New generation system concept: Motor-assisted gas turbine with pulse width modulation interleaving motor drive

Abstract

This paper introduces a new concept of power generation system called the motor-assisted gas turbine (MAGT). In the MAGT, a dual-shaft gas turbine and a motor drive are included. The conventional dual-shaft gas turbine has two shafts with different rotational speeds: a power turbine shaft and a compressor shaft. The power turbine shaft is connected to a generator and is rotated at a certain speed with respect to the grid frequency. The new idea of the MAGT is that a motor drive assists the torque of the compressor shaft. The MAGT can be used as an energy storage device, like a flywheel, by using the converter to operate the compressor at variable speeds. This paper also describes a new motor drive that reduces harmonics current in the DC-link of the frequency converter.