Circuit with inverters driven in parallel for supplying load

摘要

A circuit with parallel inverters supplying a common load with AC has the inverters driven in phase. Each inverter (1 to 3) has a control circuit for its output voltage and each has a current transformer (5 to 7) in series whose secondary is loaded with a resistance (8 to 10). One end of each resistance is connected by a switch (11 to 13) to a common busbar, and the other end of each is connected to earth through a reference resistance (14 to 16). The non-earth side of each earthing resistance is also connected to a summing point within the corresponding inverter, thereby supplying a reference voltage. Between each inverter and the load (8a) is a second switch (17 to 19), opening and closing synchronously with the corresponding first switch.