High Power Ac Steady Flow Source Developed

This dissertation presents a controllable and programmable AC current source with high stability on both frequency and output current, which consists of a PFC rectifier and a SPWM full-bridge inverter. The apparatus is mainly applied to test the heat characteristics of breakers.The design of the main circuit and the calculation of the parameters of the components are introduced in detail. The experimental results including data and waveforms of each sub-circuit of the system are given.The operation principle, the current source model and control strategy are described. The dual-loop control method adapted to current source is proposed -Outer loop is the feedback of averaged load current and inner loop is that of inductor current. The application and characteristics of Nanocrystalline alloy are presented too.