Modeling and Stability Analysis of a Fixture-Centric Airfield Lighting System

With the rapid development of the LED lighting and power electronics, LED based airfield lighting systems are currently being deployed. For better optical performance of LEDs, fixture-centric airfield lighting system architectures are being investigated. In these systems each lighting fixture includes a power electronic converter which regulates LED brightness. Since tightly regulated power converters behave as constant-power loads which may introduce instability in power electronics-based power systems, the stability assessment of the fixture-centric airfield lighting system becomes prudent. In this paper, the system-level analysis of a notional single-phase ac power-electronics-based airfield lighting system is carried out, and a stability criterion involving the number of fixtures which can be driven is developed. The system qd-axis average-value model is first derived and linearized to generate a small-signal model. Next, the application of the generalized Nyquist stability criterion predicts the small-signal stability about a given operating point. Finally, the proposed model and analysis is experimentally verified with using a proposed qd impedance measurement method. In summary, this paper develops methodologies for single-phase system analysis from both design and field application perspectives.