Electrical Signature Analysis
Electrical Signature Analysis (ESA) is the “point of the spear” of the Group’s activities in the area of equipment diagnostics and condition based maintenance. ESA is an ORNL-developed, diagnostic/prognostic technology for health monitoring of electro-mechanical equipment. ESA uses the motor or generator of an electromechanical system to provide diagnostic signals, much like a built-in transducer. Variations in the electric current or voltage are analyzed and related to the electrical and mechanical condition of the tested system. ESA provides diagnostic information that is similar to that obtained from accelerometers and other vibration sensors, and thus can provide valuable information on system performance and condition.
ESA provides several significant advantages over traditional vibration monitoring approaches that use accelerometers. These include:
- ESA requires no additional sensors – the system’s motor or generator is the transducer.
- ESA can be used to monitor equipment remotely, thus allowing most inaccessible equipment to be monitored.
- ESA gives a “global” indication of system performance, unlike an accelerometer whose measurements are often very sensitive to installation location.
ESA has been used by Dynamic System Group members for over 20 years, and has been used to diagnose faults in a wide variety of equipment including compressors, motors, generators, fuel injectors, control valves, pumps, chillers, blowers, and fans. Due to the unique characteristics of each ESA application, ORNL has developed a versatile, computer-based ESA tool called the Universal Electrical Signature Analysis System (UESAS). UESAS provides a platform that is immediately capable of collecting ESA data from a wide variety of systems and devices. Diagnostic algorithms can then be developed for each new application, and integrated into the UESAS, thus expanding it's capabilities to as many applications as desired.
Dynamic Systems Analysis and Simulation Group members continue to be recognized for their abilities in efficiently applying ESA to any specific situation, and developing application-specific analysis tools for extracting system condition information from electrical signatures. ORNL's leadership in ESA developments has resulted in a total of fifteen ESA-related patents.