Electromagnetic Transformer With a Continuously and Quickly Adjustable Voltage Ratio

This article presents a new electromagnetic transformer with a continuously and quickly adjustable voltage ratio between the output and input. The transformer uses a voltage-controlled magnetic device called magnetic flux valve to control the magnetic flux through the secondary winding. In this way, the amplitude of the output voltage induced across the secondary winding of the transformer can be regulated continuously and fast when the turn ratio and input voltage amplitude of the transformer are fixed. The configuration and working principle of the proposed transformer are elaborated. A prototype of the proposed transformer was designed and constructed. The experimental tests are performed on the prototype to validate the proposed transformer concept and demonstrate its superior performance, including continuous and nearly instantaneous output voltage regulation capability, wide output voltage variation range, and high efficiency.