SU96420A2 - Counter (or wattmeter) of active or reactive energy (power) - Google Patents

Description

Basically auth. St. No. 74490 describes a meter for recording active or reactive energy in a three-phase circuit consisting of two measuring elements with current and voltage windings having an internal phase angle of 45 °. The current windings of each of the elements of the above-mentioned counter are divided into two parts in such a way that the number of turns of one part was 0.366 turns of another part of the same element.

Such a device made it possible to switch the meter from active energy metering to reactive metering (or vice versa) by intersecting two ground supply wires.

The proposed counter is a further development of the invention, but author. St. No. 74490 and is different in that. that in it, each measuring element has only one current winding (not divided into two parts) and two autotransformer connected in a triangle are used, having terminals in points dividing coils with respect to 0.732: 0.268 and serving to supply voltage to the windings of measuring elements voltages shifted by 15 relative to the phase voltages of the controlled circuit. Such an embodiment of the device allows to expand its measurement limits.

The described device can also be used as a wattmeter or a power direction relay.

FIG. Figures 1 and 2 depict the electrical diagrams of the proposed device for the case of taking into account active and reactive energy (monopoly).

FIG. 1 is a diagram of the inclusion of elements of the active energy (power) meter. Here: voltage I-strap; 2-current windings (the beginning of the windings at points a,: end-at points b); 3 and 4-autotrgnsformat)).

The voltage windings 1 are connected to the circuit through autotransformers 3 and 4, in which a tap is made at a point dividing the winding into two parts with the ratio of turns:

/ 7: t-0.732: 0.268.

Denoting the total number of turns of each autotransformer through p, we get:

p- --P1-gp-2 "1 0.732 / 7 | and rt2 0,268rt.

The meter reading will be

Р Р, + Р ,, Р, -Q2,

where: P and Pii are indications of the first and second measuring elements,

P, is the power (energy) of the direct sequence,

Q2 is the reactive power (energy) of the reverse sequence.

To account for reactive power (energy), the elements of the meter are included as shown in FIG. 2. The designations here correspond to the designations given in FIG. one.

The counter reading in this case will be:

Р Р, + РП -Qi-P.

where i and PI; are indications of the first and second measuring elements, QI-reactive gear (energy) of the direct sequence, PS-active power (energy) of the reverse sequence.

Envisions

Claims (2)

1. A counter (or wattmeter) of active or reactive energy (power) for three (|) circuits without a conductor wire, consisting of two measuring elements with voltage and current windings having an internal phase angle of 45 auth. sgv Nb 74490, characterized in that, in order to expand the limits of measurement, each measuring element has only one current winding connected to the phase current, and two autotransformer connected in an open triangle are used, which have outputs in points dividing coils at 0.732: 0.268, and serve to supply the windings of the voltage of the IZ: Measuring elements of the voltages shifted by k.c in 15 relative to the phase voltages. 2. Use of the appliance according to claim 1 as a power direction relay. I VvW4 I pg / Fig. / i 2 L2 VWWWV4 Fa G. 2