Power factor correction method and device for discharge lamps, for example high pressure sodium lamps

摘要

The present invention relates to a method for driving and to an associated command and control device for discharge lamps (2), for example high pressure sodium lamps (2), supplied by an alternating current electrical supply network. Both the method and the device provide the use of an electronic microprocessor (7) receiving on the input side data relating to the current drawn by the lamp (7) and connected on the output side to a power switch (6) for high frequency switching of the alternating current supply to the lamp.

主权项

1. A method for driving a discharge lamp, which includes:
providing a DSP electronic processor connected between an alternating current electric supply network and the lamp; and supplying at least one starting pulse to the lamp in the switch-on phase and regulating the luminosity of the lamp in the steady state, through said DSP electronic processor, which receives on the input side data regarding the current drawn by the lamp and is connected on the output side to a stage incorporating at least one power switch for high frequency switching of the alternate current supply to the lamp, wherein said DSP electronic processor effects control and regulation of the power taken from the electrical supply network by regulating the current drawn such that it follows a sinusoidal course in phase with a reference waveform adapted to the network voltage which is measured from time to time and by changing continuously the driving frequency through the lamp switch-on period; and wherein regulation is effected by a closed loop with a loop gain which varies as a function of the phase angle of said sinusoidal course of the reference waveform and relative to its starting point.