摘要
由两个完全相同的独立的buck-boost斩波器,输入并联,输出串联构成一个DC/AC逆变器,该逆变器实现了单级功率变换,双向功率流,与传统的两级式逆变器相比,具有拓扑结构简单,同时工作的开关元件少,功率密度大,变换效率高等优点。但由于两个斩波器的输出电压要求在较宽范围内变动,故其控制方法和单独的buck-boost斩波器有所不同,本文对该电路的工作原理和控制方法进行了详细的分析,针对输出电压范围宽的特点,提出了改进的电流控制法,该控制方法采用附加扰动补偿的前馈控制和反馈控制相结合,使两个斩波器的输出电压和逆变器的输出电压都能得到准确的控制,对外界变化能作出快速准确地反应,提高了逆变器对输入电压和负载变化的响应能力。
The DC/AC buck-boost inverter consists of two DC/DC buck-boost converters which inputs connected in parallel and outputs in series. The inverter allows power flow in both direetions as while as achieves in a singte stage, In addition, advantageous over the traditional inverters are the simpler structure, less semiconductors, denser on power, more efficient in power transition. However the control strategy is quit different because of the two buck-boost dc/dc converters are required to work in a variable operating condition. This paper present a new control strategy to solve the problem based on a detailed analysis of the operating theory and the control strategy. It include compensation feed-forward loop and feed-backward loop that make possible a fast and accurate control of both converters output voltage. It also had a high immunity to external perturbations such as input voltage or output load disturbances.
出处
《电力电子》
2008年第2期21-24,共4页
Power Electronics
