A novel HPS and LED compatible driver with flexible resonant tank

High Pressure Sodium (HPS) is widely used in street lighting applications because of its maturity, reliability, high lighting efficiency, long lifetime and low cost. Light Emitting Diode (LED) is expected as the next generation of lighting source due to its continuously improving luminous efficacy, better color characteristic and super long life-time. The two lighting sources may coexist in street lighting applications for a long time. A novel HPS and LED compatible driver is proposed which is rather suitable and flexible for driving HPS and LED in street lighting applications. The proposed driver combines the LLC and LCC resonant circuits into a flexible LLCC resonant tank. The LLCC resonant tank may change to LLC or isolated LCC circuit based on the lighting source. It inherits the traditional HPS and LED drivers´ ZVS characteristics and dimmable function. The experiments of driving HPS and LED on a prototype verify the effectiveness of proposed driver.