While PV systems provide us with clean energy, they also face the threat of overvoltage caused by lightning, switching operations and other electrical faults. Therefore, choosing the right SPD is crucial to protecting system equipment. Here are some key factors to consider when choosing a PV surge protector.
1. Understand the types of SPD
PV system surge protective device are generally divided into three levels:
Primary protection: used in high-voltage environments such as substations, mainly protecting the entire system.
Secondary protection: installed in the distribution board, providing a medium level of protection, suitable for residential and commercial PV systems.
Third level protection: usually in front of the inverter, providing the last line of defense for the equipment.
Choose the appropriate type according to the size of your PV system and the installation environment.
2. Determine the protection level
The protection level of a PV SPD is usually expressed in terms of rated discharge current (In) and maximum continuous operating voltage (Uc). Consider the following when choosing:
Rated discharge current: ensure that it can handle the maximum surge that may occur.
Maximum continuous operating voltage: should be higher than the maximum operating voltage of the system to avoid frequent triggering.
3. Evaluate the installation location
The installation location of the SPD has a great impact on its performance. It is usually recommended to:
– Install it before the PV inverter to ensure that the key equipment of the system is protected.
– Protect it on both the DC and AC sides to provide comprehensive protection.
4. Consider environmental factors
Environmental factors will also affect the selection of SPD:
Temperature: Select the appropriate product according to the temperature range of the installation environment.
Humidity: In humid environments, waterproof and moisture-proof models should be selected.
Pollution level: Consider the pollution level of the SPD to ensure its reliability in a specific environment.
5. Check standards and certifications
Select DC surge protection device that meet international and domestic standards, such as:
IEC 61643: International Electrotechnical Commission standard for SPD.
UL 1449: American standard for SPD.
Make sure the selected product has relevant certifications to ensure its quality and reliability.
