DE149728C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The present invention relates to an alternating current system for electrical railways with return line feeder to divert the current from the one used for the return line Rail respectively the conductor used for this purpose, through which the voltage drop in the Current return is reduced or avoided.

To this end, the current is in the

ίο Feeder through the winding of a transformer passed, while the current return in the reverse direction 'through a other winding of the same transformer goes. This will reduce the voltage drop in the current return reduced without the voltage of the motors or the whole To change the circuit in a practically noticeable manner.

The transformer can be at the power generation point or at any other Be arranged points of the line. By arranging the windings accordingly can get any desired transformation of the voltage in the current return will.

Fig. Ι of the drawing shows schematically the application of the invention to an electrical Road or railway system with single-phase power.

The single-phase power generator α supplies alternating current to one or more cars or trains b. The current from the generator is carried through an overhead contact line or some other insulated conductor c , from which it goes to the car or train b , to go there through the drive motors or through fixed or rotating converters or power generators or other suitable devices , into which the alternating current is used or transformed, whereupon the current returns through the return conductor d. Both the rail and another completely or partially insulated conductor can serve as the return conductor.

An insulated return feed conductor e goes from ■ a point f of the return rail or the return conductor, d to the return connection terminal of the generator a. The transformer g has an iron core consisting of thin plates with two windings ρ and s, which are switched into the circuit in the manner shown. The current from one pole h of the machine α goes through the winding ρ to the contact line c, while the current return line to the other contacts h ^{1 of} the generator a partly through the return line d, partly through the return line feeder e and the winding s takes place.

As can be seen, the current flows through the windings ρ and s in opposite directions. The current in the winding ρ is by that part, which through the return line d to the pole Z? ¹ returns, larger than that which passes through the winding s . The effect of this arrangement is that the returning current or a large part of it at the point / from the current return line d is diverted because of the voltage which is induced in the winding s. Through this'

Claims (5)

the voltage difference between f and h ^{l is} reduced. The auxiliary electromotive force, which is added in this way to the return line feed conductor e through the winding s , is transmitted from the other end of the circuit, with a corresponding oppositely directed electromotive force being generated in the winding ρ. All the tension of the ίο the circuit, including that of the electric motors or the other electrical transmission devices on the wagon or train, is not affected by this arrangement, apart from a very small loss in the transformer. The effect is only to change the distribution of the voltage drop, removing it from the return line where it is detrimental and transferring it to the feed line where it is much less detrimental. The extent of this voltage transfer can be adjusted by appropriate construction of the transformer g in such a way that the voltage difference between f and fa ¹ is reduced by any desired amount. The arrangement is made practically self-regulating, ie the electromotive force added to the return line feeder e by the winding s seeks to become proportional to the current. For long lines, the catenary or distribution line can be divided into several sections, as is shown schematically in FIG. 2. There are branches on the main line c at corresponding distances to feed the line sections km n. In the connection of these line sections with the main line c , the transformers g are arranged, each of which is set up like the transformer shown in FIG. Each transformer therefore has two windings ρ and s, of which the winding ρ between the main line c and the line section k respectively. m η is, while the winding s in the return line feeder e respectively. e ¹ e ^{2 is} switched on. Several line sections can also be fed by a single transformer. In the embodiment shown in FIG. 3, five line sections k, m, n, 0 and q are fed from the main line c through a single winding ρ and an auxiliary feeder c * which is common to all line sections. The return line d at f is followed by the one with the pole Z; ^{1 of} the alternating current machine α connected return line feeder e, in which the only transformer winding s is switched on. Fig. 4 illustrates the application of the invention to a three-phase system current. The two insulated contact lines c ¹ c ² emanate from the three-phase current generator a ^l , while the rail d ^l or the return conductor serves as the third line of the three-phase system. The transformer g ^x has three windings r, t and v. The winding r is connected to the contact line c \, the winding t is connected to the contact line c ² and the winding ν is connected to the return ^{feed line e 3} . The contact lines c ¹ c ² are respectively to the poles h. h ' ^{2 of} the generator a ^l connected, while the rail d ^l or the current return conductor is connected to the return pole h ^{1 of} this generator. The current passing through the lines c ¹ c ² generates an electromotive force in the winding ν , which diverts the current from the rail d ¹ into the return line feeder e ³ and thus reduces the potential difference that was otherwise generated in the rail d ^l. To get the required. To maintain the phase relationship between the two or more windings of the transformer, which could be influenced by the inductions of the return line bar d or the return feed line e , can be done in connection with one or the other of the lines or with one or the other of the Transformer windings inducing or non-inducing balancing windings or capacitors can be applied. The application of the invention to long polyphase power lines where the Wagons or trains are fed by a number of distribution lines, does not require any special description, as this is with the exception of what has been said about the number of phases, all that applies to it Fig. 2 has reference. To reduce the tension between the catenary and the car respectively. , the pipe sections Transformers are applied. They in no way affect the essence of the present invention. Patent-A ν Proverbs: i. AC system for electric railways with one or more to the Return line or the return line connected to the return feed lines, characterized in that in the return feeder or in each the same the winding of a stationary transformer is switched on, which also has one or more windings which are switched on in the feed line or lines and those in the first-mentioned windings have an auxiliary electromotive Generate force for the purpose of reducing the voltage drop in the current to reduce or avoid recirculation. 2. An embodiment of the AC system according to claim i, characterized in that the transformer has two windings (ps) , of which one (p) is connected in series with the main feeder (c) j, while the other winding fs) with the return feeder (e) one behind the other and connected in parallel to the return rail or the current return conductor (d) (Fig. i). 3. An embodiment of the alternating current system according to claim 1, in which the power supply line is divided into several line sections and wherein several return line feed conductors are arranged, characterized by several transformers, one winding of which in the connection of the main current conductor (c) with one of the line sections, the other winding of which is switched on in the associated return feeder (Fig. 2). 4. An embodiment of the AC system according to claim 1, characterized in that one winding of the transformer between the main feeder (c) and an auxiliary feeder fc *) common to a larger number of line sections is connected (Fig. 3). 5. An embodiment of the AC system according to claim 1 for three-phase current, characterized by a transformer (g ¹ ) with three separate windings (r, t, v), two of which (r, t) in the two feed lines (c ^l , c ' ² J and the third winding (v) are switched on in the return feed line fe ^s j connected to the third (current return) conductor (d ^l ) (FIG. 4). 1 sheet of drawings. Berlin, printed in the Reichsdruckerei.