How to avoid arc generation—— Aafd fault arc detector solves the problem for you

Encore Hua Nan

【 Abstract 】： Under the national dual carbon policy , Photovoltaic power generation will play a major role in the future energy structure , At the same time, it will also enter a new era of vigorous development .2021 year , The new capacity of distributed photovoltaic power stations exceeds that of centralized power stations , It marks that distributed photovoltaic power stations have entered a stage of large-scale and rapid growth , however , And then “ safety problem ” More and more , It has reached the point of urgent need to be solved .

 

“ Security ” It is the lifeblood of all industries , It is a matter of principle of one vote veto , The safe operation of photovoltaic power station is also the foundation for the power station to obtain commercial returns . With “ The whole county promotes ” The project is constantly implemented , A large number of government agencies 、 School 、 The hospital 、 Residential roofs and gas stations 、 Photovoltaic power stations are installed on the roofs of various material sheds and industrial and commercial colored steel tiles . all the time , Photovoltaic power station “ Arc protection ” and “ Fire disaster ” Occurrence is the difficulty of photovoltaic power station 、 Pain points of rooftop power station 、 The focus of the government 、 The focus of public opinion .

【 key word 】： Photovoltaic power station ; Fault arc ; Electrical fire

1.  Preface

In recent years , Photovoltaic power station fire accidents occur frequently , This will not only damage the property of the power station 、 Power generation income , In serious cases, it will also cause building damage and personal injury , Even spread to the surrounding environment , Leading to a series of secondary disasters .

Arc generation is a common fault phenomenon in photovoltaic power stations , Because the contact falls off 、 Device aging 、 The insulation is broken 、 Poor grounding and other conditions will produce arc .

2.  Arc analysis

l  Series arc

Series arc , Also known as arcing . Series arc is usually caused by poor contact of cable plugs between components 、 The connection between the string cable and the combiner box or inverter is not reliable, etc .

l  Parallel arc

Parallel arc is mainly caused by the short circuit of positive and negative polarity conductors caused by line damage , Or caused by short circuit between string cables . When the string cable is mechanically squeezed or worn , Between the positive and negative poles , Or arc discharge will occur between different strings , This is parallel arc fault . There is also a situation that can lead to parallel arc , When the series arc in the system is not handled in time , The heat of the series arc burns out the cable insulation , Parallel arc will also be generated .

When a parallel arc occurs between the main conductors of the component array, it will cause a major fire accident . The series fault arc can be extinguished by cutting off the DC bus of the photovoltaic system or the corresponding string , However, the parallel fault arc cannot be extinguished , It may even cause greater current to flow through the arc path , Make the arc burn more violently .

at present , Arc protection function integrated in inverter , Parallel arc and grounding arc cannot be detected , But the destructive force of parallel arc is often that of series arc 10 times , The potential safety hazard is greater .

l  Grounding arc

Aging, damage or mechanical damage of components leads to ground discharge , If the components are laid flat on the roof of colored steel tiles , There will be grounding arc or leakage . This kind of fault is not easy to find , Especially in rainy days , at present , The solution is to shut down the inverter , Wait for the grounding place to dry before starting up and running , This method cannot reasonably eliminate hidden dangers , At the same time, it increases the risk of personal electric shock .

3.  Arc related standards and related applications

In order to reduce the occurrence of electrical fire , In particular, the fault arc of the end load is detected , China has issued a series of standards and policies for fault arc detection .

l 《 Fault arc detector 》GB14287.4-2014

 

According to the above national standard requirements ： The fault arc is mainly aimed at the end load , The load power is 10KW following .

l 《 Code for design of automatic fire alarm system 》GB50116-2013

9.1.6  The setting of electrical fire monitoring system shall not affect the normal operation of power supply system , It is not suitable to automatically cut off the power supply .

9.2.4  Electric fire monitoring detector with the function of detecting line fault arc , The length of the protection line should not be greater than 100m

12.4.6  The electrical circuit shall be equipped with electrical fire monitoring detector , The lighting circuit shall be equipped with the function of detecting fault arc

Electrical fire monitoring detector .

12.4.6 The article states that The height is greater than 12m The hidden danger of space is electrical fire , Therefore, the electrical fire monitoring system is set . The fire caused by lighting circuit failure accounts for... Of electrical fire 10％ about , The top of this kind of building is high , A fire is not easy to find , There's no way to put other detectors on it , Only the electrical fire monitoring detector with the function of detecting fault arc shall be set , In order to ensure the reasonable detection of fire caused by lighting circuit failure .

According to the above national standard requirements ： The fault arc is mainly aimed at the lighting circuit at the end , And the length of the detection circuit shall not exceed 100 rice .

3. AAFD The fault arc detector can reasonably monitor the fault arc at the end of the photovoltaic power station

In order to solve the problem of fault arc in photovoltaic power station , Developed by ankerui AAFD Series of fault arcs , It can reasonably monitor the fault arc of the power circuit at the end of the photovoltaic power station .

AAFD Series fault arc detectors are used to detect the fault arc in the access line （ Including fault parallel arc 、 Fault series arc ） Conduct reasonable testing , When the fault arc causing fire is detected in the line , It can give audible and visual alarm on site , And transmit the alarm information to the upper monitoring equipment , In order to achieve the purpose of early warning fire .

AAFD Series fault arc detectors are suitable for industrial and civil buildings 10KW And below , The length of the protection line should not be greater than 100 rice . The product follows the national standard GB 14287.4-2014, It can be applied to the end of photovoltaic power station 、 The nursing home 、 School 、 Commercial buildings 、 hotel 、 factory 、 warehouse 、 The library 、 The office 、 Family house 、 And places of entertainment .

An Kerui one-stop protection scheme

Solution ： Set up electrical fire monitoring system , And a fault arc detector is set in the end electric box .

  The system networking diagram is as follows ：

The fault arc can be connected AcrelEMS Enterprise microgrid energy efficiency management platform , Powerful data reception 、 Handle 、 Storage 、 Access capabilities , The platform combines power monitoring 、 Power statistics 、 Electrical safety and other functions , Interconnection , Reasonable interaction .

 

 

5、 Conclusion

The construction of photovoltaic power stations in China is in full swing , It has entered thousands of households and is closely connected with the production and life of ordinary people , How to ensure the safety of photovoltaic power stations “ Security ” It is attracting great attention from the whole industry . With the layout of photovoltaic industry by the central state-owned power group , The safety problem in the operation of the power station has been raised to the top priority . To solve this problem reasonably , It requires the whole industry to put forward innovative solutions , And constantly improve relevant standards and regulations , And implement relevant requirements in the subsequent construction of power stations .

2022 year 4 month 26 Japan , Relevant departments will meet to study the issue of strengthening infrastructure construction , Propose to build a modern infrastructure system , To achieve economic benefits 、 social results 、 Unity of safety and benefit , Serve major national strategies , Support economic and social development . As an important energy infrastructure , Safe, stable and reasonable operation is an important guarantee for economic development .

 

reference

[1]. Zhou Zhong . The application of power meters in the itemized measurement of electric energy in large public buildings [J]. Modern building electrical 2010.6

[2]. Product selection manual of ankerui Electric Co., Ltd .2020.08

[3].GB50116-2014 Code for fire protection design of buildings [S].

[4].GB14287.4-2014 Fault arc detector [S].