A novel compensating network for inverter driven single-phase high-power loads

In inductive heating applications, high-power single-phase loads, e.g. for melting furnaces, are used. Usually, they are connected to an inverter that provides the appropriate voltage and frequency. In contrast to three phase loads, the power oscillates at twice the operation frequency. To ensure a constant power extraction from the supply grid, the inverter has to contain a large energy storage, e.g. a large DC-link capacitor or inductor. In this paper, a novel approach for supplying these loads is presented that enables a significant reduction of the DC-link components. The principle is explained in detail and two modulation strategies are introduced. Finally, simulation results are given.