Research Of High Accuracy Ac Sampling Real-Time Measurement In Electric Power Supplied Traction System

This paper tells the key technology of the realtime measurement of power supply system of electric traction, namely, AC sampling. The electric locomotive is a single-phase rectified load. During it consumes electric power, feeds back a great amount of high order harmonic to energy supply system and jeopardizes the electric power quality. The control of the reactive power and the voltage has consanguineous connection with the stability and economy of the power system. But the effective control of the reactive power and the voltage depend on the accurate measurement of the reactive. During the traditional measurements of the reactive power , the asymmetry of the voltage and current arises the asymmetry error. This paper introduces the AC sampling arithmetic and emphasizes the study of measurement arithmetic under the unbalanced and distorted condition.This paper introduces IEEE Trial-Use Standard 1459-2000 and compares the old and new definitions of the apparent power S. It also gives the definitions of electric power quantities under sinusoidal, nonsinusoidal, balanced, or unbalanced condition in detail. Emulation on nonsinusoidal single-phase and nosinusoidal balanced three-phase systems are also given. There are nine kinds of arithmetic of AC sampling based sinusoidal and periodic modal in this paper. This article analyses the factors of accuracy to be influenced by AC samples from a microcomputer and discusses the way of finding solutions. This paper introduces a kind of AC sampling arithmetic, which can eliminate the asymmetry error.Aiming at different working conditions, single-phase AC sampling arithmetics are simulated under MATLAB. The simulation achieve the arithmetics of higher precision under the condition of much harmonics. In the end the paper attains arithmetics, which suit the power supply system of electric traction, by simulation with the real-timing data.