Power systems with cold stand-by using ultra capacitors

To achieve a power system of both high reliability and high efficiency, cold stand-by system is promising. It is necessary for this system to hold the output voltage for the duration of switching the malfunctioned power unit to the stand-by unit. Ultra capacitors give an interesting and simple solution to this problem. However, this device has comparatively large internal resistance and this causes power loss. This paper presents a basic study of the loss reduction of the DC power systems with cold stand-by using ultra capacitors. The power losses of the system are simulated and the method to reduce the losses is presented.