Assessment-based flux trajectory optimization for offshore line-side and machine-side converters

A novel approach to flux-based control, `assessment-based flux trajectory optimization´ (AFO), is presented and analysed, which directly takes the properties of the converter into account. It seamlessly integrates stationary operation, slow and fast dynamics. The optimal flux trajectory is defined, based on the relatively few possibilities resulting from the discrete switching states of the converter and their combination on an instantaneous basis. Within each control cycle, optimal switching states for the next control interval are selected. The criterion for optimality bases on weighted assessment rules in time domain. The paper gives basic assessment rules and resulting flux curves for stationary and dynamic operation.