KR100866097B1 - Photovoltaic system associated with power line and control method thereof - Google Patents

Abstract

The present invention relates to a grid-connected photovoltaic power generation system and its operation method.

The power generation system disclosed by the present invention includes a solar cell module, a DC / DC converter for boosting the DC power output from the solar cell module, a power regulation module for charging the boosted DC power, and a DC / DC converter or power regulation. DC / AC converter that converts DC power output from the module into AC power and supplies it to the system, and DC power output from the DC / DC converter is charged to the power control module at a time outside the peak power consumption time period, and peak power consumption time period. The control module is configured to discharge the DC power charged in the power control module to the DC / AC converter.

According to the present invention having such a configuration, even if the rated capacity of the solar cell module is lowered, the peak cut contribution can be significantly increased as compared with the prior art.

Solar power, solar cell, power storage, grid connection

Description

Grid-connected photovoltaic power generation system and its operation method {PHOTOVOLTAIC SYSTEM ASSOCIATED WITH POWER LINE AND CONTROL METHOD THEREOF}

1 is a schematic configuration diagram of a conventional grid-connected photovoltaic power generation system,

2 is a schematic configuration diagram of a grid-connected photovoltaic power generation system of the present invention,

3 is a detailed configuration diagram of a control module of the present invention;

4 is a graph showing the daily output trend of the solar cell module,

5 is a graph showing the daily charging trend of the power storage module,

Figure 6 is a graph showing the discharge pattern in the peak power consumption time.

** Description of symbols for the main parts of the drawing **

100: grid-connected photovoltaic power generation system of the present invention

110: solar cell module 120: DC / DC converter

130: power control module 140: DC / AC converter

150: control module

The present invention relates to a grid-connected photovoltaic power generation system, in particular, by storing the power obtained from the solar cell module, and supplying the stored power to the grid at the maximum power consumption time, thereby increasing the peak cut contribution of the power system It is about technology that can be made.

As is well known, soaring demand for electricity leads to a surge in the consumption of energy resources for power generation. This leads to cost and environmental problems. Therefore, in recent years, attention has been focused on grid-connected power generation system using solar as a clean energy source.

The conventional grid-connected photovoltaic power generation system 10 schematically illustrated in FIG. 1 includes a solar cell module 12 including a plurality of solar cell arrays, and a DC power output from the solar cell module to apply to a power system. The DC / AC converter 14 which converts into AC power is comprised.

Such a conventional photovoltaic power generation system can be largely evaluated in 'kWh value' and 'kW value'. The high kWh value can be understood to mean that the utilization rate (system utilization rate) is expressed as shown in Equation 1 below. In other words, the greater the amount of power output in a system of the same capacity, the higher the 'kWh value'.

............ [수학식 1]

............ Equation 1

For example, in Tokyo, Japan, the utilization rate is 11.4%, and the solar power system is rated for about 2.7 hours out of 24 hours a day.

In contrast, the 'kW value' is a concept based on the contribution to securing the power reserve ratio, and the 'kW value' may vary depending on how much power can be generated and supplied to the grid during peak power consumption. Conventional peak cut contribution of the photovoltaic power generation system as shown in FIG. 1 is about 17% to 35%. For example, a system in which the solar cell module has a rated capacity of 1 [kWp] contributes to a peak cut in the range of 0.17 [kW] to 0.35 [kW].

Currently, 3 [kWp] PV system is recognized as a standard in Korea. Applying to the peak cut contributions mentioned above (17% to 35%), only a quantitative increase of 0.51 to 1.05 [kW] is achieved. Moreover, the increase in rated capacity can be understood as increasing the solar cell module, which adds to the burden of system construction cost.

Accordingly, an object of the present invention is to provide a grid-connected photovoltaic power generation system and a method of operating the same, which can lower the rated capacity of the solar cell module and improve the peak cut contribution or efficiency thereof.

In order to realize this characteristic purpose, the grid-connected photovoltaic power generation system includes a solar cell module constituting a plurality of solar cell arrays, a DC / DC converter for boosting the DC power output from the solar cell module, and a DC / DC converter. Power control module to charge the DC power output from the power supply, DC / AC converter that converts the DC power output from the power control module to the AC power supply to the system, and controls each configuration for the preset peak power consumption time It includes a control module for storing data.

The control module of the present invention charges the power control module with a DC power output from the DC / DC converter at a time outside the peak power consumption time period, while discharging the DC power charged to the power control module during the peak power consumption time period. Supply to grid via / AC converter.

Specific features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. In the meantime, when it is determined that the detailed description of the known functions and configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

2 is a schematic configuration diagram of a grid-connected photovoltaic power generation system (hereinafter, referred to as a 'power generation system') of the present invention. The power generation system 100 of FIG. 2 constitutes a solar cell module 110, a DC / DC converter 120, a power regulation module 130, a DC / AC converter 140, and a control module 150.

Specifically, the solar cell module 110 configures a plurality of photovoltaic cell array arrays to convert and output sunlight into a direct current power source, and the DC / DC converter 120 outputs from the solar cell module 110. Boost the DC power supply and output it.

The power regulation module 130 charges or discharges the boosted DC power output from the DC / DC converter 120. Although not shown in the drawings, the power control module 130 includes a power storage unit such as a rechargeable battery for charging and discharging.

The DC / AC converter 140 converts the DC power output from the DC / DC converter 120 or the power control module 130 into AC power and supplies it to the system (power system) P and the load L.

As shown in FIG. 3, the control module 150 basically controls the components 110 to 140 as described above. The DC / DC converter controller 152, the DC / AC converter controller 154, and power control are shown in FIG. 3. The module controller 156 and the control data storage unit 158 are included.

The DC / DC converter controller 152 controls the DC / DC converter 120 through a first PWM control signal, and the power regulation module controller 154 controls the charge / discharge function of the power regulation module 130. The DC / AC converter controller 156 controls the DC / AC converter 140 through the second PWM control signal. The control data storage unit 158 stores a plurality of control-related data, in particular, time data for the peak power consumption time zone.

Hereinafter, the characteristic control aspects of the control module 150 having such a configuration will be described in more detail. First, the control module 150 charges the power control module 130 with the DC power output from the solar cell module 110 except for the peak power consumption time period set in the time data during the day. The trend of the DC power output from the solar cell module 110 during the day is similar to the graph of FIG. 4. Specifically, the section from the sunrise to the sunset shown on the time axis of the figure is the actual operating time of the solar cell module 110. As described above, the DC power output from the solar cell module 110 is stored (charged) in the power storage module 130 in the form as shown in FIG. 5 via the DC / DC converter 120.

On the other hand, the time zone when the power consumption of the system is imminent, that is, the peak power consumption time zone ranges from several hours per day. For example, in the summer, the time zone is formed in the range of 14:00 to 17:00 (about 3 hours). Therefore, during peak power consumption time period, the control module 150 discharges the DC power charged in the power storage module 130 and supplies it to the system through the DC / AC converter 140. Here, the peak power consumption time zone is a discharge time zone.

The charging and discharging aspects of the power storage module 130 may be understood as shown in FIG. 6. Referring to FIG. 6, a discharge of a DC power charged in the power storage module 130 is performed at a predetermined discharge time period (peak power consumption time period), and the discharged DC power is applied to the DC / AC converter 140. Finally fed to the system.

Here, assuming that the peak cut contribution of the conventional power generation system using a 3 [kWp] solar cell module is about 17% to 35%, the power generation system according to the present invention having the same rated capacity corresponds to the rated capacity at the peak power consumption period. As power is generated, the effect of about 2.85 to 5.88 times the peak cut contribution of the conventional power generation system can be expected. Therefore, even if the power generation system of the present invention is lowered to 1 [kWp] level, the value of 'kW' is significantly increased since 0.95 to 1.96 times can be expected based on the peak cut effect of the existing 3 [kWp] level system.

According to the present invention as described above, even if the rated capacity of the solar cell module is lowered 'kW value' can be significantly increased compared to the conventional. Therefore, it is possible to build a photovoltaic system with high 'kW value' at a low price. This can greatly contribute to the formation of the civilian market.

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be understood by those skilled in the art that many modifications and variations can be made to the invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

Claims (3)

In grid-connected photovoltaic power generation system, A solar cell module 110 comprising a plurality of solar cell arrays, a DC / DC converter 120 for boosting the DC power output from the solar cell module, and the power to charge the DC power output from the DC / DC converter Control module 130, a DC / AC converter 140 for converting the DC power output from the DC / DC converter or the power control module to AC power supply to the system, and the control module 150 for controlling each configuration ; Including; The control module 150 includes a DC / DC converter module controller 152 for generating a first PWM control signal for controlling the DC / DC converter, and a power control for controlling a charge / discharge function of the power regulation module. Peak power consumption time zone, which is the time zone when the module control unit 154, the DC / AC converter module control unit 156 for generating a second PWM control signal for controlling the DC / AC converter, and the system's power consumption are imminent. Configure a control data storage unit 158 for storing data for, The control module charges the DC power output from the DC / DC converter to the power control module at a time outside the peak power consumption time period, and discharges the DC power charged to the power control module at the peak power time. Grid-connected photovoltaic power generation system characterized in that supplied to the grid via / AC converter. delete A solar cell module 110 comprising a plurality of solar cell arrays, a DC / DC converter 120 for boosting the DC power output from the solar cell module, and the power to charge the DC power output from the DC / DC converter The control module 130, the DC / AC converter 140 for converting the DC power output from the DC / DC converter or the power control module into AC power and supplying the system to the system, and controlling each component and setting a predetermined peak power consumption. In the operation method of the grid-connected photovoltaic power generation system 100 including a control module 150 for storing data for the time zone, Charging DC power of the solar cell module to the power control module at a time outside the peak power consumption time zone; And Discharging the DC power charged in the power control module during the peak power consumption time period and supplying it to the system through the DC / AC converter; Method of operating a grid-tied photovoltaic power generation system comprising a.

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