Abstract: A method of converting a DC voltage to a sinusoidal AC voltage by way of a circuit comprising a single-phase inverter in a bridge configuration is disclosed. To output a voltage to a truly sinusoidal pattern even in the presence of load variations, the method provides for control of the inverter switching using the sliding mode technique and pulse width modulation with a three-level output voltage. Also disclosed is a circuit for implementing the method.

Abstract: A DC/AC converter is disclosed which has an inverter coupled to a load via a transformer. A control signal generator causes the inverter to switch according to a predetermined procedure, and a feedback loop is responsive to at least one state quantity of the circuit to act on the control signal generator and modify the state quantities so as to ensure a predetermined stable pattern for the output AC voltage. To prevent the transformer from becoming saturated, a circuit device is provided which includes correcting means effective to sense in the inverter output voltage an unbalance causing the appearance of a DC component at the primary of the transformer and to apply a correction signal to the control signal generator for so modifying the switch signals as to cancel the unbalance.