Power Quality Articles & Analysis

The power supply of telephone plants and FM/TV relay stations has always entailed numerous problems and specific needs which are difficult to meet, among them: to assure the safety of operators working on the plants, according to the law to assure continuity of operation to the plants to create a compact distribution system for all loads usually present in relay stations to limit the costs ...

By IREM SpA

Harmonics in the distribution network have become an area of keen interest for utilities, power consumers and academic researchers due to its potentially disruptive impact on economy. This interest has lead to the development of a large number of standards that contain the problems as well as technological solutions to meet the specifications of the standards. In this paper, we discuss the ...

By Inderscience Publishers

An adaptive hysteresis current and voltage control technique for controlling Unified Power Quality Conditioner (UPQC) is proposed in this paper. The novelty of the proposed method is the series and shunt active power filters (APF) present in the UPQC has been controlled by the separate adaptive controllers for reducing the voltage and current perturbations. Here, the adaptive control technique ...

By Inderscience Publishers

Wavelet transforms have fundamentally been used to detect the major features of power quality events, as the transforms adapt to dynamic signals and are appropriate for capturing time-localised, short-period phenomena. The multiwavelets technique is proposed here to classify power quality events. This leads to easy extraction of a quality feature set, which is further used for classification and ...

By Inderscience Publishers

Detection and classification of power system disturbances is necessary to ensure good power supply. The paper presents a method for accurate classification of power quality signals using support vector machines (SVM) with optimised time–frequency kernels. The Cohen's class of time–frequency–transformation has been chosen as the kernel for the SVM. A stochastic genetic algorithm (StGA) has been ...

By Inderscience Publishers

This paper deals with the power quality improvement at the utility interface of a telecommunication switched mode power supply (SMPS) of 12 kW rating. The first stage of this SMPS consists of a 6–pulse diode bridge converter that performs ac–dc conversion yielding an unregulated dc voltage. In the second stage, two boost rectifiers are connected together which feed to a boost dc–dc full bridge ...

By Inderscience Publishers

In this paper, a set of full-wave AC-DC converters are investigated for power quality improvement in AC mains and DC output. A detailed classification of these full-wave AC-DC converter configurations is made in different transformer connections and several new configurations of isolated and non-isolated full-wave AC-DC converters are developed to meet specific application requirements. The ...

By Inderscience Publishers

The objective of this paper is to implement an ADAptive LINear Element (ADALINE) for real-time measurement of harmonics in load current waveform using a digital signal processor (DSP). Harmonics cause many ill effects and reduce power quality. Harmonics are being measured by fast fourier transform (FFT) algorithm executed on a microprocessor or DSP system. The FFT algorithm implemented as per ...

By Inderscience Publishers

Disturbances such as voltage sag, swell, interruption and harmonics are very typical in a power system. Power quality monitoring should be capable of identifying these disturbances to initiate mitigation action and protect sensitive loads. This paper presents wavelet–neural network–based detection and classification of power quality disturbances. Wavelet transform has the ability to analyse ...

By Inderscience Publishers

Unified power quality conditioner (UPQC) is a combination of series and shunt active power filters with a common DC link. This device is used to enhance power quality by injecting required amount of Volt–Ampere (VA) into the system. In view of the cost effectiveness, it is desirable to have VA loading of UPQC without compromising the compensation capability. This paper presents a methodology to ...

By Inderscience Publishers

This paper deals with a three–level Neutral Point Clamped (NPC) rectifier–based midpoint converter–fed Switched Reluctance Motor (SRM) drive. The three–level NPC rectifier for midpoint converter–fed SRM drive is used for improving power quality at AC mains and to balance the DC link capacitor voltages. The proposed three–level NPC rectifier is designed, modelled and its performance simulated ...

By Inderscience Publishers

With the increasingly widespread use of sensitive electrical and electronic equipment, it is essential to have a “clean” and stable mains power supply to protect and make critical applications reliable. IREM Steroguard Line Conditioners represent the solution for most of the disturbances coming from the electrical network: they offer complete galvanic isolation of the ...

By IREM SpA

Power quality has emerged as a challenging area in the context of deregulation, wherein electricity distribution buyers and sellers carry out mutually agreed-upon exchanges. A market for active power and reactive power is installed in many places as a result of a deregulation process. However, the power-quality-related market is in the developing stage. For a given site, the power quality ...

By Inderscience Publishers

Introduction The protection of Data Centers through static uninterruptible power supplies is essential to ensure continuity of the power supply and prevent damage caused by voltage and frequency anomalies. The simple supply of electricity is not enough to guarantee the continuity of operations of a Data Centre which, if not adequately protected with UPS systems, is subject to operational ...

By Riello UPS Spa

This work presents a new technique for the identification of multiple power quality disturbances in industrial power systems. This new technique is developed based on change detection filter (CDF) and machine intelligence techniques like the local linear radial basis function neural network (LLRBFNN) and decision tree (DT). The proposed change detection filter has been designed in one cycle back ...

By Inderscience Publishers

A new mathematical index is investigated in this paper which improves the power quality of a system through providing a tool for online voltage sag mitigation. The index is developed mathematically and applied on transmission and distribution networks. Furthermore, it is verified for its compatibility through the use of a tap changing transformer scheme. Two loading variation scenarios, ...

By Inderscience Publishers

Everything you ever wanted to know about uninterruptible power systems but were afraid to ask. By Chris Loeffler, Product Manager, BladeUPS and Data Center Solutions, Distributed Power Quality, and Ed Spears, Product Manager, Eaton Power Quality Solutions Operation Eaton Corporation Executive summary Budgeting for electricity, securing adequate supplies of it and finding ways to use less of it ...

By Eaton Corporation

This article identifies, characterises and analyses International Organisation for Standardisation (ISO) and International Atomic Energy Agency (IAEA) normative requirements for the development and implementation of quality management systems in nuclear organisations. The applicable standards are identified and their requirements are characterised and reviewed. The correspondence and correlation ...

By Inderscience Publishers

This paper deals with the power quality improvement of AC mains in Direct Torque-Controlled (DTC) permanent magnet synchronous motor (PMSM) drive using active wave shaping techniques. For this purpose, different topologies for active wave shaping of AC mains current in DTC-based PMSM drive such as single- and two-switch boost power factor correction (PFC) AC–DC converter, asymmetrical two-switch ...

By Inderscience Publishers

To enhance the distribution power quality and maintains the voltage stability is a challenging tasks in the complex distribution network. This can be achieved through the distributed generation (DG). In this paper, a hybrid technique has been proposed which improves the distribution stability by allocating the DG at the optimal place. This technique uses the artificial neural network (ANN) and ...

By Inderscience Publishers