【作者】 林勇；

【导师】 张一工；

【作者基本信息】 华北电力大学 ， 电力电子与电力传动， 2001， 硕士

【摘要】 电力系统仿真是工程师和研究人员研究电力系统各种物理现象的有效方法，一般而言，电力系统仿真可分为数字仿真、物理仿真和数字模拟混合式仿真。 在电力系统混合仿真系统中，当数字模型需要模拟输出时，都需要功率放大器。专门制作的线性功率放大器价格极其昂贵，D类功率放大器输出谐波含量较高，死区问题引起的波形失真较大。在本论文中，研制了一种新型三进制多电平功率放大器。 三进制多电平功率放大器就是采用多电平技术，通常是采用多级直流电压合成阶梯电压波，去逼近所需的电压波形。理论上，随着直流电压级数的增多，合成的阶梯电压波接近正弦波，从而减少谐波；因为采用的是开关器件，其效率较高；又因为其结构特点，控制较简单，常用于较高电压较大功率场合。 本文在详细分析多电平变换器拓扑结构的基础上，提出了三进制多电平功率放大器的拓扑结构，并推导了三进制多电平功率放大器的数学模型，提出了基于SHE技术的控制策略，并详细分析了这种控制策略的数学模型、计算方法、迭代初值的选取和控制实现方法。 在论文工作中，研制了一台以PHILIPS单片机80C552为控制核心的单相三级三进制多电平功率放大器的实验装置，来检验文中的分析结论，并设计了通过硬件引入死区时间的电路。更多还原

【Abstract】 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.更多还原