Patent GB-628827-A (GB)
Title: Improvements in and relating to dynamo electric machines of the metadyne kind
IPC: H02K47/16
Filed: 1946-09-20
Abstract: 628,827. Exciting dynamo-electric machines ; automatic control systems. HOLLYER, E. B., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Sept. 20, 1946, No. 28266. [Classes 35 and 38 (iv)] [Also in Group XXXVII] A metadyne transformer has excitation arrangemente comprising. controlling windings on the metadyne, amplifying means connected with said windings and arranged to produce a magnetomotive force acting in line with the magnetomotive force produced by the input current flowing through the armature of the metadyne whereby to cause generation of electromotive force between the output brushes of the metadyne, and to produce a second magnetomotive force acting in line with the magnetomotive force produced by the output current flowing through said armature, whereby to cause generation of electromotive force between the input brushes of the metadyne, control means for determining the magnitude of the output current of the metadyne connected in an input circuit of said amplifying means to produce in said input circuit a fixed or controlling quantity, the amplifying means being differentially responsive to said input quantity and to the output current of the metadyne for determining said first magnetomotive force, and control means for determining the magnitude of the input current of the metadyne connected in an input circuit of said amplifying means to produce in said input circuit a fixed or controlling quantity, the amplifying means being differentially responsive to said second input quantity and to the current flowing in the input circuit of the machine for determining said second magnetomotive force. A metadyne transformer 1 has its primary brushes a and c connected to supply-lines L1 and L2, and is arranged to apply traction motors M1 and M2. Exciters ER and EW are provided. These are preferably metadyne machines and may be mechanically coupled to the main metadyne armature. The machine ER excites stator windings S which produce magnetic flux for generation of voltage between brushes a and c of the main machine. Control windings 2 and 3 of the exciter ER normally act in opposition, the winding 3 being excited in accordance with the actual value of the main metadyne primary current, and the winding 2 in accordance with a desired value of said current. A backelectromotive force is therefore produced between the brushes a and c to maintain the primary current of the machine 1 at a value set by the excitation of the winding 2. The exciter EW similarly supplies a stator winding P to maintain the secondary current of the main machine at a value determined by the degree of excitation of a control winding 5 which is opposed by a winding 6 excited in accordance with the secondary current of the the main machine. Operation as an ordinary metadyne transformer may be afforded by adjustment of the exciter EW to control the traction motor current, the machine ER controlling the primary current of the main metadyne to maintain it in operation at constant speed. The resultant change of main metadyne excitation due to a sudden increase of line voltage is without substantial effect on the voltage applied to the traction motors. An increase of primary current is countered by an increase of back-electromotive force between the primary brushes. The excitation of windings 2 and 5 may be adjusted so that no current is drawn from the line. The equipment may then operate under motoring or regenerative conditions as a flywheel machine giving out energy from, or storing energy in, a flywheel coupled with the metadyne. The machine 1 is self-exciting as a motor or generator. Specifications 616,916, 616,917, 628,828, 628,829, 628,830 and 628,831 are referred to.