Surge protection devices (SPDs) are used to protect electrical equipment from the effects of surges, impulses and other temporary over-voltage events. Many such events are caused by lightning strikes to and switching operations within a power system.
All SPDs have a finite lifespan. A SPD is degraded over time due to exposure to repeated impulses, over-voltages, excessive temperatures etc. Eventually, this degradation leads to the SPD failing completely, at which point the equipment is no longer adequately protected. Until recently, the degradation of SPDs was assessed visually, e.g., via indicator LEDs, requiring physical access to the SPDs. Often, these SPDs are installed in restricted areas, such as an electrical switchboard, which can only be accessed by qualified personnel.
The present paper describes a new generation of SPDs that has been developed, broadly called “smart SPDs”. The new technology involves integration of wireless (Bluetooth, WiFi, etc) functionality into the SPDs to monitor parameters such as applied / operating voltage, temperature, number of surges, amplitude of surges, leakage current, protection / degradation level, etc.
Hence, the technology not only facilitates a quantitative assessment of SPD degradation but also allows the user / owner to monitor other variables that can help to diagnose problems within a facility. The paper will provide the following perspectives around the technology: