INDUSTRIAL ROTARY FREQUENCY CONVERTER MACHINE TO GENERATE HIGHER FREQUENCY TO DRIVE SQUIRREL CAGE MACHINES FROM 120Hz POWER SOURCE

Abstract

Industrial rotary frequency converter machine to generate higher frequency to drive squirrel cage machines from 120Hz power source is presented. Rotary frequency converters are machines that convert power from one frequency to another. They were commonly used to provide DC power for commercial, industrial and railway electrification from an AC power source. And It works by converting the input AC into rotary mechanical power. Meaning, the input power spins a motor. This motor transmits its power to the generator, which converts the mechanical power into the required AC output power. Squirrel cage induction machines are widely used in industrial and domestic. The rotor is cylindrical mounted on the shaft that contains copper or aluminum bars. Due to its ruggedness in construction and low maintenance found applications in industrial drives, mills, turning machines, pump, fan and blowers. Synchronous machines may be used along with squirrel cage induction machine may be used as a frequency converter to generate a frequency different from that of the utility company. The squirrel cage machine revolves faster, because the squirrel cage machine speed is slightly less than twice the 60Hz synchronous speed of 1800r/min it received from 120Hz power from the rotor of the frequency converter. As the speed was vary, the rotor was turning at 900r/min in the same direction as the rotating stator magnetic field, only 30Hz frequency was generated by the machine and frequency of 90Hz was generated it revolved at 900r/min in the opposite direction of the rotating field. When a six-pole industrial rotary frequency converter machine was connected with a nominal speed of 1200r/min and driven by a 3600r/min squirrel cage induction machine, the highest frequency that was obtained in the combination was a 60Hz input to the stator of the wound rotor machine creates a magnetic field rotating at 1200r/min, and the squirrel cage machine turns the rotor at 3600r/min in the opposite direction to the rotating stator magnetic field thus, generate a frequency of 240Hz as highest. While the lowest when the squirrel cage machine turns the rotor at 3600r/min in the same direction as the rotating stator magnetic field, the field cut the rotor winding at 2400r/min and generated frequency was 120Hz. (There was some slip due to the machines that makes both frequencies became slightly lower. Industrial Rotary Frequency Converter machine speed was increased to drive the industrial machine faster. This was achieved by connecting the stator of the industrial rotary frequency converter machine to 60Hz power supply and the rotor been driven at 1800r/min by the synchronous machine. The direction of rotation was opposite to that of the resolving magnetic field created by the stator windings and turning the frequency of the rotor output voltage to 120Hz. Because; the electrical power delivered by a rotary frequency converter comes from two sources: The electrical power supply to which the stator windings are connected and the mechanical power delivered to rotating rotor shaft. The machine revolves faster in speed and this method can be used to drives an industrial machine where faster and higher speed is requires. This is recommended for machine designers, Engineers and industries when the industrial machines require faster and higher speed