ABSTRACT
With the development of industrial technology, power electronics, computer technology and automatic control technology have become the three most important technologies. Among these technologies, the Uninterruptible Power System (UPS) lays a solid foundation for industrial development. UPS is a kind of energy storage device and its main component is an inverter, which allows the power to be output by voltage stabilisation and frequency stabilisation. UPS is mainly used in a single computer, computer network systems or other electronic power devices to provide an uninterrupted power supply (Josep et al., 2009).
