Anto Joseph, Seok-Min Kim, Sze Sing Lee, Arun Dominic, and Kyo-Beum Lee, "Boost multi-level NPC-fed VS large rated asynchronous pumped storage hydrogenerating unit," IET Electric Power Applications, vol. 13, no. 10, pp. 1488–1496, Oct. 2019. -SCI > Paper

Power converter redundancy in multi-channel voltage source inverter (VSI) fed large rated doubly fed induction machine (DFIM) is

challengeable and it is not yet adopted in any of the commissioned variable speed pumped storage power plant. Multi-channel VSI

is a fundamental part in DFIM which controls real and reactive power of the machine. This paper presents fault tolerant operation

of a large rated DFIM hydro unit at open switch faults in back-to-back VSI. A technique for diagnosing the open switch faults in grid

side and machine side converters is proposed. Open switch fault is detected based on the variation in rotor currents and dc link

voltage, which reduce the computational efforts during fault diagnosis. A 250 MW DFIM with five-channel three-level VSI (each 8

MVA) is simulated in Matlab/Simulink environment to observe the drive behavior. A 2.2 kW DFIM is tested in the laboratory to

endorse the simulation results.