2) The business case is necessary for accelerating adoption of these advanced concepts will be driven, primarily, by lowering the initial cost and enhancing the value of microgrids.
As the generated power produced by these sources is either dc or variable frequency ac, power conversion plays an important role in DG systems 1–4, entailing wide application of power electronics in this area 5.
This inverter has two modes of operation and it serves two application:
1. Can be used in inverter or ac/ac converter applications
2. Can be used for power quality conditioner in microgrid system.
This dual-output four-leg inverter is used in a microgrid to control the transmitted power between a microsource and a weak utility while conditioning the power supplied to the microgrid.
The inverter is capable of producing two sets of three phase voltages for supplying balanced or unbalanced three-phase loads. It can also supply two triple sets of single-phase loads, each set of its own frequency and each voltage of its own amplitude.
The given inverter operates in equal frequency (EF) mode and different frequency (DF) mode of operation. In equal frequency (EF) mode voltage amplitudes are independent whereas their frequencies are equal. In different frequency (DF) mode of operation the output voltages are fully independent in terms of amplitudes and frequencies. There are many advantages of EF mode over DF mode: the maximized voltage utilization and minimized converter power loss 6.
Since in this application the converter is functioning in EF mode, therefore it has advantages of high dc bus voltage utilization, lower device ratings, and less dissipated switching power 6. This inverter also reduces use of two separate four-leg converters, use of two separate four-leg converters may result in a complex system using two dissimilar power converters and a large number of power switches. The proposed system retains all the desirable characteristics of the conventional one. Also, it replaces the two dissimilar converters with one integrated structure which uses less number of switches and reduces the system complexity and cost.