High frequency generator for an inductive shrinking unit

This work presents the design and tests of a low power (10 kW), medium frequency (100 kHz), inductive heating system, to provide energy to a shrinking unit dedicated to replace the mechanical tool-holders used at present in different machine-tools. The tool holder is a solid ring, which is expanded by the inductive heater to change tools, and cooled to shrink it, holding the tool with a bigger force than the standard mechanical units. The power generator works in resonance, the power switches operate in zero current switching mode (ZCS), and the power control operates in a modified delta mode also known as pulse density control. The power output is continually controlled from 10% to a 100% of maximum, and is regulated against external factors such as variations in input voltage, temperature, and different tool holder sizes and shapes