Based On Sliding Mode Control For Dc-ac Inverter

The DC-AC inverter is an important part of power electronics. It is used in many applications. In some key field , the output voltage of inverter should be ideal sine wave.The conventional inverter topologies are push-pull, half-bridge and full-bridge. In this paper a novel inverter topology is discussed. It consists of two symmetrical DC-DC converters. These converters produce a sine wave output with a same dc bias. The modulation of each converter is 180?out of phase with the other. The load is connected differentially across the converters. Thus, whereas a dc bias appears at each end of the load, with respect to ground, the differential dc voltage across the load is zero. The output voltage is sine wave.The sliding mode control which has been widely used in DC -DC converter is applied to improve the characteristic of inverter output voltage. The main advantage of the sliding mode control over the classical control schemes is its robustness for plant parameter variations. It is insusceptible to plant variations that leads to good dynamics and steady-state response in the ideal case.In this paper, three inverter topologies based on sliding mode control (Buck, Boost and Buck-boost) are discussed. Operation and sliding mode control strategy of each are analyzed in detail. Design of three inverters is also given concretely. The main purpose of this paper is research of Buck inverter based on sliding mode control. A 500W (DC-800Hz) Buck inverter is designed. The experimental results prove the Buck inverter based on sliding mode control has good dynamics and steady-state response and its output voltage is a ideal sine wave.