DE1055675B - Parallel connection of synchronous generators - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT LETTER 1055675

ON REPORTING DAY:

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL:

EDITION DEC
PATENT LETTERING:

DBP 1055675 KL.21d2 9

INTERNAT. KL. H 02 fc JULY 3, 1957

April 23, 1959
OCTOBER 15, 1959

agrees with the exposition

When synchronous generators are operated in parallel using the known compounding circuit If the choke, current transformer and rectifier are excited, it is desirable to have the same excitation currents to get the reactive load distribution of the. Generators will be the same. As long as the resistances of the Field windings of the generators are the same size, the field windings can be used in a known manner connect in parallel. Since the voltages and resistances are the same, the currents must also be the same being. In the case of unequal field resistances, as is the case with a warm and a cold one, for example Machine can occur despite the same design, but then the reactive current component of the generators would also according to the different pathogen: flows are of different sizes. This also applies if excitation lines have been connected in parallel upstream of the rectifier, i.e. on the three-phase current side.

Because with a compounding circuit via a current transformer, choke and rectifier, the no-load excitation current has approximately the same value at every operating temperature of the excitation field, one must just make sure that the load components of the generators working in parallel in every operating state are equal to each other.

This is achieved according to the present invention in a way that is explained here for three generators working in parallel on a consumer circuit 8, but can be used for any number of generators: The generators 1, 11 and 21 are controlled via the chokes 2, 12 and 22, the current transformers 3, 13 and 23 and the rectifiers 4, 14 and 24 are energized in a manner known per se. In contrast to the known compounding circuit, however, the current transformers 3, 13 and 23 are not primarily flowed through by the generator armature current, but each receive a current from a current transformer 7 known per se, common to all generators, which records the entire load current. Depending on the number of generators switched on, the number of turns of the secondary winding of the current transformer 7 is changed by means of the taps 9 a, 9 b and 9 c. With three generators, for example, three different numbers of turns are required, which are tapped off through the three connections 9a, 9b and 9c. 9 a is intended for one generator, 9 6 for two generators and 9 c for three generators. The secondary current of the current transformer 7 is at the same time the primary current for the current transformers 3, 13 and 23 of the individual generators. When all three generators are operated in parallel, these current transformers 3, 13 and 23 are connected in series on the primary side, so that an equal load share is enforced for the excitation of each generator. Will be a generator that works with the armature parallel connection
of synchronous generators

Patented for:

Hans Still Aktiengesellschaft,
Hamburg-Billstedt.

Dr.-Ing. Fritz Kümmel, Hamburg,

and Dipl.-Ing. Herbert Noppe, Hamburg-Wandsbek,

have been named as inventors

windings via switch 5, IS or 25 with the Busbar is connected, switched off, so must at the same time with the switch 5, 15 or 25 of the corresponding switches 6, 16 or 26 are switched over, the primary side of the converter 3, 13 and 23 opens and instead creates a direct current path. A switch 5, 15 belongs to each generator or 25 and a changeover switch 6, 16 or 26. These two switches can be operated in any way, e.g. B. electrically or mechanically, analogously coupled to one another.

In the arrangement according to the present invention is used to compensate for the load current im The generator did not use the current drawn from the current transformer 7 on the individual generator excitation circuits divided, but this current flows through the compounding current transformer, which is primarily connected in series 3, 13 and 23, so that the same load-dependent excitation current is forced in each generator becomes, even if the field windings have different temperatures and thus different Have resistance.

In this way the task at hand becomes advantageous solved that every generator ', regardless of the field winding temperature and thus of the field resistance, receives the same excitation current.

Claims (3)

Patent claims: 1. Parallel connection of synchronous generators via chokes, current transformers and rectifiers are excited, characterized in that the primary windings of the current transformer (3, 13 and 23) all connected in parallel with the armature windings Generators over the secondary winding of a known per se, the current 909 623/422 all current transformers leading generators are connected in series. 2. Parallel connection of synchronous generators according to claim 1, characterized in that the da3 common secondary current transformer is tapped so that one of the number of in Series connected current transformers (3, 13 and 23) corresponding voltage can be tapped. 3. Parallel connection of synchronous generators according to claim 1 or claims 1 and 2, characterized in that the generator switches (5, 15, 25) in pairs with the current transformer switches (6, 16, 26) are coupled. Considered publications:
German patent specification No. 761 904. 1 sheet of drawings