This paper experimentally reveals some of the resources offered by the instantaneous active electric power in describing the state of three-phase AC induction asynchronous electric motors (with a squirrel-cage rotor) operating under no-load conditions. A mechanical power is required to rotate the rotor with no load, and this mechanical power is satisfactorily reflected in the constant and variable part of instantaneous active electric power. The variable part of this electrical power should necessarily have a periodic component with the same period as the period of rotation of the rotor. This paper proposes a procedure for extracting this periodic component description (as a pattern by means of a selective averaging of instantaneous active electrical power) and analysis. The time origin of this pattern is defined by the time of a selected first passage through the origin of an angular marker placed on the rotor, detectable by a proximity sensor (e.g., a laser sensor). The usefulness of the pattern in describing the state of the motor rotor has been demonstrated by several simple experiments, which show that a slight change in the no-load running conditions of the motor (e.g., by placing a dynamically unbalanced mass on the rotor) has clear effects in changing the shape of the pattern.
This paper experimentally reveals some of the resources offered by the evolution of the instantaneous active electric power in describing the state of three-phase AC induction asynchronous electric motors (with squirrel-cage rotor) operating under no-load conditions. A mechanical power is required to rotate the rotor at no-load and this mechanical power is satisfactorily reflected in the constant and variable part of instantaneous active electric power. The variable part of this electrical power should necessarily have a periodic component with the same period as the period of rotation of the rotor. The paper proposes a procedure for extracting this periodic component description (as a pattern, by means of a selective averaging of instantaneous active electrical power) and analysis. The time origin of this pattern is defined by the time of a selected first passage through the origin of an angular marker placed on the rotor, detectable by a proximity sensor (e.g. a laser sensor). The usefulness of the pattern in describing the state of the motor rotor has been demonstrated by several simple experiments which show that a slight change in the no-load running conditions of the motor (e.g. by placing a dynamically unbalanced mass on the rotor) has clear effects in changing the shape of the pattern.
1 March 2026 in Bulletin of the Polytechnic Institute of Iași. Machine constructions Section
Additive manufacturing based on Fused Deposition Modelling (FDM) technology is increasingly being integrated into the Industry 4.0 context, where real-time monitoring and process transparency are essential for improving the reliability of the manufacturing process. This paper presents the development of a graphical user interface (GUI) for real-time monitoring of FDM 3D printing using serial data acquisition. The experiments were carried out on a Creality Ender 3 S1 Pro printer, from which parameters such as nozzle temperature, build plate temperature, feed rate and the position of the current layer were collected and displayed in real time. Real-time monitoring of FDM 3d printing using serial data proposed is feasible for Taguchi based experimental setups offering great traceability, process monitoring and report generation. Visual monitoring of the process was carried out using a GoPro camera. The developed system contributes to increasing process transparency and improving the traceability of parameters and defects that occur during printing.