Single-phase generator The early generators for those single-phase traction networks are single-phase generators. Even with newer three-phase motors which were introduced to some modern trains, the single-phases transmission for traction networks survive their time and are still in use in many railways today. However, many traction power stations have replaced their generators over time to use three-phase generators and convert into single-phase for transmission. In the early development of hydroelectricity, single-phase generators played an important role in demonstrating the benefits of alternating current. In 1891, a 3,000 volts and 133 Hz single-phase generator of 100 horsepower was installed at Ames Hydroelectric Generating
Single system image Single system image In distributed computing, a single system image (SSI) cluster is a cluster of machines that appears to be one single system. The concept is often considered synonymous with that of a distributed operating system, but a single image may be presented for more limited purposes, just job scheduling for instance, which may be achieved by means of an additional layer of software over conventional operating system images running on each node. The interest in SSI clusters is based on the perception that they may be simpler to use and administer than more specialized clusters. Different SSI systems