount according to the information received from the irradiation amount measurement unit 180a and the remaining battery level measurement unit 180b (S1207) (Step 1208). If the current set amount is equal to or greater than the set amount, it is determined whether the remaining amount of the battery is greater than the set value (1209). If the current set amount is equal to or less than the set amount, (S1218).

If it is determined that the residual amount of the battery is equal to or greater than the set value and the solar radiation amount is equal to or greater than the preset amount, the mode control unit 190 releases the second battery charging mode and sets the first battery discharge mode. If the remaining amount of the battery is less than the set value, the mode control unit 190 maintains the second battery charging mode if the current solar irradiation amount is equal to or greater than the preset amount. Also, the mode control unit 190 sets the first battery setting mode when the solar radiation amount is less than the preset amount and the remaining amount of the battery is less than the set value.

When the second battery discharge mode is set, the mode control unit 190 performs power supply control according to the second battery discharge mode as shown in FIG. 7 (S1211).

 Specifically, the mode control unit 190 causes the charging unit 130 to operate in the discharging mode with the first switch SW1 turned off and the second switch SW2 turned on. Thus, the supply of commercial power to the system 21 is interrupted, the DC voltage provided by the solar cell 22 is supplied to the load side, and the DC voltage of the battery 200 is supplied to the load side. At this time, if the power of the battery 200 is not sufficient or the power of the solar cell 22 is insufficient and the power supplied to the load is insufficient, the mode control unit 190 turns on the first switch SW1 to turn on the system 21 ) To be supplied to the load.

When the first battery discharge mode is set, the mode control unit 190 performs the power supply control shown in FIG. 7, and also grasps the current solar radiation amount through the solar radiation amount received from the irradiation amount measurement unit 180a (S1212) It is determined whether the solar radiation amount is less than the set amount (S1213).

If the current solar radiation amount is less than the set amount, the mode control unit 190 cancels the first battery discharge mode and sets the second battery discharge mode (S1214).

If it is determined in step S1208 that the battery remaining amount is equal to or greater than the set value or the current solar irradiance is less than the preset amount, the mode control unit 190 sets the second battery discharge mode in step S12014.

When the second battery discharge mode is set, the mode control unit 190 performs power supply control according to the second battery discharge mode as shown in FIG. Specifically, when the second battery discharge mode is set, the mode control unit 190 turns off the first and second switches SW1 and SW2, and causes the charge / discharge unit 130 to operate in the discharge mode. The supply of the commercial power supply of the system 21 and the DC voltage provided by the solar battery 22 is interrupted and the DC voltage of the battery 200 is supplied to the load. At this time, the mode controller 190 turns on the first switch SW1 to supply the commercial power of the system 21 to the load when the power of the battery 200 is not sufficient and the power supplied to the load is insufficient.

Meanwhile, the mode control unit 190 continuously monitors the current time to determine whether the current time has entered the night time zone. That is, the mode control unit 190 determines whether the current time is PM 11:00 (or PM 10:00) (S1216).

The mode control unit 190 sets the first battery charging mode when it determines that the current time has entered the night time zone, and keeps the current mode if it has not yet entered the night time zone.

The mode control unit 190 sets the power failure mode when the power is not supplied to the device 100 due to the pruning during each mode for the ESS operation, So that the load can be normally supplied with power. Of course, when the commercial power is normally supplied from the system 21, the mode control unit 190 cancels the power failure mode.

When the internal failure of the UPS 100 occurs and the power fails to be supplied to the load via the three-phase rectifier 110 and the three-phase inverter 120, the mode controller 190 sets the internal failure mode And turns off the switch CSR1 located between the three-phase inverter 120 and the load side, and turns on the third switch located on the power supply line PATH1 to bypass the commercial power load side of the system 21 .

In the case of maintenance work or the like, the mode control unit 190 sets the manual bypass mode, turns off the first switch SW1, and turns on the fourth switch SW4 located on the bypass power supply line PATH2 And the commercial power of the system 21 is bypassed to the load side.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

110: Three-phase rectifier 120: Three-phase inverter
130: a charging part 140a: a first filter part
140b: second filter unit 150: DC voltage and input power factor controller
160: Output voltage controller 170: DC-DC converter
180a: a solar radiation amount measurement unit 180b:
190: mode control unit 21:
22: Solar cell 200: Battery

Claims (11)

A three-phase three-level PWM rectifier for converting an AC input power supplied from the system into a DC power and outputting it, converting the DC power to an AC power and discharging power to the system,
A three-phase three-level PWM inverter that converts DC power to AC power and supplies the AC power to the load;
A DC-DC converter that converts the power generated from the solar cell into a stable DC voltage,
Phase three-level PWM rectifier, an output terminal of the DC-DC converter, and an input terminal of the three-phase three-level PWM inverter, the charging unit charging the battery with the input DC voltage and discharging the voltage of the battery ,
A radiation amount measuring unit for measuring the radiation amount,
A battery remaining amount measuring unit for measuring a remaining amount of the battery,
A first battery charging mode is set at a predetermined time, a current solar irradiance provided by the irradiation amount measuring unit and a remaining battery amount provided by the remaining battery power measuring unit are compared with a set set value, 1 < / RTI > three-level PWM rectifier during the first battery charging mode by performing at least one of the first battery discharge mode, the second battery discharge mode and the second battery discharge mode, Phase three-level PWM rectifier to be supplied to the load and the battery during the second battery charging mode, and to supply the DC power of the three-phase three-level PWM rectifier to the load and the battery during the second battery charging mode, The power source of the solar cell and the power source of the battery are provided to the load in the battery discharge mode, Mode control unit for the power to be provided to the load Li,
Phase three-phase PWM rectifier, recognizes an error of the DC voltage output from the three-phase three-level PWM rectifier and an input current of each of three phases, A DC voltage and an input power factor controller for providing a PWM signal to the switching elements of the three-phase three-level PWM rectifier using the respective input currents and the error of the DC voltage, and
Phase three-level PWM inverter, and recognizes an error of the AC voltage output by the three-phase three-level PWM inverter and a DC voltage input to the three-phase three-level PWM inverter, An output voltage controller for providing a PWM signal to the switching elements of the three-phase three-level PWM inverter using the error of the AC voltage and the DC voltage,
/ RTI >
The three-phase three-level PWM rectifier and the three-phase three-level PWM inverter have an energy storage function capable of generating three-phase four-wire output voltages by arranging three three-level inverter bridges constituted by four switching elements in a T- Non - transformer type uninterruptible power supply. delete delete The method of claim 1,
The DC voltage and input power factor controller
A phase detector for detecting a change in phase and phase of the AC input power and outputting a sine value,
And a DC voltage control command value output from the three-phase three-level PWM rectifier is compared with a DC voltage control command value to detect a first error value, and a DC voltage to output a current command value of each phase corresponding to the first error value The controller,
A plurality of phase current controllers each for calculating a duty control amount corresponding to a current command value of the corresponding phase using the input current detection value of each phase and the detected value of the DC voltage,
And a plurality of phase rectification PWM generators receiving the duty control amount and providing a PWM signal to the four switching elements of each phase constituting the three-phase three-level PWM rectifier. 5. The method of claim 4,
Each of the plurality of phase rectification PWM generators
A 3-level pulse width modulator for receiving the duty information received from the phase current controller to generate on / off information, which is a duty value corresponding to the duty information,
A switch for receiving the on or off information to set a dead time between the switching elements and outputting the PWM signal as an on or off signal to each switching element in accordance with the on or off information based on the set dead time, A transformer type uninterruptible power supply having an energy storage function including a signal generator. The method of claim 1,
The output voltage controller
A phase detector for detecting a change in phase and phase of the AC input power and outputting a sine value,
An error of the AC voltage is detected by comparing an AC voltage detection value of the corresponding phase and an output voltage control command value of the corresponding phase so that each of the three-phase AC voltage outputted from the three-phase three-level PWM inverter has a set magnitude and phase, A plurality of inverter output voltage controllers for calculating and outputting duty information corresponding to the error of the AC voltage using the detected value of the DC voltage and the load current detection value of the DC voltage,
And a switching signal generator for receiving the duty information to set a dead time between the switching elements and outputting the PWM signal as an ON or OFF signal to each switching element in accordance with the set dead time A non - transformer type uninterruptible power supply having an energy storage function. The method of claim 6,
Wherein the sine value of the phase detector has an energy storage function in which a first compensation phase due to a delay component of the PLL circuit is reflected in a phase detected using a PLL circuit. 8. The method of claim 7,
And a phase compensator for receiving the sine value of the phase detector and correcting a sine value of the phase detector according to the load current and providing a corrected sine value to the inverter output voltage controller. Transformer type uninterruptible power supply. The method of claim 1,
Wherein the mode control unit has an energy storage function in which the set time at which the first battery charging mode is set is an initial time of a night time electricity time zone. 10. The method according to claim 8 or 9,
Wherein the mode control unit keeps the first battery charging mode when the current solar irradiation amount is less than the first predetermined amount and the remaining amount of the battery is less than the first predetermined value in a state in which one mode is set, And sets the second battery discharge mode when the remaining amount of the battery is less than the first predetermined amount and the remaining amount of the battery is equal to or less than the first set value, And an energy storage function for setting the first battery discharge mode when the current solar irradiation amount is equal to or greater than the first predetermined amount and the remaining amount of the battery is equal to or greater than the first predetermined value Non - transformer type uninterruptible power supply. 11. The method of claim 10,
The mode control unit sets the power failure mode when the AC input power is not applied from the system, and provides at least one of the power of the battery and the power of the solar cell to the load. When an internal failure occurs, an internal failure mode is set A bypass transformer having an energy storing function for bypassing the AC input power provided from the system to the load side through the first power supply line and bypassing the AC input power supplied from the system to the load side through the second power supply line when the manual bypass operation mode is set, Uninterruptible power supply.

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