SU560241A1 - Simulation device for determining the static and dynamic characteristics of asynchronous machines - Google Patents

Description

through two groups of transformers 3 and 4, which simulate the functions of setting and measuring and coaxially the stator electric circuits in the longitudinal (3) and transverse (4) machine axes, are connected to the analog computing unit 5, which solves the differential equations of the asynchronous machine in the ax x d and q . The analog computing unit 5 is also connected by its inputs and outputs to the periodization unit 6, which reproduces the movement of the rotor relative to the magnetic field of the machine as a function of sliding.

The model (block 1) is made of a grid of active linear resistors 7-12 (Fig. 2), which reproduce the magnetic conductivities of the stator slots, the rotor and the air gap, and the nonlinear resistors 13, 14 and 15, leading respectively the magnetic conductivities of the backrest stator section spacing, stator teeth and rotor teeth.

In the model (block 2), the active resistances of the rod in the areas of the shorting ring of the original are reproduced respectively by capacitors 16-20 (Fig. 2), the linear resistor 21 simulates the dispersion of the sections of the shorting ring. Thus, capacitors 16-20, together with active resistors 8-In 21 (Fig. 2), reproduce electromagnetic processes in the slot region of the rotor (Fig. 3) and the short-circuiting ring. Due to the fact that the inductive resistances of the rod vary along the groove height (the inductive resistance is greatest at the bottom, the groove in the upper part is the smallest), to reproduce the current displacement, the groove area is divided along the groove height into a number of elementary sections inductive resistance within the same elementary area could be assumed constant. FIG. 3 for a bottle groove of such portions four. The magnetic conductivities of the selected sections of the groove are reproduced on the model by connected in series active resistors 8-I, and the active resistances of the rod sections are capacitive 16-19, one of the terminals of which is connected to a common terminal and each of the others to a node conductivity of the corresponding and previous sections. In the nominal mode of operation of an asynchronous motor, the active resistance of the rod is greater than the inductive resistance, as a result of which the current perimeterly flows in the lower thickened part of the rod. Therefore, in the case of simulating the nominal mode, it is possible to exclude from consideration capacitors 16, 17, 18. Then the squirrel cage circuit, which includes two adjacent rods and sections of shorting rings between them, the replacement circuit of which is shown in FIG. 4, it is possible to simulate a circuit including active resistors and capacitors according to FIG. 4, b.

In accordance with the Kirchhoff law for the circuit in FIG. 4, but we can write

, (cn + art.) ,, -.LCTJ / G

dt

dt

d:

+ Gs. (/ from, + / С.,) + 2, G, + 2L,, (1)

where e - EMF, induced in the contour of the flowKoMF in the gap, coupled with the considered contour;

K, GK-respectively, the inductance and resistance of the section of short-circuiting rings;

jf-cT, is the scattering inductance and the resistance of the rod, respectively.

If we integrate the bang (1), we get

F: LCT (/ v. + IcT.) + Gett J (/ st, + ctj dt +

+ 2r, + 2L, i ,.

(2)

A similar equation can be written for a circuit on phpg. 4, b.

E. (/ st, + / st.) + - (/ st, + / st.) dt +

 J

+ -. dt + l, R ,, (3)

tK J

where E is the voltage of the model corresponding to the flow Φ. in the gap coupled to the circuit;

RCT :, RK - active resistance, reproducing the inductance of the LCT rod and the total inductance of the sections of the rings 2 LK /

CCT. CK - capacitances reproducing, respectively, the electrical conductivities of the rod and both sections of the rings;

st2gk

Ic2, / k - TOK1I models corresponding to the currents of TCTI rods, icT2 and sections of IK rings.

Consequently, the processes in the circuits in FIG. 4, a and b are similar. Similarly, the similarity of the processes and the model with the account of the capacitors 16, 17, 18 and the original in any other mode can also be shown. However, at the same time, there is no need for a conclusion of the arguments describing these orocesses, due to the structural similarity of the model and the original.

Since the rotor part of the grid model (Fig. 2) is fixed relative to the stator part, modeling electromagnetic processes IB of the rotor and stator is possible in the coordinate system d q, rigidly connected with the rotor. At the same time, on the analog-grid 1 model, the field formed by the magnetizing force of the rotor winding and the fundamental harmonic can be investigated.

magnetizing force of the stator winding.

Thus, the simulator for determining the static and dynamic characteristics of asynchronous machines reflects the actual internal configuration of the electrical and magnetonically conducting parts, taking into account the nonlinear properties of magnetic value and current displacement, in the rotor winding.

Claims (3)

1. Dunaevsky S. Ya., Krylov O. A., Mazi L. V. Modeling of elements of electromechanical systems. M., Energie. 1966, p. 34 2. Kopylov I. P., Mamedov F. A., Bespalov B. Ya. Mathematical modeling of asynchronous machines. M., Energie, 1969, p. 148. 3. Avtopskoe certificate of the USSR № 347767, cl. G 06G 7/69, 08.24.72. i tow  -%, 77 ± ffJT -cm Sk / 20 / whose -IK FIG.