Thermal protection for successively starting three phase induction motors using Particle Swarm Optimization technique

In this paper a thermal protection technique is presented by applying Particle Swarm Optimization (PSO) technique to thermally protect three phase Induction Motors (IMs), that are being successively starting, from operating beyond the IM thermal limits. This approach is implemented with PSO so as to determine the number of starting and operating times versus the IM thermal capability. This leads to a great improvement in the industry of thermal protection relays. The proposed simulation is conducted using Matlab-Simulink for simulating the induction motor. The model is successively started through constant periodic time switching pulses with varying duty cycles. The output of the modeled induction motor is fed to a developed PSO technique program to find the optimal number of operating cycles regarding the duration of the duty cycle. The thermal capability is the main limitation for the number of starting cycles. The Induction motor will be inhibited from starting after reaching the thermal capacity limit. The developed model is tested to give satisfactory results.