KR20240008165A - String optima, solar power generation system, and method for fine-tuning amount of power generation in string module units - Google Patents

Abstract

The present invention relates to a string optima that finely adjusts the power generation amount of each string module, and to a solar power generation system and method, which are connected between the output terminal of each of the plurality of solar cell strings constituting the solar power generation system and the inverter. A string optimizer that boosts or bypasses the voltage applied from a solar cell string and outputs the output, comprising: a control unit that controls the operation of the string optimizer based on a preset control algorithm; A booster unit that boosts or bypasses the voltage transmitted from the solar cell string and outputs it; And a switch unit that controls the boosting voltage of the booster unit by on/off control of the control unit, wherein the control unit determines the predicted power generation amount of the solar power generation system predicted in advance on the previous day and the actual power generation amount of the solar power generation system. In response to a request signal for fine adjustment of the power generation generated by the comparative analysis results, the boosting voltage is adjusted by adjusting the on/off time of the switch unit, thereby finely adjusting the power generation output per string module unit of the solar power generation system, There is an advantage in that the error between the predicted power generation amount predicted in advance for the solar power generation system and the actual power generation amount can be adjusted within a preset tolerance rate.

Description

String Optima, which finely adjusts the power generation of each string module, and a solar power generation system and method {STRING OPTIMA, SOLAR POWER GENERATION SYSTEM, AND METHOD FOR FINE-TUNING AMOUNT OF POWER GENERATION IN STRING MODULE UNITS}

The present invention relates to a solar power generation system, and more specifically, to a string optima and method for finely adjusting the power generation amount of a string module unit, and to a solar power generation system to which the same is applied.

Since renewable energy generation such as solar power generation and wind power generation obtains energy from nature that cannot be controlled by humans, unexpected fluctuations in power generation may occur, which is called output volatility.

This output volatility did not have a significant impact on the power system in the past when the proportion of renewable energy generation was not high, but as the proportion of renewable energy increases due to environmental demands such as reduction of fossil energy and zero pollution, its impact on the power system gradually increases. there is. In other words, in a situation where the rate of renewable energy generation is high, if unexpected fluctuations in power generation occur due to uncontrollable natural factors such as solar radiation and wind speed, side effects such as power outages due to uncertainty in power supply may result.

In order to minimize these side effects and maintain power supply and demand balance and electricity quality, it is essential to predict the amount of power produced by renewable energy facilities.

Therefore, various technologies have been developed to predict the power generation of renewable energy power generation facilities. In Korea Patent No. 10-2230548, a power generation prediction and efficiency diagnosis system for solar power generation facilities using the FRBFNN model is disclosed.

According to the above patent, FRBFNN is used to generate a prediction model that receives solar radiation and the temperature of the solar module as input and outputs AC power, and by using this, the power generation amount of solar power generation facilities is predicted and the decrease in efficiency is prevented. You can judge.

Meanwhile, as the accuracy of power generation prediction increases, the power system can be operated stably and smoothly.

As a result, at the Korea Power Exchange, operators who have recruited collective power resources of 20 MW or more predict and submit renewable energy power generation in advance one day in advance, and pay a settlement fee (incentive) if the forecast is performed within a certain error rate (e.g., 8%) on the same day. A renewable energy power generation prediction system is being introduced.

Therefore, in renewable energy power plants, it is necessary to accurately predict the predicted power generation in advance and at the same time adjust the actual power generation to within the error rate of the predicted power generation.

Korean Patent No. 10-2230548

Therefore, the present invention finely adjusts the amount of power output by string module of the solar power generation system, allowing the error between the predicted power generation amount predicted in advance for the solar power generation system and the actual power generation amount to be adjusted within a preset tolerance rate. We aim to provide string optima and solar power generation systems and methods.

In addition, the present invention calculates the prediction error rate up to that point at each preset period, and adjusts the boosting rate of the string optima for after the time of calculating the prediction error rate based on the prediction error rate, thereby making it possible to fine-tune the power generation of the string module unit. We would like to provide a string optima and solar power generation system and method that enable this.

In addition, the present invention predicts the remaining power generation amount for the remaining time from that point to the end of daily solar power generation at each time point at which the prediction error rate is calculated, and the actual power generation amount generated up to the time of calculating the prediction error rate and the predicted remaining power generation amount. String Optima, which allows the actual power generation amount of the solar power generation system to be slightly increased by including the voltage below the effective voltage output from any solar cell string in the power generation amount if the sum is less than the predicted power generation amount predicted the previous day, and We would like to provide a solar power generation system and method.

In order to achieve the above object, the string optima provided by the present invention is connected between the output terminal of each of the plurality of solar cell strings constituting the solar power generation system and the inverter, and boosts or biases the voltage applied from the solar cell string. A string optimizer that passes and outputs, comprising: a control unit that controls the operation of the string optimizer based on a preset control algorithm; A booster unit that boosts or bypasses the voltage transmitted from the solar cell string and outputs it; And a switch unit that controls the boosting voltage of the booster unit by on/off control of the control unit, wherein the control unit determines the predicted power generation amount of the solar power generation system predicted in advance on the previous day and the actual power generation amount of the solar power generation system. The boosting voltage is adjusted by adjusting the on/off time of the switch unit in response to a request signal for fine adjustment of power generation generated by the comparative analysis result.

Meanwhile, in order to achieve the above object, the solar power generation system provided by the present invention is connected between the output terminal of each of a plurality of solar cell strings and an inverter, and outputs the voltage applied from the solar cell string by boosting or bypassing it. A solar power generation system including a plurality of string optima, comprising: a predicted power generation storage unit that stores the predicted power generation amount of the solar power generation system predicted in advance the previous day by reflecting weather forecast data; an actual power generation measurement unit that measures the power generation amount by time of the solar power generation system and calculates the actual power generation by accumulating the power generation by time zone; an actual power generation storage unit that stores the actual power generation amount; A prediction error rate calculation unit that calculates a prediction error rate by comparing and analyzing the predicted power generation and the actual power generation at each prediction error rate calculation time that is repeated at a preset cycle; and a power generation fine adjustment unit that corrects the error between the predicted power generation amount and the actual power generation amount by adjusting the boosting voltage of the string optima based on the prediction error rate.

In addition, in order to achieve the above object, the method of fine-tuning the power generation amount of the solar power generation system provided by the present invention is connected between the output terminal of each of the plurality of solar cell strings and the inverter to boost or boost the voltage applied from the solar cell string. In the method of fine-tuning the power generation of a solar power generation system having a plurality of string optima that are bypassed and output, the predicted power generation amount is stored to store the predicted power generation amount of the solar power generation system predicted in advance the previous day by reflecting weather forecast data. step; An actual power generation measurement step of measuring the power generation amount of the solar power generation system for each time period and calculating the actual power generation amount by accumulating the power generation amount for each time period; An actual power generation storage step of storing the actual power generation amount; A prediction error rate calculation step of calculating a prediction error rate by comparing and analyzing the predicted power generation amount and the actual power generation time at each prediction error rate calculation time repeated at a preset period; And a power generation fine adjustment step of correcting the error between the predicted power generation amount and the actual power generation amount by adjusting the boosting voltage of the string optima based on the prediction error rate.

The string optima, solar power generation system, and method of the present invention described above finely adjust the amount of power output in each string module unit of the solar power generation system, thereby matching the predicted power generation amount predicted in advance for the solar power generation system and the actual power generation amount. It has the advantage of allowing the error with the power generation amount to be adjusted within a preset tolerance rate.

In addition, the present invention calculates the prediction error rate up to that point at each preset period, and adjusts the boosting rate of the string optima for after the time of calculating the prediction error rate based on the prediction error rate, thereby making it possible to fine-tune the power generation of the string module unit. There is an advantage in allowing it to happen.

In addition, the present invention predicts the remaining power generation amount for the remaining time from that point to the end of daily solar power generation at each time point at which the prediction error rate is calculated, and the actual power generation amount generated up to the time of calculating the prediction error rate and the predicted remaining power generation amount. If the sum of is less than the predicted power generation predicted the previous day, there is an advantage in that the actual power generation of the solar power generation system can be slightly increased by including the voltage below the effective voltage output from any solar cell string in the power generation.

1 is a schematic block diagram of a solar power generation system according to an embodiment of the present invention.
Figure 2 is a schematic block diagram of a string optima according to an embodiment of the present invention.
Figures 3 to 6 are processing flowcharts for a method of finely adjusting the amount of power generation in units of string modules of a solar power generation system according to an embodiment of the present invention.

Below, embodiments of the present invention will be described with reference to the attached drawings, and will be described in detail so that those skilled in the art can easily practice the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Meanwhile, in order to clearly explain the present invention in the drawings, parts unrelated to the description are omitted, and similar parts are given similar reference numerals throughout the specification. In addition, descriptions of parts that can be easily understood by those skilled in the art are omitted even if detailed descriptions are omitted.

Throughout the specification and claims, when it is said that a part includes a certain component, this means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

1 is a schematic block diagram of a solar power generation system according to an embodiment of the present invention. Referring to FIG. 1, a solar power generation system according to an embodiment of the present invention includes at least one solar cell string 100 composed of a plurality of solar cell modules 110, a solar power connection panel 200, and It is configured to include an inverter 300.

The solar cell string 100 receives sunlight and produces DC power, and the solar cell connection panel 200 connects the DC power produced by each solar cell string 100 in series and parallel to collect the necessary power, and the inverter (300) receives DC power from the solar power connection panel (200), converts it into AC power, and outputs it to the power system.

For this purpose, the connection panel 200 includes at least one string optimizer 210, a prediction model generator 220, a weather information receiver 230, a power generation prediction unit 240, a predicted power generation storage unit 250, and an actual power generation amount. It includes a measurement unit 260, an actual power generation storage unit 270, a prediction error rate calculation unit 280, and a power generation fine adjustment unit 290.

The string optimizer 210 is connected to the output terminal of each solar cell string 100, and supplies the output voltage of the corresponding solar cell string to the inverter 300, providing optimal equalization in line with the output voltage of other neighboring string optima. Outputs voltage. At this time, the equalization voltage boosting method for the string optimizer 210 to output the equalization voltage may refer to known technologies (e.g., Korean Patent No. 10-2242814, etc.).

In addition, the string optima 210 is connected one to one to the output terminal of each of the plurality of solar cell strings 100, so that when a low voltage lower than the starting voltage of the inverter 300 is produced in the corresponding solar cell string 100, The low voltage is boosted and output. For example, each of the string optima 210 outputs a low voltage lower than the starting voltage of the inverter 300 from the solar cell string 100 due to changes in various environmental conditions such as sunset, sunrise, clouds, sea fog, fog, etc. In this case, the string optimizer 210 converts the low voltage into generated power by boosting it, thereby improving the generation efficiency of the solar power generation system. A schematic block diagram of this string optima 210 is illustrated in FIG. 2.

Figure 2 is a schematic block diagram of a string optimizer according to an embodiment of the present invention. Referring to Figures 1 and 2, the string optimizer 210 according to an embodiment of the present invention includes a booster unit 211, It includes a switch unit 212 and a control unit 213.

The booster unit 211 boosts or bypasses the voltage transmitted from the solar cell string 100 and outputs it. That is, the booster unit 211 receives the generated power of the corresponding solar cell string 100 and outputs the voltage corresponding to the generated power by boosting or bypassing it under the control of the switch unit 212, which will be described later.

For this purpose, the booster unit 211 includes an inductor connected in series between the input and output terminals of the string optimizer 210, first and second diodes, and a capacitor connected in the ground direction between the first and second diodes. It can be configured. Additionally, the boosting voltage of the booster unit 211 may be determined by the switch unit 212, which will be described later. For example, the boosting voltage may increase in proportion to the on time of the switch SW included in the switch unit 212.

The switch unit 212 controls the boosting voltage of the booster unit 211 by on/off control of the control unit 213, which will be described later. That is, the switch unit 212 has a switch (SW) that is turned on/off under the control of the control unit 213, and the boosting voltage of the booster unit 211 increases in proportion to the on time of the switch (SW). can be decided.

The control unit 213 controls the operation of the string optimizer 210 based on a preset control algorithm and transmits a control signal to the switch unit 212 to control on/off of the switch SW.

To this end, the control unit 213 may finely adjust the boosting voltage by turning the switch SW on/off in response to a power generation fine adjustment request signal generated by the power generation fine adjustment unit 290, which will be described later.

At this time, the power generation fine adjustment request signal is a signal generated by a comparative analysis result of the predicted power generation amount of the solar power generation system predicted in advance the previous day and the actual power generation amount of the solar power generation system. This is a signal generated by the power generation fine-tuning unit 290 to correct when the error between the actual power generation and the predicted power generation predicted the previous day exceeds a preset tolerance rate.

In response to the power generation fine adjustment request signal, the control unit 213 adjusts the boosting ratio of the string optimizer 210, that is, by adjusting the on time of the switch (SW), to control the corresponding solar cell string 100. The generated power can be increased or decreased, and as a result, the amount of power generated per solar cell string 100 can be finely adjusted. For example, in response to the power generation fine adjustment request signal, the control unit 213 slightly increases the actual power generation of the solar power generation system by increasing the on time of the switch (SW), or By shortening the on time, the boosting ratio of the string optimizer 210 can be adjusted to slightly reduce the actual power generation of the solar power generation system.

Meanwhile, the power generation fine-tuning unit 290 increases the output voltage of the string optimizer when the error between the actual power generation and the predicted power generation predicted on the previous day exceeds a preset tolerance rate, but the actual power generation is less than the predicted power generation. A request signal for fine adjustment of power generation can be generated. That is, when the above two conditions are simultaneously satisfied, the power generation fine adjustment unit 290 uses the output voltage of any solar cell string 100 that outputs a low level voltage that is not sufficient to drive the inverter 300. A request signal for fine adjustment of power generation can be generated to increase power generation.

Then, the control unit 213 compares the input voltage of the string optimizer 210 with the starting voltage of the inverter 300 in response to the power generation fine adjustment request signal, and as a result of the comparison, the input voltage of the string optimizer 210 is If it is lower than the starting voltage of the inverter 300, the on/off time of the switch SW is adjusted to boost the output voltage of the string optimizer 210 up to the starting voltage of the inverter 300. This is so that the output voltage of the boosted string optima 210 forces the inverter 300 to wake up.

In addition, when the inverter 300 is forced to wake up due to the boosting described above, and the voltage at the output terminal of the string optimizer 210 decreases in response, that is, the inverter 300 wakes up. Due to this, current flows from the solar cell string 100 to the inverter 300, and as a result, when the voltage at the output terminal of the string optimizer 210 is lowered, the control unit 213 adjusts the output voltage of the string optimizer 210. The on/off time of the switch (SW) is adjusted to boost to the MPPT starting voltage of the inverter (300).

In this way, the string optimizer 210 converts the low output voltage of the corresponding solar cell string 100 into the generated power of the solar power generation system in response to the power generation fine adjustment request signal, thereby increasing the output of the solar power generation system. It can be fine-tuned in an increasing direction. In other words, the String Optima 210 of the present invention can slightly increase the generated power of the solar power generation system by converting the low voltage into generated power, thereby reducing the power generation amount of the solar power generation system due to environmental factors. Deterioration can be corrected.

The prediction model generator 220 generates weather observation data for a predetermined past period (e.g., the past three months, etc.) for the area where the corresponding solar power generation system is installed, and a period corresponding to the weather observation data (i.e., the above-mentioned A power generation prediction model for the solar power generation system is created by learning the power generation performance data (i.e., power generation, etc.) of the solar power generation system for a period identical to a predetermined past period. For example, the prediction model generator 220 learns weather observation data from March 1, 2020 to May 31, 2020, and power generation performance data of the solar power generation system during the same period to generate the solar power generation system. A power generation prediction model for the power generation system can be created.

At this time, the prediction model generator 220 may generate a power generation prediction model for each time period. For example, the prediction model generator 220 can generate a power generation prediction model for each time zone, such as 09:00 to 09:59 and 10:00 to 10:59, while the solar power generation system is in operation. there is.

The weather information receiver 230 receives weather information from a Korea Meteorological Administration server (not shown) that provides weather information for the area where the solar power generation system is installed. For this purpose, the weather information receiver 230 provides an interface with a communication network. In particular, a communication interface with the Korea Meteorological Administration server (not shown) may be provided.

The power generation prediction unit 240 predicts the next day's power generation amount for the solar power generation system. To this end, the power generation prediction unit 240 reflects the weather information received through the weather information receiver 230 (i.e., next-day weather forecast data for the area where the solar power generation system is installed) into the power generation prediction model to Predict the next day's power generation for the photovoltaic power generation system.

The predicted power generation storage unit 250 stores the predicted power generation amount of the solar power generation system, which was predicted in advance on the previous day by reflecting weather forecast data. At this time, the predicted power generation storage unit 250 may receive and store the predicted information from the power generation prediction unit 240, or may store the predicted power generation amount predicted in advance on the previous day in a separate external device. In the latter case, the predicted power generation storage unit 250 may further include a communication interface unit for data exchange with a separate device that generates the predicted power generation amount.

The actual power generation measurement unit 260 measures the power generation amount for each time period of the solar power generation system, and calculates the actual power generation amount by accumulating the power generation amount for each time period. To this end, the actual power generation measurement unit 260 may detect the output voltage at each output terminal of the plurality of string optima 210 for each preset time period.

The actual power generation storage unit 270 stores the actual power generation calculated by the actual power generation measurement unit 260. In particular, the actual power generation storage unit 270 stores the cumulatively calculated actual power generation amount and the power generation amount for each time slot, and the power generation amount for each time slot may also include corresponding time information.

The prediction error rate calculation unit 280 calculates the prediction error rate by comparing and analyzing the predicted power generation amount and the actual power generation amount at each prediction error rate calculation time that is repeated at a preset period. To this end, the prediction error rate calculation unit 280 first calculates the actual remaining power generation by subtracting the actual power generation accumulated up to the prediction error rate calculation time from the predicted power generation, and then from the prediction error rate calculation time to the end of daily solar power generation. The predicted remaining power generation amount, which is the power generation amount for the remaining remaining time, can be predicted, and the prediction error rate can be calculated based on the difference between the predicted remaining power generation amount and the actual remaining power generation amount.

For example, if the starting point of operation of the solar power generation system is 9 o'clock and the preset period for calculating the prediction error rate is 1 hour, the prediction error rate calculation time is 1 from 10 o'clock to the end of operation of the solar power generation system. There is a time interval, and the prediction error rate calculation unit 280 can calculate the prediction error rate at each prediction error rate calculation time.

Additionally, the prediction error rate calculation unit 280 may calculate the prediction error rate based on Equation 1 below.

At this time, facility capacity refers to the power generation capacity of the relevant solar power generation system.

The power generation fine adjustment unit 290 adjusts the boosting voltage of the string optimizer 210 based on the prediction error rate, thereby correcting the error between the predicted power generation amount and the actual power generation amount. That is, when the prediction error rate exceeds the preset allowable error rate, the power generation fine adjustment unit 290 adjusts the boosting rate of the string optimizer 210 by adjusting the duty ratio of the preset boosting control signal to adjust the actual remaining power generation amount. It can be increased/decreased.

At this time, the tolerance rate is a specific value designated by the Korea Power Exchange and may be a value stored as a reference value for paying incentives according to the error rate of the solar power generation system. In other words, according to the renewable energy power generation prediction system, the Korea Power Exchange can pay incentives to power plants whose error rate is within the measured value, and the allowable error rate may be the error rate designated for this purpose. For example, when the tolerance rate is 6%, the Korea Power Exchange applies the settlement unit price differentially to solar power plants with a forecast error rate of less than 6% and solar power plants with a forecast error rate of more than 6%. A settlement price of 4 won/kWh is applied to solar power plants with a forecast error rate of 6% or less, and a settlement price of 3 won/kWh is applied to solar power plants with a forecast error rate of more than 6% but less than 8%. This allows incentives to be provided to solar power plants with low prediction error rates.

Therefore, in order to lower the prediction error rate, the solar power generation system must generate the actual power generation within the prediction error rate of the predicted power generation predicted the previous day. For this, the power generation fine adjustment unit 290 is a string module included in the solar power generation system. By adjusting the boosting voltage in units, the amount of power generation is fine-tuned.

In particular, when the prediction error rate exceeds the preset allowable error rate but the predicted remaining power generation amount is less than the actual remaining power generation amount, the power generation fine adjustment unit 290 generates power from the solar cell string and then discards the voltage below the inverter start voltage. It can be used to fine-tune the solar power generation system to increase its power generation.

To this end, the power generation fine adjustment unit 290 monitors the input voltage of each of the string optima 210, detects at least one string optima whose input voltage is less than the start voltage of the corresponding inverter, and detects the at least one string optima whose input voltage is less than the start voltage of the corresponding inverter. Each of the string optima is controlled to boost the output voltage of each optimizer up to the starting voltage of the corresponding inverter 300. This is to force wake up the corresponding inverter 300.

And when the output voltage of the corresponding string optima falls in response to the forced wake-up of the inverter 300, that is, due to the wake-up of the inverter 300, the solar cell string 100 When current flows from to the inverter 300 and the voltage at the output terminal of the string optimizer 210 is lowered, the power generation fine adjustment unit 290 boosts the output voltage of the string optimizer up to the MPPT start voltage of the corresponding inverter. Thus, each of the string optima can be controlled to increase the actual power generation.

To this end, the power generation fine adjustment unit 290 may monitor the input/output terminal voltage of each of the string optimizers 210.

The interlocking action between the control unit 213 and the power generation fine adjustment unit 290 to adjust the boosting voltage of the string optima 210 is as mentioned in the description of the string optima 210 with reference to FIGS. 1 and 2. Redundant explanations are omitted.

Meanwhile, each of the above devices for fine-tuning the power generation of the solar power generation system (prediction model generator 220, weather information receiver 230, power generation prediction unit 240, predicted power generation storage unit 250, actual power generation) The measurement unit 260, the actual power generation storage unit 270, the prediction error rate calculation unit 280, and the power generation fine adjustment unit 290) are implemented inside the connection panel 200, as illustrated in FIG. It can be implemented separately at a specific location in the photovoltaic power generation system.

The inverter 300 performs MPPT on the output voltage of the string optimizer 210, converts the result into AC power, and connects it to the grid.

3 to 6 are processing flowcharts of a method for finely adjusting the power generation amount in units of string modules of a solar power generation system according to an embodiment of the present invention, and FIG. 3 is a solar power generation system according to an embodiment of the present invention. It is a schematic processing flowchart of the method for fine-tuning the power generation, and FIG. 4 is a schematic processing flowchart of the prediction error rate calculation process illustrated in FIG. 3, and FIG. 5 is an embodiment of the power generation fine-tuning process illustrated in FIG. 3. FIG. 6 is a schematic processing flowchart for another embodiment of the power generation fine-tuning process illustrated in FIG. 3.

With reference to FIGS. 1 to 6 , a method of finely adjusting the power generation amount in units of string modules of a solar power generation system according to an embodiment of the present invention is as follows.

First, in step S110, the prediction model generator 220 learns weather observation data for a predetermined past period for the area where the solar power generation system is installed, and power generation performance data of the solar power generation system during the past period. Thus, a power generation prediction model for each time period for the solar power generation system is generated. To this end, the prediction model generator 220 collects weather observation data for the past period from the weather information receiver 230, or stores weather observation data collected in real time from the weather information receiver 230 for a certain period of time. You can utilize it.

In step S120, the power generation prediction unit 240 reflects the next day's weather forecast data collected from the weather information receiver 230 into the power generation prediction model to predict the next day's power generation for the solar power generation system.

In step S210, the predicted power generation storage unit 250 stores the next day's power generation predicted in step S120 (hereinafter referred to as predicted power generation).

In the example of FIG. 3, the line (A) displayed between step S120 and step S210 is a date dividing line displayed to separate the days, and the next day's predicted power generation generated in step S120 is the predicted power generation predicted the previous day in step S210. It is recognized and saved. If the date dividing line (A) is displayed in steps S210 and S220, step S210 will recognize and store the next day's predicted power generation generated in step S120 as the next day's predicted power generation.

Meanwhile, in steps S120 and S210, date information corresponding to the predicted power generation amount can be managed together.

In step S220, the actual power generation measurement unit 260 measures the power generation amount for each time period of the solar power generation system, and calculates the actual power generation amount by accumulating the power generation amount for each time period.

In step S230, the actual power generation storage unit 270 stores the actual power generation amount.

In step S240, the prediction error rate calculation unit 280 calculates the prediction error rate by comparing and analyzing the predicted power generation amount and the actual power generation amount at each prediction error rate calculation time that is repeated at a preset period. To this end, the prediction error rate calculation unit 280 calculates the actual remaining power generation amount in step S241, and calculates the actual remaining power generation amount by subtracting the actual power generation amount accumulated up to the time of calculating the prediction error rate from the predicted power generation amount, and calculates the actual remaining power generation amount in step S242. , the predicted remaining power generation amount is predicted, and the predicted remaining power generation amount, which is the power generation amount for the remaining time from the time of calculating the prediction error rate to the end point of daily solar power generation, is predicted. And, in step S243, the prediction error rate calculation unit 280 calculates the prediction error rate based on the difference between the predicted remaining power generation amount and the actual remaining power generation amount.

In step S250, the power generation fine adjustment unit 290 adjusts the boosting voltage of the string optima based on the prediction error rate to correct the error between the predicted power generation amount and the actual power generation amount. To this end, the power generation fine-tuning unit 290 determines whether the prediction error rate exceeds a preset tolerance rate in step S251, and if the prediction error rate exceeds the preset tolerance rate, the boosting rate in step S252. Adjust. That is, in step S252, the power generation fine adjustment unit 290 adjusts the boosting ratio of the string optima by adjusting the duty ratio of a preset boosting control signal to increase/decrease the actual remaining power generation amount. If it is greater than the predicted remaining power generation amount, the value is reduced, and if not, the actual remaining power generation amount is increased.

Meanwhile, Figure 6 shows another embodiment of step S250. Referring to Figure 6, the power generation fine-tuning unit 290 determines whether the prediction error rate exceeds a preset allowable error rate in step S310, and the prediction If the error rate exceeds the preset allowable error rate, steps S320 to S360 are performed. That is, the power generation fine-tuning unit 290 compares the actual power generation amount and the predicted power generation amount of the solar power generation system in step S320, and when the predicted power generation amount exceeds the actual power generation amount, detects the power generation fine adjustment target in step S330. . To this end, the power generation fine-tuning unit 290 monitors the input voltage of each of the string optima and detects at least one string optimizer whose input voltage is less than the start voltage of the corresponding inverter as the target for fine power generation amount adjustment. This is to enable fine adjustment to increase the generated power of the solar power generation system by utilizing the voltage below the inverter starting voltage that is generated from the solar cell string and then discarded.

In addition, the power generation fine-tuning unit 290 performs steps S340 and S350 to fine-tune the power generation of the solar cell string corresponding to the string optima detected in step S330. In step S340, the at least one detected Each of the string optima is controlled to boost the output voltage of each of the string optima to the start voltage of the corresponding inverter (so-called first boosting) to force wake up the corresponding inverter, and in step S350, When the output voltage of the corresponding string optima falls in response to the forced wake-up of the inverter, that is, due to the wake-up of the inverter 300, the inverter 300 is disconnected from the solar cell string 100. When current flows to the side, and as a result, the voltage at the output terminal of the string optimizer 210 is lowered, the power generation fine adjustment unit 290 boosts the output voltage of the string optimizer up to the MPPT start voltage of the corresponding inverter (aka, the second Boosting) controls each of the string optima to increase the actual power generation.

Meanwhile, as a result of the comparison in step S320, if the predicted power generation amount does not exceed the actual power generation amount, the power generation fine adjustment unit 290 finely adjusts the power generation amount by adjusting the boosting ratio in step S360. In particular, in step S360, the boosting ratio can be adjusted to a level to lower the boosting voltage.

When explaining the method of fine-tuning the power generation amount in units of string modules of the solar power generation system referring to FIGS. 1 to 6, when explaining each step, string optima referring to FIGS. 1 and 2, or the solar power generation system. Redundant description of the disclosed content has been omitted.

In this way, the present invention fine-tunes the amount of power output by string module units of the solar power generation system, thereby adjusting the error between the predicted power generation amount predicted in advance for the solar power generation system and the actual power generation amount within a preset tolerance rate. , It has the feature of fine-tuning the power generation of the string module unit by calculating the prediction error rate up to that point at each preset cycle and adjusting the boosting rate of the string optima for the period after the prediction error rate calculation time based on the prediction error rate. .

In particular, the present invention predicts the remaining power generation amount for the remaining time from that point to the end of daily solar power generation at each time point at which the prediction error rate is calculated, and calculates the actual power generation amount generated up to the time of calculating the prediction error rate and the predicted remaining power generation amount. If the sum of is less than the predicted power generation predicted the previous day, there is an advantage in that the actual power generation of the solar power generation system can be slightly increased by including the voltage below the effective voltage output from any solar cell string in the power generation.

Although the embodiments of the present invention have been described above, the scope of the rights of the present invention is not limited thereto, and the present invention can be easily modified from the embodiments by those skilled in the art in the technical field to which the present invention belongs and is recognized as equivalent. Includes all changes and modifications to the extent permitted.

100: solar cell string 110: solar cell module
200: Connection board 210: String Optima
220: prediction model generation unit 230: weather information reception unit
240: power generation prediction unit 250: predicted power generation storage unit
260: Actual power generation measurement unit 270: Actual power generation storage unit
280: Prediction error rate calculation unit 290: Power generation fine adjustment unit

Claims (12)

In the string optima, which is connected between the output terminal of each of the plurality of solar cell strings constituting the solar power generation system and an inverter, and outputs the voltage applied from the solar cell string by boosting or bypassing,
a control unit that controls the operation of the string optimizer based on a preset control algorithm;
A booster unit that boosts or bypasses the voltage transmitted from the solar cell string and outputs it; and
It includes a switch unit that controls the boosting voltage of the booster unit by on/off control of the control unit,
The control unit
In response to a request signal for fine adjustment of power generation generated by a comparative analysis result of the predicted power generation amount of the solar power generation system predicted in advance the previous day and the actual power generation amount of the solar power generation system, the on/off time of the switch unit is adjusted. String optimizer, characterized in that adjusting the boosting voltage. The method of claim 1, wherein the control unit
In response to the power generation fine adjustment request signal to increase the output voltage of the string optimizer,
Compare the input voltage of the string optimizer with the starting voltage of the inverter,
When the input voltage of the string optimizer is less than the starting voltage of the inverter, the output voltage of the string optimizer is boosted up to the starting voltage of the inverter to force wake up the inverter, adjusting the on/off time of the switch unit ,
When the output voltage of the string optima falls in response to a forced wake-up of the inverter, the on/off time of the switch unit is adjusted to boost the output voltage of the string optima up to the MPPT start voltage of the inverter. String optimization with . In the solar power generation system, which is connected between the output terminal of each of the plurality of solar cell strings and an inverter, and includes a plurality of string optima that boost or bypass the voltage applied from the solar cell string and output the output,
a predicted power generation storage unit that stores the predicted power generation amount of the solar power generation system, which was predicted in advance the previous day by reflecting weather forecast data;
an actual power generation measurement unit that measures the power generation amount by time of the solar power generation system and calculates the actual power generation by accumulating the power generation by time zone;
an actual power generation storage unit that stores the actual power generation amount;
A prediction error rate calculation unit that calculates a prediction error rate by comparing and analyzing the predicted power generation and the actual power generation at each prediction error rate calculation time that is repeated at a preset cycle; and
A solar power generation system comprising a power generation fine adjustment unit that adjusts the boosting voltage of the string optima based on the prediction error rate to correct the error between the predicted power generation amount and the actual power generation amount. According to paragraph 3,
By learning weather observation data for a predetermined past period for the area where the solar power generation system is installed and power generation performance data of the solar power generation system during the past period, a power generation prediction model for each time period for the solar power generation system is created. A prediction model generation unit that generates; and
A solar power generation system further comprising a power generation prediction unit that predicts the next day's power generation for the solar power generation system by reflecting the next day's weather forecast data into the power generation prediction model. The method of claim 3, wherein the prediction error rate calculation unit
Calculate the actual remaining power generation by subtracting the actual power generation accumulated up to the time of calculating the prediction error rate from the predicted power generation,
Predict the predicted remaining power generation amount, which is the amount of power generation for the remaining time from the time of calculating the prediction error rate to the end time of daily solar power generation,
A solar power generation system, characterized in that the prediction error rate is calculated based on the difference between the predicted remaining power generation amount and the actual remaining power generation amount. The method of claim 5, wherein the power generation fine adjustment unit
If the prediction error rate exceeds the preset tolerance rate,
A solar power generation system characterized in that the actual remaining power generation amount is increased/decreased by adjusting the boosting ratio of the string optima by adjusting the duty ratio of a preset boosting control signal. The method of claim 5, wherein the power generation fine adjustment unit
If the prediction error rate exceeds a preset allowable error rate, but the predicted remaining power generation amount is less than the actual remaining power generation amount,
Monitoring the input voltage of each of the string optima to detect at least one string optima whose input voltage is less than the starting voltage of the corresponding inverter,
Boosting the output voltage of each of the detected at least one string optima to the start voltage of the corresponding inverter and controlling each of the string optima to force wake up the corresponding inverter,
When the output voltage of the corresponding String Optima falls in response to the forced wake-up of the inverter, the String Optima boosts the output voltage of the String Optima to the MPPT start voltage of the corresponding inverter to increase the actual power generation. A solar power generation system characterized by controlling each of them. A method for fine-tuning the power generation of a solar power generation system including a plurality of string optima connected between the output terminals of each of the plurality of solar cell strings and an inverter, and outputting the voltage applied from the solar cell strings by boosting or bypassing the output terminal. ,
A predicted power generation storage step of storing the predicted power generation amount of the solar power generation system, which was predicted in advance the previous day by reflecting weather forecast data;
An actual power generation measurement step of measuring the power generation amount of the solar power generation system for each time period and calculating the actual power generation amount by accumulating the power generation amount for each time period;
An actual power generation storage step of storing the actual power generation amount;
A prediction error rate calculation step of calculating a prediction error rate by comparing and analyzing the predicted power generation amount and the actual power generation time at each prediction error rate calculation time repeated at a preset period; and
A method for fine-tuning the power generation amount of a solar power generation system, comprising a power generation fine-tuning step of correcting the error between the predicted power generation amount and the actual power generation amount by adjusting the boosting voltage of the string optima based on the prediction error rate. According to clause 8,
By learning weather observation data for a predetermined past period for the area where the solar power generation system is installed and power generation performance data of the solar power generation system during the past period, a power generation prediction model for each time period for the solar power generation system is created. A prediction model generation step; and
A power generation prediction step of predicting the next day's power generation for the solar power generation system by reflecting the next day's weather forecast data to the power generation prediction model. The method of claim 8, wherein the prediction error rate calculation step is
A first step of calculating the actual remaining power generation by subtracting the actual power generation accumulated up to the time of calculating the prediction error rate from the predicted power generation;
A second step of predicting the predicted remaining power generation amount, which is the amount of power generation for the remaining time from the time of calculating the prediction error rate to the end point of daily solar power generation; and
A method for fine-tuning the power generation amount of a solar power generation system, comprising a third step of calculating the prediction error rate based on the difference between the predicted remaining power generation amount and the actual remaining power generation amount. The method of claim 10, wherein the power generation fine adjustment step is
If the prediction error rate exceeds the preset tolerance rate,
A method for fine-tuning the power generation amount of a solar power generation system, characterized in that the actual remaining power generation amount is increased/decreased by adjusting the boosting ratio of the string optima by adjusting the duty ratio of a preset boosting control signal. The method of claim 10, wherein the power generation fine adjustment step is
If the prediction error rate exceeds a preset allowable error rate, but the predicted remaining power generation amount is less than the actual remaining power generation amount,
A power generation fine adjustment target detection step of monitoring the input voltage of each of the string optima and detecting at least one string optima whose input voltage is less than the starting voltage of the corresponding inverter;
A first boosting step of controlling each of the string optima to boost the output voltage of each of the detected at least one string optima to the starting voltage of the corresponding inverter to force wake up the corresponding inverter; and
When the output voltage of the corresponding String Optima falls in response to the forced wake-up of the inverter, the String Optima boosts the output voltage of the String Optima to the MPPT start voltage of the corresponding inverter to increase the actual power generation. A method for fine-tuning the power generation amount of a solar power generation system, comprising a second boosting step for controlling each of the following.

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