Design considerations for current transformer based energy harvesting for electronics attached to electric motor

Energy harvesting or scavenging from environment is being researched intensively. The main motivation of the research is to develop a maintenance free energy source for ubiquitous electronics, such as wireless sensors or sensor networks. The on-line condition monitoring of electric motors requires also sensors that are installed at the motor. In this case, the energy required by sensors could be harvested from a magnetic field. In this article, current transformer based energy harvesting is considered. A switch-mode power supply utilizing current transformer is designed. It is tested in laboratory with the mains supply and variable speed drive. According to the tests carried out, the current transformer based power sources are a feasible alternative to supply the electronics attached to an electric motor.