SU474765A1 - Single phase induction phase shifter - Google Patents

Description

The invention relates to the field of phase-measuring technology and can be used as a phase-matching device in AC circuits, as well as an angle sensor in angle-to-code-type converters and in phase tracking systems, in particular, in gun control systems and software control of metalworking machines.

Known single-phase induction phase shifter containing W, the load of the quadrature winding and two series-connected / C-circuits connected between the output ends of the sinus and cosine windings. The connection point of the / C-circuits is connected to the second ends of the windings. The output voltage is removed from the load connected between the junction points of the resistors and capacitors. The execution of the phase shifter according to this scheme allows the frequency range of using the phase shifter to be extended towards the lower frequencies. The presence of two customizable jRC circuits complicates the circuit and causes a considerable investment of time on setting up these circuits. Because of the impossibility of setting up the KC-circuits, the phase shifter has an increased angular error, and for the exact operation of the phase shifter it is necessary that both of the C-circuits are identical.

The purpose of the invention is to expand the frequency range of work towards low frequencies.

This is achieved by connecting between the output ends of the sinus and cosine G1 windings W of the electric capacitor.

The drawing shows a diagram of the proposed single-phase induction phase shifter.

The phase shifter contains a rotating transformer /, phase-shifting RCr price, adjustable quadrature load: winding W, capacitor C, ..

The following designations are introduced into the phase shifter circuit: - W winding winding; SzS4 - quadrature winding W; f | f2 - sinusna winding; - kosnusna winding W; g, - additional resistor / C / d-value; C - electric capacitor / SGD-circuit; R - resistor / SGD-circuit; С „- electric capacitor included in the phase shifter circuit for an extended frequency range used in the direction of low frequencies; - load quadrature winding W.

The effect of extending the frequency range using the phase shifter towards the low frequencies is achieved by the fact that due to the electric capacitor C ,, connected between the output ends of the sinus and cosine windings W, the polyener 1e of the setting conditions of the phase shifter becomes possible. Thus, it becomes possible for an error-free operation of the phase shifter at frequencies below the lower limit of the frequency range of operation (theoretically, if the effects of other sources of error are not taken into account).

The electrical and magnetic non-perpendicularity of the windings of the HF has a significant effect on the value of the lower limit of the frequency dianzone of the operation of the phase shifter. The value of the additional resistor Gd is shifted to a more negative region. The inclusion of the capacitor Cd between the output ends of the sinus and cosine windings causes the transformation of the values of the additional resistor from a region of negative values to a region of positive values. Thereby, the frequency range of using the phase shifter is extended to lower frequencies. Switching between the output windings W of the capacitor C „is equivalent to increasing the parasitic capacitance between these windings. From the literature it is known that the presence of a parasitic capacitance between the sinus and cosine windings W causes an increase in the angular error of the phase shifter.

Indeed, if the phase shifter was tuned before switching on the parasitic capacitor (or capacitor C ;,), i.e. its error is minimal, then the connection of the parasitic capacitance causes an increase in the angular error.

Such co-structural technological factors, such as the non-perpendicularity of secondary windings of the BT, their non-ideality, the presence of a parasitic capacitance, can be compensated for by the restructuring of the A / D-chain. When all the tuning conditions are fulfilled, the output signal of the phase shifter will not contain an error signal.

For example, taking into account the parasitic capacitance (or capacitor Cn) between the sinus and cosine windings W, the conditions for the zeroing of the error signal (conditions of the setting of the phase shifter) are

D) vV-gt (I

- R

 t

4 g 2 g h- / 2 -

X ,,

L 1 - 1

2j (m (, G, - L,. G,), X, (X ,,

Yy

G CH-A5

About v2

2Af -)

An Lrf -f DGZ / -) Lz

rl + xl}

A - ,,, (/ i -I-- A ;,)

A-., - r, -

G-, -

r r xs

- - | rf-.

Xm

- y

I + l-5

2.r (. Ul, g, dj 1 1.V, r2A;:, (, A-,

fl + l 72 +: lg

P

.

; X - capacitance

Lp y

Noah resistance of the capacitor C phase shifting Sgd-tsii; And, - capacitance of parasitic capacitance or capacitor C ,,; ri, Xs - active and inductive sonrotation of the excitation winding VT; gy, lz - active and inductive resistance of the secondary windings of the high voltage; х, „- co-resistance of mutual induction between the primary and secondary windings of the VT.

With n, the conditions listed are converted into the usual setting conditions characteristic of an ideal phase shifter.

In the phase shifter circuit, the setting of capacitor C is not required. Its approximate nominal values can be determined by calculation. However, the value of the capacitor is most necessary.

Cn is determined experimentally. As the studies showed, the optimal values of С „correspond to the values of m / d 10-100 cm. Therefore, when determining the size of the capacitor С„, they are presented as follows:

the tunable phase shifter includes a randomly taken capacitor, after which the RCr setting is made. If, however, Gd is 100 ohms, then the value of C decreases. If the values of C С are too large, a decrease in the transmission coefficient of the phase shifter is observed by more than 5-10%.

Subject invention

A single-phase induction phase shifter containing a rotating transformer (VT), phase-shifting SGD-circuit, adjustable load of the quadrature winding, characterized in that, in order to expand the frequency range of operation in the direction of low frequencies, an electrical capacitor is connected between the output ends of the sinus and cosine VT windings.

k, n