This article is devoted to the task of selection of photovoltaic power system inverter that would comprehend to all of the demands that could be applied to it. The challenge of creating efficient and reliable converter for the renewable energy systems that implies solar panels as primary energy sources is well-known since the first day of their existence as a possible choice for the role of the only power source in the system. The great breakthrough in the field of photovoltaic power system converters design was achieved in late 80’s-early 90’s years of the 20th century due to the several positive circumstances that included rapid evolution of the semiconductor industry at whole which sums up in the development of a new generation of power switches that was capable to operate in higher voltage and current ranges which was unreachable for the prior generation switches and new microcontrollers that was able to maintain more complex control algorithms than ones that were used before which in general resulted in significant downsizing of the resulting device and made it possible to practically develop power inverters with complex topologies that was considered over sophisticated and unreliable before. These factors leaded to the development of numerous new topologies with the main goal of transformation losses reduction and power efficiency increase. The desired result was obtained either thru the fulfilling the demands invoked by the photovoltaic sources operation features (z-source topologies) or power system topology features and reduction of output voltage THD ratio (multilevel inverters). But consideration of only one type of factors has not allowed achieving the maximum result in power losses task. Thus solution of the determined task should be started from complete identification and broad consideration of the main factors that define set of demands that converter has to face. In this article parameters of THD ratio of the inverter’s output voltage, photovoltaic source’s operation features and power system topology specifics were considered as the most valuable parameters that affects the power conversion losses values and was discovered in details based on a survey of the existing publications in the field of the study, international and local standards of consumer voltage quality parameters and practical results of the most popular and widespread topologies simulation in order to obtain an output voltage THD ratio. The achieved results demonstrate that inverter topology that would be able to satisfy all of the requirements has to have modular structure to be able to maintain the proper THD ratio and connect to the most popular types of the photovoltaic power system topologies and be based on the z-source topologies to imply the photovoltaic sources operation features. Therefore as a conclusion a cascaded multilevel inverter with a separated input DC sources topology that is based on quasi-z-source modules was recommended as a solution that could also be used as a base for the further power converter development.