Abstract
When medium- or high-voltage power conversion is preferred for renewable energy sources, multilevel power converters have received much of the interest in this area as methods for enhancing the conversion efficiency and cost effectiveness. In such cases, multilevel, multi-input multi-output (MIMO) configurations of DC-DC converters come to the scenario for integrating several sources together, especially considering the stringent regulatory needs and the requirement of multistage power conversion systems. Considering the above facts, a three-level dual input dual output (DIDO) buck-boost converter, as the simplest form of MIMO converter, is proposed in this paper for DC-link voltage regulation. The capability of this converter for cross regulating the DC-link voltage is analyzed in detail to support a three-level neutral point clamped inverter-based grid connection in the future. The cross-regulation capability is examined under a new type of pulse delay control (PDC) strategy and later compared with a three-level boost converter (TLBC). Compared to conventional boost converters, the high-voltage three-level buck boost converter (TLBBC) with PDC exhibits a wide controllability range and cross regulation capability. These enhanced features are extremely important for better regulating variable output renewable energy sources such as solar, wind, wave, marine current, etc. The simulation and experimental results are provided to validate the claim.
Highlights
DC-DC converters have been widely used or proposed for different applications, recently for grid-tied renewable power conversion systems [1,2,3,4]
The normal boost operation used for supporting neutral point clamped (NPC) inverters in grid-connected photovoltaic systems can be replaced with multilevel DC-DC converters for improving the overall performance of the system
A three-level boost converter with a new pulse delay control (PDC) strategy is proposed for the DC-link voltage regulation and neutral point voltage balancing for three-level neutral point clamped (NPC) inverter; see [13,14]
Summary
DC-DC converters have been widely used or proposed for different applications, recently for grid-tied renewable power conversion systems [1,2,3,4]. Since the power transmission from distant or offshore renewables is efficient in medium or high voltage, conventional converter topologies are replaced by their multilevel counterparts. The normal boost operation used for supporting neutral point clamped (NPC) inverters in grid-connected photovoltaic systems can be replaced with multilevel DC-DC converters for improving the overall performance of the system. They play a key role in resolving the drawbacks of certain multilevel inverter topologies. A three-level boost converter with a new PDC strategy is proposed for the DC-link voltage regulation and neutral point voltage balancing for three-level neutral point clamped (NPC) inverter; see [13,14].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
