Adjustable-Voltage-Ratio Magneto-Electric Transformer

This paper presents a novel adjustable-voltage-ratio (AVR) transformer made using magneto-electric materials. Given a fixed-amplitude alternating current voltage input, the AVR transformer can output an ac voltage whose amplitude can be adjusted continuously from zero volts to the maximum value determined by the design. The core(s) of the AVR transformer are laminated and made of bonded layers of Metglas^® foils and lead zirconate titanate (PZT) sheets. By adjusting the voltage applied on the PZT sheets of the core, the magnetic reluctance of the core can be altered to control the magnetic flux in the core by utilizing the converse magneto-electric (CME) effect. Thus, the voltages inducted by the time-changing magnetic fluxes can be controlled. This novel concept provides a new solution to electric power control and conversion.