Prof. Xiaoming Yuan
Huazhong University Of Science And Technology
Title: Amplitude/frequency modulation as nature of AC waveform evolution and challenges/status/methodologies in AC system stability analysis

Abstract: As penetration level increases the internal voltage of converters evolves through modulation in its amplitude and frequency, rather than harmonics appearing in the instantaneous value as a result. The physics and mathematics of the current excited therefore in the grid as well as its active and reactive components projected to the internal voltage of time-varying amplitude/frequency is fundamentally a new subject of area and is the origin of challenges in stability modelling and analysis. The "amplitude/frequency modulation" methodology selects amplitude/frequency of the internal voltage, as well as active/reactive current or power as state variables of analytics with the incremental changes of which will exhibit weak non-linear relations that can be reasonably linearized during initial period of the dynamics away from its operating points of the variables. The methodology is universally applicable for analyzing power systems of diversified devices with varied nature of physics and multiple time-scale structures including conventional electric machines as well as wind or photovoltaic generations etc.

Biography: Dr Yuan has been full professor with Huazhong university of sci. & tech. since 2011, and he served as Chief Engineer of electrical engineering for the global research center of the General Electric company prior to his university career. He is pioneer in the area of dynamics of power electronics dominated large power systems, and he developed the "amplitude/frequency modulation theory" for analysizing dynamics of general AC power systems.