Máster en Fotovoltaica
Protection of Photovoltaic Panels – What Should You Keep in Mind?
Adequate protection of photovoltaic panels, tailored to their characteristics, is a key factor ensuring their long-term and safe operation under environmental conditions. Properly selected and installed protections safeguard the system from overvoltage, overloads, and other risks that may lead to severe failures. Appropriate technological solutions not only minimize the risk of damage but also enhance the performance and reliability of the entire installation. Discover how to make the protection of photovoltaic panels effective and reliable!
What is the Purpose of Photovoltaic System Protection?
Proper protection of a PV installation prevents overloads, short circuits, and damages caused by existing weather conditions or voltage fluctuations. It is crucial that all system components – including the protections – must be appropriately selected and installed in compliance with current standards while being perfectly matched to the type of installation and its mode of operation. Most protections, primarily due to their importance in any system, are relatively low-cost yet highly effective. Thus, good protection for a photovoltaic system does not have to be expensive.
AC and DC Protections – Photovoltaics with Proper Safeguards
In a PV installation, we distinguish between AC protections (alternating current) and DC protections (direct current), which are fundamental for protecting both the panels and other components of the complete system. DC protections safeguard circuits from excessive current and overvoltage in the part of the system where electricity is generated and transferred from the panels to the inverter. On the other hand, AC protections are applied on the inverter side, where DC is converted to AC, to protect the rest of the installation, including connections to the power grid and user devices. As can be seen, protecting a PV system is complex, which is why it’s worth understanding both concepts in more detail in the following guide.
DC Protection for Photovoltaics
DC protection of a photovoltaic installation is crucial for the safety and longevity of the entire system. Direct current-based installations are highly vulnerable to surges caused by lightning strikes, which can damage both the panels and inverters. The use of additional DC protections helps to avoid such problems, protecting not only the equipment but also preventing fire risks. Inverters come equipped with standard surge protection, but these are not always sufficient to handle extreme voltage spikes.
For this reason, modern photovoltaic systems utilize enhanced DC PV protections, such as modular and standard DC overcurrent circuit breakers and surge arresters. These devices provide a high level of protection while being easy to operate and maintain thanks to their modular design. If protection is triggered and the surge arrester is damaged, only the damaged module can be quickly and easily replaced, restoring system functionality without the need for a complete dismantling. Additionally, there are various types of fuse links available on the market, which are also designed for easy replacement after activation, minimizing system downtime and enabling a fast return to normal operation.
AC Protection for Photovoltaics
AC protection in photovoltaic installations is essential for ensuring the long-term and safe operation of the entire system. The AC side, meaning the part of the installation after the conversion of DC from the panels into AC, is particularly prone to overvoltage caused by changes in the electrical grid or weather conditions such as lightning. Proper use of AC protections on the alternating current side helps minimize the risk of inverter damage and other system components. Adequate protection and safeguarding of the inverter on the AC side can also prevent costly repairs and equipment replacements, which directly translates into financial savings and energy supply continuity.
Various AC protections are available on the market to complement a compatible photovoltaic installation.
- Surge arresters used in AC installations are one of the fundamental protection elements that effectively safeguard the system from the effects of overvoltage. They are equipped with replaceable cartridges, allowing for quick and easy replacement in case of activation, without the need for dismantling the entire system. This is a significant advantage for installers since surge protection should feature maximum modularity, meaning its maintenance requires less effort.
- Overcurrent circuit breakers are essential protection elements in photovoltaic installations on the AC side, safeguarding the system from potential overloads and short circuits. These operate by automatically disconnecting the electrical circuit when the current exceeds the safe level set for a given circuit. Their design allows for easy system recovery after an issue occurs, which is a significant advantage compared to older protection systems that required fuse replacement. Overcurrent protections are available in various types, each suited to specific load types and current characteristics. This allows for the precise customization of protections to the specifics of individual parts of a photovoltaic installation. Overcurrent circuit breakers can significantly enhance the level of protection for your installation.
- Residual current devices – also known as RCDs or ground fault circuit interrupters (GFCIs) – are a key protection element in photovoltaic installations. Their primary function is to prevent electric shock and fires by instantly disconnecting power when they detect an imbalance between the current flowing in and out of a circuit. This imbalance may occur, for example, when current flows outside of a device, such as onto its housing. RCDs are equipped with mechanisms for quickly detecting such irregularities, which is crucial for user safety and protecting electrical equipment from damage. Properly installed in an electrical circuit, RCDs are the first line of defense against potential failures or dangerous incidents in a photovoltaic system. Using RCDs significantly increases the safety of photovoltaic system operation.
As you can see, whether you use SPD surge arresters or other types of protection, it is crucial to ensure they are well-suited to the system. Only then are protections most effective and best meet their intended goals. If you’re unsure which AC/DC photovoltaic protection to choose, contact specialists – they will help, advise, and explain the details.
FAQ:
1. What is DC protection in photovoltaics?
DC protection in photovoltaics safeguards the installation from overvoltage, overloads, and short circuits on the direct current (DC) side, which can occur due to lightning strikes. This prevents damage to panels and the inverter while minimizing the risk of fire.
2. What is the purpose of AC protection in photovoltaics?
AC protection in photovoltaics protects the system on the alternating current (AC) side from overvoltage, overloads, and short circuits. It prevents damage to the inverter and home installation, ensuring continuity of electricity supply.
3. What photovoltaic protections are recommended?
Recommended photovoltaic protections include surge arresters, overcurrent circuit breakers, and residual current devices. Surge arresters protect against sudden voltage spikes, while overcurrent and residual current circuit breakers protect against overloads, short circuits, and electric shock.