KR101456122B1 - Apparatus and method for fault diagnosis of photovoltaic module - Google Patents

Abstract

An apparatus for diagnosing a fault in a solar module and a method for the same are disclosed. The apparatus for diagnosing a fault in a solar module includes: a voltage detection unit which measures an open circuit voltage of the solar module; a PWM control unit which adjusts a pulse applied to the open circuit voltage if the open circuit voltage is greater than or equal to a preset voltage; a characteristic graph generation unit which measures the open circuit voltage, to which the pulse adjusted by the PWM control unit is applied, and generates a characteristic graph of the solar module; a memory unit which stores the characteristic graph of the solar module using a preset time as a unit; and a fault determination unit which determines whether a fault occurs in the solar module based on the history of changes in the characteristic graph of the solar module, which is stored in the memory unit. Therefore, the apparatus calculates a characteristic curve of the solar module by itself without receiving an input of information on the solar module, thereby accurately determining whether a fault occurs in the solar module using the calculated characteristic curve.

Description

[0001] APPARATUS AND METHOD FOR FAULT DIAGNOSIS OF PHOTOVOLTAIC MODULE [0002]

The present invention relates to a photovoltaic power generation system, and more particularly, to a device for diagnosing a failure of a solar cell module and a method using the same.

As global climate change conventions and problems of depletion of energy resources are emerging, interest in solar energy is rising and research is being actively carried out to use solar energy efficiently.

In Korea, researches are being conducted to supply power generated by alternative energy to the commercial grid. In particular, a photovoltaic power generation system using solar energy converts sunlight into electric power (direct current) by a solar cell, and converts the direct current into an alternating current for use in an ordinary household through an inverter.

The photovoltaic power generation system is a power generation system that converts sunlight directly into electric energy by photoelectric effect by receiving sunlight incident on the surface. The photovoltaic power generation system does not generate environmental pollutants because it is not physically accompanied by chemical change, and because there is no mechanical moving part, it is durable and has a semi-permanent life due to no abrasion due to noise and friction. Because of these advantages, it is possible to minimize the operation management cost, and thus PV power generation is attracting attention as a stable energy source among renewable energy resources

On the other hand, various faults can occur in the PV system. For example, various failures such as a failure of a switching element of an inverter, a failure of a capacitor or an inductor in a low-frequency filter, and a failure of a solar cell module may occur. Such failure may cause a fault to spread to the entire solar power generation system, The operation of the photovoltaic system can be stopped.

Particularly, failure of the solar cell module may cause over discharge of the battery and abnormal load. Conventionally, in order to diagnose a failure of a solar cell module, a trouble diagnosis unit is installed for each solar cell module, and the abnormality of the solar cell module is judged by comparing the generation amount of each solar cell module.

However, in a photovoltaic power generation system composed of only one or two solar cell modules such as a solar street lamp, it is difficult to judge a failed solar cell module by comparing power generation amount between the solar cell modules. Further, when a plurality of solar cell modules fail at the same time, it is difficult to judge a failed solar cell module by a method of comparing the amount of generated power between the solar cell modules.

An object of the present invention is to provide an apparatus for determining whether a solar cell module malfunctions by applying PWM to an open-circuit voltage of the solar cell module.

It is another object of the present invention to provide a method for determining whether a solar cell module is faulty by applying PWM to an open-circuit voltage of the solar cell module.

According to an aspect of the present invention, there is provided a fault diagnosis apparatus for a solar cell power generation system including a voltage detector for measuring an open circuit voltage of a solar cell module, A characteristic graph generation unit for generating a characteristic graph of the solar cell module by measuring an open circuit voltage applied by a pulse controlled by the PWM control unit, And a failure determination unit for determining whether the solar cell module is malfunctioning based on a history of changes in characteristic graphs of the solar cell modules stored in the memory unit.

Here, the failure determining unit may determine that an abnormality has occurred in the solar cell module if the open-circuit voltage is not detected to be equal to or higher than a predetermined voltage for a predetermined time.

According to another aspect of the present invention, there is provided a fault diagnosis method for a photovoltaic power generation apparatus, comprising: measuring an open circuit voltage of a solar cell module; Generating a characteristic graph of the solar cell module by measuring an open-circuit voltage to which the adjusted pulse is applied; and controlling the characteristic graph of the solar cell module to a predetermined time unit And determining whether the solar cell module is malfunctioning based on a history of change in the characteristic graph of the stored solar cell module.

The fault diagnosis apparatus and the fault diagnosis method for the solar cell module according to the embodiment of the present invention can calculate the characteristic graph of the solar cell module by itself without inputting the information of the solar cell module, Thereby determining whether the solar cell module is malfunctioning.

In addition, the characteristic graph can be generated by applying PWM to the voltage generated in the solar cell module, and the failure of the solar cell module can be diagnosed by using the characteristic graph.

1 is a block diagram illustrating a fault diagnosis apparatus for a solar cell module according to an embodiment of the present invention.
2 is a graph showing voltage and current measured over time in the photovoltaic device according to the embodiment of the present invention.
3 is a graph showing voltage and current measured in a specific time range in the photovoltaic device according to the embodiment of the present invention.
4 is a graph illustrating voltage characteristics measured by applying PWM according to an embodiment of the present invention.
5 is a graph for explaining the abnormality of the solar cell module according to the characteristics of the voltage measured by applying the PWM according to the embodiment of the present invention.
FIG. 6 is a flowchart illustrating a method of determining whether a solar cell module is faulty using a voltage measured by applying PWM according to an embodiment of the present invention. Referring to FIG.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, A, B, etc. may be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a fault diagnosis apparatus for a solar cell module according to an embodiment of the present invention.

1, a fault diagnosis apparatus 100 for a solar cell module according to an embodiment of the present invention includes a voltage detecting unit 110, a characteristic curve generating unit 120, a PWM control unit 130, a memory unit 150, A failure determination unit 140, and a display unit 160. [ Here, the fault diagnosis apparatus 100 of the solar cell module can be mounted not only on a large scale solar power generation system but also on a solar street lamp including one or two solar cell modules.

The voltage detector 110 may measure the open circuit voltage of the solar cell module. Here, the open-circuit voltage may mean a voltage between both terminals in a state in which the output terminal of the solar battery cell or module is opened.

The characteristic graph generating unit 120 can generate a characteristic graph of the solar cell module using the open voltage in units of a predetermined time.

The PWM controller 130 can adjust a pulse applied to the open-circuit voltage when the open-circuit voltage is equal to or higher than a predetermined voltage.

Therefore, the characteristic graph generating unit 120 can generate a characteristic graph of the solar cell module by measuring the open-circuit voltage applied with the pulse controlled by the PWM controller 130. [

The display unit 160 may display the status of the solar cell module based on the determination by the failure determination unit 140. [ For example, the display unit 160 may display a green LED when the solar cell module is in a normal state, a yellow LED when the solar cell module is in a state requiring cleaning, In case of failure, it can be indicated by red LED. Also, when the state of the solar cell module is in a fault state, the display unit 160 may display a red LED and generate an alarm sound.

In addition, the display unit 160 may be connected to the failure determination unit 140 by wire or wireless. For example, the display unit 160 may be wirelessly connected to the failure determination unit 140, and may be located at a position where the administrator can easily confirm the failure.

Although the configuration of the apparatus 100 for diagnosing a fault of the solar cell module according to the embodiment of the present invention has been described with reference to each constituent unit for convenience of explanation, at least two of the constituent units may be combined to form one constituent unit, May be divided into a plurality of constituent parts to perform the functions and the case of the integrated and separate embodiments of each constituent part is also included in the scope of the present invention unless the essence of the present invention is satisfied.

For example, the functions performed by the characteristic graph generation unit 120, the PWM control unit 130, and the failure determination unit 140 may be performed by one processor. That is, the characteristic curve or the correlation table of the solar cell module can be generated by the microprocessor built in the fault diagnosis apparatus 100 of the solar cell module, and the failure or the failure of the solar cell module using the characteristic graph of the solar cell module Can be judged.

FIG. 2 is a graph showing voltage and current measured over time in the photovoltaic device according to the embodiment of the present invention. FIG. 3 is a graph showing the voltage and current measured in a specific time range in the photovoltaic device according to the embodiment of the present invention. And current.

FIG. 2 is a graph showing changes with time of the open-circuit voltage (Voc), the actual generation voltage (Vmax), and the current amount during power generation (I) of the solar cell module according to the embodiment of the present invention. 3, it can be seen that the open-circuit voltage Voc, the actual generated voltage Vmax, and the generated current amount I vary in correlation with each other. In particular, it can be seen that there is a difference between the open-circuit voltage (Voc) and the actual generated voltage (Vmax) in the section indicated by A. The voltage of the section indicating such a difference can be called a cut-in voltage. Figure 3 more clearly shows the section labeled A.

The photovoltaic power generation device has a characteristic that when a voltage exceeding a predetermined voltage is generated from the solar cell module, the battery is charged with electric power. Therefore, a large difference may occur between the open-circuit voltage Voc and the actual generated voltage Vmax on the basis of a constant voltage (for example, 12 V) or more, which may cause a cut-in voltage .

For example, the cut-in voltage may be approximately 12V, which may occur at sunrise. In other words, before the sunrise, there is no development, and the sunrise can start to develop.

FIG. 4 is a graph showing the characteristics of a voltage measured by applying PWM according to an embodiment of the present invention. FIG. 5 is a graph showing the characteristics of a solar cell module according to an embodiment of the present invention, And a graph for explaining whether or not it is.

1, a fault diagnosis apparatus for a solar cell module according to an embodiment of the present invention will be described.

The voltage detector 110 may measure the open circuit voltage of the solar cell module.

The PWM controller 130 can adjust a pulse applied to the open-circuit voltage when the open-circuit voltage is equal to or higher than a predetermined voltage. Here, the preset voltage may refer to the cut-in voltage described above. For example, the preset voltage may be about 12 volts when the sun is at sunrise.

The characteristic graph generating unit 120 may generate a characteristic graph of the solar cell module by measuring an open-circuit voltage applied with a pulse controlled by the PWM controller 130. [

4 is an exemplary diagram showing a characteristic graph generated by the characteristic graph generating unit 120. As shown in FIG. Referring to FIG. 4, the voltage measured in the solar cell module may vary between the open-circuit voltage Voc and the actual generated voltage Vmax according to the pulse applied by the PWM controller 170.

For example, when 0% PWM (Pulse Width Modulation) is applied, the voltage measured in the solar cell module is the open-circuit voltage (Voc) .

Further, as the graph moves in the direction of the arrow shown in Fig. 4, it indicates that the solar cell module is aged. That is, as the solar cell module ages, the measured open-circuit voltage Voc and the actual generated voltage Vmax become low. For example, referring to FIG. 5, the case of B indicates a case where an abnormality occurs due to aging of the solar cell module or the like, and the case of C indicates a normal state.

The memory unit 150 may store the characteristic graph of the solar cell module displayed as shown in FIG. 4 on a predetermined time basis, and the predetermined time may be set to one day.

The failure determination unit 140 can determine whether the solar cell module is malfunctioning based on the history of the characteristic graph of the solar cell module stored in the memory unit 150. [ That is, it is possible to determine whether the solar cell module is faulty through the criteria shown in FIG.

In addition, if the open-circuit voltage is not detected to be equal to or higher than the preset voltage for a predetermined time, the failure determination unit 140 can determine that an abnormality has occurred in the solar cell module. Here, a predetermined period of time can be set by the administrator, and may be one day, one week, or the like.

FIG. 6 is a flowchart illustrating a method of determining whether a solar cell module is faulty using a voltage measured by applying PWM according to an embodiment of the present invention. Referring to FIG.

The open circuit voltage of the solar cell module can be measured (S610).

It can be determined whether the open-circuit voltage is equal to or higher than a predetermined voltage (S620). Here, the preset voltage may refer to the cut-in voltage described above. For example, the preset voltage may be about 12 volts when the sun is at sunrise.

When the open-circuit voltage is equal to or higher than a predetermined voltage, a pulse applied to the open-circuit voltage can be adjusted (S630).

A characteristic graph of the solar cell module can be generated by measuring the open voltage to which the adjusted pulse is applied (S640). That is, a characteristic graph of the solar cell module as shown in Fig. 4 can be generated.

The characteristic graph of the solar cell module can be stored in units of a preset time (S650). Here, the predetermined time may be set to one day.

The failure of the solar cell module can be determined based on the history of the stored characteristic graph of the stored solar cell module (S660). That is, it is possible to determine whether the solar cell module is malfunctioning based on the criteria shown in FIG.

Further, if the open-circuit voltage is not detected over the preset voltage for a predetermined time, it can be determined that an abnormality has occurred in the solar cell module. Here, a predetermined period of time can be set by the administrator, and may be one day, one week, or the like.

Finally, the user or the manager can be informed of the failure of the solar cell module (S670).

The operation of the fault diagnosis method for the photovoltaic apparatus according to the embodiment of the present invention described above can be implemented as a computer-readable program or a code on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is read by a computer. The computer-readable recording medium may also be distributed and distributed in a networked computer system so that a computer-readable program or code can be stored and executed in a distributed manner.

The fault diagnosis apparatus and the fault diagnosis method for the solar cell module according to the embodiments of the present invention may be implemented by calculating the characteristic graph of the solar cell module by itself without inputting the information of the solar cell module, It is possible to determine whether the solar cell module is malfunctioning or not.

In addition, the characteristic graph can be generated by applying PWM to the voltage generated in the solar cell module, and the failure of the solar cell module can be diagnosed by using the characteristic graph.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

100: Fault diagnosis device of solar cell module
110: Voltage detection unit 120: Characteristic graph generation unit
130: PWM control unit 140:
150: memory unit 160: display unit

Claims (8)

A voltage detector for measuring an open circuit voltage of the solar cell module;
A PWM controller for adjusting a pulse applied to the open-circuit voltage when the open-circuit voltage is equal to or higher than a predetermined voltage;
A characteristic graph generating unit for generating a characteristic graph of the solar cell module by measuring an open-circuit voltage applied by the pulse controlled by the PWM controller;
A memory unit for storing a characteristic graph of the solar cell module in units of a preset time; And
And a failure determination unit for determining whether or not the solar cell module is faulty based on a history of change in a characteristic graph of the solar cell module stored in the memory unit. The method according to claim 1,
Further comprising a display unit for indicating whether the solar cell module is faulty or not by means of an LED. The method according to claim 1,
Wherein the predetermined time is one day. The method according to claim 1,
Wherein the failure determination unit
And determines that an abnormality has occurred in the solar cell module if the open-circuit voltage is not detected to be equal to or higher than the preset voltage for a predetermined period of time. Measuring an open circuit voltage of the solar cell module;
Adjusting a pulse applied to the open-circuit voltage when the open-circuit voltage exceeds a predetermined voltage;
Measuring an open-circuit voltage applied the adjusted pulse to generate a characteristic graph of the solar cell module;
Storing a characteristic graph of the solar cell module in units of a preset time; And
And determining whether the solar cell module is malfunctioning based on a history of change of a characteristic graph of the stored solar cell module. The method of claim 5,
Further comprising the step of indicating the failure of the solar cell module with an LED. The method of claim 5,
Wherein the predetermined time is one day. The method of claim 5,
The step of determining whether the solar cell module is faulty comprises the steps of:
And determining that an abnormality has occurred in the solar cell module if the open-circuit voltage is not detected to be higher than the preset voltage for a predetermined period of time.

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