Interpolation modelling of acoustic resonance in high pressure sodium lamp

For decades, high pressure sodium (HPS) lamp has been developed to operate at high frequency in order to increase its lighting efficiency. However, it may present standing waves, acoustic resonances (AR), which can result in arc distortion, flickering, extinction and lamp deterioration in the most severe case. At high frequency, the lamp has quasi resistive behaviour with small hysteresis, which can be represented by an equivalent resistance. This paper proposes a simple interpolation model of an HPS lamp 150 W including the presence of acoustic resonances. The simulation of lamp circuit is studied and shows a good agreement with the experimental results. This model will be very useful to study, detect and control the AR.