For the high/medium voltage-based applications, modular multilevel converter (MMC) is the most promising technology among all other due to its better harmonic performance, higher efficiency and its modular structure. The conventional structure of three phase MMC consists of three phase leg with two arms in each phase. Each arm is incorporated with N number of sub-modules (SMs) connected in series with an arm inductor. To solve the above problem, a new converter configuration is derived from MMC to integrate one or more dc source/load with one or more ac source/load in the mixed dc/ac grid. The proposed converter topologies eliminated the needs of extra converter required for the integrations. Also, these converters can integrate the dc/ac grids at different voltage levels. This is due to presence of SMs which leads to the distributed capacitors voltages.
Figure (1) Multiport converter type-3 for integrating multiple dc and ac grids; (2) Multiport converter type-4 for integrating multiple dc and ac grids
The conventional modular multilevel converter provides only two ports one for DC and AC. However, for connecting more number of ports, additional converters are needed to be connected, which increases the overall volume of the converter and also the overall cost of the system.
The proposed invention is a multiport modular multilevel converter that can be reconfigured to interconnect multiple ports without the need for adding any additional converter.
- The multiple configurations proposed allow the interconnections of various dc and ac ports using modular multilevel converter.
- The proposed invention is suitable to integrate different grids with various voltage levels.
- The proposed invention allows the power exchange within multiple grids.
Tested and Validated
3
It’s a cost-effective solution due to the reduced additional converters required for interconnecting multiple grids at different voltage levels.
It has applications in interconnection of distribution and transmission grids at different voltage levels.
202321004082
475600