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”
Category Archives: Case Studies
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”
Measuring PQ Issues in a Bus Depot Using Unipower HW and Software
Published by Unipower AB, Metallgatan 4C, 44132 Alingsås, Sweden. Email: info@unipower.se Introduction This case study explores how advanced power quality measurement technology facilitated the diagnosis of severe power quality disturbances in a bus depot. These disturbances, which neither the bus operator nor the bus manufacturer initially attributed to electrical quality issues, were ultimately traced toContinue reading “Measuring PQ Issues in a Bus Depot Using Unipower HW and Software”
Dynamic Voltage Restorer for Voltage Unbalance Mitigation and Voltage Profile Improvement in Distribution Network
Publishd by Ahmed A. Abdullah AL-KARAKCHI1, Enaam ALBANNA2, Alya H. AL-RIFAIE3, Northern Technical University (1,2,3) ORCID: 1. 0000-0003-1151-3015; 2. 0000-0002-3974-0116; 3. 0000-0002-7978-2193 Abstract. Unbalanced network voltage damages utility and end-user equipment. Electrified trains, single-phase distributed generators, and line-toline connected industrial loads can increase voltage imbalances. Using Dynamic Voltage Restorer (DVR) at appropriate places is oneContinue reading “Dynamic Voltage Restorer for Voltage Unbalance Mitigation and Voltage Profile Improvement in Distribution Network”
Extra High Voltage Transmission Line Lightening Protection using Surge Arrester
Published by Ali HAMOODI, Rasha MOHAMMED, Bashar SALIH, Northern Technical University, Engineering technical college Abstract. The objective of this work was to protect the transmission line (T.L.) from the lightning effect. In the last decades, several methodologies have been employed for the rise of lightning performance on the T.L Lightning with high values of currentContinue reading “Extra High Voltage Transmission Line Lightening Protection using Surge Arrester”
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”
An Overview of Harmonics in Electrical Systems
Published by Wesco | Anixter, Wesco International. What are harmonics? In an electric power system, a harmonic is a voltage or current at a multiple of the fundamental frequency of the system. Harmonics can best be described as the shape or characteristics of a voltage or current waveform relative to its fundamental frequency. When waveforms deviate from a sinewaveContinue reading “An Overview of Harmonics in Electrical Systems”
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”
Evaluating Direction of Harmonics – Power Harmonics
Published by Unipower AB, Metallgatan 4C, 44132 Alingsås, Sweden. Email: info@unipower.se One important issue is how to trace the source of harmonics. The example below shows harmonic filters connected until 11.00 and there is no voltage distortion as expected. After 11.00 the filters were disconnected due to a fault and voltage harmonics can be seen.Continue reading “Evaluating Direction of Harmonics – Power Harmonics”
Power Quality Blog 