Um electric arc It is a high-intensity electrical discharge that occurs when an electric current es through an insulating medium, such as air, ionizing it and creating a conductive channel.
In photovoltaic systems, these events can be triggered by connection failures, corrosion, component wear or adverse environmental conditions.
The occurrence of electric arcs represents a serious risk, as they generate intense heat, ultraviolet light and shock waves, which can cause fires, damage to equipment and serious injuries to people.
Photovoltaic inverters are essential equipment for converting the electrical energy generated by photovoltaic modules into usable alternating current. However, the growing demand for solar energy and the complexity of photovoltaic systems increase the likelihood of electric arcs occurring.
In this scenario, protection against electric arcs becomes essential to ensure the safety and reliability of photovoltaic systems. The Arc Fault Protection Device (AFCI) emerges as an effective solution to detect and interrupt electric arcs in the early stages, minimizing the risks and damages associated with these events.
Although electric arcs may seem like a distant phenomenon, they are a reality in many electrical systems. In this text, we will explore the causes, impacts and factors that contribute to the occurrence of electric arcs in photovoltaic systems, with the aim of understanding the importance of protection against these events.
Common causes of arcing in photovoltaic systems
- Loose connections: Failure to properly tighten electrical connections can generate resistance and heat, increasing the risk of arcing.
- Corrosion: Exposure of metal components to moisture and corrosive agents can deteriorate the materials, compromising electrical conductivity and facilitating the occurrence of arcs.
- Component wear: Over time, electrical components can wear out, losing their insulating properties and becoming more susceptible to electrical faults and arcs.
- Insulation failures: Damage to insulation on cables, connectors and other components can create paths for electrical current, generating arcs.
How does arc flash impact photovoltaic components?
- In modules, electrical arcs can damage cells, causing loss of efficiency and even complete module failure;
- Inverters are sensitive electronic equipment and can be seriously damaged by electrical arcs, resulting in failure and high repair costs;
- Cables can be burned or melted by electrical arcs, compromising system integrity and increasing the risk of fire;
- Junction boxes, which contain several connections, are critical points and can be the source of electric arcs, affecting the entire system.
What are the main factors that influence the occurrence of electric arcs?
- Environmental conditions: Temperature, humidity and exposure to corrosive agents can accelerate the degradation process of components and increase the likelihood of electrical arcs;
- Installation quality: A poorly executed installation, with low-quality components and inadequate workmanship, is more likely to present problems and failures, including the occurrence of electric arcs;
- Components used: Choosing low-quality components or components that are not suitable for the application can compromise the safety of the system and increase the risk of electric arcs.
Given the risks associated with electric arcs in photovoltaic systems, the search for effective solutions to prevent fires and ensure the safety of these installations is essential.
The Arc Fault Protection Device (AFCI) emerges as a promising technology to meet this demand.
What is an AFCI?
AFCI is a protective device designed to detect the characteristic signs of an electrical arc in the early stages and interrupt electrical power before the arc turns into a fire.
This technology uses advanced algorithms and sensitive sensors to identify the small variations in voltage and current that indicate the presence of an electrical arc.
But how does AFCI work?
AFCI operation is based on detecting specific characteristics of electric arcs.
Electric arcs generate high-frequency harmonics that can be detected by AFCI sensors. The presence of an electric arc causes abrupt variations in voltage and current, which are identified by the device's algorithms. Also, the formation of an electric arc increases the impedance of the circuit, which can also be detected by the AFCI.
There are different types of AFCI, which differ in the sensors and algorithms used. We have the electronic AFCI, which uses electronic circuits to detect the characteristics of electric arcs. And the electromechanical AFCI: It combines mechanical and electronic elements to detect and interrupt arcs.
The use of AFCI in photovoltaic systems can prevent fires, as AFCI is capable of detecting and interrupting electrical arcs in the early stages, preventing the spread of fire and minimizing damage.
By interrupting the electrical supply in the event of an electric arc, the AFCI protects the equipment in the photovoltaic system from damage, helps to increase the useful life of the photovoltaic system components, reducing the need for maintenance and replacement, demonstrates compliance with safety standards and ensures the reliability of the system.
The problem of arc flashes in solar power systems is not limited to national borders. In many parts of the world, the growing adoption of solar energy has been accompanied by an increase in arc flash incidents.
Safety in photovoltaic systems is a highly relevant topic and, therefore, several standards and regulations have been developed to guarantee the protection of people and property.
- Inmetro Ordinance No. 515/2023: Determines the mandatory nature of AFCI for inverters with power up to 75 kW, with a deadline for adaptation until December 1, 2024;
- IEC 62446: This international standard establishes the requirements for protection against electric arcs in photovoltaic systems, including the test methods for arc fault protection devices;
- Other standards: In addition to the ordinances of the Inmetro, other technical standards, such as those of ABNT and IEEE, establish requirements for the installation and maintenance of photovoltaic systems, including protection against electric arcs.
The presence of AFCI in photovoltaic inverters is essential to ensure the safety of your solar installations. By quickly detecting and interrupting electrical arcs, AFCI protects your investment, your family and the environment.
Canadian Solar inverters stand out for already having the AFCI integrated and having the best components on the market, such as German IGBTs, Texas Instruments and Intel processors, American relays, Japanese fans and other cutting-edge components.
This combination of cutting-edge technology and high-quality components ensures superior performance, greater durability and a lower incidence of failures. When you choose a Canadian Solar inverter, you are investing in a reliable and safe product that offers the best value for money on the market.
Don't compromise on the safety of your solar installation, count on the quality and reliability of Canadian Solar products. Your solar energy deserves the best protection.
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
