KR20150085227A - The control device and method for Energy Storage System - Google Patents

Abstract

An apparatus for controlling an energy storage system according to an embodiment includes: a renewable energy unit for supplying renewable energy; A battery for supplying battery power; A first DC-DC converter connected to the renewable energy unit, for converting and outputting a voltage output from the renewable energy unit; A second DC-DC converter connected to the battery, for converting and outputting a voltage output from the battery; An inverter coupled to the first DC-DC converter and the second DC-DC converter; A power system connected to the inverter and supplying a power system voltage; And a power controller for controlling at least one of the first DC-DC converter, the second DC-DC converter, and the inverter so that an input voltage of the inverter is constant.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an energy storage system,

An embodiment relates to an energy storage system and a control method thereof.

Recently, the importance of renewable energy has been newly recognized according to the changes in the domestic and overseas environment. Particularly, among the new and renewable energy, the photovoltaic power generation system which uses the solar energy to generate electric power has recently become popular due to the fact that there is no pollution, and it is easy to install and maintain. The photovoltaic power generation system is a system that converts DC power generated by solar cells into AC power, and supplies power to the load in conjunction with the system. When the generated power of the solar cell is smaller than the power consumption of the load, the power of the solar cell is consumed in the load, and the system supplies the shortage. And, when the generated power of the solar cell is larger than the power consumption of the load, surplus power consumed in the load among the generated power of the solar cell is supplied to the system as reverse current power.

On the other hand, the power storage system is a system that stores surplus power generated in the nighttime from the system in the energy storage device and uses it in the daytime. Such a power storage system is a system that suppresses the peak of the generated power in the daytime and utilizes the nighttime power. The power storage system is advantageous in that it can be installed in a general customer space by reducing the space by using a battery as an energy storage device and power can be supplied from the battery in case of power failure.

The energy storage system is a concept that blends the renewable energy generation system represented by solar energy with the power storage system. The battery can store the surplus power of the renewable energy and the system, and can supply the load to the load. In addition, it can supply the stable power to the load even in case of power failure.

The energy storage system has a plurality of converters and inverters for converting the developed energy to various levels of power. Here, since the inverter must stably supply the generated power from the solar cell and the power from the battery to the system, the output control of the inverter is important.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an energy storage system having high power efficiency and a control method thereof.

It is another object of the present invention to provide an energy storage system and a control method thereof that can be independently controlled independently of the power balance.

It is another object of the present invention to provide a safe energy storage system and a control method thereof.

It is another object of the present invention to provide an energy storage system capable of supplying power even during a power failure and a control method thereof.

An energy storage system according to an embodiment includes a renewable energy unit supplying renewable energy power; A battery for supplying battery power; A first DC-DC converter connected to the renewable energy unit, for converting and outputting a voltage output from the renewable energy unit; A second DC-DC converter connected to the battery, for converting and outputting a voltage output from the battery; An inverter coupled to the first DC-DC converter and the second DC-DC converter; A power system connected to the inverter and supplying a power system voltage; And a power controller for controlling at least one of the first DC-DC converter, the second DC-DC converter, and the inverter so that an input voltage of the inverter is constant.

Also, the power controller may control the inverter to output a positive power to the power system if the renewable energy generator is in the first mode in which the battery is discharged.

In addition, the power control unit may be configured such that when the renewable energy portion is generated and the battery is charged, if the power generation power of the renewable energy portion is larger than the charging power of the battery, Can be controlled.

In addition, when the renewable energy portion is generated and the battery is charged, the power control portion may determine that the generator is in a third mode in which the generated power of the renewable energy portion is smaller than the charging power of the battery, Can be controlled.

Also, the power control unit may control the inverter to output negative power to the power system if the renewable energy unit does not generate electricity and the battery is charged in the fourth mode.

In addition, the power control unit may control the inverter to output a positive power to the power system if the renewable energy unit does not generate electricity and the battery is in a fifth mode in which the battery is discharged.

A power control method of an energy storage system according to an embodiment of the present invention includes the steps of: detecting whether a new / renewable energy unit for supplying renewable energy power is developed; Detecting charging or discharging of the battery supplying the battery power; And a first DC-DC converter having one end connected to an output terminal of the renewable energy unit and a second DC-DC converter connected to the battery output terminal, depending on whether the renewable energy unit is generated and whether the battery is charged or discharged , And the other end is connected to a power system for supplying the power system voltage.

Also, the step of controlling the power output from the inverter may control the power output from the inverter such that the input voltage of the inverter is constant.

In addition, the step of controlling the power output from the inverter may include a first mode in which the renewable energy portion is generated and the battery is discharged, and when the renewable energy portion is generated and the battery is charged, A third mode in which the generated power is smaller than the charge power of the battery, and a fifth mode in which the renewable energy portion does not generate and the battery discharges, the inverter controls to output the positive power to the power system .

In addition, the step of controlling the power output from the inverter may include a second mode in which the renewable energy portion is generated and the generated power of the renewable energy portion is greater than the charging power of the battery when the battery is charged, The inverter can control to output negative power to the power system if the energy is not generated in the fourth mode and the battery is charged.

According to the energy storage system and the control method thereof according to the embodiment, power efficiency can be increased.

According to the energy storage system and the control method thereof according to the embodiment, independent control can be performed irrespective of the power balance.

According to the energy storage system and the control method thereof according to the embodiment, safety can be enhanced.

According to the energy storage system and the control method thereof according to the embodiment, power can be supplied even during a power failure.

1 is a block diagram schematically showing a configuration of an energy storage system according to an embodiment.
FIGS. 2A to 2C are diagrams showing current flows according to three modes when the energy storage system according to the embodiment operates in a daytime. FIG.
3 is a waveform diagram showing voltage and current according to a mode change when the energy storage system according to the embodiment operates in the daytime.
FIGS. 4A and 4B are diagrams illustrating current flows according to two modes when the energy storage system according to the embodiment operates at night. FIG.
5 is a waveform diagram showing voltage and current according to a mode change when the energy storage system according to the embodiment operates at night.
6 is a flowchart showing a power control method of the energy storage system according to the embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. It is to be understood, however, that the appended drawings illustrate the use of the present invention in order to more easily explain the present invention, and the scope of the embodiments is not limited to the range of the accompanying drawings. You will know.

In addition, the upper or lower reference of each component is described with reference to the drawings. The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

In the description of the embodiments, in the case of being described as being placed on "above or below" each element, the upper (upper) or lower (lower) or under includes both two elements being directly in contact with each other or one or more other elements being disposed indirectly between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram schematically showing a configuration of an energy storage system according to an embodiment. 1, the energy storage system 100 according to the embodiment includes a renewable energy unit 110, a battery 120, a first DC-DC converter 130, a second DC-DC converter 140 An inverter 150, a power system 160, a load 170, a power control unit 180, and a system management unit 190.

The renewable energy unit 110 may be composed of a solar cell, a wind power plant, a tidal power plant, or a geothermal power plant. The new and renewable energy department 110 can generate renewable energy by generating energy from natural conditions such as solar heat, sunlight, wind power, tidal power, or geothermal energy as electric energy. Here, the renewable energy power may be DC power. In the embodiment, the renewable energy unit 110 is formed of a solar cell. The renewable energy unit 110 may include a first terminal (+) and a second terminal (-).

The battery 120 can supply battery power. Here, the battery 120 may be a secondary battery capable of charging and discharging. For example, the battery 120 may be a Li-ion battery. The battery 120 may be constituted by a plurality of small capacity battery cells or may be constituted by one large capacity battery cell to realize large capacity power. Here, the battery energy power may be DC power.

The first DC-DC converter 130 is connected to the renewable energy unit 110, and can convert DC power output from the renewable energy unit 110 into DC power of a different level and output the DC power. The level of DC power output from the first DC-DC converter 130 is not necessarily fixed, and may be variously set according to a desired level in the energy storage system 100 according to the embodiment.

The second DC-DC converter 140 is connected to the battery 120, and can convert DC power output from the battery 120 into DC power of another level and output the DC power. The level of the DC power output from the second DC-DC converter 140 is not necessarily fixed, and can be variously set according to a desired level in the energy storage system 100 according to the embodiment.

The inverter 150 is connected to the first DC-DC converter 130 and the second DC-DC converter 140 and can convert the input DC power into alternating current (AC) . Inverter 150 may also be coupled to power system 160. In this manner, the inverter 150 can convert the input DC power into AC power and output it. In this case, the inverter 150 may be a high frequency inverter capable of outputting AC power having a high frequency.

The power system 160 can supply grid power as an electrical link over a large area including power plants, substations, and power transmission lines. Here, the grid power may be AC power. The power system 170 is connected to the inverter 150 and the power output from the first DC-DC converter 130 and the second DC-DC converter 140 supplies the inverted power through the inverter 150 And can supply the grid power output from the power system 160 to the load 170.

The load 170 is connected to the inverter 150 and the power system 170 and can receive AC power output from the inverter 150. Further, the system power output from the power system 160 can be supplied. The load 170 may be a home or industrial facility using AC power.

The power control unit 180 may control at least one of the first DC-DC converter 130, the second DC-DC converter 140, and the inverter 150 so that the input voltage of the inverter 150 is constant. 1, the input voltage of the inverter 150 is the output voltage of the first DC-DC converter 130 and the output voltage of the second DC-DC converter 140. As shown in FIG. Therefore, the power control unit 180 can control the energy storage system 100 to maintain the output voltages of the first DC-DC converter 130 and the second DC-DC converter 140 at a constant level. At this time, the power control unit 180 can detect whether the renewable energy unit 110 is generated and whether the battery 120 is charged / discharged, and control the energy storage system 100 according to the sensed result .

The power control unit 180 includes a renewable energy sensor 181, a maximum power point tracking (MPPT) unit 182, a renewable energy control unit 183, a charge / discharge control unit 184, A control unit 185 and an output current control unit 186.

The renewable energy sensor 181 can sense the voltage and current output from the renewable energy unit 110. More specifically, the renewable energy sensor 181 is connected to the output terminal of the renewable energy unit 110 and the input terminal of the first DC-DC converter 130, and the voltage and current outputted from the renewable energy unit 110 Can be detected. The renewable energy sensor 181 can exchange information with the maximum power point tracking unit 182. The voltage and current detected by the renewable energy sensor 181 are transmitted to the maximum power point tracking unit 182 .

The maximum power point tracking unit 182 receives the voltage and current of the renewable energy unit 110 from the renewable energy sensor 181 and calculates the maximum power point of the renewable energy unit 110 based on the received voltage and current You can search for points. In addition, the maximum power point tracking unit 182 can generate an instruction value of the output current of the first DC-DC converter 130 based on the maximum power point searched. The command value of the output current of the first DC-DC converter 130 generated in the maximum power point tracking unit 182 may be transmitted to the renewable energy control unit 183. [

The renewable energy control unit 183 can control the first DC-DC converter 130 according to the command value received from the maximum power point tracking unit 182. [ More specifically, the renewable energy control unit 183 can control the first DC-DC converter 130 so that the output voltage of the first DC-DC converter 130 is maintained at a constant level.

The charge / discharge controller 184 can sense the voltage and current output from the battery 120. [ More specifically, the charge / discharge controller 184 is connected to the output terminal of the battery 120, the input terminal of the second DC-DC converter 140, and the output terminal of the second DC-DC converter 140, It is possible to detect the voltage and the current output from the inverter. In addition, current and voltage output from the second DC-DC converter 140 can be sensed. The charging / discharging controller 184 may control the second DC-DC converter 140 according to the command value of the output current of the second DC-DC converter 140 received from the system manager 190.

The DC link voltage control unit 185 may generate an instruction value of the output current of the inverter 150 to keep the DC link voltage constant. Here, the DC link voltage may be the output voltage of the first DC-DC converter 130 and the second DC-DC converter 140, and the input voltage of the inverter 150. The DC link voltage control unit 185 is connected to the output terminals of the first DC-DC converter 130 and the second DC-DC converter 140 and the input terminal of the inverter 150, and can sense the DC link voltage. DC link voltage control unit 185 may transmit an instruction value of an output current of the generated inverter 150 to the output current control unit 186. [

The output current control unit 186 can control the inverter 150. [ More specifically, the output current control unit 186 is connected to the output terminal of the inverter 150 to sense the output voltage and current of the inverter 150, and outputs the output of the inverter 150 received from the DC link voltage control unit 185 The inverter 150 can be controlled according to the command value of the current.

The system management unit 190 can manage the operation of the energy storage system 100 as a whole. The system management unit 190 may include an interface unit 191, a system control unit 192, a power management unit 193, and a PV power system (PV PCS) system control unit 194.

The interface unit 191 can communicate with the outside of the energy storage system 100. The interface unit 191 may be a module for performing wireless communication or a module capable of performing CAN (Controller Area Network) communication and may communicate with the outside of the energy storage system 100, And the like.

The system control unit 192 can manage the overall operation of the energy storage system 100. More specifically, it is possible to start and stop the energy storage system 100 and to process information received from outside.

The power management unit 193 can select the operation mode of the energy storage system 100 and can perform the management of the battery 120. [

The PV PCS system control unit 194 can control the start and stop of the first DC-DC converter and can perform communication with other parts constituting the system management unit 190.

FIGS. 2A to 2C are diagrams showing current flows according to three modes when the energy storage system according to the embodiment operates in the daytime. FIG. 3 is a diagram illustrating a case where the energy storage system according to the embodiment operates in the daytime, Fig. 8 is a waveform diagram showing voltage and current according to a mode change. Fig.

Hereinafter, the power control operation of the energy storage system 100 according to the embodiment of the present invention will be described with reference to Figs. 1, 2A to 2C, and 3. Fig.

In the case of a day in which solar energy can be used, the renewable energy unit 110 can supply the energy storage system 100 with the power generated by solar and sunlight. That is, in the case of a daytime, the renewable energy unit 110 can generate electricity.

In the first mode in which the new and renewable energy unit 110 is generated and the battery 120 is discharged, as shown in FIG. 2A, the power generated by the renewable energy unit 110 and the power generated by the battery 120 Power may be supplied to the power system 160. At this time, the first DC-DC converter 130, the second DC-DC converter 140, and the inverter 150 operate, and the power Pins developed by the renewable energy unit 110 and the battery 120 The sum of the discharged electric power Pinb may be equal to the electric power Pout input to the electric power system 160. [

In the case of the second mode in which the renewable energy unit 110 is generated and the battery 120 is charged and the generated power of the renewable energy unit 110 is greater than the charged power of the battery 120, The power generated by the renewable energy unit 110 may be supplied to the battery 120 and the power system 160. [ At this time, the first DC-DC converter 130, the second DC-DC converter 140, and the inverter 150 operate, and the battery 120 is discharged from the power Pins generated by the renewable energy unit 110 If the charged power Pinb is reduced, it may be the same as the power Pout input to the power system 160. [

In the case of the third mode in which the renewable energy 110 is generated and the generated power of the renewable energy unit 110 is smaller than the charged power of the battery 120 when the battery 120 is charged, The power generated by the renewable energy unit 110 and the power output from the power system 160 can be supplied to the battery 120. [ At this time, the first DC-DC converter 130, the second DC-DC converter 140, and the inverter 150 operate, and the power Pins generated by the renewable energy unit 110 and the power system 160, The power Pout output from the battery 120 may be equal to the power Pinb charged to the battery 120. [

When the energy storage system 100 is driven, the renewable energy unit 110 is energized and the battery 120 is in a first mode state in which the charged electric power is discharged. When time passes in the first mode, all the power charged in the battery 120 is discharged. That is, as shown in FIG. 3, the battery current is decreased, the battery current changes from positive to zero, and the battery 120 is charged with electric power. Accordingly, when the renewable energy unit 110 is being developed and the battery is charged, the energy storage system 100 is in a third mode in which the generated power of the renewable energy unit 110 is less than the charged power of the battery 120 do. When the time elapses in the third mode, the renewable energy unit 110 reaches the maximum power point, and accordingly, when the solar current continuously increases, the third mode is converted to the second mode. Therefore, when the renewable energy unit 110 is being developed and the battery is charged, the energy storage system 100 is in the second mode in which the generated power of the renewable energy unit 110 is higher than the charged power of the battery 120 do. As shown in Fig. 3, the DC link voltage remains constant despite the mode change of the daytime.

Since the sum of the power generated by the renewable energy unit 110 and the charge / discharge power of the battery 120 matches the input / output power to the power system 160, the battery 120 is overcharged, 120 can be prevented from being damaged or destroyed. For example, it is possible to prevent a phenomenon in which the battery 120 is overcharged and a fire is generated in the battery 120.

Further, even when the mode of the daytime changes, the energy storage system can be independently controlled without considering the balance of power. As a result, it is possible to construct a high-efficiency and safe energy storage system. In addition, since the positive power can be continuously supplied to the system without interruption even in the case of a power failure, the function as the uninterruptible power supply can also be realized.

FIGS. 4A and 4B are views showing a current flow according to two modes when the energy storage system according to the embodiment operates in the daytime, FIG. 5 is a diagram illustrating a case where the energy storage system according to the embodiment operates at night, Fig. 8 is a waveform diagram showing voltage and current according to a mode change. Fig.

Hereinafter, the power control operation of the energy storage system 100 according to the nighttime embodiment will be described with reference to FIGS. 1, 4A, 4B and 5.

In the case of nighttime when solar energy is not available, the renewable energy unit 110 can not supply electric power.

When the renewable energy unit 110 does not generate electricity and the battery 120 is charged in the fourth mode, power output from the power system 160 may be supplied to the battery, as shown in FIG. 4A. At this time, only the second DC-DC converter 140 and the inverter 150 operate, and the power Pout output from the power system 160 may be equal to the power Pinb charged in the battery 120 .

4B, the electric power discharged from the battery 120 can be supplied to the electric power system 160. The electric power discharged from the battery 120 is supplied to the electric power system 160, have. At this time, only the second DC-DC converter 140 and the inverter 150 operate, and the power Pinb discharged from the battery 120 may be equal to the power Pout input to the power system 160 .

At night, the energy storage system 100 enters a fifth mode in which the renewable energy unit 120 does not generate electricity and the battery 120 discharges the charged power. When the time passes in the fifth mode, all the electric power charged in the battery 120 is discharged. That is, as shown in FIG. 5, the battery current is reduced, the battery current changes from positive to zero, and the battery 120 is charged with power. Accordingly, the energy storage system 100 is in the state of the fourth mode in which the power output from the power system 160 is charged in the battery 120. [ As shown in Fig. 5, the DC link voltage remains constant despite the mode change at night.

Thus, since the charge / discharge power of the battery 120 and the input / output power to the power system 160 are identical to each other, it is possible to prevent the battery 120 from overcharging and damaging or destroying the battery 120 . For example, it is possible to prevent a phenomenon in which the battery 120 is overcharged and a fire is generated in the battery 120.

Further, even when the night mode is changed, the energy storage system 100 can be independently controlled without considering the balance of power. Accordingly, it is possible to construct the energy storage system 100 with high power efficiency and safety. In addition, since the positive power can be continuously supplied to the system without interruption even in the case of a power failure, the function as the uninterruptible power supply can also be realized.

6 is a flowchart showing a power control method of the energy storage system according to the embodiment. Hereinafter, a power control method of an energy storage system according to an embodiment will be described with reference to FIGS.

In operation 600, it is detected whether or not the renewable energy unit for supplying renewable energy is developed. As a result of the detection, if the new and renewable energy unit 110 develops, operation 610 is performed. Otherwise, operation 620 is performed.

In operation 610, the mode of the energy storage system operating during the day is determined, and the power of the energy storage system is controlled according to the determined mode.

The mode of the energy storage system 100 operating in the daytime may be changed depending on whether the battery 120 supplying the battery power is charged or discharged and the magnitude of the generated power of the renewable energy unit 110 and the battery 120 And controls the power of the energy storage system 100 according to the determination result. 1, a first DC-DC converter 130 connected to the output terminal of the renewable energy unit 110, and a second DC-DC converter 140 connected to the output terminal of the battery 120, And the other end of which is connected to the power system 160 that supplies the power system.

The energy storage system 100 according to the embodiment operates according to the three modes shown in Figs. 2A to 2C in the case of daytime, and as shown in Fig. 3, the first mode, the third mode, and the second mode In order.

2A to 2C and 3, it can be seen that the sum of the power generated by the renewable energy unit 110 and the charge / discharge power of the battery 120 is equal to the input / output power to the power system 160 . Also, it can be seen that each mode continuously changes without interruption.

Accordingly, it is possible to prevent the battery 120 from being damaged due to overcharging and the battery 120 being damaged or broken, and the energy storage system 100 can be independently controlled without considering the balance of power. As a result, it is possible to construct a high-efficiency and safe energy storage system. In addition, since the positive power can be continuously supplied to the system without interruption even in the case of a power failure, the function as the uninterruptible power supply can also be realized.

In operation 620, the mode of the energy storage system operating at night is determined, and the power of the energy storage system is controlled according to the determined mode.

The mode of the energy storage system 100 operating at night is determined according to whether the battery 120 supplying the battery power is charged or discharged and the power of the energy storage system 100 is controlled according to the determination result. 1, a first DC-DC converter 130 connected to the output terminal of the renewable energy unit 110, and a second DC-DC converter 140 connected to the output terminal of the battery 120, And the other end of which is connected to the power system 160 that supplies the power system.

The energy storage system 100 according to the embodiment operates according to the two modes shown in FIGS. 4A and 4B at night, and operates in the order of the fifth mode and the fourth mode, as shown in FIG. can do.

4A, 4B and 5, it can be seen that the charge / discharge power of the battery 120 coincides with the input / output power to the power system 160. Also, it can be seen that each mode continuously changes without interruption.

Accordingly, it is possible to prevent the battery 120 from being damaged due to overcharging and the battery 120 being damaged or broken, and the energy storage system 100 can be independently controlled without considering the balance of power. As a result, it is possible to construct a high-efficiency and safe energy storage system. In addition, since the positive power can be continuously supplied to the system without interruption even in the case of a power failure, the function as the uninterruptible power supply can also be realized.

The features, structures, effects and the like described in the embodiments are included in one embodiment of the present invention, and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be appreciated that many variations and applications not illustrated are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: Energy storage system
110: Department of Renewable Energy
120: Battery
130: first DC-DC converter
140: second DC-DC converter
150: Inverter
160: Power system
170: Load
180:
190:

Claims (10)

New & Renewable Energy Division to supply renewable energy power;
A battery for supplying battery power;
A first DC-DC converter connected to the renewable energy unit, for converting and outputting a voltage output from the renewable energy unit;
A second DC-DC converter connected to the battery, for converting and outputting a voltage output from the battery;
An inverter coupled to the first DC-DC converter and the second DC-DC converter;
A power system connected to the inverter and supplying a power system voltage; And
And a power controller for controlling at least one of the first DC-DC converter, the second DC-DC converter, and the inverter so that an input voltage of the inverter is constant. The apparatus of claim 1, wherein the power control unit
Wherein the inverter controls the power system to output a positive power when the renewable energy generator is in a first mode in which the battery is discharged. The apparatus of claim 1, wherein the power control unit
Wherein when the renewable energy portion develops and the battery is charged, if the power generation power of the renewable energy portion is larger than the charge power of the battery, the inverter controls the energy to be output to the power system Storage system. The apparatus of claim 1, wherein the power control unit
Wherein when the renewable energy portion develops and the battery is charged, if the generated power of the renewable energy portion is smaller than the charge power of the battery, the inverter controls the energy to be output to the power system Storage system. The apparatus of claim 1, wherein the power control unit
Wherein the inverter controls the inverter to output negative power to the power system if the renewable energy portion does not generate electricity and the battery is charged in a fourth mode. The apparatus of claim 1, wherein the power control unit
Wherein the inverter controls the power system so as to output a positive power to the power system if the renewable energy is not generated and the battery is discharged. Detecting whether a new and renewable energy unit supplying new and renewable energy is developed;
Detecting charging or discharging of the battery supplying the battery power; And
A first DC-DC converter having one end connected to an output terminal of the renewable energy unit and a second DC-DC converter connected to the battery output terminal, depending on whether the renewable energy unit is generated and whether the battery is charged or discharged, And the other end is connected to a power system that supplies a power system voltage. 8. The method of claim 7, wherein the step of controlling the power output by the inverter
And controlling power output from the inverter such that an input voltage of the inverter is constant. 9. The method of claim 8, wherein the step of controlling the power output by the inverter
A third mode in which the renewable energy portion develops and the battery discharges, a third mode in which the renewable energy portion develops and the generated power of the renewable energy portion is less than the charge power of the battery when the battery is charged, And a fifth mode in which the renewable energy portion does not generate electricity and the battery discharges, the inverter controls the power system to output a positive power to the power system. 9. The method of claim 8, wherein the step of controlling the power output by the inverter
A second mode in which the renewable energy portion generates electricity and the generated power of the renewable energy portion is greater than a charging power of the battery when the battery is charged, Mode, the inverter controls the power system to output negative power.

Images