A switched-capacitor-based current compensator for mitigating the effect of long cable connecting between LED driver and light source

In large-scale LED lighting installation, it is sometimes unavoidable to use a long cable to connect light sources to LED drivers. Since LED drivers deliver pulse-width-modulated current, such long cable inductance effect prolongs the rise time of the current pulse and hence adversely affects the luminous output. In addition, the energy stored in cable will be discharging to the LEDs during the off state, giving rise a negative voltage across the terminals of light source, and eventually shortening the lifetime of the light sources. A switched-capacitor-based current compensator is proposed to suppress the current pulse distortion and maintain the LED voltage positive. The idea is based on recycling the energy stored in the cable with a switched capacitor network at the end of a current pulse, and then drives the light source synchronously with the driver at the beginning of the next current pulse. Topological states, operations and experimental results will be given.