Frequency Error Compensation Method for Reactive Power Measurement by Digital Phase-shifting Method under Fixed Frequency Sampling

Abstract

The invention discloses a digital phase shift method reactive power measurement frequency error compensation method under fixed-frequency sampling; the frequency error compensation method comprises the following steps: building an angle error compensation parameter list and a ratio error compensation parameter list; calculating translation points corresponding to digital phase shift according to real frequency measured values, and index values of compensated angle errors and ratio errors in the compensation parameter lists; obtaining compensation values from the parameter lists according to the index values, and combining with the translation points so as to calculate the reactive power, thus measuring and compensating reactive power. A normal digital phase shift method is added with the angle error and ratio error real time correction functions, thus always keeping the digital phase shift to reach accurate 90 degrees even under the fixed frequency sampling and changing frequencies, and realizing highly accurate measurement of the reactive power; the method can effectively solve the problems that the normal digital phase shift method is large in errors when measuring the reactive power frequency influence amount under fixed frequency sampling; the digital phase shift method reactive power measurement frequency error compensation method is high in reactive measuring precision, and not affected by the frequency fluctuations.

Description

technical field [0001] The invention specifically relates to a frequency error compensation method for measuring reactive power by a digital phase-shifting method under fixed-frequency sampling. Background technique [0002] With the development of national economy and technology and the improvement of people's living standards, electric energy has become an indispensable secondary energy source in people's production and life, bringing endless convenience to people's production and life. [0003] However, the reactive power content in the power system is increasing day by day. Because the reactive power flowing in the grid will cause the change of the supply voltage and the loss of the transmission line, the power management department pays more and more attention to the reactive power. Therefore, reactive power has become one of the key monitoring parameters of power system power quality measurement equipment or instruments, and it is indispensable in reactive power compen...

AI Technical Summary

Problems solved by technology

Therefore, using fixed frequency sampling and conventional digital phase shifting method to measure reactive power has a relatively large frequency influence error, which limits its application.

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