GB151810A - Improvements in means for starting up synchronous rotary converters and other electrical machines of a like character - Google Patents

Abstract

151,810. Electric Construction Co., and Tonkinson, W. Sept. 11, 1919. Systems depending on the use of two or more machines.-A synchronous rotary converter or other synchronous machine A is started up by means of an induction motor D having one or more pairs of poles less than the machine A, and the rotor E of the motor is connected to an auxiliary armature F rotating within a magnet yoke G, the auxiliary armature and magnet yoke having a number of poles equal to the difference between the number of poles of the motor D and machine A. The armature F is mounted on the same shaft C as the rotor D and armature B of the machine A, or on a shaft coupled to the shaft C. The motor D is started by closing switches J, L, the magnet yoke G being excited from the continuous-current side of the converter soon after the set begins to speed up. The motor D tends to run at a speed above the synchronous speed, but this tendency is overcome by the counter electromotive force generated in the armature F. When the set reaches the synchronous speed, the main switch H is closed and the switches J, L are opened, leaving the motor D and auxiliary armature running light. If desired, a clutch may be provided to allow the motor and auxiliary armature to be disconnected from the converter after starting up. Resistances h may be provided to check the initial rush of current in the starting-motor.