SU362417A1 - DEVICE OF PHASE-SENSITIVE SQUARE DECOMPOSITION OF SIGNAL - Google Patents

Description

one

The present invention relates to the field of measurement technology and automatic control systems and can be applied in two-channel automatic systems, for example, automatic AC compensators.

Known two-channel systems (including measurement), containing paths with double signal conversion (demodulator-filter-modulator). Double conversion of the signal improves the dipamic properties of the system.

The disadvantages of such systems are as follows.

In the presence of a quadrature (in-phase) signal at the input of a path that separates an in-phase (quadrature) signal, a significant interference is obtained at the output of this path, which can cause a displacement of the bullet level of the signal and reduce the sensitivity of the executive to the useful signal.

Each of the channels contains a double conversion path, which complicates the device.

The aim of the invention is to simplify the device.

The goal is achieved by the fact that the output of one channel is connected to the input of another channel.

FIG. 1-3, various embodiments of the device are presented.

The proposed device consists of two channels, on the separated inputs of which the same signal is fed.

The output of one channel is connected in series with the input of the other channel, with the connection polarity chosen such that the output in-phase (quadrature) signal is subtracted from the in-phase (quadrature) component of the input signal of another channel.

There are several options for implementing such a system.

The proposed device contains (see FIG. 1) a demodulator /, a filter 2 and a modulator 3.

Such a two-channel system makes it possible to separate the siphase and quadrature components of the voltages Uc. and (7kV, bypassing one of the transformation paths and without the need to form a quadrature reference voltage Uon or a phase-shifting chain that rotates the input signal by 90 °. However, to accurately separate the orthogonal components of the signal, the path conversion coefficient, i.e., the ratio of the in-phase component of the voltage U (coincident in phase with the voltage t / on) to the siphase component of the voltage LBX must be stable, equal to unity, and real. filter time.

The second variant (see Fig. 2) allows more accurately than in the first variant, to distinguish the quadrature signal at the output of the lower channel due to the selectivity of the lower path in phase.

The third option (see Fig. 3) ensures the operation of each path in conditions of a low signal level quadrature with respect to the signal allocated in this path. This allows, at the same filter time constant as in sushi devices, to reduce the noise signal at the output of each path or at the same noise level to reduce the time constant of both filters.

Input and output signals must be of the same shape (for example, rectangular or sinusoidal). To obtain a sinusoidal signal at the outputs (with a sinusoidal signal at the input), a selective filter must be placed behind the modulator, which is tuned to the main harmonic of the signal.

Since the filter may introduce phase distortions, the phase of the modulator reference voltage is chosen so that the phase shift between it and the reference voltage of the demodulator (or the input voltage component to be compensated) compensates the phase distortions.

The inputs of both channels must be electrically separated, for example, the input signals must be removed from the secondary windings of the transformer.

Subject invention

A phase-sensitive quadrature signal decomposition device, consisting of two parallel channels, including modulators, demodulators and filters, characterized in that, in order to simplify the device, the output of one channel is connected to the input of another channel.

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