The Research On A New Triple Multilevel Amplifier

Power system simulation is one of the most important methods for engineers to study the different phenomena in the system. There are three kinds of simulation methods, the physical system simulation methods, the numerical system simulation methods and the hybrid system simulation methods. In the hybrid power system simulator when the numerical parts need analog outputs, the power amplifier is one of the indispensably necessary parts. However, the linear power amplifier specially made is prohibiting expensive. The class D amplifier's output include plenty of harmonics and the dead-time cause distortion of output waveform. In this paper, a new triple multilevel power amplifier is proposed to replace the linear and class D amplifiers. The new triple multilevel power amplifier adopts multilevel theory. The general structure of the multilevel power amplifier is to synthesize a sinusoidal voltage from several levels of voltages, typically obtained from capacitor voltage sources. As the number of levels increases, the synthesized output waveform adds more steps, producing a staircase wave which approaches the sinusoidal wave with minimum harmonic distortion in theory. Ultimately, a zero harmonic distortion of the output wave can be obtained by an infinite number of levels. More levels also mean higher voltages and power can be obtained. In this paper, a detailed description of the topology of triple multilevel power amplifier and its math model is deduced. We give a new control strategy: A optimal control with SHE (Selective Harmonic Elimination) by using a general storage method. Its math model, calculation and the selection of initial values are analyzed. A prototype triple multilevel amplifier which employs 80C552 single chip as the core of the controller has been built to test our theory.