DE121513C

DE121513C -

Info

Publication number: DE121513C
Application number: DE1899121513D
Authority: DE
Filing date: 1899-12-20
Anticipated expiration: 1919-12-21

Description

KAISERLICHESIMPERIAL

PATENTAMT.PATENT OFFICE.

PATENTSCHRIFTPATENT LETTERING

- M 121513 KLASSE 21 e. - M 121513 CLASS 21 e.

Elektricitätszähler für Drehstrom. Patentirt im Deutschen Reiche vom 21. Dezember 1899 ab. Electricity meter for three-phase current. Patented in the German Empire on December 21, 1899.

Bei allen bekannten Drehstromzählern, welche sich nicht nur darauf beschränken, die Arbeit eines gleichmäßig belasteten Drehstromkreises zu registriren, sondern auch bei beliebiger Belastung der einzelnen Phasen richtig zeigen, sind mindestens zwei Nebenschluß- oder Spannungsstromkreise vorhanden, so daß der Tag und Nacht andauernde Wattverlust, welcher zum größten Theile in Vorschaltwiderständen oder Drosselspulen, also nutzlos vergeudet wird, gegenüber dem eines gewöhnlichen Wechselström'zählers verdoppelt ist.With all known three-phase electricity meters, which are not limited to to register the work of an evenly loaded three-phase circuit, but also at correctly show any load on the individual phases, at least two shunt- or voltage circuits are available, so that the day and night continuous watt loss, which for the most part in series resistors or inductors, that is is wasted uselessly, compared to that of an ordinary alternating current meter is.

Gleichzeitig erfordert jeder der beiden Nebenschlüßstromkreise bei gegebener Spannung für die oben genannten Vorschaltwiderstände, welche schon aus dem Grunde sehr groß sein müssen, damit der erwähnte Wattverlust möglichst gering wird, sehr viel feines und somit theueres Drahtmaterial, durch dessen außerordentliche Feinheit wiederum die Sicherheit des Zählers gegen die verhältnißmäßig häufig vorkommenden Drahtbrüche bedeutend herabgemindert wird.At the same time, each of the two shunt circuits for a given voltage requires for the above mentioned series resistors, which for the very reason must be large so that the mentioned watt loss is as low as possible, very much fine and thus expensive wire material, in turn due to its extraordinary fineness the security of the meter against the relatively frequent wire breaks is significantly reduced.

Die ,schon erwähnten Nachtheile werden bei der folgenden Anordnung auf ein Minimum beschränkt, weil bei derselben nur ein Spannungsstromkreis anstatt deren zwei oder gar drei, wie bei den zur Zeit bekannten Anordnungen, zur Verwendung gelangt.The disadvantages already mentioned are reduced to a minimum with the following arrangement limited because with the same only one voltage circuit instead of two or even three, as in the currently known arrangements, are used.

Zu diesem Zwecke ist es nur nöthig, auf den beweglichen Theil eines auf dem Induktionsprincip beruhenden Elektricitätszählers irgend zwei der drei vorhandenen Hauptströme in Verbindung mit derjenigen der drei Spannungen einwirken zu lassen, deren Phase bei gleichmäßiger inductionsloser Belastung der Drehstromabzweigung um 30° gegen die Phase des dritten Hauptstromes verschoben ist.For this purpose it is only necessary to focus on the movable part of one on the principle of induction based electricity meter any two of the three main currents present in connection with that of the to allow three voltages to act, their phase with an even inductive load the three-phase branch is shifted by 30 ° against the phase of the third main current.

Die älteste Gleichung für die Drehstromarbeit enthält sechs Größen, die drei Hauptströme und die drei Hauptspannungen. Aus dieser Gleichung ist durch mathematische Entwicklung die bekannte Beziehung hervorgegangen, welche nur noch vier Größen, zwei Hauptströme und zwei Hauptspannungen, enthält. Nach dieser letzteren sind die in einem Hausanschluß verbrauchten Watt w bei Benutzung der in der Fig. 3 eingetragenen Bezeichnungen für Ströme und Spannungen,The oldest equation for three-phase work contains six quantities, the three main currents and the three main voltages. From this equation, the well-known relationship emerged through mathematical development, which now contains only four quantities, two main currents and two main voltages. According to the latter, the watts w consumed in a house connection are when the designations for currents and voltages entered in FIG. 3 are used,

w = e_a J₂ cos (e_lt J.₂) — e₂ J₁ cos (e₂, J₁). I. w = e _a J ₂ cos (e _lt J. ₂ ) - e ₂ J ₁ cos (e ₂ , J ₁ ). I.

Die in der Klammer stehenden Buchstaben geben den Phasendifferenzwinkel der beiden eingeklammerten Größen an. Eine für die Praxis ganz wesentliche weitere Vereinfachung der ursprünglichen Gleichung wird dadurch ermöglicht, daß man die Messung auf solche Drehstromanlagen beschränkt, bei denen die Spannung e, gleich der Spannung e₂ ist. Für solche Fälle nimmt obige Gleichung zunächst folgende Form an:The letters in brackets indicate the phase difference angle of the two quantities in brackets. A further simplification of the original equation, which is very important in practice, is made possible by limiting the measurement to three-phase systems in which the voltage e ₁ is equal to the voltage e 2. For such cases, the above equation initially takes the following form:

w = e₂ J₂ cos (e₂, J₂ -\- e_lt e₂) II. — e₂ J₁ cos (e₂, J₁), w = e ₂ J ₂ cos (e ₂ , J ₂ - \ - e _lt e ₂ ) II. - e ₂ J ₁ cos (e ₂ , J ₁ ),

weil O₁ e₂ -f- e₂ J₂ -j- J₂ e_x =· ö.
Diese Gleichung enthält nur noch drei Größen,because O ₁ e ₂ -f- e ₂ J ₂ -j- J ₂ e _x = · ö.
This equation contains only three quantities,

(2. Auflage, ausgegeben am iy. Mai(2nd edition, issued on May

Claims

two main currents and one voltage. The fact that only one voltage is used in the meter means that the expensive and space-consuming ballast coils can be dispensed with at the usual voltages and the watt loss caused by the voltage current, which lasts day and night, is reduced by half. Such a counter only contains one voltage circuit. In AC motor meters built on the Ferraris principle, the voltage current is also strongly shifted against the phase of the voltage, so that with the same magnitude of the voltage current, the watt loss is significantly reduced compared to other meters. Finally, we must not forget the advantage that arises from the fact that the voltage otherwise destroyed in the series resistors in this case acts entirely as a driving force, so that the voltage current may be smaller than in meters with series resistor under otherwise identical conditions. The force P exerted on its short-circuit armature by an alternating current meter built according to Ferraris' principle is known to be proportional to the product of the two currents generating the rotating field times the sine of the phase difference angle of both currents. In order to make this force P proportional to the watt w laid down in equation II above, one only needs three quantities according to this equation, i. i. two main currents and a voltage to act drivingly on the armature, namely one lets the current generated by the voltage e2 interact once with the one main current J2, the other time with the main current J1. The parts of the voltage current that interact with the main currents J2 and J1 are denoted by L2 and iv so the driving force is ^ P = J2 z2 sin (J2, I2) + J1 I1 sin (J1, I1). By shifting these two parts i2 and Z1 of the voltage current accordingly one can achieve that:

1. sin (J ₂ , i ₂ ) = cos (e ₂ , J ₂ + e _v <? ₂ j,

2. sin (J ₁ , ij = cos (e. ₂ , J ₁ ) becomes,
this is the case if:

i A. J ₂ h + A. e ₂ ^J 2. + A. e _x e ₂ = 90 ⁰ and

J ₁

A. e ₂ J \ = 9 °° i ^st

Since in the first case / $ _ e ₂

and A_ J-2 h -f A- e-2 J-2 = Α. e »
°

Z ₂ = 90 ⁰ -f I2O ° =

= 180

= 120 ⁰ so must 30 ⁰

A shift of the phase by 180 ° is achieved by a simple current reversal, so that one _{only has to reverse the part of the voltage circuit which interacts with the main current J 2} and, moreover, to shift the relevant part of the current backwards by 30 °.

It is also in the second case:

A. J ₁ h + Α. e ₂ J ₁ = Α. <? _{2 line} ₁ ;
thus / ^ _ e ₂ Z ₁ = 90 °.

The co-operating with the main stream J ₁ part z'j the voltage current must be therefore moved to 90 ⁰ to the voltage phase. The two desired shifts in the phase of the voltage current can be brought about by the circuit shown in FIG.

The self-induction of the shunt circuit is so long changed by controlling the partly current Z ₁ connected in parallel inductionslosen resistance, as well as by varying the inductive Theiles of Spannungsstfomkreises until the total current Z ₂ to 30 ⁰ and the portion of current Z ₁ to 9 am g ^s g ^s the phase of the voltage e ₂ remains.

1 and 2 are two views of the implementation of such a counter with Help the driving force of patent 112441 protected electricity meter for, alternating current shown.

Patent-A ν SPRU ch:

An electricity meter for three-phase current, characterized in that only a shunt circuit is used to measure the energy consumed in an arbitrarily loaded three-phase branch, the current of which interacts with two main currents and is generated by the voltage whose phase with uniform inductive load of the three branches compared to the Phase of the two main currents ^{appears shifted by 90 0} ^{and Γ50 0} , for the purpose of making the electricity meter as compendious and inexpensive as possible and of reducing the continuous watt consumption by voltage currents to a minimum.

1 sheet of drawings.