SU83469A1 - Frequency relay - Google Patents

Description

The subject of the invention is the frequency relay, whose action is based on the phase reversal in the parallel circuit when the frequency is changed and on the use of an in- polarized relay connected to the parallel circuit through a roller.

From the known frequency relays of this type, the proposed relay is distinguished by increased sensitivity, which is achieved by supplying the winding of the polarized relay with two voltages, of which one is proportional to the total current of the circuit, and the second creates an initial polarization through the rectifier bridge.

FIG. 1 is a diagram of the relay; and in fig. 2 and 3 curves of currents and voltages in relays.

The parallel circuit CL included in the controlled pep is tuned to the specified nominal frequency and reacts to its changes, acquiring properties of equivalent capacitance with increasing frequency and equivalent inductance when decreasing. A step-down transformer Tpi is connected in series with this circuit, the secondary winding of which has a derived middle point. This transformer is used to supply the signal voltage U with a frequency deviation from the nominal value to the circuit.

For the constant polarization of the circuit, a Gros transformer is used. Its secondary winding has an inferred center point taken from it and the voltage “) e voltage U„ is known to be greater than any possible signal pair taken from the secondary winding of the Tpi transformer and synchronously controls the alternate opening of the B-, So, BS and B valves (for example, solid straighteners). These valves serve as distribution valves for the signal current.

Tanks C | -C and variable resistances Rj-R-2 are used to initially adjust the equilibrium of the arms of the circuit. The capacitances CR and CC shunt the resistors Ri and Rn for the variable component of the current.

M 83469

Adjustable resistance is used to set the initial phase voltage shift at the terminals of the secondary winding of the transformer Tr-2. The initial phase of this voltage must lag behind the phase of the initial voltage of the signal taken from the secondary winding of the transformer Gr at the rated frequency by exactly 90.

The capacitance C is used to smooth the rectified voltage at the terminals of the polarized PR relay. The relay is made with the neutral position of the core and the two extreme positions determined by the sign of the flow through the coil of the direct current relay.

The effect of the circuit is illustrated by the curves shown in FIG. 2 and 3.

FIG. Figure 2 shows the voltages and currents to the main circuits and in the load at a 90 ° phase shift between the pins of the secondary windings of the transformers Tp and Fig. 3 shows the voltage and currents in the main circuits and in the load at some decrease in the frequency under study and the phase shift caused by the decrease in the frequency between the voltages on the secondary windings of the Tr and Tr transformers by 30 °.

FIG. 2, a and 3, and a voltage curve is shown on the halves A and the secondary winding of the transformer Tpz in FIG. 2.6 and 3.6 voltages on the halves G ti D of the secondary winding of the transformer in FIG. 2, and 3, the e-currents through the valves B, and, in FIG. 2.g and 3, r-currents through the valves By and Bf ,; in fig. 2, d and 3, d-difference of currents through a pair of synchronous 1-valve; in fig. 2, ei 3, e- current through the load (active resistance).

For the case of FIG. 2 we have f „-f --90. In this case, the constant component of the current through the relay is.

For the case of FIG. 3 we have Wed ,, -f ,. 30, t. 90 ° 90 ° Nde ed; ohm constant was 1O current flow through the relay is positive.

It is logical for this with a certain increase in frequency and the corresponding phase shifts of 90-f, | -, 270, the constant component of the current through the relay will be negative.

Thus, the magnitude of the voltage on the terminals of the relay is given by the size of the signal signal, but depends on the phase shift: f / ,,, a and / cos (φ „.

Depending on the sign of the change in the phase of the signal signal and. characterizing the sign of the change in the frequency of the alternating voltage source under investigation f /,., through the winding of a polarized PR relay, a current of one or another direction will flow, which will cause the closure of one of the other contacts of one or another actuator.

G1 p d d eme and z o b r with t e and u

A frequency relay based on the phase reversal in a parallel circuit when the frequency changes, characterized in that, in order to increase the sensitivity, a polarized relay is used, connected between the midpoints of the rhetorical transformers of the current and voltage circuits connected to the parallel circuit. the contour and adventures of their secondary windings to different diagonals of the rectifying bridge - for supplying to the winding of the relay the voltage of the primary polarization and the voltage proportional to the current in the circuit parallel to ntura.

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