Patent GB-190706092-A (GB)
Title: Improvements in and relating to Systems of Electrical Distribution.
Inventor: TAYLOR ALFRED MILLS
IPC: H02J7/34
Filed: 1907-03-13
Granted: 1908-05-13
Abstract: 6092. Taylor, A. M. March 13. Motors, controlling.-In isolated battery systems as described in Specifications No. 25,620, A.D. 1904, and Nos. 1528 and 10,495, A.D. 1905, [Abridgment Class Electricity, regulating &c.], automatic means, set in operation by a relay controlled timeswitch, or by a battery charge switch, or by a lighting circuit, are provided to ensure that the generator of the system when required to run as a motor from the battery shall attain a given speed or synchronism with the main supply current before the local load is transferred from the mains to the battery. Such means comprise a succession of automatic switches, one of which is controlled by a time-limit relay 119, which is set to operate when the required speed has been attained. The preferred type of switches used is one which is held in one position against the action of a strong spring, which, when released, closes it into a set of contacts or on to a fresh set of contacts. The switches are shown slightly inclined from the vertical position they are supposed to occupy. Fig. 1 shows an arrangement for controlling a motor generator consisting of a direct-current generator a and a three-phase synchronous motor b. Switches 102, 103, which are preferably linked together, are first operated by the solenoid 106. Circuits through the following are thereby closed (1) battery d, armature a, and resistance 112 ; (2) battery d, generator field winding 113, and motor field winding 115 ; (3) battery d and the operating-coil 119 of the time-limit device referred to above. In addition, the armature windings 122 of the motor b are connected to a fractional voltage of the transformer or equivalent potential reducer 127 supplied from the mains h, i, i<1>. The set therefore speeds up, being brought into synchronism owing to the currents supplied to the motor windings by the potential reducer. The time-limit device, which may be of any type, and which has been adjusted to act when this condition is reached, next operates the solenoid 131 by closing the gap 129. The switch 125 is thus thrown, and full voltage applied to the motor. The switch 132, short-circuiting the armature resistance 112, and the main switch m may then be thrown as and and when required, thus putting the local load on to the battery d, the motor generator running under reverse conditions. In a second method, Fig. 2, the switch 102 is first thrown as in the previous case. This opens the circuit of the solenoid 106, and closes (1) the circuit between the battery d, field coil 113 of the generator, and the field resistance and regulator 3, and (2) the circuit including the armature a and resistance 112. The field 115 of the motor, or of the rotary converter if such is used, is permanently connected across the battery terminals. A cord 135<a> connected to the switch 102 releases a trigger 135 of a clock-work mechanism 139, which releases consecutively the triggers 137, 141, so closing, first, the switch 138 short-circuiting the armature resistance 112, and, second, the switch 142, thus (1) putting a fractional voltage on to the armature b of the motor, and (2) closing the circuit of the operating-coil 143 of the time-limit device, which, as before, operates the switch 146 to put full voltage on to the armature when sychronism has been reached. The throwing of the switch 146 also closes a gap in the circuit of a solenoid 148, which is consequently operated when the insulated bar 159 on the time-switch arm n bridges the contacts 156, 158. This results in the opening of the switch m, and the disconnexion of the motor b from the mains. At the same instant, the generator circuit is interrupted by the switch 162 and the solenoid 161. The batteries t, which operate the various solenoids, may be one and the same battery or may be a portion of the battery d. A third method, for use when the system comprises a compensated induction motor a, Fig. 3, normally driving a power load, and a generator b connected by an automatic clutch 165, has an arrangement of switches operated in the order 102, 138, 166, and in the manner explained with reference to Fig. 2. The switch 166 is operated by the time limit relay, to connect the shafts when the speed has become almost equal. The switches m, 162 may be operated as in the preceding case.