CONVERTERS OF PHASE SHIFT FOR INFORMATION AND MEASURING SYSTEMS OF THE OIL AND GAS INDUSTRY

摘要

Converters of phase shift (phase shifters and calibrators of a phase) find broad application, both in control systems, and in information and measuring systems – high-precision phase shifters.Converters of phase shift are put as a part of precision two-phase generators, in compensators, compensative phase meters and also in the phase meter of equipment, etc. The important place among information and measuring devices is taken by the devices using a compensation method of measurement. In oil and gas branch automatic compensators of alternating current at measurement of conductivity of clay solutions and boring waters (automatic saline tester) are used, at measurement of a consumption of clay solution by electromagnetic sensors, to research of dynamic properties of automatic measuring devices, in geophysical surveys for definition of orthogonal components of a signal of the sensor (electronic logging station).The actual direction of works in the field of electric phase is finding of decisions for exact measurement and reproduction of a corner of phase shift between two voltages.In article the way of creation of broadband converters of phase shift on the basis of the functional digital-analog converter (DAC). The device consists of the block of the broadband quadrature device and the block of functional transformation. Mathematical and circuitry models of the converter of phase shift on the basis of hybrid functional DAC with use of spline approximation are developed. It is established that at increase in an order of a spline of n the accuracy of approach of sinus and cosine dependences increases by 10, and at increase in quantity of intervals of approximation accuracy increases not less than twice. Pilot studies of the converter of phase shifts with resolution 0.02° on the basis of 12-digit functional DAC with spline approximation showed, the reproduction error on a corner of phase shift makes 0.04° that conforms to requirements imposed to standards of a corner of phase shift of the first category (0.01o – 0.2o).