A Galvanically Isolated Single-Phase Inverter Topology With Flux-Rate Control Based Harmonic Filtering Scheme

This work presents a galvanically isolated single-phase inverter topology with a flux-rate control-based harmonic filtering scheme. The proposed topology consists of a high-power primary inverter that operates at low frequency and establishes the primary flux. A low-power secondary inverter that operates at high frequency is associated with another limb of the magnetic core, which controls the flux rate. The undesired harmonic components present in the primary flux are filtered by controlling the flux rate to provide a sinusoidal output voltage at the load. These two inverters and the load side of the proposed topology are associated with the three-limbed magnetic core. The load side of the proposed inverter topology is galvanically isolated from the rest of the circuit. That causes the load side of the proposed inverter to be free from any power electronics components and passive filters. Hence, the inverter is suitable for medium to high voltage applications without modifying the power semiconductor device ratings. The proposed inverter is modeled using the popular bond-graph modeling technique, and the dynamic equations are obtained from the model. The derived dynamic model is simulated, and a lab build prototype is utilized to verify the working of the proposed inverter topology.