KR102186867B1 - Diagnosis apparatus and method of photovoltaic inverter using analysis of power quality - Google Patents

Abstract

The present invention relates to an apparatus and method for diagnosing a photovoltaic inverter using power quality analysis for diagnosing a deterioration state of an electrolytic capacitor of a photovoltaic inverter by using a regression analysis of inverter harmonics with respect to solar insolation. The solar inverter diagnosis apparatus using power quality analysis according to the present invention may include a measurement unit, a communication unit, an analysis unit, a determination unit, a data storage unit, and an output unit. The measurement unit measures the insolation data of sunlight and the harmonic value of the solar inverter in real time. The communication unit remotely transmits and receives the data measured by the measurement unit and the control signal of the determination unit. The analysis unit performs statistical linear regression analysis using the solar insolation data and harmonic values measured by the measurement unit. The determination unit compares and analyzes the result of linear regression analysis of the analysis unit with the solar insolation data and harmonic values measured in real time by the measurement unit to determine a deterioration abnormality of the electrolytic capacitor of the solar inverter. The data storage unit may store solar insolation data and harmonic values measured at the initial installation of the solar inverter. In addition, the data storage unit may store data as a result of performing a statistical linear regression analysis by using the initial solar insolation data and harmonic values previously stored in the data storage unit by the analysis unit. In addition, the data storage unit may store solar radiation data measured in real time by the measurement unit and a harmonic value of the solar inverter. The output unit may be operated under the control of a determination unit to display an abnormal state of the solar inverter capacitor.

Description

TECHNICAL FIELD The diagnosis apparatus and method of photovoltaic inverter using power quality analysis {Diagnosis apparatus and method of photovoltaic inverter using analysis of power quality}

The present invention relates to an apparatus and method for diagnosing a photovoltaic inverter using power quality analysis, and the power quality for diagnosing the deterioration state of an electrolytic capacitor of a photovoltaic inverter by using a regression analysis of the inverter harmonics to the amount of solar irradiation. It relates to a solar inverter diagnostic apparatus and method using the analysis.

In general, a photovoltaic power generation system converts light energy into electrical energy, a solar cell module that converts light energy into electrical energy, a connection panel that collects the direct current produced by the solar cell module and supplies it to an inverter, and the connection It includes an inverter that converts DC power collected in the class to AC power.

Here, the electrolytic capacitor, which is a major component of the solar inverter, is a consumable item and is known as a major cause of failure of the solar inverter. The electrolytic capacitor of the solar inverter is used in the construction of a DC filter that smoothes the waveform and reduces ripple of a DC power source, and an AC filter that functions as a filter that suppresses harmonics supplied to the load.

These electrolytic capacitors are very vulnerable to temperature and have an average lifespan of 5 to 7 years, but due to the nature of the field mainly installed outdoors, the lifespan may be shorter. In a solar inverter, when the inverter suddenly stops due to a capacitor failure, economic loss increases according to the time required for replacement of the inverter. Therefore, it is desirable to reduce the economic loss by predicting and preparing for a failure state in advance.

Korean Patent Registration No. 10-1238620 (announced on February 28, 2013)

Accordingly, the technical problem to be achieved by the present invention is to solve the conventional disadvantages, to prevent economic loss due to sudden failure and stoppage of the solar inverter, and to secure the safety of electrical equipment.

A photovoltaic inverter diagnosis apparatus using power quality analysis according to an aspect of the present invention for achieving this technical problem may include a measurement unit, a communication unit, an analysis unit, a determination unit, a data storage unit, and an output unit.

The measurement unit measures the insolation data of sunlight and the harmonic value of the solar inverter in real time. The communication unit remotely transmits and receives the data measured by the measurement unit and the control signal of the determination unit. The analysis unit performs statistical linear regression analysis using the solar insolation data and harmonic values measured by the measurement unit.

The determination unit compares and analyzes the result of linear regression analysis of the analysis unit with the solar insolation data and harmonic values measured in real time by the measurement unit to determine a deterioration abnormality of the electrolytic capacitor of the solar inverter.

The data storage unit may store solar insolation data and harmonic values measured at the initial installation of the solar inverter. In addition, the data storage unit may store data as a result of performing a statistical linear regression analysis by using the initial solar insolation data and harmonic values previously stored in the data storage unit by the analysis unit. In addition, the data storage unit may store solar radiation data measured in real time by the measurement unit and a harmonic value of the solar inverter. The output unit may be operated under the control of a determination unit to display an abnormal state of the solar inverter capacitor.

In addition, the solar inverter diagnosis method using power quality analysis according to another aspect of the present invention includes the step of extracting the insolation data of the slope of the sunlight (S10), measuring the harmonic value of the solar inverter according to the extracted solar radiation data. Step S20 and performing statistical linear regression analysis using the extracted solar insolation data and harmonic values (S30) may be included.

In addition, the step of extracting solar insolation data in real time and measuring the harmonics value of the solar inverter according to the solar insolation in real time (S40), the solar insolation data and harmonics values measured in real time, and the result data of linear regression analysis The step of comparing and analyzing (S50), determining whether a solar inverter capacitor is deteriorated based on a preset reference range using the comparison analysis result (S60), and the abnormal state of the solar inverter capacitor according to the determination result It may include a step (S70) to output and display.

As described above, the solar inverter diagnostic apparatus and method using the power quality analysis according to the present invention diagnoses the deterioration state of the electrolytic capacitor, which is a major consumable component of the solar inverter, so that the solar inverter stops due to sudden failure. There is an effect that can prevent accidents. In addition, there is an effect of preventing economic loss due to failure and ensuring safety of electrical equipment by predicting deterioration failure in advance before failure of the solar inverter and performing preventive maintenance in advance.

1 is a configuration diagram showing a solar inverter diagnostic apparatus using power quality analysis according to an embodiment of the present invention.
2 is a diagram showing harmonic characteristics of a solar inverter according to an embodiment of the present invention.
3A, 3B, and 3C are views showing total harmonic distortion (THD) according to solar irradiation according to an embodiment of the present invention.
4 is a flowchart illustrating a method of diagnosing a solar inverter using power quality analysis according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In addition, terms such as "... unit", "... group", and "... module" described in the specification mean a unit that processes at least one function or operation, which is implemented by hardware or software or a combination of hardware and software. Can be.

Hereinafter, the present invention will be described in detail by describing a preferred embodiment of the present invention with reference to the accompanying drawings.

The same reference numerals in each drawing indicate the same members.

1 is a configuration diagram showing a solar inverter diagnostic apparatus using power quality analysis according to an embodiment of the present invention, Figure 2 is a view showing the harmonic characteristics of the solar inverter according to an embodiment of the present invention. That is, FIG. 2 is a diagram illustrating an amount of change in harmonics according to the amount of solar radiation in the solar inverter according to an embodiment of the present invention.

A photovoltaic inverter diagnosis apparatus and method using power quality analysis according to an embodiment of the present invention relates to an apparatus and method for diagnosing the photovoltaic inverter 20 through analysis of secondary-side power quality data of the photovoltaic inverter 20. .

The solar inverter diagnostic device 10 using power quality analysis according to an embodiment of the present invention receives the measured data from the measuring device 11 and the measuring device 11 connected to the solar inverter 20 remotely. A diagnostic server 12 for diagnosing the solar inverter 20 may be included.

The measurement device 11 may include a measurement unit 100 and a first communication unit 210. In addition, the measurement unit 100 is connected to the meteorological measurement module 110 for measuring the amount of solar radiation and the solar inverter 20 to measure the harmonic value of the solar inverter 20 at all times. Can include.

The diagnosis server 12 may include a second communication unit 220, an analysis unit 300, a determination unit 400, a data storage unit 500, and an output unit 600. The second communication unit 220 may remotely receive data measured by the measurement unit 100 using the first communication unit 210.

The analysis unit 300 may perform a statistical linear regression analysis using the solar insolation data and harmonic values measured through the measurement unit 100 and previously stored in the data storage unit 500. Here, the solar insolation data and harmonic values stored in advance in the data storage unit 500 may be initial data measured at the initial installation of the solar inverter 20.

In addition, as shown in FIG. 2, the analysis unit 300 may extract linearized data of harmonics according to the amount of insolation by performing a statistical linear regression analysis through a plurality of data measured using the measurement unit 100.

In addition, the determination unit 400 may compare and analyze the result of the linear regression analysis of the analysis unit 300 and the data measured in real time by the measurement unit 100 to determine the deterioration abnormality of the capacitor of the solar inverter 20. . In addition, the determination unit 400 determines whether or not the measured data in real time is out of a preset reference range, and when out of the reference range, generates notification information for a deterioration abnormality of the capacitor of the solar inverter 20, and the output unit ( 600) can be displayed.

In addition, the determination unit 400 may transmit a control signal to the measurement unit 100 to change a measurement period in which the measurement unit 100 measures the solar radiation data and the harmonic value of the solar inverter 20 in real time. .

When the electrolytic capacitor is deteriorated in the solar inverter 20, the solar inverter 20 stops due to an abnormality in the output voltage and current of the solar inverter 20 or a harmonic problem occurs.

In general, the AC filter of the solar inverter 20 is a passive filter based on LC series resonance and is designed to fit the rated capacity, so it has a characteristic of increasing harmonics in a region with low solar radiation and low power generation. The determination unit 400 according to the present invention performs a comparative analysis between the linearized value and the harmonic value according to the actual amount of insolation through regression analysis of the harmonic value according to the amount of insolation, so that the electrolytic capacitor of the solar inverter 20 is abnormal. Can be diagnosed.

In addition, the determination unit 400 determines when an error of more than a certain ratio occurs between the linearized value and the harmonic value according to the actual amount of insolation through statistical linear regression analysis using the comparison analysis result, and the solar inverter 20 It is possible to predict the failure timing of the electrolytic capacitor of, and perform the inspection notification function of the solar inverter 20.

That is, the determination unit 400 predicts and informs the remaining life of the electrolytic capacitor of the solar inverter 20 so that the user can decide in advance the replacement time of the electrolytic capacitor, and the sudden change of the solar inverter 20 It can prevent breakdown and stop accident.

3A, 3B, and 3C are views showing total harmonic distortion (THD) according to solar irradiation according to an embodiment of the present invention. That is, FIG. 3A is a view showing the current THD (Total Harmonic Distortion) (A1) at a solar radiation amount of 700 W/m ² at a predetermined time, and FIG. 3B is a view showing the solar radiation amount at a predetermined time of 400 W/m. ² is a diagram showing the current THD (Total Harmonic Distortion) (A2), and FIG. 3C is a current THD (Total Harmonic Distortion, Total Harmonic Distortion) at a predetermined point in time of 200 W/m ² It is a figure showing A3).

As shown in FIGS. 3A, 3B, and 3C, the solar inverter diagnostic apparatus 10 using power quality analysis according to an embodiment of the present invention uses a total harmonic distortion (THD). It is possible to diagnose whether there is an abnormality in the electrolytic capacitor of (20).

The analysis unit 300 may extract THD (Total Harmonic Distortion) based on the solar insolation data measured using the measurement unit 100 and the harmonic value of the solar inverter 20.

The THD for the harmonic of the solar inverter 20 can be calculated using the following [Equation 1] and [Equation 2].

[Equation 1]

는 태양광 인버터(20)의 고조파에 대한 전압 THD이고,

는 기본파 전압의 RMS(Root Meam Square) 값이며,

는 각 차수별 고조파 전압의 RMS 값이다.From here,

Is the voltage THD for the harmonics of the solar inverter 20,

Is the RMS (Root Meam Square) value of the fundamental wave voltage,

Is the RMS value of the harmonic voltage for each order.

[Equation 2]

는 태양광 인버터(20)의 고조파에 대한 전류 THD이고,

는 기본파 전류의 RMS 값이며,

는 각 차수별 고조파 전류의 RMS 값이다.From here,

Is the current THD for harmonics of the solar inverter 20,

Is the RMS value of the fundamental wave current,

Is the RMS value of the harmonic current for each order.

In addition, the determination unit 400 compares and analyzes the reference THD previously extracted through the analysis unit 300 and stored in the data storage unit 500 and the real-time THD extracted using the data measured in real time, and the solar inverter 20 ) It is possible to judge the deterioration abnormality of the capacitor.

That is, the determination unit 400 determines whether the THD extracted in real time is out of a preset reference range compared to the reference THD, and when it is out of the reference range, the solar inverter 20 notifies the deterioration abnormality notification information of the capacitor. It can be generated and displayed by controlling the output unit 600.

The data storage unit 500 may store solar insolation data and harmonic values measured at the initial installation of the solar inverter 20. In addition, the data storage unit 500 may store data as a result of performing a statistical linear regression analysis using the initial solar insolation data and harmonic values previously stored in the data storage unit 500 by the analysis unit 300. In addition, the data storage unit 500 may store solar radiation data measured in real time by the measurement unit 100 and a harmonic value of the solar inverter 20.

The communication unit 200 may remotely transmit and receive data measured by the measurement unit 100 and a control signal of the determination unit 400. That is, the data measured by the measurement unit 100 is transmitted to the second communication unit 220 using the first communication unit 210, and the control signal of the determination unit 400 is generated using the second communication unit 220. 1 Can be transmitted to the communication unit 210. The output unit 600 may be operated under the control of the determination unit 400 to display an abnormal state of the solar inverter 20 capacitor.

4 is a flowchart illustrating a method of diagnosing a solar inverter using power quality analysis according to an embodiment of the present invention. In the solar inverter diagnostic method using power quality analysis according to an embodiment of the present invention, the step of extracting the insolation of the inclined surface of sunlight (S10), and measuring the harmonic value of the solar inverter 20 according to the amount of solar insolation ( S20) and performing a statistical linear regression analysis using the extracted solar insolation and harmonic values (S30).

Here, in the step of extracting the amount of solar radiation (S10), the amount of solar radiation may be measured using the measurement unit 100, or information regarding the amount of solar radiation may be received from the Meteorological Agency. In addition, the step of performing statistical linear regression analysis (S30) collects information on the amount of solar insolation and the harmonic value of the solar inverter 20 according to the amount of solar insolation at the initial installation of the solar inverter 20, and the collected By performing statistical linear regression analysis using the data, it is possible to extract a reference harmonic value according to the amount of solar insolation.

In addition, in the solar inverter diagnosis method using power quality analysis according to an embodiment of the present invention, the step of extracting solar insolation in real time and measuring a harmonic value of the solar inverter 20 according to the solar insolation in real time ( S40) and comparing and analyzing the data measured in real time with the result data of the linear regression analysis (S50).

In addition, the step of determining whether the solar inverter 20 capacitor is deteriorated based on a preset reference range using the comparison analysis result (S60), and outputs the abnormal state of the solar inverter 20 capacitor according to the determination result. It may include a step (S70) indicated by.

In addition, the step of determining whether the deterioration is abnormal (S60) is performed using the comparison analysis result so that the user can determine in advance the replacement timing of the solar inverter 20 electrolytic capacitor. It may involve estimating the timing of failure and remaining life.

As described above, the solar inverter diagnostic apparatus and method using power quality analysis according to an embodiment of the present invention is a deterioration state of the electrolytic capacitor, which is a major consumable component of the solar inverter 20, through regression analysis of the inverter harmonics with respect to solar irradiation. By diagnosing the photovoltaic inverter 20, there is an effect of preventing economic loss due to sudden failure and stopping of the solar inverter 20, and securing the safety of electrical equipment.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and is easily changed from the embodiments of the present invention by those of ordinary skill in the art to which the present invention belongs. It includes all changes to the extent deemed acceptable.

10: photovoltaic inverter diagnostic device 11: measuring device
12: diagnostic server 20: solar inverter
100: measuring unit 110: meteorological measurement module
120: harmonic measurement module 200: communication unit
210: first communication unit 220: second communication unit
300: analysis unit 400: judgment unit
500: data storage unit 600: output unit
A1, A2, A3: Total Harmonic Distortion (THD)

Claims (6)

A measuring unit for measuring insolation data of solar light and a harmonic value of the solar inverter in real time;
An analysis unit for performing statistical linear regression analysis using the solar insolation data and harmonic values measured by the measurement unit;
A determination unit for determining a deterioration abnormality of the electrolytic capacitor of the solar inverter by comparing and analyzing the result of the linear regression analysis of the analysis unit with the solar insolation data and harmonic values measured in real time by the measurement unit;
A communication unit for remotely transmitting and receiving data measured by the measurement unit and a control signal of the determination unit; And
And an output unit that is operated according to the control of the determination unit to display an abnormal state of the solar inverter capacitor. 2. A solar inverter diagnosis apparatus using power quality analysis, comprising: a.
The method of claim 1,
The analysis unit performs a statistical linear regression analysis based on the plurality of solar insolation data measured using the measuring unit and the harmonic values of the solar inverter, and extracts linearization data of the solar inverter harmonics according to the solar insolation. Solar inverter diagnosis device using power quality analysis.
The method of claim 1,
The determination unit performs power quality analysis, characterized in that it determines whether or not the measured data in real time is out of a preset reference range through the measurement unit, and generates notification information of a deterioration abnormality of the solar inverter capacitor when it is out of the reference range. Photovoltaic inverter diagnostic device.
The method of claim 1,
The determination unit transmits a control signal to the measurement unit, and changes the measurement period in which the measurement unit measures the solar insolation data and the harmonic value of the solar inverter in real time.
Extracting data on insolation of the inclined surface of sunlight (S10);
Measuring a harmonic value of the solar inverter according to the extracted solar insolation data (S20);
Performing statistical linear regression analysis using the extracted solar insolation data and harmonic values (S30);
Extracting solar insolation data in real time, and measuring a harmonic value of a solar inverter according to the solar insolation in real time (S40);
Comparing and analyzing the solar insolation data and harmonic values measured in real time and the result data of the linear regression analysis (S50);
Determining whether the solar inverter capacitor is deteriorated or not based on a preset reference range using the comparison analysis result (S60); And
A method for diagnosing a solar inverter using power quality analysis comprising the step (S70) of outputting and displaying an abnormal state of the solar inverter capacitor according to a result of determining the abnormality.
The method of claim 5,
The step (S60) of determining whether the deterioration is abnormal
Power quality analysis, characterized in that it determines whether or not the solar insolation data and harmonic values measured in real time are out of a preset reference range, and generates notification information of deterioration abnormality of the solar inverter capacitor when out of the reference range. Solar inverter diagnostic method used.

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