Performances of a Contactless Energy Transfer System for Rotary Ultrasonic Machining Applications

Abstract

In rotary ultrasonic machining (RUM), the contactless energy transfer (CET) system based on the rotary transformer can replace the well-established slip ring technology to supply power for the revolving ultrasonic vibrator. However, the transfer efficiency and power output capability of the CET system is usually a pair of contradictions. The high voltage of the compensation element is prone to occur, especially in high power applications, which is dangerous. In this paper, for four basic compensation topologies, the mathematical models of the transfer efficiency, the load impedance and the compensation elements' voltages are presented. The compensation elements are optimized for improving the transfer efficiency. The effects of coil turns on the transfer efficiency, the load impedance and the compensation elements' voltages are researched. The coil turns are optimized to control the load impedance of the power supply and the voltages of the compensation elements. The experimental results basically agree with the theoretical results. The optimized CET system not only has high transfer efficiency, but also has high power output capability. At the same time, the high voltages of compensation elements are avoided effectively and the safety of the system is guaranteed. INDEX TERMS Rotary ultrasonic machining (RUM), contactless energy transfer (CET), transfer efficiency, power output capability, local high voltage, coil turns optimization.

Research on novel matching topology and characteristics of rotary ultrasonic machining system with inductive contactless power transmitter

“…Based on this idea, researchers have proposed four matching topologies to connect reactance elements in the primary and secondary circuits respectively in parallel-parallel, parallel-series, series-parallel and series-series, and a plenty of researches on the circuit transmission characteristics of different topology have been conducted. Zhu et al [8][9] proposed a mathematical model for calculating the value of bilateral matching capacitance, and established a mathematical model for transmission efficiency, load impedance and matching element voltage for four basic matching topologies. The influence of coil turns on transmission efficiency, load impedance and matching element voltage has been studied.…”

Design of a contactless powered and piezoelectric-actuated tool for non-resonant low-frequency vibration-assisted machining of brittle-hard materials

“…A matching energy transmission concept was realized for the previously fixed actuator design. Due to the rotation of the tool, this energy supply solution is realized in the form of a contactless energy transfer (CET) interface designed for machining applications [14]. The working frequency can be practically adjusted in an appropriate range of 100 Hz to 1 kHz.…”