KR101245827B1 - Diagnostic apparatus for shadow and defect of pv module using mic - Google Patents

Abstract

PURPOSE: An apparatus for detecting shadow and failure of a photovoltaic module is provided to predict a problem generated from a solar cell module by monitoring the amount of power generation of an MiC by each solar cell module based on the estimated amount of solar cell power generation according to an amount of sunshine and ambient temperature. CONSTITUTION: A solar cell module(100) includes a micro inverter converter(20). The micro inverter converter measures current at a first measurement point(14) in a rear side of a first cell module(11) and a second measurement point(15) in a rear side of a bypass diode connected with a second cell module(12). The micro inverter converter measures a voltage at a third measurement point(16) in a front side of the first measurement point and a third cell module(13). The micro inverter converter outputs AC current after converting DC current transmitted from each cell module into AC current and measures shadow or failure of the cell module in comparison with a predetermined reference value.

Description

Device for detecting shadow and failure of photovoltaic module using micro inverter converter {Diagnostic apparatus for Shadow and defect of PV Module using MiC}

The present invention relates to a photovoltaic device, and in particular, each solar module is provided with a micro inverter converter (MiC) in order to improve energy efficiency and cost reduction in the field of photovoltaic power generation, and in real time module unit in the MiC The present invention relates to a device for detecting shade and failure of a photovoltaic module using a micro inverter converter that performs environmental / situation response, power / environmental monitoring.

The photovoltaic power generation system is pollution-free and the solar power generation system that converts unlimited solar energy directly into electrical energy is not only mechanical vibration and noise, but also operation and maintenance because the power generation part and control part are composed of semiconductor elements and electronic components. The cost of management can be minimized, so it is already a big axis of renewable energy.

Therefore, in order to improve energy efficiency and reduce cost of solar power generation system, domestic private / public organizations are focusing on improving power generation efficiency of each module (Cell / PCS / ESS) unit, but solar energy efficiency of each solar cell module unit Improvements have been limited, requiring new approaches to improve efficiency in the use of solar energy.

In addition, in order to expand the market and create markets in Korea, the development of solar cell and solar cell module-related technologies, as well as the increase in the amount of generation of the solar power generation system occupying the end of the value chain and the development of the solar power generation system The importance of improving efficiency is increasing, and it is urgent to develop a solar system related technology in which not only various solar related technologies but also IT technologies are fused from a system point of view.

Moreover, photovoltaic module (PV module), which is an essential component of photovoltaic power generation system installed in Korea for 5-7 years, starts to show whitening phenomenon, electrode corrosion phenomenon, insulation breakdown phenomenon, etc. Subsequently, there is a great problem for long-term reliability and long-life technology, and the development of monitoring technology is urgent.

Although the lifetime of the PV module shows a problem in durability depending on the installation method and the installation environment, more important facts raise many problems depending on the photovoltaic module constituent material and manufacturing process.

The solar module has been installed in the dissemination business under strict examination criteria by establishing the performance evaluation standard of the solar modules and introducing the certification system. However, the solar modules installed so far have not been subjected to durability evaluation, and have been installed and distributed only on the power generation performance.

In particular, in the conventional photovoltaic power generation system, since there is an abnormality only in the PV Module Array (a group in which a plurality of PV modules are connected in series), it is not possible to know which photovoltaic module has a failure when the photovoltaic module fails. In this case, if the solar module failure is not handled in advance in terms of management of the photovoltaic system, there is a problem that can damage the system and economic loss caused by the photovoltaic system not operating normally.

As a result, many research institutes are actively researching and developing materials and manufacturing technologies for the long-term life of PV modules. In just a few years, it presents many problems.

Therefore, there is an urgent need to secure a technology for maintenance and management that eliminates the economic loss caused by the photovoltaic system not operating normally and the overload of the system caused by the malfunction.

1 and 2 are 170Wp-class PV modules stringed into 72 solar cells, and in the case of FIG. 1, sunlight is normally transmitted to the solar modules to operate normally without any problem. In the case of 2, the shading of the SCc24 solar cell due to cracks or surroundings of solar cells or natural falling objects (algae droppings, dust, snow, fallen leaves) is a problem even though the solar cell 1 is a problem. As the internal resistance of SCc1 increases, current flows through D3, so that the entire SCc1 ~ SCc24 solar cell cannot produce power, resulting in the solar module's power output being 2 to 3 minutes (about 56Wp). Falls. In addition, it causes deterioration due to internal resistance of the SCc24 solar cell, which causes yellowing of EVA sheet, which is a component of the photovoltaic module, and damage of the solar module due to hot spot, which prevents power generation. .

3 is an I-V curve according to the operation of a PV module currently produced at home and abroad. 1) is the IV curve when the solar module is in normal operation, and 2) and 3) are the cases where sunlight is not transmitted normally due to cracks or shadows on some solar cells of the solar module. 3) is the IV curve when there is no bypass diode. At this time, in the case of 1) there is no power loss, in the case of 2) the power loss is reduced by half, but in the case of 3) it does not produce power at all.

However, even when using bypass diodes to bypass the current as shown in 2), it was not possible to find out which solar module failed or what problem occurred when the solar modules were installed in series of 9-20.

In order to solve such a problem, the inventor of the present invention has proposed the patent registration No. 1000734 (hereinafter, referred to as a prior invention), but in the preceding invention, the solar light using a shunt sensor and a USN (Ubiquitous Sensor Network) Moulde Implemented in a way that detects the abnormality of the module, there is a problem that the output is reduced due to the voltage drop across the shunt sensor, a kind of resistor, and the economic problem that must install the shunt sensor after each bypass diode Was exposed.

The present invention provides a crack or shading of each PV module in a micro inverter converter (MiC) to manage a photovoltaic system for effective system construction of a high efficiency large area module and improvement of photovoltaic system efficiency. By measuring the fluctuation information on the amount of electricity generated by the power generation system and implementing the system to monitor continuously, it provides the device to detect the shade and failure of the solar module using the micro inverter converter based on power / environmental monitoring and control. There is a purpose.

In addition, the present invention implements a micro-inverter (MiC) based on a processor SoC based on the integrated sensing (voltage / current / temperature) suitable for high-efficiency large-area module, installed in each solar module, through systematic operation management through IT convergence It is another object of the present invention to provide a device for detecting a shading and failure of a solar module using a micro inverter converter that can provide a manager with a monitoring result of a solar power plant operating situation in real time.

Apparatus for detecting the shading and failure of the photovoltaic module using a micro inverter converter according to the present invention is a plurality of cell modules are connected in series with a plurality of solar cells, bypass diodes D1, D2 for bypassing the current of each cell module In the photovoltaic module comprising a, D3, the photovoltaic module measures a current value at a first measurement point that is a rear side of the first cell module and a second measurement point that is a rear side of the bypass diode D2 connected in parallel to the second cell module. And a micro inverter converter (MiC) for measuring a voltage value at the first measurement point 14 and the third measurement point, which is the front side of the third cell module, wherein the MiC converts the direct current transmitted from each cell module into an alternating current. Simultaneously outputs the current value measured at the first measurement point and the second measurement point, and the voltage value measured at the first measurement point and the third measurement point and compares the preset reference value to measure the occurrence or failure of the cell module. And that in its technical characteristics.

The device for detecting the shading and failure of the photovoltaic module using the micro inverter converter according to the present invention monitors the amount of generation of MiC for each solar cell module based on the amount of sunlight and the amount of photovoltaic power generation according to the ambient temperature, and thus By analyzing and monitoring the difference in generation amount, it is possible to predict the problem occurring in the solar cell module.

In addition, by implementing Soc (system on chip) integrating high-efficiency MiC, communication module and processor, it provides the base technology for commercialization of large-capacity module, integrated management of prediction and module through information of each MiC module data. Implementing control system technology improves energy efficiency by more than 10% and reduces maintenance costs by more than 15%.

1 is a power supply diagram schematically showing a process in which a current PV module is normally communicated,
FIG. 2 is a power supply diagram schematically illustrating a change in current flow when cracks occur in a specific solar cell constituting the PV module of FIG. 1 or shading occurs due to a foreign material. FIG.
3 is an IV curve according to the operation of the PV module,
4 is a schematic configuration diagram of an apparatus for detecting a shadow and a failure of a solar module using a micro inverter converter as an embodiment of the present invention;
5a to 5c are IV curve diagrams appearing when an error occurs in the individual cell module provided in FIG.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to the present invention, the bypass diode acts as a switching power supply due to an increase in resistance caused by cracks generated in a solar cell or an increase in resistance caused by shading (fallen leaves, algae discharge). Apply the principle of measuring the current flowing to detect the failure of the corresponding cell line, but as described below, using a magnetic field hole hole sensor (Hole Current Transmitter Sensor) without a voltage drop in the current measurement In addition, it converts direct current into alternating current and measures current value and voltage value in MiC (Micrco Inverter Converter) with high power conversion efficiency, and detects the failure of solar cell, and transmits the detection result to outside for real time monitoring. It is characterized by technology implementation.

In general, a PV module is composed of a solar cell line in which a plurality of solar cells are connected in series, and a bypass diode that bypasses current. Since a voltage is applied in the reverse direction of the pass diode, no current flows through the bypass diode. However, when a shade occurs in the cell, a current flows through the bypass diode by bypassing a solar cell having increased electrical resistance.

In the present invention, the current flowing through the bypass diode is detected by the current sensor inside the MiC (Micrco Inverter Converter) installed in the solar module and transmitted to the external monitoring device through the wired / wireless communication network to determine whether the solar module is broken or not. Implemented to monitor.

The MiC is attached to the rear of the PV module, an electronic device that directly converts direct current (DC) power generated in each solar module into AC (AC) power, according to an embodiment of the present invention A high frequency transformer can be used as a flyback method to create a half-period sinusoidal waveform in the DC stage and to connect to the system using an SCR bridge. At this time, the biggest difference between the MiC applied to the present invention and the conventional central inverter configuration is the presence or absence of a DC reverse blocking diode in the connection panel, and when the efficiency of the MiC is 92% or more, it is in a competitive advantage compared to the central inverter. The results of the study are reported.

Therefore, the present invention has a technical feature of adding a function of measuring the current and voltage of the solar module to the MiC efficiency of 92% or more, and to monitor the measured information from the outside through the communication module.

4 illustrates an operation process based on a solar module in which three cell modules are implemented as an embodiment of the present invention.

The photovoltaic module 100 includes a plurality of cell modules 11, 12, 13 connected with a plurality of solar cells in series, and bypass diodes D1, D2, and D3 bypassing currents of the respective cell modules. It is configured by.

At this time, the micro inverter converter (MiC) 20 provided in the solar module 100 converts the direct current transmitted from each cell module 11, 12, 13 into an alternating current, and simultaneously outputs the first cell. The current value is measured at the first measurement point 14, which is the rear side of the module 11, and the second measurement point 15, which is the rear side of the bypass diode D2 connected in parallel with the second cell module 12, and the first measurement point 14 ) And the third measurement point 16, which is the front side of the third cell module 13, to measure the voltage value.

In addition, in the MiC 20, a current value measured at the first measurement point 14 and the second measurement point 15 and a voltage value measured at the first measurement point 14 and the third measurement point 16 are preset reference values. Compared to the detection of shadow or failure of the cell module.

Particularly, in the present invention, in order to minimize the voltage drop in the measurement process of the first measurement point 14 and the second measurement point 15, a current is generated by a hole CT sensor (Hole Current Transmitter Sensor) of a non-contact magnetic field method. The value is measured, which prevents a malfunction due to a drop in output.

At this time, it is a matter of course that a conventional shunt sensor (shunt sensor) can be used in place of the hole CT sensor when measuring current.

During operation of the solar module 100, the MiC 20 detects I ₃ and I ₂ and diagnoses an abnormality of each cell module 11, 12, 13.

First, when I ₃ approaches a reference value preset in the design stage of the solar module 100, the first cell module 11 to the third cell module 13 diagnose that it operates normally.

Second, when I ₃ is less than or equal to the reference value and I ₂ is not detected, it is diagnosed that an error has occurred in any one or both of the first cell module 11 and the third cell module 13.

Third, when I ₂ is detected, an abnormality has occurred in the second cell module 12, and P _t calculated by I ₃ and the total voltage value between the first measurement point 14 and the third measurement point 16, and The degree of shading of the second cell module may be measured by comparing the second voltage value between the first measurement point and the second measurement point and P ₂ calculated by I ₂ .

In this case, a case where an abnormality occurs in any one of each of the cell modules 11, 12, 13 may be classified by an I-V curve in FIGS. 5A to 5C.

That is, FIG. 5A illustrates a case where an abnormality occurs in the third cell module 13 and the current value drops rapidly after V2. FIG. 5B illustrates a case where an abnormality occurs in the second cell module 12 and the current values correspond to V1. 5C shows a sharp drop between V2 and FIG. 5C, when an abnormality occurs in the first cell module 11, the current value rapidly increases while passing through V1 while maintaining a low current value.

On the other hand, in the Mic (20) of the cell module (11) (12) (13) by any one or more communication modules of the wireless transmission and reception (Tx / Rx) communication module for wireless communication or wired transmission and reception communication module for wired communication The abnormal operation is transmitted to the external management system 200.

In this case, the circuit board inside the MiC 20 includes a plurality of electrical elements (resistance, capacitance, etc.) including a processor (MCU), a wireless transmission / reception (Tx / Rx) communication module, or wired communication for integration of a circuit. It is desirable to implement a wired transmit / receive communication module as a Soc (system on chip) that implements a single chip, and decide which electric element is to be integrated into a Soc or separately formed according to the use environment and purpose of use at the product design stage. do.

In addition, the external management system 200 is transferred to the external wired and wireless communication module 210 for receiving a signal transmitted wirelessly from the wireless transmission and reception communication module of the MiC 20 and the wired transmission and reception communication module of the MiC 20 by wire. It is configured to include any one or more of the state monitoring control box 220 for receiving a signal, the signal transmitted from the internal wired and wireless communication module 210 and the state monitoring control box 220 is the monitoring device 230 of the manager It is outputted whether or not the solar module has abnormal operation.

In this case, the monitoring device 230 may be provided with a monitor to visually display the status information, and if necessary, generates a separate emergency signal including an alarm sound to call the administrator's attention, or the manager's mobile phone Of course, it can be configured to send an emergency signal.

In addition, the MiC 20 receives the detection values of the temperature sensors 17, 18 and 19 installed adjacent to each of the cell modules 11, 12, and 13, and when the temperature is higher than the set temperature, by the built-in communication module. It may be implemented to transmit an emergency signal to the external management system 200.

Therefore, the manager is to identify the failure of the photovoltaic power generation system including the Solar Cell Line / PV Module / PV System through the monitoring device 230 implemented in the external management system 200, PV modules (PV) having a problem By quickly replacing the module or MiC, it is possible to prevent overload of the system caused by economic loss and malfunction caused by the PV system not operating normally.

In addition, the present invention analyzes the amount of power generation using the data information measuring the current of the solar cell line and the current flowing in the PV module (PV Module), continuously monitoring the amount of power generation, and monitors information on the amount of power generation situation By providing it to the employer through the system, the owner can accurately grasp the equipment operation in real time.

The present invention as described above is not limited to the above-described specific embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention claimed in the claims. will be.

1: Foreign substance
10: cell module 11: first cell module
12: second cell module 13: third cell module
14: first measurement point 15: second measurement point
16: third measuring point 17, 18, 19: temperature sensor
20: Mic (Micro inverter Converter)
100: solar module
200: external management system 210: external wireless communication module
220: state monitoring control box 230: monitoring device

Claims (5)

In the solar module comprising a plurality of cell modules connected in series with a plurality of solar cells and bypass diodes D1, D2, D3 for bypassing the current of each cell module,
The solar module 100 includes a first measurement point 14, which is a rear side of the first cell module 11, and a second measurement point 15, which is a rear side of the bypass diode D2 connected in parallel to the second cell module 12. A micro inverter converter (MiC) 20 is provided which measures a current value and measures a voltage value at the first measurement point 14 and the third measurement point 16 which is the front side of the third cell module 13.
The MiC 20 converts the direct current transmitted from each cell module 11, 12, 13 into an alternating current and outputs the alternating current, and at the same time the current value measured at the first measurement point 14 and the second measurement point 15 and And comparing the voltage values measured at the first measurement point 14 and the third measurement point 16 with a preset reference value to measure whether the cell module is shaded or broken. Devices for detecting shadows and breakdowns.
The method of claim 1,
The first measurement point (14) and the second measurement point (15) using a micro-inverter converter, characterized in that for measuring the current value by a non-contact magnetic field hole hole sensor (Hole Current Transmitter Sensor); Device to detect shadow and failure of optical module
The method of claim 1,
The MiC 20 operates abnormally by the cell modules 11, 12, 13 by any one or more communication modules of a wireless transmit / receive (Tx / Rx) communication module for wireless communication or a wired transmit / receive communication module for wired communication. Apparatus for detecting the shading and failure of the photovoltaic module using a micro inverter converter, characterized in that for transmitting to the outside.
The method of claim 3, wherein
The circuit board inside the MiC 20 includes a resistor (R), a capacitance (C), a processor (MCU), a wireless transmit / receive (Tx / Rx) communication module or a wired transmit / receive communication module for wire communication. Apparatus for detecting the shading and failure of the photovoltaic module using a micro inverter converter, characterized in that a plurality of electrical elements are implemented as Soc (system on chip).
The method of claim 1,
The MiC 20 receives the detection values of the temperature sensors 17, 18 and 19 installed adjacent to each of the cell modules 11, 12, 13, and receives an emergency signal to the outside by the communication module when the detected temperature is higher than the set temperature. Apparatus for detecting the shading and failure of the photovoltaic module using a micro inverter converter, characterized in that for transmitting.

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