SU381041A1 - DIGITAL PHASOMETER - Google Patents

Description

one

The invention relates to the field of phase-measuring technology and can be used to create devices for indicating the angle between two voltages, between voltage and current, as well as the stick out angle of the rotor of synchronous machines.

Digital phase meters for measuring phase angles between two voltages are known, comprising an electronic key controlled by zero voltage transducers, the angle between which is measured, a pulse counter, a memory register, and a control for resetting the counter and transferring values from the counter to Register us, using, as the sensor of the counting pulses generator of a stable frequency. The disadvantage of these phase meters is the large measurement error during transients associated with a change in frequency, due to the absence of tight synchronization of the frequency of the counting pulses with the frequency of the signals.

The aim of the invention is the elimination of measurement errors caused by the non-synchronization of the frequency of the counting pulses and the frequency of the signals with changes in the near-early days.

This goal is achieved by the fact that the device is equipped with a counting pulse sensor, made in the form of a rotating body (disk, drum or gear), with uniform marking according to the number of degrees or fractions of a circle rigidly connected to the shaft of a synchronous lgashina, and reading device, output which is connected to the counting input of the electronic key.

The drawing shows the block diagram of the proposed phase meter.

The digital phase meter contains a counting pulse sensor 1, which is rigidly connected to the shaft of the synchronous machine, with

markup 2, reader 3, key - /. reference zero voltage sensor 5, signal voltage zero transition sensor 6, pulse number counter 7, control circuit 8, memory register 9 and digital indicator W.

The device works as follows. When the rotor of the synchronous machine rotates, the counting pulses from the reader 3 are continuously fed to the input of the key 4;

two stable positions. At the moment the pulse arrives from sensor 5, the key opens and transmits pulses to the counter, and at the moment of arrival of the pulse from sensor 6 the key closes. Thus, counter 7 counts the number of pulses proportional to the angle between the reference voltage and the signal voltage in degrees.

Since the counted number of pulses pr .mo depends only on the measured angle and

does not depend on the speed of rotation of the rotor, the device fundamentally does not have the error associated with the change of frequency, and retains a high accuracy of measured transient pulses. After the end of the countdown, the control circuit S outputs a transfer pulse of the measured value to memory register 9, where this value is fixed until the next measurement arrives, and a reset pulse to the zero of counter 7. With the arrival of the next start pulse opening key 4, the process is measured and repeated and the result of each subsequent measurement replaces in the memory register 9 the result of the previous one. The digital display shows the value recorded in the register. From the measurement memory register, the angle value in the form of a code is transferred to a printing device or to a system of experimental results, for example, to the input of a digital computer. Subject of the Invention A digital phase meter for measuring phase angles between two voltages, in particular, the stick out angle of a synchronous mash rotor, containing zero crossing sensors of the reference l measuring pair, the outputs of which are connected to the control inputs of the key and the output of which are series-connected pulse counter, memory register and digital indicator, while the controlled inputs of the counter and memory register are connected to the outputs of the control circuit, the input of which is connected to the output of the transition sensor via Measured voltage, characterized in that, in order to eliminate measurement errors caused by non-synchronism of the frequency of the counting pulses and the frequency of the signals, and to obtain the value of the measured angle directly in degrees, it is equipped with a reading device and a sensor of counting pulses with uniform marking according to the number of degrees or fractions of degrees of a circle and rigidly connected to the shaft of the synchronous machine, and the output of the sensor reader is connected to the counting input of the electron key.

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Output

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