A Novel Detection and Protection Method of Rectifying Effect for HID Lamps

An effective method of eliminating acoustic resonance in high intensity discharge (HID) lamps is put forward. When the low frequency sine wave is added to the control loop, the frequency of the lamp current is variable. So the standing wave is not occurred in the arc tube. The best range of modulate frequency was chosen by Fourier analysis of Saber simulation. The simulation results were used for 250 W and 400 W HID lamps. This method is effective in eliminating acoustic resonance and ensures the stability of the arc and the light. Furthermore the bandpass sampling theorem is used to implement the voltage and current sampling of lamps, which reduces the sampling frequency greatly. The sampled data is transmitted to the PC server terminal with the network based on power line and GPRS. The data reconstruction and rectifying effect detection are carried out in PC, which provides a universal testing method for a variety of products and guarantees the safety of power system in a sense.