Power conversion circuit and device

Abstract

In a multilevel power conversion circuit, output harmonic waves and electromagnetic noise can be reduced as the number of output levels is increased. This, however, increases the number of elements constituting the circuit, causing the degree of difficulty in mounting to increase, cost to increase, and reliability to decrease. It is necessary to provide a circuit configuration, a design method, and a mounting method for obtaining, at low cost, a multilevel power conversion circuit using a large number of elements. A power conversion circuit is used as a unit module and is equipped with input and output terminals each mounted on the main circuit in an open state, wherein the input and output terminals have a mechanism by which the input and output terminals can be flexibly interconnected with the input and output terminals of another same module. A plurality of the highly expandable power conversion circuit modules are used and combined using various connection methods to obtain multilevel power conversion circuits having various configurations. This makes it possible to change power conversion circuit performances and characteristics, such as the number of levels, voltage, current, power, the number of phases, etc., only by reconfiguring the modules and to provide a multilevel power conversion circuit most suitable for various applications at low cost.