Patent GB-310007-A (GB)
Title: Improvements in control systems for power plant comprising prime movers, electric generators and motors driven thereby, and particularly for electric locomotives of thischaracter
IPC: H02P9/00
Filed: 1929-04-18
Abstract: 310,007. Associated Electrical Industries, Ltd., (Assignees of Herr, H. T.). April 19, 1928, [Convention date']. Dynamos and motors combined for transmitting power.-In petrol-electric locomotives or other moving or stationary power plant in which energy developed by a prime mover is utilized by several motors controlled from a common controller, the motor controller also controls the prime mover, for example, by action on the governor. In coupled locomotives each having a prime, mover such as a Diesel engine, an electric generator 14, Fig. 4, with an exciter 15 and electric motors 20, each controller 31 controls all prime movers and motors, but only one controller is operable at a time. Each controller may be arranged to allow isolation of a prime mover and to isolate all prime movers automatically during reversal of the motors. Each controller has one lever 32 controlling a reversing switch 17 for the motors through electric leads 34, and another lever 33 controlling a series-parallel switch 18 for the motors and also controlling the governor of the prime mover through pneumatic or other controls 43, the electric, pneumatic, &c. controls being coupled between locomotives. Controller construction. The control lever 33, Fig. 6, controls the air pressure in a chamber 59 and so in the control tube 43. Valves 63, 67 respectively control the admission of air to the chamber 59 from a high-pressure line 40 and the release of air from the chamber, the valves being operated according to the position of a diaphragm 56 balanced between the upward pressure in the chamber 59 and the downward pressure of a spring 54, with or without the upward pressure of a spring 78. The pressure of the spring 54 is varied by vertical movement of a part 52 produced through screw mechanism 50 when the lever 33 is rotated so that the position of the lever 33 determines the control pressure in thetube 43. Rotation of the lever 33 may also rotate an electric controller 160 for the seriesparallel switch 18 or may indirectly move such electric controller. Rotation of the lever 32 rotates a shaft 85 carrying an electric controller 86 for the reversing switch 17 and controls a valve 79 closing the connections between the chamber 59 and the pipes 40, 43, and so isolating the controller, whenever the lever 32 is in an intermediate position between its correct " forward " and " reverse " positions. The levers 82, 33 are interlocked by a recessed plate 90 moving with the lever 33 and a disc 87 and recessed plate 88 moving with the shaft 85. The lever 32 is detachable and has a tongue 97 engaging a shaped recess 98 so that the lever 32 must be depressed before being turned from its " forward '' to its " reverse " position and vice versa. The arrangement is such that the lever 33 can only be turned when the lever 32 is in its " forward " or " reverse " position, and lever 32 can only be operated when the lever 33 is in its " off " position. A modified construction (Fig. 8, not shown) of the controller valves 63, 67 is described. Prime mover control. The air pressure in the line 43 controls pneumatic governing mechanism on the prime mover directly or through a pneumatic relay, Fig. 13, in which a diaphragm 105 is moved by the control pressure in the line 43 connected to the chamber 107 and controls valves 109, 113 between the supply pipe 40 and the secondary control 47 connected to the chamber 106. A modified relay (Fig. 14, not shown) is described. The relays may reproduce or amplify control pressure changes. The pressure in the line 43 or 47 controls the position of a piston 153, Fig. 15, in the governor control and so operates slide valves 152 to control the admission or exhaustion of air from a. cylinder 149. A piston 148 in the cylinder 149 is connected to the slide 152 by a linkage 156 and spring 154, the two pistons balancing in a postion depending on the control pressure. Movement of the piston 148 rotates a pivoted frame 140 to vary the point of application of a roller 140 to a lever 134 pivoted at 135, a spring 135 pressing the roller 140 downwards. The lever 134 opposes the centrifugal weights 133 of the governor to vary the governor setting according to the position of the roller 140 and operates a valve 137 for a servo-motor 138 operating a shaft 139 controlling the amount of fuel injected to the engine. The movements of the frame 140 may also control the time of injection as at 157, Fig. 4. Magnetic cut-out valves are operated by push-buttons on the controllers 31 to isolate any engine. Control of series-parallel switches. The seriesparallel switches 18, Fig. 4, may be controlled electrically or pneumatically by the controller 31 with or without a pneumatic relay such as that described above with reference to Fig. 13, or a sliding electric switch (Fig. 17, not shown) governing the switch 18 may be operated by the air pressure in the control line 43, or as shown at 165, Fig. 4, by movements of the governor piston 153 described above. In a pneumatic control, the pressure in the line 43 controls a piston 199, Fig. 23, retarded by springs 200, 201 of different strength, so that a slide valve 208 is operated with a time-lag. The valve 208 controls the pressure admitted from air supply to pipes leading to the series-parallel switch, the time-lag allowing acceleration of the engine before operation of the series-parallel switch. One spring only may be used to operate the valve 208 without a time-delay. In another modification (Fig. 28, not shown) the valve 208 is operated by two pistons. One piston controls the air supply to the other and the two are balanced through a spring and lever, no substantial flow of air coming from the control pipe.