Stability and harmonic analysis of a transient current limiter in distribution system (original) (raw)
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Performance Analysis of Transient Current Limiters in a Distribution System
Engineering, Technology & Applied Science Research, 2018
This paper deals with the performance evaluation of a three-phase transient current limiter in distribution systems. A simulation model based on mathematical model of a three-phase, transient current limiter has been developed. The problem is formulated to justify the stable and harmonic free twelve-pulse and six-pulse converter based transient current limiter. Firstly, conventional methods like Bode Plot, Nyquist Plot and Nichols Chart are used to investigate the stability of twelve-pulse and six-pulse converter based transient current limiter. Next, a comparative analysis using fast Fourier transform is used to check the system harmonics using MATLAB simulation. The proposed design is found to be more efficient in making the system stable and harmonic free.
Analysis and Study of Currents Harmonic Propagation in Electrical Distribution System
2018
The increasing use in the industry of non-linear loads based on the power electronic elements introduced serious perturbation problems in the electric power distribution grids. One of the parameters of this system is the waveform which must be as close as possible to a sinusoid. Line currents of three-phase and twelve bridge rectifier suffer from high total harmonic distortion of current (THDi). In this paper we makes an analysis and investigation of harmonics currents propagation in real electric power system with one or tow non-linear loads , the first is a three phase full-wave bridge rectifier (P6) and the seconde is a twelve-pulse bridge (P12) installed in deferent nodes 1 and 2 into an existing distribution network (radial type). In our work we present that this THDi is higher than IEEE standards. © 2017International Egyptian Engineering and Technology Journal. This is an open access article published and hosting by IEETJ, available online in (http://ieetj.com/archive/)
Analysis of Harmonics and Harmonic Mitigation Methods in Distribution Systems
The harmonic distortion is the change in the waveform of the voltage from the ideal sinusoidal waveform. It is caused by the wide use of non-linear loads that draw current in abrupt pulses rather than in a smooth sinusoidal manner. Thus, it is important to consider harmonic problems in the power system and offer solutions to mitigation of harmonics. This paper, firstly, discusses about the sources of harmonic distortion and harmonic consequences in power system network. Then by application of phase shifting transformers, harmonic mitigation explained. Besides, other alternatives to mitigate harmonic effects on the system components utilizing harmonic filters are given. Finally, simulation using Electromagnetic Transient Analysis Program (ETAP) has been done.
Harmonics Consideration of a RSFCL in a 11kV Distribution System
As electric power systems grow and become more interconnected, at some points, the available fault currents levels exceed the maximum short-circuit ratings of the switchgear. Superconducting fault current limiters (SFCLs) can limit the prospective short-circuit currents to lower levels, so that the underrated switchgears can be operated safely. Due to its simple structure and lower price, the resistive type superconducting fault current limiter (RSFCL) is being used widely in practical experiences. Since RSFCLs are installed to provide high levels of power quality for customers with sensitive loads, it is necessary to investigate their harmonic generation. In this paper, harmonic generation of a RSFCL installed in a distribution system is investigated considering the current total harmonic distortion (THD). A method is presented for harmonic reduction based on proper determination of the high temperature superconducting (HTS) element volume. It is concluded that the THD reduces as the HTS element volume decreases. Also, since decrease in HTS element volume leads to decrease in limiting behaviour of the RSFCL, an optimization should be achieved between the limiting behaviour and the current THD level. This optimization results in the proper volume determination of the HTS element.
ANALYSIS AND MITIGATION OF HARMONICS IN 11KV DISTRIBUTION SYSTEM
Power quality is major problem in power distribution system and harmonic distortion is one of them. Harmonic distortion problem occurs due to uses of nonlinear loads like adjustable speed drives, power electronics converters, electronic ballasts etc.. Large considerations of these nonlinear loads have the potential to raise harmonic voltage and currents in a power distribution system to unacceptable high levels that can adversely affect the system. In this paper we consider 11kv distribution line and for mitigation of this harmonic distortion, shunt active power filter is widely used in a distribution system. We are interested Shunt active power filter using instantaneous active and reactive power (p-q) theory for compensating the load current harmonics and reactive power. The advantage of the p-q theory is that it is instantaneous and it works in the time domain.
Harmonic Analysis of 6-Pulse and 12-Pulse Converter Models
his paper discusses the impact of using 6-pulse and 12-pulse rectifier circuit commonly found in HVDC systems. The 12-pulse rectifier circuit is known to be more expensive, but produces the reduced input current harmonics and output voltage ripples. The Multi-pulse configuration consists of several six-pulse converter units in either series or parallel on the DC side. These units are phaseshifted with respect to each other by the transformer connection. This paper presents the modeling and simulation of both 6-pulse and 12-pulse rectifier topologies to compare their input current harmonics, output voltage ripples and also total Harmonic Distortion (THD) as well. The input current waveform, voltage waveform and THD have been observed. The rectifiers are modeled and simulated using MATLAB software to compare their harmonic levels.
DSTATCOM With LCL Filter Topology for Mitigation of Harmonics in Distribution System
2017
In this paper a Distribution Static Compensator (DSTATCOM) with LCL filter topology has been planned to compensate varied issues of power quality in distribution system with non linear loads. A 2 level voltage source inverter (VSI) is employed in conjunction with LCL filter to extend voltage support to the VSI. The instantaneous reactive power theory has applied for the effective and economical operating of the DSTATCOM, for this hysteresis current controller (HCC) is enforced to come up with pulses to the VSI and PI controller is employed to keep up constant DC link voltage. The proposed DSTATCOM topology has compensated Source Current Harmonics by injecting shunt currents into the distribution system. Planned topology has been simulated by using MATLAB/SIMULINK.
Simposio Internacional Sobre La Calidad De La Energia Electrica Sicel, 2014
This paper presents some guidelines and mitigation strategies to reduce harmonics in electrical distribution systems by applying transformers with different windings connections or phase shifting. The study of some models of nonlinear loads in distribution systems is performed, through the incorporation of transformers with different winding connections. The increase of non-linear loads in the supply network, specifically the harmonic loads, the saturation in ferromagnetic devices and the system susceptibility are the main research issues. The models of nonlinear loads and phase shifting transformers are implemented in ATP-EMTP. Case simulations with different transformer windings connections are performed on an IEEE test feeder. The conclusions show the reduction of the harmonics levels in the electrical distribution systems, specifically with the installation of Specially Connected Transformers (SCTs) and transformer with connections Dy1, Dz0 and Dy11.
IEEE Transactions on Power Electronics, 2009
This paper presents a new solution for filtering current harmonics in three-phase four-wire networks. The original four-branch star (FBS) filter topology presented in this paper is characterized by a particular layout of single-phase inductances and capacitors, without using any transformer or special electromagnetic device. Via this layout, a power filter, with two different and simultaneous resonance frequencies and sequences, is achieved-one frequency for positive-/negative-sequence and another one for zero-sequence components. This filter topology can work either as a passive filter, when only passive components are employed, or as a hybrid filter, when its behavior is improved by integrating a power converter into the filter structure. The paper analyzes the proposed topology, and derives fundamental concepts about the control of the resulting hybrid power filter. From this analysis, a specific implementation of a three-phase four-wire hybrid power filter is presented as an illustrative application of the filtering topology. An extensive evaluation using simulation and experimental results from a DSP-based laboratory prototype is conducted in order to verify and validate the good performance achieved by the proposed FBS passive/hybrid power filter. Index Terms-Active power filters, hybrid power filters, passive power filters, power line filters, power system harmonics, reactive power control. I. INTRODUCTION I NTERNATIONAL standard regulating current harmonics in distribution networks [1]-[3] reflects the importance of the problem originated by current harmonics in terms of power quality, reliability, and continuity of supply, mainly at low-voltage (LV) levels. Current harmonics in distribution grids mostly result from the widespread usage of nonlinear loads. Discharge lamps and power-electronics-based equipments are two frequent examples of nonlinear loads in residential, commercial, and industrial facilities. Currents harmonics also have a significant effect on medium-voltage (MV) and LV networks due to the Manuscript
Investigation on the effect of shunt capacitor and shunt filter on harmonic in distribution system
2008 IEEE 2nd International Power and Energy Conference, 2008
Nowadays nonlinear loads are widely used in many consumer equipment and power systems. The main problem in using of nonlinear loads is harmonic distortion. This paper will discuss the effect of application of shunt capacitor banks and shunt filter banks to reduce harmonic distortion in the power system, which will result in the increasing of the system efficiency .With installed of shunt capacitor banks and shunt filter banks, the voltage and harmonic distortion at each bus will be improved. This research was used MiPOWER software. The results will be shown in Total Harmonic Distortion (THD), Telephone Influence Factor (TIF) and voltages at each bus in the system.