| Power amplifier is used in many fields, such as sound amplifier and electric vibration generator. Till now, many power amplifiers use linear circuits. Linear power amplifier has low distortion and good linearity, but it has high loss and so low efficiencies. In order to overcome the drawbacks of linear power amplifier, the switching power amplifier is presented and gets more and more attentions. Considering improving the output waveforms and increasing the output frequency, paper includes the contents as follows.In the first place, paper analyses the control scheme for the switching power amplifier. Based on the multilevel inverter and in conditions of improving the output waveforms and increasing the output frequency, paper selects the Triangular carrier phase shifting SPWM technique, which can increase the effective frequency of switching power amplifier, and to improve the output waveforms and increase the output frequency.In the second place, paper researches the topology extends based on Triangular carrier phase shifting SPWM technique. Triangular carrier phase shifting SPWM technique starts with cascade multi-level circuit, in order to make switching power amplifier have more topology selections, paper researches the applications of Triangular carrier phase shifting SPWM technique in the other topologies, and summarizes some rules of the topology extends. In addition, with simulation analyses, paper gives the applicable output frequency ranges and the applicable fields, which will become a reference of the selections of the switching power amplifier topologies base on Triangular carrier phase shifting SPWM technique.Finally, paper designs a 2.5KW, 20KHZ prototype with the interleave topology of multilevel inverter. The hardware circuit and software circuit of the switching power amplifier are respectively analyzed in this paper. The experimental results verify the availability of the switching power amplifier based on Triangular carrier phase shifting SPWM technique. |
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