The conventional microinverters with transformers and multiple-stage system increases the cost, weight and size, lowering the effectiveness and power density of PV system. It is therefore desirable to prevent using these methods for a microinverter. However, extra care must be taken to prevent component stress, excess switching and conduction losses, ground leakage currents and harmonics. Several transformerless buck–boost inverters have lately been suggested to address various issues. Due to the availability of a number of buck–boost inverter-topology for the solar PV system, it is often difficult to identify when to choose the appropriate topology. Therefore, in order to present a clear view of the advancement of transformerless buck–boost inverters for next-generation grid-integrated PV systems, this article seeks to explore multiple buck–boost topologies with an extensive analytical comparison. Computer simulations for the 70 W system have been conducted in PLECS software to strengthen the results and comparisons, as well as to provide more insight into the features of the distinct topologies for the building-integrated photovoltaic implementation. At the later part, voltage and current stress in each component, efficiency and total harmonic distortion of the system are provided with a general summary, as well as, a technology roadmap.

中文翻译：

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单级无变压器降压-升压型微型逆变器的研究

具有变压器和多级系统的常规微型逆变器增加了成本，重量和尺寸，降低了光伏系统的效率和功率密度。因此，期望防止将这些方法用于微型逆变器。但是，必须格外小心，以防止组件应力，过多的开关和传导损耗，接地漏电流和谐波。最近提出了几种无变压器降压-升压型逆变器来解决各种问题。由于太阳能光伏系统具有多种降压-升压型逆变器拓扑，因此通常很难确定何时选择适当的拓扑。因此，为了清楚地展示下一代电网集成式光伏系统无变压器降压-升压型逆变器的发展，本文旨在通过广泛的分析比较来探索多种降压-升压拓扑。70瓦系统的计算机仿真已在PLECS软件中进行，以加强结果和比较，并为建筑物集成式光伏实现方案的不同拓扑结构提供更多信息。在后面的部分中，提供了概述，技术路线图，每个组件中的电压和电流应力，效率和系统的总谐波失真。以及为建筑物集成的光伏实现方案提供不同拓扑结构的特征的更多见解。在后面的部分中，提供了概述，技术路线图，每个组件中的电压和电流应力，效率和系统的总谐波失真。以及为建筑物集成的光伏实现方案提供不同拓扑结构的特征的更多见解。在后面的部分中，提供了概述，技术路线图，每个组件中的电压和电流应力，效率和系统的总谐波失真。