MEPT Control of Distributed Power Generation System with PMSG based Direct-drive Turbo-expander

摘要

The distributed energy system with turbo-expander is one of the important development directions of clean energy technology in the future. The permanent magnet synchronous generator (PMSG) based direct-drive turbo-expander, with the advantages of compact structure, high speed and high power density, has gradually attracted the attention of researchers all over the world. In this paper, a maximum efficiency point tracking (MEPT) strategy for the distributed power generation system with PMSG based direct-drive turbo-expander is investigated. With the consideration of thermal, fluid and electrical coupling factors, compensation control based on pressure feedback linearization of the turbine inlet, speed PI control and the optimal speed tracking of PMSG under converter control are studied, to achieve an optimal system efficiency under strong non-linear variable operating conditions. A 300kW prototype for Organic Rankine cycle (ORC) based geothermal power generation is proposed. Simulation and experiment study are carried out, and the results validate the theoretical analysis.