Investigation of the effect of led driver's inrush current on the switching elements

Light Emitting Diode (LED), which converts electrical energy into light energy, is more preferred in lighting systems since it is more efficient, long-lasting, maintenance-free, fast switching, low energy consumption and controllable compared to other light sources. However, since this technology is still in the maturation stage, problems that need to be studied can be encountered. As with power supplies, LED drivers have built-in capacitors. Capacitors that charge fast within a short time from the moment of powering, create a sudden current that can reach 1200 times the nominal current. This causes serious damage to the alternating current circuit elements. For this reason, in LED lighting technology, LED fixtures, engineers and lighting designers require intense efforts to investigate and improve the compatibility and suitability of the driver type and switching elements. In this thesis, by using two contactors with AC-5a and AC-6b operating categories according to IEC 60947-4-1, the capacitive effect created by the LED lighting circuits on the contactors on the contactors was examined by experiments and problems were identified. According to the experimental results; Contactor manufacturers recommend contactors with operating category AC-5a for led loads. Considering that the inrush currents generated during the commissioning of the led loads reach up to 1000 times the nominal current of the lamp, it can be stated that AC-5a is not suitable for led loads. Contactors with operating category AC-6b for led loads carry higher inrush currents than AC-5a. In SEM images, AC-6b class contactors are more suitable for led loads. In this case, certain standards must be set in the contactors to switch the led loads. In order to prevent the great costs and loss of life that may be caused by the increase of electric fires in recent years, at the end of our study, solutions have been offered to overcome this problem and to set certain standards. Key Words: LED, LED driving, Inrush current