Analysis of Seasonality and Causes of Equipment and Facility Failures in Electric Power Distribution Networks

Published by Andrzej Ł. CHOJNACKI, Kielce University of Technology, Department of Power Engineering ORCID: 0000-0002-9227-7538 Abstract. The article presents the results of analyses concerning the seasonality and causes of damage to equipment and facilities operated in 110kV, MV and LV power distribution networks. These facilities include 110kV overhead lines, 110kV/SN substations, MV overhead and cableContinue reading “Analysis of Seasonality and Causes of Equipment and Facility Failures in Electric Power Distribution Networks”

UPS Problem at Datacentre

Published by Unipower AB, Case Study: UPS Problem at Datacentre, Date: January 29th, 2017. Email: info@unipower.se Summary A software development company builds a new datacentre and experience problems with the UPS units and a hard drive failure. A monitoring system, PQ Secure from Unipower AB, was installed and it could be determined that the UPS units,Continue reading “UPS Problem at Datacentre”

Choosing The Right Equipment

Published by Unipower AB, Metallgatan 4C, 44132 Alingsås, Sweden. Email: info@unipower.se What do you need to measure? Power quality is assessed based on a number of power quality parameters. Today’s instruments usually handle the most common parameters such as voltage, current, power, harmonics, voltage dips, flicker and transients. Often it is difficult to say in advanceContinue reading “Choosing The Right Equipment”

Example of Frequency Variations causing SlowScan Recording

Published by Jonny Carlsson, Unipower AB, Case Study: Example of Frequency Variations causing SlowScan Recording, Date: October 25th, 2011. http://www.unipower.se In the following examples a Unipower UP2210 Power Quality meter is measuring SlowScan events. The SlowScan trig level is set to 50Hz +- 0.15Hz with a recorder time of 120 seconds. Example 1:The voltage level isContinue reading “Example of Frequency Variations causing SlowScan Recording”

Container Harbour in Gothenburg

Published by Jonny Carlsson, Unipower AB, Case Study: Container Harbour in Gothenburg, Date: November 8th, 2010. http://www.unipower.se The most important problem was the sags that were caused by the container cranes. The cranes created a lot of high reactive power during the start of the lift procedure. The high currents caused high demand on the transformerContinue reading “Container Harbour in Gothenburg”

Harmonic Information Management System

Published by 1. Johan ADOLFSSON, Director, Unipower AB, ja@unipower.se, 2. Peter ANDERSSON, CEO, Unipower AB, psa@unipower.se, 3. Nilesh CHINTALWAR, GM, PCI Ltd, nilesh@prime-pci.in, 4. Shital SHAH, PCI Ltd, shitalshah@prime-pci.in INTRODUCTION In the vast majority of countries today there are regulations and standards implemented that specify the maximum level of harmonic content. Some countries implement theContinue reading “Harmonic Information Management System”

Transient Detection using Peak Detectors

Published by Jonny Carlsson, Unipower AB, http://www.unipower.se Background The main problem with transients in the electrical network is that a high voltage potential might break the isolation barrier in for example cables or other equipment in the electrical network. It may also harm semiconductors that are sensitive of high voltage. A transient voltage is byContinue reading “Transient Detection using Peak Detectors”

New Technology for PQ Measurements using Auto-Calibration on Capacitive Tap on Inductive Current Transformer

Published by Jonny CARLSSON – Unipower AB, David HOLMBERG – AB Vattenfall, Jan ÖSTLUND – ABB AB Abstract A method of real-time calibrating the voltage signal from the Capacitive Tap on an ABB Current Transformer using Unipowers ‘UP-2210R/ABB Capacitive tap Module’ has produced accurate results of unbalance, harmonics and transients with no limitation in bandwidth.Continue reading “New Technology for PQ Measurements using Auto-Calibration on Capacitive Tap on Inductive Current Transformer”

Power Quality Improvement in Distributed Generation System under varying Load Conditions using PWM and Hysteresis Controller

Published Vijayshree G1, Sumathi S2, RNSIT, Bangalore,Karnataka,India(1). RNSIT, Bangalore,Karnataka, India(2) Abstract – This paper proposes a power system network modeled using a microgrid, integrated with wind and solar photovoltaic (PV) resources, along with the battery energy storage system (BESS) connected to the three-phase grid feeding the linear and nonlinear load. The simulation is carried outContinue reading “Power Quality Improvement in Distributed Generation System under varying Load Conditions using PWM and Hysteresis Controller”

Upstream Frequency Disturbance

Published by Unipower AB, Metallgatan 4C, 44132 Alingsås, Sweden. Email: info@unipower.se We have received questions about disturbances in the grid. Do we have any examples? Here is an interesting example showing how disturbances spread through the network. A major frequency disturbance occured in Scandinavia on December 1, 2005. In this comparison we have compared measuring dataContinue reading “Upstream Frequency Disturbance”