“…This problem can be approached by using choppers with as many phases as there are strings; in this case, however, maximum power point tracking is required for each chopper, which means more current sensors for each phase, and therefore, higher cost. There are a number of methods to reduce the current sensors and to cut the cost using pulse currents in DC bus, for example, a reconstruction technique using the condition of a zero sum of phase currents in a three-phase inverter 1 and reconstruction techniques for multiphase choppers. 2,3 This paper proposes, first, a method for phase current reconstruction to estimate phase currents using a matrix of switching states in every leg and common DC bus current, and, second, an extended method in which a part of the said matrix is replaced with photovoltaic string's voltage (PV) voltage and inverter output.…”