Browsing Conference Papers by Author "Rens, Johan"
Now showing items 120 of 26

The application of modern technology in power quality management
Stander, Tiaan; Rens, Johan (IEEE, 2009)Little business integration of power quality management (PQM) is forthcoming amongst electrical utilities all over Southern Africa. Restricted access to proper information is the main reason. A integration of tools, ... 
Attenuation effect with nonlinear loads for small standalone grids
Bottenberg, Agknaton; Rens, Johan; Van Ryckeghem, Jurgen; Debruyne, Colin; Knockaert, Jos (IEEE, 2016)This paper presents the effect of nonlinear loads on the overall voltage quality in small powered standalone (islanded) systems. The iterative effect between current and voltage distortion is related to the source's ... 
Continuous harmonic impedance assessment using online measurements
Serfontein, Duan; Rens, Johan; Botha, Gerhard; Desmet, Jan (IEEE, 2015)The quantification of harmonic emission requires an accurate representation of the network harmonic impedances. A number of techniques have been proposed to make the assessment of the network harmonic impedances practical ... 
Dcbus voltage balancing controllers for split dclink fourwire inverters and their impact on the quality of the injected currents
Bozalakov, Dimitar; Rens, Johan; Meersman, Bart; Bottenberg, Agknaton; Desmet, Jan (IET, 2017)The increasing share of singlephase distributed generation units in lowvoltage grids causes voltage unbalance problems and overvoltages. Therefore, the need for power quality improving control strategies of gridconnected ... 
Decongestion of the distribution grid via optimised location of PVbattery systems
Van Ryckeghem, Jurgen; Rens, Johan; Delerue, Thijs; Bottenberg, Agknaton; Desmet, Jan (IET, 2017)In order to achieve the energy targets for 2020, further integration of renewable energy sources is required. Hence, there was a need to investigate possible solutions to achieve a reliable network without loss of production. ... 
A discriminative approach to harmonic emission assessment
Peterson, Brandon; Rens, Johan; Botha, Gerhard; Desmet, Jan (IEEE, 2015)With the onset of renewable power sources onto the network, such as Photovoltaic power plants contributing to Total Harmonic Distortion (THD) in voltage, a methodology to quantify their contribution to the THD in voltage ... 
The effect of a reduced power quality on the energy efficiency of standalone generator systems
Debruyne, Colin; Rens, Johan; De Kock, Jan; Desmet, Jan (IEEE, 2016)It has already been thoroughly validated that the efficiency of direct online motors is susceptible towards certain power quality parameters such as voltage unbalance or harmonic voltage distortion. It can be assumed that ... 
The effect of real network phase disturbances on the calculation of IEC 61000430 parameters
Rens, Johan; De Kock, Jan; Van Wyk, Willie; Van Zyl, Jacobus (IEEE, 2014)Real life network dynamic phenomena are used to demonstrate how the calculation of IEC 61000430 parameters can be affected. The voltage frequency can change instantaneously at a point in the network due to a shift in the ... 
Evaluation of harmonic distortion from multiple renewable sources at a distribution substation
Peterson, Brandon; Rens, Johan; Botha, Gerhard; Meyer, Jan; Desmet, Jan (IEEE, 2017)Harmonic emission assessment in a distribution network with existing background voltage harmonics is a challenge for Renewable Power Producers (RPP) aiming to achieve grid code compliance. Dynamic interaction of harmonic ... 
Field performance of ambient modal estimation in small signal stability
Van Rooyen, Tian; Rens, Johan; Desmet, Jan (IEEE, 2015)Small signal stability is one focus of Wide Area Measurement Systems (WAMS). WAMS systems are becoming more widespread, driven by availability of synchrophasor data from Phasor Measurement Units (PMUs). In this paper, two ... 
Harmonic emission assessment on a distribution network: the opportunity for the prevailing angle in harmonic phasors
Peterson, Brandon; Rens, Johan; Desmet, Jan (IET, 2017)Harmonic emission assessment in highvoltage networks with a number of renewable power plants (RPP) interconnected is challenging. A sound scientific methodology readily accessible to engineers is needed to validate ... 
Harmonic impedance assessment using prevailing phasors
Serfontein, Duan; Rens, Johan; Botha, Gerhard (IEEE, 2018)In accordance with the IEC 6100036, the evaluation of the harmonic emissions requires an accurate harmonic impedance representation of the system. However, the assessment of a harmonic impedance is understood to be a ... 
Improved event based method for harmonic impedance assessment
Serfontein, Duan; Rens, Johan; Botha, Gerhard; Desmet, Jan (IEEE, 2016)The quantification of harmonic emission requires an accurate model of the network harmonic impedances. A number of techniques have been proposed for the assessment of the network harmonic impedances to be practical and ... 
The improvement of system damping by grid integration of PV energy sources
Hattingh, JanHendrik; Rens, Johan; Botha, Gerhard (IEEE, 2017)The impact of static generators on power system small signal stability is evaluated by means of microsynchrophasors collected in a distribution system using a class A Power Quality recorder that also functions as a Phasor ... 
Modeling and validation of losses due to unbalanced loading of standalone generators
Debruyne, Colin; Rens, Johan; Sergeant, Peter; Desmet, Jan (IEEE, 2017)The goal of this paper is to evaluate the possibility of deriving a simple lumped electrical model of the additional losses in standalone synchronous generators due to unbalanced loading. An in depth analysis will reveal ... 
On the assessment of harmonic emission in distribution networks: opportunity for the prevailing harmonic phase angle
Peterson, Brandon; Rens, Johan; Botha, Gerhard; Meyer, Jan; Desmet, Jan (IEEE, 2016)Harmonic emission assessment for Grid Code compliance of Renewable Power Plants (RPP) has to be fair and pragmatic. The CIGRE C4.109 method lacks the ability to determine which harmonic currents have a positive or negative ... 
On the development of a power quality benchmarking model
Rens, Johan (IEEE, 2009)The development of a Power Quality (PQ) Benchmarking model is presented. Practical results are discussed to motivate the need of adding value to recorded PQ data by means of benchmarking PQ performance. The importance, ... 
On the reporting of power quality
Rens, Johan; Stander, Tiaan (IEEE, 2011)The reporting of power quality (PQ) requires consideration as different users of information on Quality of Supply (QoS) have different needs. Reporting on the compliancy of voltage regulation in terms of a PQ standard can ... 
An overview of the application of phasor measurement units (PMUs) and network coherent data in an interconnected power network: a case for Namibia
Gope, Gideon; Rens, Johan; John, Samuel (Elsevier, 2017)This paper presents the technological background, the structure of a timestamp for network coherent data and the emerging documentation on the data requirements for applications making use of network coherent data. ... 
A practical evaluation of harmonic emission assessment
Serfontein, Duan; Rens, Johan (IEEE, 2011)This paper reports an evaluation of harmonic emission assessment. The results obtained by the Harmonic Vector Method are correlated to the behavior of harmonic active power by means of synchronized measurements in a ...