SU788027A1 - Method and device for setting quadrature between two harmonic signals - Google Patents

Description

The invention relates to electrical measuring equipment and can be used in devices for tolerance control of impedance parameters, bridges and alternators of alternating current. A known method of setting the quadrature between two harmonic signals, implemented in the device and based on the formation of additional signals, the first additional signal being equal to the time interval, the beginning of which coincides with the transition point of one of the harmonic signals through the zero level from minus to plus (with a plus on nus), and the end coincides with the nearest transition point of the second harmonic signal and from minus to plus (from plus to minus), the second additional signal equals the time interval, the beginning which coincides with the transition point of the second harmonic signal from minus to plus (from plus to minus), and the end coincides with the nearest transition point of the first harmonic signal through the zero level from plus to minus (from minus to plus), the third additional signal is proportional to the difference of the first and the second additional signals, and information about the direction of the deviation of the phase shift between the harmonic signals from the quadrature is obtained by the sign of the third additional signal 13. The disadvantage of the spider is its low fast action, since to obtain information about the direction of deviation of the actual phase shift between the gart of the unified signals from the curve, a time interval from half a period to one and a half periods of one of them is required depending on the moment of the measurement start. The known method of setting the quadrature between two harmonic signals (establishing the quadrature between the vectors and the difference of the compared harmonic signals) is based on the formation of additional signals, and the first additional signal (narrow pulse) will form. at the moment when one of the signals reaches its positive extreme value, the second additional signal is formed equal to the instantaneous value of the second harmonic signal at the time of the first additional signal, and the information about the direction of the phase deviation

the shift between the two harmonic signals from the quadrature receive the sign of the second additional signal 2

The disadvantage of this method is its low speed, since information about the direction of deviation of the actual phase shift between two harmonic signals from the quadrature is obtained once in a time equal to the period of one of the harmonic signals taken as the reference.

A device is known for setting the quadrature between two harmonic signals (establishing the quadrature between the sum and difference vectors of the harmonic signals being compared) 2, which contains two matching blocks, the output of one of which is connected to the control input of the key, the signal input of which is connected to the output of the second matching unit 2

A disadvantage of the known device is its low speed, since the information about the direction of deviation of the actual phase shift between two harmonic signals from the square is received once in a time equal to the period of one of the harmonic signals taken as the reference.

 The purpose of the invention is to increase speed.

The goal is achieved by the fact that in the quadrature setting method between two harmonic signals based on receiving additional signals, the first additional signal (a narrow pulse) is optimized when one of the harmonic signals reaches its positive extremum, the second additional signal is formed equal to the instantaneous value of the second harmonic signal at the time of the first additional signal, (a third additional signal (a narrow pulse) is blown at the moment when the first garm reaches They generate a fourth additional signal equal to the instantaneous value of the second harmonic signal at the time of the third additional signal, form the fifth and sixth additional signals equal to the instantaneous values of the first harmonic signal at the moments of the first and third additional signals, respectively, form the seventh additional signal, the sign of which depends on the ratio of the signs of the second and fifth or fourth and sixth complement nyh signals, the coincidence of signs of these signals corresponds to a negative (positive) value and a mismatch corresponds to a positive (negative) value of the seventh auxiliary signal, information on the direction of deviation of the actual shift gazovogo formed by squaring the sign of the seventh auxiliary signal.

The implementation of the proposed method is achieved in that the device containing the first and second matching blocks, the output of the first of which is connected to the input of the positive extremum generator, and the output of the second matching block is connected to the signal input of the first key, equipped with a second key, the negative extremum generator, the OR element modulo two, the output of the first matching unit connected to the signal input of the second key and through a negative extremum driver with one of the input in OR gate, the second input of which is connected to the positive output of the extremum and the output - to the control inputs of the first and second keys, the outputs of which are respectively connected to first and second inputs of the modulo two adder.

The formation of the seventh additional signal, the polarity of which depends on the ratio of the instantaneous values of the first and second harmonic signals at the time the first harmonic signal reaches its nearest extremum from the beginning of the measurement, provides information on the direction of deviation of the actual phase shift between the two harmonics signals from the quadrature during the time of no more than half the period of the harmonic signal, taken as the reference.

FIG. 1 shows time diagrams (diagrams of Fig. 1a correspond to the case of an actual phase shift between the harmonic signals K / 2, diagrams of Fig. 1b - the phase shift SK / S); in fig. 2 block diagram of the device that implements the proposed method.

The method is carried out as follows.

At the moments when one of the harmonic signals, for example, U., are reached, the positive and negative extremes are formed, respectively, the first and third additional signals (Fig. 1a, line c). Form the second and fourth additional signals (fig. 1a, line c) equal to the instantaneous values of the harmonic signal

and fifth and sixth additional

-)

Claims (2)

signals (Fig. 1a, line d), equal to the instantaneous values of the harmonic signal. 1a line a), According to the ratio of the signs of the second and fifth or fourth and sixth additional signals form the seventh additional signal (Fig. 1a, line e) With a real phase shift between the harmonic signals U and U2. less than 1G / 2, the signs of the second and fifth or fourth and sixth additional signals are the same, and the seventh additional signal has a negative polarity (Fig. 1a, row a with real phase shift between the harmonic signals and and more (Fig. 1b) signs of the second and The fifth or fourth and sixth additional signals are opposite, and the seventh additional signal has a positive polarity (Fig. 16, line e). The device (Fig. 2) implementing the proposed method contains the first and second matching blocks 1 and 2, formed the telephones of positive 3 and negative 4 extrema, the element OR 5, keys b and 7, modulo two adders.8 The harmonic signals U and Ll-j (Fig. 1, line a) between which 1.1i need to be squared, through the first and the second matching blocks 1 and 2 are fed to the signal inputs of keys b and 7, respectively, and the signal and, moreover, to the inputs of the formers of positive 3 and negative 4 extrema, the narrow pulses from the outputs of which at the moments of reaching the signal U, respectively, positive and negative extremes are given at the entrance Elem that OR 5, pulses (FIG. 1, the line from the output of which opens the keys b 7. Signals (Fig. 1, lines c and d) of their outputs equal to the instantaneous values of the harmonic signals U and and, respectively, at the moments of pulse supply from the circuit OR 5, arrive at the first and the second inputs of the modulo two 8, the polarity of the signal (Fig. 1, row.e), the output of which provides unambiguous information about the direction of deviation of the actual phase shift between the harmonic signal1-1I U and U from the quadrature. The use of the proposed method and the device realizing it allows a significant increase in the fast action of establishing a quadrature between two harmonic signals. Claim 1. The method of setting the quadrature between two harmonic signals, based on the formation of additional signals, the first additional signal (a narrow pulse is formed when one of the harmonic signals reaches its positive extremum, the second additional signal is equal to the instantaneous value of the second harmonic signal at the time of the first additional signal signal, about t and h and 1d and with the fact that, in order to improve speed, Normalize the third additional signal (narrow pulse) when the first harmonic signal reaches its negative extremum, a fourth additional signal, equal to the instantaneous r, is generated, the second harmonic signal at the instant of the third additional signal, the fifth and sixth additional signals are generated, which are equal to the instantaneous values of the first harmonic signal at times actions of the first and third additional signals, respectively, form the seventh additional signal, the sign of which depends on the ratio of the signs of the second and n th or fourth and sixth auxiliary signals, the coincidence of signs of these signals corresponds to a negative (positive) value and a mismatch corresponds to a positive (negative) value of the seventh additional signa la, information on the direction of deviation nor the actual phase shift of the quadrature form of the sign of the seventh auxiliary signal. 2, A device implementing the method of claim 1, comprising the first and second matching blocks, the output of the first of which is connected to the input of a positive extremum generator, and the output of the second matching block is connected to the signal input of the first key, characterized in that it is provided with a second key, a negative extremum generator, an OR element and a modulo two adder, with the output of the first matching unit connected to the signal input of the second key and through the negative extremum generator with one of the inputs of the OR element, the second input of which is connected to the output of the positive extremum shaper, and the output to the control inputs of the first and second keys, the outputs of which are connected respectively to the first and second inputs of the modulo two. Sources of information taken into account during the examination 1. USSR author's certificate 568696, class G 01 R 17/00, 1976. 2. USSR author's certificate for application 2498799/24, cl. G 01 R 19/06, 1977. and. / Ui Vjx