New Smart Sensor for Voltage Unbalance Measurements in Electrical Power Systems

Abstract

This paper deals with voltage unbalances and how they can be quantified according to the standards. Firstly, a comparison between the different unbalance voltage factors is conducted in order to remark on their divergences. Secondly, according to the standard that better represents the phenomenon, i.e., EN 50160, a new methodology is proposed to quantify the voltage unbalance factor (VUF). In order to do so, it is recommended to measure the voltage unbalance in three-phase installations by means of a new smart sensor based on a single voltage sensor, which measures the direct-current (DC) voltage at the output of a three-phase diode bridge rectifier, while current methods make use of three voltage sensors (which can measure either phase-to-neutral voltages or phase-to-phase voltages). Furthermore, both simulation and experimental results have been carried out to validate the proposed methodology. Finally, a new voltage unbalance factor (and the corresponding methodology to obtain it from the measured DC voltage) is proposed.

Dynamic Voltage Restorer with a Novel Robust control strategy to improve Power Quality issues in Distribution Network

“…However, a common issue with traditional SMC is the occurrence of chattering, which can affect control performance [12]. To tackle this challenge, a range of algorithms has been employed to mitigate chattering effects, including real-twisting, super-twisting, smoothsuper twisting, optimum, suboptimal, global, integral, and state-observer algorithms [4], [13]- [15]. These algorithms aim to reduce or eliminate the oscillations and rapid changes in control signals that can occur in certain control systems, helping to achieve more stable and efficient performance.…”

Calibration Method of a Wideband AC Resistance Voltage Divider Based on an Equivalent Model

“…AC resistance voltage dividers are widely used for various levels of voltage measurement [ 1 , 2 , 3 , 4 , 5 , 6 ], and because the frequency characteristics of resistance voltage divider ratios are easier to achieve than those of electromagnetic transformers and other voltage divider test methods [ 7 , 8 , 9 , 10 , 11 , 12 ], precision AC resistance voltage dividers are often used under audio or power harmonic measurement conditions to divide higher voltages into lower voltages for measurement, and corresponding national standards have been introduced [ 13 , 14 , 15 , 16 ]. However, due to the growing demand for harmonic power measurements, precision resistive voltage dividers require tight control of phase shifts and reduced measurement errors [ 17 , 18 , 19 ].…”

Improved Method for Determining Voltage Unbalance Factor Using Induction Motors

“…In practice, the correct measurement of the voltage unbalance factor (VUF) is necessary in measurement and control systems such as [1], where, due to the large variations in the power absorbed by trains, it is not possible to adequately limit the unbalance in the threephase voltages with which, in order to correctly determine the unbalance of the system, it is necessary to accurately calculate the voltage unbalance factor based on the power consumed by the trains, or [2] where the inaccuracy of the formulas that make them unusable when an unbalanced system is connected has been taken into account because they do not consider the active and reactive powers separately. In [3], how to quantify voltage unbalances according to the standards is discussed, and a new methodology is proposed to quantify the voltage unbalance factor (VUF) by measuring the voltage unbalance in three-phase installations by means of a new intelligent sensor based on a unique voltage sensor, which measures the voltage in direct current (DC).…”