Solving Isolation- and Power Supply Problems for Current Monitoring in High Voltage Power Line Application

Power transmission and distribution (T&D) systems have evolved into vast interconnected power delivery networks that link multiple distributed power generators with different end user loads. A critical system requirement is to recover operation as quickly as possible whenever there is a fault condition that interrupts service. The system must monitor individual branches of the distribution grid and quickly locate a fault condition. This function, known primarily as fault indication (FI) or fault circuit indication becomes more important as the requirements for grid reliability and availability become more critical. State of the art FI are equipped with lithium batteries and need to be periodically maintained. This cause additional maintenance costs for power plants- and utility companies. New, maintenance-free FI system is composed of functional blocks such as energy harvesting, power management, processor, analog front-end (AFE) circuitry and communication interfaces [1]. The most important requirements of the maintenance-free FI design are high reliability, fast communication interface, efficient energy harvesting and ultralow power consumption.