Defending Against Voltage Surges: Surge Protection Devices for Photovoltaic Systems

Photovoltaic power systems are often exposed to large open spaces, such as outdoor areas or rooftops of buildings. Charged clouds accumulating above such open spaces tend to discharge in the form of lightning, leading to a high probability of voltage surges. The broader the area, the greater the likelihood of destructive surges. Surges can easily damage sensitive components within photovoltaic equipment, affecting the operation and reliability of the solar system and even posing a threat to personal safety. In addition to lightning, significant switch surges can occur during the opening and closing of high-power circuits, the connection or disconnection of inductive and capacitive loads, and the disconnection of large electrical systems or transformers, causing harm to related equipment and circuits. Therefore, surge protection is crucial for maintaining the lifespan and stable operation of photovoltaic power systems.

Different Types of Surge Protection Devices

Type 1: With extremely powerful energy from lightning strikes, surge protection devices (SPDs), also called surge protectors, dissipate lightning energy in a graded manner, gradually releasing it to the ground. The Type 1 SPDs can dissipate direct lightning currents or the enormous energy conducted when the power transmission line suffers a direct lightning strike.

Type 2: The Type 2 surge protectors are designed to protect against residual voltage from the front stage and protection against induced lightning in the area. After the front stage has dissipated the large surge voltage and energy, some considerable energy can still be conducted, posing a threat to other devices in the system. This requires the Type 2 surge protectors to further absorb it.

Type 3: The ultimate goal of the Type 3 of surge protectors is to reduce the value of residual surge voltage again, preventing the surge energy from damaging equipment. Its lightning current carrying capacity should not be less than 10 kA. For particularly important or sensitive electronic devices, Type 3 protection is necessary, and it can also protect electrical equipment from the transient overvoltage generated within the system.

Key Parameters of Surge Protection Devices

Maximum Continuous Operating Voltage (Ucpv): The maximum continuous voltage that the SPD can withstand without triggering a protective response, a crucial parameter for the long-term reliability of the device.

Voltage Protection Level (Up): It indicates the voltage threshold at which SPDs activate and start to provide protection.

Nominal Discharge Current (In): The maximum surge current that SPDs can handle without failure or performance degradation, reflecting the device’s ability to dissipate transient surge energy.

Maximum Discharge Current (Imax): The maximum surge current that SPDs can safely transfer, providing information about the device’s ability to handle high-energy transient events.

Short-Circuit Current Rating (Iscpv): The maximum fault current that SPDs can safely withstand without causing damage, ensuring the device can handle short-circuit conditions.

Response Time: The time it takes for SPDs to detect overvoltage, respond, and start diverting surge current.

Protection Type and Mode: SPDs can be classified based on their type (Type 1, Type 2, or Type 3) and protection mode (e.g., common mode, differential mode). The choice of device type depends on the specific requirements and location within the solar power system.

Selection and Installation of Surge Protection Devices

Surge protection devices should always be installed upstream of the equipment to be protected. They should provide surge protection from the positive and negative terminals to ground at the DC output of solar panels, at the combiner boxes of multiple solar panels, and at the AC output of inverters. The correct selection and installation of surge protectors depend mainly on the maximum continuous operating voltage, voltage protection level and nominal discharge current parameters. Before actual installation, a careful assessment of the system and installation environment by professionals is necessary to choose the right equipment.

Advantages of SPDs with Remote Signal Contacts

Remote signal contacts, usually connected to the disconnect component inside the surge protector, serve as a device that provides warning information. In normal operation, it is in a short-circuited state and outputs a short-circuit signal. When the surge protector becomes overheated, causing the disconnect component to open, the remote signal component (relay) is triggered. The normally closed end opens while the normally open end closes, transmitting an open circuit signal to the signal collector. Surge protectors with remote signal contacts can provide timely information about the operating status. When the surge protector is damaged, maintenance personnel can quickly receive an alarm signal and promptly replace the damaged surge protector to prevent accidents.

Beny’s Innovative Surge Protection Solutions

DC Surge Protection Devices: Engineered in alignment with the IEC/EN 61643-31 standard, Beny’s DC surge protection devices cater to solar power systems operating at 600V, 1000V, and 1500V, furnishing T1 and T1+T2-class protection. Incorporating a built-in thermal disconnect for fault indication and the option of remote signal contacts, these devices deliver swift, nanosecond-level responses to surge voltages, ensuring the stability of the system. Compliant with TÜV Rheinland, RoHS, and CE certification standards, and fortified by a 5-year warranty, these surge protection devices provide a steadfast guarantee for the secure and stable operation of solar systems.

AC Surge Protection Devices: The primary safeguard for low-voltage electrical systems, Type 2 SPDs, finds their place in electrical distribution panels to halt the propagation of overvoltages and shield connected loads. Beny’s AC surge protection devices adhere to the EN 61643 standard, delivering Type 2 protection of up to 385V to shield AC equipment and circuits. Comprising a base part and insertable high-energy MOV protection modules, these surge protection devices boast optional remote signal contacts and feature a built-in thermal disconnect for fault indication. Crafted from UV-resistant and flame-retardant materials and backed by a 5-year warranty, they offer users assurance and peace of mind.

Tailoring solutions to meet the unique needs of users and system configurations, Beny is well-equipped to conduct a thorough analysis of system conditions. It can offer the most fitting surge protection devices that not only enhance system stability but also ensure heightened reliability. With its own AC and DC surge protection device factory and a robust supply chain, Beny extends its services to customers globally.

As a crucial electronic device in photovoltaic power systems, surge protection devices protect equipment such as solar panels and inverters from surge voltages, improving the safety and stability of system operation. Beny, as a leading manufacturer of photovoltaic components, always focuses on innovation, delving deep into the field to provide users with safe and reliable high-quality DC power transmission and distribution solutions.