SU1396234A1 - Multimotor a.c. drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in electric drives of bridge cranes, movable bridges, conveyors, etc. The purpose of the invention is to simplify the coordinated angular positions of the rotors of the asynchronous electric motors at start and reverse. The multi-motor electric drive contains two asynchronous motors with a phase rotor and an individual load 3 (4), a three-phase induction resistor 5 with windings 6, 7 connected to the rotor terminals of the asynchronous motors 1, 2. Leveling the rotational frequencies of the motors is due to the magnetic coupling of the circuits rotor.

Description

with CO

O5

with

I The invention relates to electrical engineering I and can be used in electric drives of bridge cranes, movable bridges, conveyors, and so on.

The purpose of the invention is to simplify the coordination of the angular positions of the rotors of the asyn-5 chronical motors during skidding and reverse. The drawing shows the principle electric circuit of a multi-motor i-non-resistive current drive. I The multi-motor electric drive of the alternating current contains two asynchronous motors 1 and 2 with a phase rotor, the shafts of which are connected to the corresponding load 3 or 4, an induction resistor 5 with two three-phase windings 6 and 7, the ends of the phases of each of the windings 6 and 7 are combined, the beginning of the phases of each of. The windings 6 and 7 are connected to the terminals of the windings of the rotor of the corresponding I asynchronous motor 1 or 2.

n is the ratio of the numbers of turns of the primary and secondary windings of an inductively coupled circuit element;

Zii Rupi- | -ja) Lupi;

Z22 (RuP2-f-jwLup2) n-;

Zb Z2I jojMn.

Since the condition for the equality of velocities is the equality of the emf | and Ё2, then

l | Z || - (- l2Z | 2 1 | Z | 2.-2 - - 2il1 We determine the value of the current Ig:

(3)

2

Z rrzzk

222 - Z2I

(four)

Thus, it can be seen from equation (4) that when the current Ii changes, the current {2 and vice versa changes accordingly, i.e. The magnetically coupled circuits continuously mutually influence the multi-motor action of each other, resulting in the leveling of the electric drive in a mutual 20 °. The speeds of rotation of both engines, I influence, of two inductively coupled circuits, formed by circumferences of 6 and 7 miles.

The proposed .multi-motor elec- tronic | rheostat 5. The condition of an alternating current equalizer is not in its essence; The rotational speeds of both engines differ from the electric working voltage, and 1 and 2 is the emf balance of their rotors. 25 la (ERV), therefore, it can be called the elec- tary balance equation has the following general form: the romagnetic working shaft (EMRV).

EMRV in comparison with ERV is characterized by the fact that it provides the possibility of separate start-up of drive motors operating on a common load, 30 but not having a mechanical connection. In addition, during a joint launch,

(one)

Ei URLjpi + ULUp, -t-UMi;

E2 URLJP2- -UiUP2 + UM2,

where is URUP | I | Rb Ri; IjLUPi lijuLiUPi; to them | wM12;

URUP2 i2RL P2; UlliP2 l2 jtl l4- P2;

UM2 jcoMii;

Yo | - EMF of the rotor of the first engine; 2 - EMF of the second motor rotor;

Rup | and jooLupi - active and inductive sleep-35 induction rheostat motivations related to the first engine; Rup2 and j (i) Lup2 - active and inductive necessity of preliminary synchronization of the angular positions of the rotors.

Claims (1)

Invention Formula A multi-motor electric drive containing two asynchronous motors with a phase rotor, three-phase induction rheostat with one three-phase anti-inductive winding, the ends of which are combined, a rheostat, relate to the second motor and are connected to the winding terminals the body; the rotor of one induction motor, jwM - resistance of mutual induction - characterized by the fact that, in order to simplify; Connected to the terminals of the winding. rotor of another asynchronous motor in accordance with the phasing of the first asynchronous ((f is the frequency of the rotor current). We transform the system of equations (1) into the equations of the quadrupole Ei I | Zj i - | -I2Z | 2;  + I2Z22, where E2 E2p; 12 i-4; 50 engine n is the ratio of the numbers of turns of the primary and secondary windings of an inductively coupled circuit element; Zii Rupi- | -ja) Lupi; Z22 (RuP2-f-jwLup2) n-; Zb Z2I jojMn. Since the condition for the equality of velocities is the equality of the emf | and Ё2, then l | Z || - (- l2Z | 2 1 | Z | 2.-2 - - 2il1 We determine the value of the current Ig: (3) 2 Z rrzzk 222 - Z2I (four) that izme bind lei. the need for preliminary synchronization of the angular positions of the rotors. Invention Formula gogo asynh vii from phases 50 engine