Comparison of power converters with DC and AC link

At present, power converter systems with a DC link (on the basis of hard switching) dominate in the field of power electronics. Low loss switching processes can be achieved by using zero current switching (ZCS) and zero voltage switching (ZVS). Without additional resonant circuits in the load or switch branches, ZCS and ZVS can be applied in DC and AC link converters, in which the main switch arms have commutating units. In this paper, a comparative view of the characteristics of hard switching DC link and soft switching DC and AC link converters is presented. Essential dissipative components are investigated and checked by measurements at various working points for a single-phase converter. The calculation of the total losses of three-phase power converter systems in various working points is the basis of a comparison of several systems. Specific advantages and disadvantages of these power converters are discussed