Design, Development, and Testing of a Flexible Combined Heat and Power (F-CHP) System With 10-kV SiC MOSFET-Based Power Conditioning System (PCS) Converter

Abstract

This paper discusses the design, development, and testing of a flexible combined heat and power (F-CHP) system. It includes two parts: the power conditioning system (PCS) converter, which connects the system to the grid and is the key component to provide grid support services, and the F-CHP central controller, which accommodates the control of local sources, local loads, and the PCS converter. The functions and structures of the central controller are discussed. The central controller's system-level performances are verified with hardware-in-the-loop (HIL) tests, and the mode transition and grid transient performances are validated with power electronic converter-based hardware testbed (HTB) tests. The PCS converter is designed with 10 kV SiC MOSFETs. The grid requirements are considered in the 13.8 kV/1 MW PCS converter design, and the impact of different requirements on the converter design is identified. Also, converter scalability is studied with the paralleling operation. Two 13.8 kV/100 kW converter prototypes are developed to verify the converter design and scalability. The second prototype is an improved design of the first one; the volume is reduced by 49% and the efficiency at the rated output power is increased from 96.4% to 98.4%. The test results of the converter performances, grid support functions, and parallel operation are also discussed.INDEX TERMS 10 kV SiC MOSFET, Flexible Combined Heat and Power (F-CHP) System, grid support, grid requirements, medium voltage converter, power conditioning system (PCS).