Modular Multilevel Converter for Transmission-Level Battery Storage (GR-11-04)
Principal Investigator: Dr. Roy McCann
This project investigates the design of a modular multilevel power converter (MMC) for interfacing battery energy storage to the transmission-level electric utility grid. An investigation of appropriate energy storage technologies will be conducted in order to set the parameters for the converter design. The converter will then be optimized in terms of a multi-stage output topology, switching device selection, and DC-DC battery interface. Overall, this provides a basis for developing MW capacity transmission-level modular multi-stage converters. Grid storage technologies will be mainly considered for the functions of frequency regulation, damping of sub-synchronous resonance, voltage support, and reserve capacity. Relative costs, power levels, and charge/discharge profiles will be tabulated and used to establish the range of parameters for a converter that will be suitable for grid-connected energy storage technologies. The project will include the development of an IEEE-style benchmark of a regional transmission system that would benefit from battery storage with an SSSC interface. A prototype SSSC z-source converter will be built and validated based on the analysis and simulations described above.