Patent GB-403823-A (GB)
Title: Improvements in or relating to internal combustion engineelectric power units
IPC: H02P9/00
Filed: 1933-02-02
Abstract: 403,823. Systems for transmitting mechanical power; automatic regulation. SULZER FRERES SOC. ANON., Winterthur, Switzerland. Feb. 2, 1933, No. 3198. Convention date, March 24, 1932. [Class 38 (iv).] The load and speed of an internal-combustion engine driving an electric power plant is maintained constant at an adjustable value by means of a control generator driven by the engine and a piston valve operated in accordance with the voltage of the said generator to regulate the supply of pressure medium to a cylinder operating a rheostat in the excitation circuit of the generator. The control generator voltage may be directly operative or it may operate against a constant voltage from a source such as a battery. A variable resistance in the output or in the excitation circuit of the control generator may be used to determine the engine speed or torque and the loading of a centrifugal governor on the engine may be simultaneously adjusted. The control generator may supply current to plant auxiliaries. Fig. 1 shows an engine 1 driving a main generator 2 and a control generator 4. Two relays 8, 9 control solenoids 14, 15 jointly so that, at an engine speed below the value determined by the adjustment of a resistance 10 the solenoid 15 is excited, and at a speed above that value the solenoid 14 is energized. A piston valve 16 is thus operated to set a piston 17 in such a position as will adjust a resistance 22 in the excitation circuit of the main generator to maintain a suitable load on the engine. In a modification a single oscillating relay controls alternatively the circuits of the solenoids 14, 15 and in a further modification two solenoids act on the piston valve in opposition one being energized by a constant voltage and the other by the voltage of the control generator. The setting of the piston 17 may be controlled by a lever 39 adapted to adjust a sleeve varying the point of cut off effected by the piston valve. Excessive field current during starting may be prevented by an additional resistance in the excitation circuit of the main generator 2 ; the range of regulation and the resistance 22 is thus limited. The lever 11 adjusting the resistance 10 may be connected with means 26 controlling the loading of the governor 23. The Specification as open to inspection under Sect. 91 described also a modification in which an electric motor was driven in opposite directions to adjust the resistance in the field circuit of the main generator according to the predominance one of two field windings energized respectively by a constant voltage and by the voltage of the control generator. The lever 11 in this modification adjusted a resistance in the field circuit of the control generator and also the governor loading. The range of regulation of the resistance in the main generator field circuit was limited in this modification by electromagnetic means locking the resistance motor or the electric motor and energized by the driver at will. This subject-matter does not appear in the Specification as accepted.