Umrichterschaltung

The converter circuit (100) has inverter (102) whose direct current (DC) voltage terminal (104) is coupled to DC voltage terminal (110) of inverter (108). The DC voltage terminals (104,110) and alternating voltage terminals (106,112) of inverters are connected respectively so as to supply alternating current or direct current. The inverters (102,108) are connected serially in loading/unloading state, and parallelly in driving state. Independent claims are included for the following: (1) drive system; and (2) method for operating converter circuit.