Event date:
Aug 30 2021 9:00 am

A Low Harmonic, Reduced Common Mode Voltage oriented Multi-Drive System: Investigation and Development

Dr. Jahangir Ikram
Prof. Nauman Ahmad Zaffar
Akbar Ali Khan
EE Reading Room
PhD Synopsis defense
Variable frequency drives being the key component of industrial electro-mechanical processes, have been on a continuous path of improvement to better deal with the associated power quality concerns. Moreover, there are significant number of processes, which require multiple motors employed to work in parallel. This ultimately gives the idea of common DC-link based multi-drive systems. The idea of performance improvements can be exploited with the additional degrees of freedom of control in multi-drive systems to produce an overall improved efficiency and quality. This research work will first investigate ways to improve the quality of power drawn from common DC link capacitor using a reduced common voltage oriented modulation methods. In addition, high amount of ripples in dc link current are produced due to high frequency switching and AC power drawn for an inductive load system such as motors. This work investigates the development and manipulation of modified space vector pulse width modulation methods to reduce the ripple component in DC link current, as well as to suppress common mode voltage by design, for the two inverters working in parallel. The analytical formulation of DC link current as a piece-wise function of output currents has been utilized to find the limitation on DC link ripple current among different SVPWM methods. Then the idea of interleaving has been used to achieve the optimum cross compensations of reactive power, through ripple minimization, for multi-inverter systems. This idea can be implemented on the dynamically changing motor loads via integration of these modified schemes as a second step. Finally, the challenges of rectification stage synchronism with the interleaved inverter modulation, will be dealt to analyzed an overall AC to AC multi-drive systems with improved power quality, reduced ripple and reduced common mode voltage.

Zoom Link:  https://lums-edu-pk.zoom.us/j/94555686464?pwd=aWFkOVBNWDBpcm1GQzZGcDhjellYUT09

Meeting ID: 945 5568 6464

Passcode:    979273