A novel power quality monitor for commercial airplanes

A novel approach to measuring power bus conditions at the line replaceable unit (LRU) on operating commercial airplanes has been developed. Steady state and transient conditions can cause intermittent operation in avionics that may result in a no-fault-found (NFF) condition. Suppliers and airlines spend significant resources attempting to determine the root cause of the no-fault-found. Without measured field conditions, root cause determination can be problematic. The ultimate goal of this study is to better understand the power quality of the electrical systems at all electrical systems interfaces, which allows suppliers of electrical equipment such as avionics produce more robust, higher reliability, and lower cost equipment. This also aids in the definition of future airplane design requirements. This paper describes the development of the Aircraft Environment Monitor - Power Quality (AEM-PQ), including its monitoring algorithm, hardware and sensing scheme. Additionally, results from lab and flight tests are presented.