SU376857A1 - PATEKT1Sh-T? HSh1iS1 - Google Patents

Description

one

The proposed phase shifter can be used in automation devices to accurately measure and set the phase of an alternating voltage.

Phase shifters are known in which active-reactive bridges with different time constants are included in the sinus and cosine windings of a rotating transformer. In such phase shifters, an additional active reactive circuit connected to the sinus or cosine winding of a rotating transformer is used to reduce the error from changing the frequency of the supply voltage and increase the electrical reduction. However, this phase shifter has a significant drawback - a significant error when changing the size of the active and reactive elements.

The aim of the invention is to reduce the phase shifter error caused by a change in the size of the active and reactive elements.

In the proposed phase shifter, this goal is achieved by including in the output diagonal of one of the bridges a phase inverter in the form of a transformer, the output of which is connected in series with the output of the other bridge.

The invention is illustrated in the drawing, which shows a circuit diagram of a phase shifter.

The phase shifter contains a sine-cosine rotating transformer with a stator winding 1, a sine rotor winding 2 and a cosine rotor winding 3.

An actively reactive chain is connected to the sinus winding 2, consisting of a capacitor 4 (Ci) and a resistor 5 (R), the time constant of which is:

3 ::

.R,

where co is the angular frequency of the voltage supply of the phase shifter.

An active-reactive chain is connected to the cosine winding 3, consisting of a capacitor 6 (Sat) and a resistor 7 (Ri), the time constant of which is:

ST

20

a - C, -

The rotor windings 2 and 5, due to the diversions from the middle points, form two bridge circuits connected to them, the output diagonals of which are connected in series and form the first output of the phase shifter (LBI.IXI).

The phase inverter 8 is a transformer with a primary winding 9 and a secondary winding 10. The winding 9 (input of the phase inverter) is connected to the output diagonal of the bridge of the sinus winding 2, and the winding 10 (output of the phase inverter) is connected in series with the output diagonal of the bridge of the cosine winding 3, image second

phase shifter output (t / Bbixa).

The proposed phase shifter works as follows.

The stator winding 2 of the rotary transformer is powered by a variable sinusoidal voltage Lnx- The voltage at the output of the phase inverter (winding 10) differs in phase by 180 ° from the voltage of the output diagonal of the sinus winding bridge 2. The rotation of the rotor of the rotary transformer is at an angle causing the change phase voltage / vykh relative to phase voltage f / vyhg by law:

er 2a.

In order to obtain high linearity characteristics of the phase shifter with small overall phase inverters, the output diagonal of the cosine winding bridge 3 should include a load equal to the input resistance of the phase inverter.

In practice, this leads to the connection of a second transformer, the phase of the output voltage of which does not change by 180 °.

Subject invention

A phase shifter containing a sine and cosine windings, each of which is connected to the middle points, is divided into two parts, which together with the active and reactive resistances form bridges, characterized in that, in order to reduce temperature faults, a phase inverter is included in the output diagonal of one of the bridges. in the form of a transformer, the output of which is connected in series with the diagonal of the other bridge.

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