SU109384A1 - Method of switching three-phase asynchronous short-circuited motors into a single-phase network - Google Patents

Description

When powering three-phase asynchronous short-thrust motors from one () 4) of the Asian network, the inclusion of the stator windings of the motor according to the inverted-phase star circuit is used.

The proposed method for the occlusion of such engines is more sophisticated than the known methods, since it allows for a better engine performance due to a more uniform load on its phases. For this, the inverted phase of the asynchronous motor is connected in series with a.1.1 electric capacitor.

To increase the starting time of similar engines, it is proposed to start them up as an incomplete (partial) star with a capacitor in the single phase circuit, and after the end of the hog switch to the full star circuit with a capacitor in the inverted phase circuit.

FIG. 1 image of a three-phase asynchronous motor. H connection to a single-phase network; in fig. 2 diagram

its launch G1ri on.chautomatic mtravleiiii.

Motor start-up, 1 start of operation 1 of the junction of the stator windings .4, B and C (Fig. 1) not by (partially) star e with the C / x capacitor in the circuit and single phase. At the same time unipolar rubi.T1 n1G1-; P is set to the upper limit.

After the engine reaches its full rotational speed, it is possible to cut the engine, and the speed will be reduced to the lowest number. When this is done, the stator winding B overlaps the 1st full-star circuit with the Toii phase inverted into which the capacitor Ck is inserted (the cell and the end of each phase are denoted by X and X).

In order to evaluate the characteristics, the capacity in the co-selection phase is increased by the number of the plugs,: by 50% in comparison with the value of the capacitance required for symmetrical inclusion of the O6NIOTOK stators into a full star.

 in the course of the move 1gate. According to the partial star scheme, it provides a good starting torque and shortens the run-up time of the rocket, however, the engine's full rotation with this circuit after reaching the normal speed is not possible due to a large overload of the condetator phase. Switching the stator winding with a zero-star star circuit with an inverted phase allows the engine to work very well after it is injected into the course without overloading the co-necator phase.

Switching the stator windings when the engine is started from an incomplete star circuit with an inverted capacitor phase into the star circuit is produced by the contactor K. (Fig. 2), the coil of which is welded to the H-paralized capacitor phase. As the motor accelerates. The voltage of the capacitor phase also increases at a certain rotational speed (70-80% of nominal) contactor L | it works.

Switching the motor to the mains and stopping it to a drain is usually done using a conventional K2 contactor or magnetic nuskat.h.

Subject and B about with with and N and

1. The method of switching three-phase asynchronous short-circuited motors into a single-phase network according to the inverted-phase full-star scheme; and with the fact that, in order to improve engine performance by more uniform loading of the machine phases, an electric capacitor is connected in series into the stump of the reverse phase.

2. Method 1, which differs from H1 and the fact that the start-up of the engine is triggered according to the scheme of an incomplete (partial) star e with a capacitor in the value of a single phase, in order to increase the start-up torque, and after the start-up switch (for example, automatically - with the help of an electromagnetic contactor excited by the capacitor: capacitor phase) to the circuit of a full star with an unbroken phase and with a capacitor in its value.