Current harmonics analysis of non-linear single-phase loads in a three-phase network

2004 ◽  
Author(s):  
V. Spitsa ◽  
A. Alexandrovitz
Keyword(s):  
Single Phase ◽  
Current Harmonics ◽  
Three Phase ◽  
Non Linear

scholarly journals Effect of load current harmonics on vibration of three-phase generator

2018 ◽  
Vol 197 ◽  
pp. 11023
Author(s):  
I Made Wiwit Kastawan
Keyword(s):  
Single Phase ◽  
Electrical Power ◽  
Electrical Power System ◽  
Negative Effects ◽  
Load Current ◽  
Current Harmonics ◽  
Three Phase ◽  
Non Linear ◽  
Electrical Loads ◽  
Linear Loading

Almost all today electrical loads are considered non-linear such as switch mode power supply (SMPS) for powering computer and mobile phone or variable speed drive (VSD) for driving home and industrial electric motors. These loads generate ac non-sinusoidal current containing a lot of harmonics as indicated by its high total harmonics distortion (THD) figure. Current harmonics bring negative effects into all electrical power system components, including three-phase generator. This paper provides analysis of load current harmonics effects on vibration of three-phase generator. Three different laboratory experiments have been conducted i.e. three-phase linear resistive loading, non-linear loading with a three-phase ac/dc converter and non-linear loading with three single-phase capacitor filtered ac/dc converters. Results show that the higher load current harmonics content the higher is vibration of the three-phase generator. Non-linear loading with a three-phase ac/dc converter that generate about 24.7% THD gives an increase of 4.3% and 5.5% in average of vertical and horizontal vibrations of the three-phase generator respectively. Further, non-linear loading with three single-phase capacitor filtered ac/dc converters that generate THD as high as 74.9% gives significant increase of 28.1% and 23.6% in average of vertical and horizontal vibrations respectively.

scholarly journals Simulation, Design, and Analysis of 3-Level Shunt Active Harmonic Filter using T-Typed NPC (TNPC) Topology

10.29007/s9ch ◽  
2018 ◽  
Author(s):  
Mitrajsinh Janaksinh Chudasama ◽  
Prof. Dr. P. N. Tekwani ◽  
Siddharthsingh K Chauhan ◽  
Vinod Patel
Keyword(s):  
Reactive Power ◽  
Simulation Design ◽  
Current Harmonics ◽  
Synchronous Reference Frame ◽  
Three Phase ◽  
Harmonic Filter ◽  
Non Linear ◽  
Point Of Common Coupling ◽  
Switched Mode Power Supply ◽  
Parallel Resonance

Power quality at the source side deteriorates due to current harmonics which are introduced in the power system by non-linear loads, originating a vital difficulty. Rectifiers, variable speed drive, switched mode power supply, etc. types of non-linear loads create such harmonics. Con- ventional technique to eliminate such harmonics is use of passive filters but this technique has the disadvantage of series and parallel resonance within the network impedance, overcompen- sation of reactive power at fundamental frequency and poor flexibility. Shunt Active Harmonic Filters (SAHF) are generally used to reduce current harmonics. The active harmonic filters introduce remunerating currents into the source to neutralize the harmonics possessed by the load current. The compensating currents will be derived by sensing three-phase voltages at the Point of Common Coupling (PCC) and load currents. Efforts are made in this study to ana- lyze Fast Fourier Transform (FFT) algorithm, Instantaneous Reactive Power (IRP) technique, and Synchronous Reference Frame (SRF) technique used to derive the reference compensating currents. These compensating currents act as reference currents for the fixed switching based current controllers which generate control signals for the SAHF employing three-level T-type Neutral Point Clamped (TNPC) topology of converter.

Microtransformers for Teaching and System Stability Research

1986 ◽  
Vol 23 (2) ◽  
pp. 121-125
Author(s):  
P. H. G. Allen ◽  
K. J. D'Souza
Keyword(s):  
Single Phase ◽  
Second Order ◽  
System Stability ◽  
Rotating Machines ◽  
Linear Features ◽  
Three Phase ◽  
Non Linear ◽  
Design And Manufacture

Large transformers, like highly rated rotating machines, can be modelled in ‘micro’ form to demonstrate significant second order, non-linear, features. The design and manufacture of 3 kVA (nominal) rating three-phase and three single-phase transformer bank units, all with three-limb cores and 0.17 per unit leakage reactance are described.

scholarly journals Novel ripple reduction method using three-level inverters with unipolar PWM

2021 ◽  
Vol 22 (3) ◽  
pp. 1272
Author(s):  
Paiboon Kiatsookkanatorn ◽  
Napat Watjanatepin
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Current Harmonics ◽  
Switching Patterns ◽  
Unipolar Pulse ◽  
Three Phase ◽  
Ripple Reduction ◽  
Novel Method ◽  
Dipolar Modulation ◽  
Current Ripple

This paper proposes a novel method to reduce voltage and current ripple for the inverters by using three-level inverters with unipolar pulse width modulation (PWM) (3LFB-2U). A simple technique of switching signal generation by using carrier-based dipolar modulation of three-phase three-level inverters is extended to single-phase inverters that can be done by generating all possible switching patterns of the single-phase three-level inverters. Moreover, the concept of carrier-based dipolar modulation and the construction of reference voltages from desired output voltage and added zero voltage to control unipolar switching is also shown. The research results reveal that the proposed method can reduce the voltage and current ripple. Furthermore, the voltage and current harmonics can reduce by 27.80% and 1.79%, respectively less than two-level inverters without a loss of a simple modulation to generate the switching signals.

scholarly journals Design of Neuro-Fuzzy Controller for Stabilization of Single Phase Stand-Alone PV Power System

2018 ◽  
Vol 7 (3) ◽  
pp. 176
Author(s):  
Hitendra Singh Thakur ◽  
Ram Narayan Patel
Keyword(s):  
Power System ◽  
Single Phase ◽  
Fuzzy Inference ◽  
Fuzzy Controller ◽  
Phase System ◽  
Inference System ◽  
Current Harmonics ◽  
Synchronous Reference Frame ◽  
Neuro Fuzzy ◽  
Three Phase

For the three phase power electronic and drive applications, vector control or the synchronous reference frame (SRF) based control concept is well accepted and settled amongst the research communities. Although the SRF concept has gained popularity and appreciation in developing the three phase controllers, still the concept has not reached the same level in case of a single phase system. The work presented in this paper is mainly concerned to the design of a hybrid Artificial Neural Network and Fuzzy Logic based controller for a single phase stand-alone photo-voltaic (PV) power system. The adaptive neuro fuzzy inference system (ANFIS) controller proposed in this paper is chiefly meant for improving the transient and steady state responses; for minimizing the distorting effect of the low order load current harmonics encountered particularly in case of switching the drive based inductive loads and to help maintain the inverter output voltage constant under different loading circumstances. The result obtained through simulation work, shows the effectiveness of the proposed controller as compared with the previously established research works.

scholarly journals Power Quality Improvement using UPQC with Single and Three-Phase Non-linear Loads in Countryside Areas

2019 ◽  
Vol 9 (4) ◽  
pp. 18-24
Author(s):  
Shuchi Vishnoi ◽  
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Single Phase ◽  
Phase Distribution ◽  
Control Strategies ◽  
Electrical Power ◽  
Synchronous Reference Frame ◽  
Three Phase ◽  
Non Linear ◽  
Distribution Grids

This paper is intended to simulate a power quality conditioning device, Unified Power Quality Conditioner (UPQC), in countryside areas for non-linear loading. From past decades there is much increase in the requirement of the good quality electrical power in single phase distribution grids established in these locations. Due to technical advancement, three-phase loads are practiced more than single phase loads so that the demand for three phase distribution grids is growing. But the installation process of three-phase grids, at countryside areas, is not an economic option and to get access to these systems is a very challenging task. So a neighbouring three-phase distribution system is required to be established at the location, where single-phase to three-phase UPQC with single wire earth return is appropriate for the end user due to economic considerations. A dual compensation strategy is implemented to obtain the reference quantities for controlling the converters. The proposed idea is accomplished to eliminate voltage harmonics and mitigate further instabilities and power quality problems. This system allows the balanced and regulated voltage with lower harmonic content. Synchronous Reference Frame (SRF) based controllers are considered to organize the input grid current and the load voltages of the UPQC. The present prototype under consideration analyses and validates the compensation and controlling techniques using PI controller. The control strategies are simulated using MATLAB/SIMULINK.

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