scholarly journals Quaternion-valued single-phase model for three-phase power system

2018 ◽  
Vol 69 (2) ◽  
pp. 183-186
Author(s):  
Xiaoming Gou ◽  
Zhiwen Liu ◽  
Wei Liu ◽  
Yougen Xu ◽  
Jiabin Wang
Keyword(s):  
Power Systems ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Minimum Variance ◽  
Music Algorithm ◽  
Three Phase ◽  
Minimum Variance Distortionless Response ◽  
Zero Sequence ◽  
Phase Signal ◽  
The Fourier Transform

Abstract In this work, a quaternion-valued model is proposed in lieu of the Clarke’s α, β transformation to convert three-phase quantities to a hypercomplex single-phase signal. The concatenated signal can be used for harmonic distortion detection in three-phase power systems. In particular, the proposed model maps all the harmonic frequencies into frequencies in the quaternion domain, while the Clarke’s transformation-based methods will fail to detect the zero sequence voltages. Based on the quaternion-valued model, the Fourier transform, the minimum variance distortionless response (MVDR) algorithm and the multiple signal classification (MUSIC) algorithm are presented as examples to detect harmonic distortion. Simulations are provided to demonstrate the potentials of this new modeling method.

scholarly journals Hybrid power quality conditioner for three-phase four-wire power systems

2020 ◽  
Vol 178 ◽  
pp. 01009
Author(s):  
Maxim Chernyshov ◽  
Valery Dovgun ◽  
Sergei Temerbaev ◽  
Zumeyra Shakurova
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Single Phase ◽  
Hybrid Power ◽  
Three Phase ◽  
Zero Sequence ◽  
Network Operation ◽  
Power Quality Conditioner ◽  
Wire System ◽  
Nonlinear Nature

The article considers a hybrid power quality conditioner (HQPC) for 3-phase 4-wire systems with a distributed modular structure. Some conditioner modules provide compensation for the component currents and voltages that form the negative and zero sequence systems. The open structure of the HQPC, consisting of independent modules, allows compensating for distortions of currents and voltages of the 3-phase network caused by the nonlinear nature and asymmetry of single-phase loads. The compensation characteristics of the proposed conditioner were researched using a model developed in the MatLab environment. The simulation showed that the proposed conditioner can ensure normalization of power quality in 3-phase 4-wire system at various modes of network operation.

scholarly journals Multivariable polynomial fitting of controlled single-phase nonlinear load of input current total harmonic distortion

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 137-142
Author(s):  
Roman Sikora ◽  
Przemysław Markiewicz ◽  
Wiesława Pabjańczyk
Keyword(s):  
Mathematical Model ◽  
Power Systems ◽  
Single Phase ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Polynomial Fitting ◽  
Nonlinear Load ◽  
Multivariable Polynomial ◽  
Led Luminaire

Abstract The power systems usually include a number of nonlinear receivers. Nonlinear receivers are the source of disturbances generated to the power system in the form of higher harmonics. The level of these disturbances describes the total harmonic distortion coefficient THD. Its value depends on many factors. One of them are the deformation and change in RMS value of supply voltage. A modern LED luminaire is a nonlinear receiver as well. The paper presents the results of the analysis of the influence of change in RMS value of supply voltage and the level of dimming of the tested luminaire on the value of the current THD. The analysis was made using a mathematical model based on multivariable polynomial fitting.

Power Invariance Transformation in Power Systems

2000 ◽  
Vol 37 (2) ◽  
pp. 180-189
Author(s):  
J. Heydeman ◽  
W. W. Schongs
Keyword(s):  
Power Systems ◽  
Single Phase ◽  
Positive Sequence ◽  
Equivalent Representation ◽  
Symmetrical Components ◽  
Three Phase ◽  
Sequence Components ◽  
Invariance Transformation

Many textbooks describe a balanced three-phase circuit by a single-phase equivalent representation. Confusion may arise amongst students regarding per-unit values of line-to-line voltages and phase voltages and, therefore, about the magnitudes of currents and powers. This paper proposes that students must first be taught symmetrical components based on power invariance transformation. A balanced three-phase circuit is to be described only in terms of positive sequence components. In the authors' experience, students understand this approach better and make fewer errors in per-unit calculation than when they use the single-phase equivalent representation.

scholarly journals Simulation and Analysis of a Three-phase Shunt Active Power Filter

2020 ◽  
pp. 162-166
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Harmonic Distortion ◽  
Active Power Filter ◽  
Active Power ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Three Phase ◽  
Non Linear ◽  
The Impact

This paper presents the simulation-based study and results of a three-phase shunt active power filter (SAPF) for power quality improvement. The power quality of the power systems is degraded because of the presence of non-linear loads at the consumer end. The SAPF can reduce the impact of harmonics caused by the non-linear loads. The analyzed SAPF system is modeled and simulated using MATLAB-Simulink workspace. The ultimate goal of this study is to improve the total harmonic distortion of the system as per the standards defined by IEEE-519.

scholarly journals Simulation of single phase photovoltaic system based on fuzzy logic control with multilevel inverter

2019 ◽  
Vol 107 ◽  
pp. 02003 ◽  
Author(s):  
Ezzaldden Raweh ◽  
Wei Pi ◽  
Omar Busati ◽  
Abdul Rehman ◽  
Saif Mubbarak ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Power Systems ◽  
Fuzzy Logic Control ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Optimal Operation ◽  
Multilevel Inverter ◽  
Photovoltaic System ◽  
Logic Control

To control the solar power, reliability and stability are two main challenges. In addition, the total harmonic distortion (THD) must be within limits for optimal operation. In an inverter, the harmonics are produced during the conversion of DC power to AC power, which will affect the power electronic devices. Therefore, to overcome such challenges in high voltage and high power systems multilevel inverter (MLI) topology is more useful. Such type of inverters uses various DC voltage levels to generate the stepped AC at its output, approaching the sinusoidal shape. The cascaded H-bridge, capacitor-clamped, and diode-clamped are the most commonly used multilevel inverters topologies. For photovoltaic (PV) usage, cascaded H-bridge (CHB) MLI is more adaptive among the three topologies, where for each H-bridge unit; each PV model behaves as an isolated DC source. This paper specifically focused on the simulation of PV power as a source to the system and displayed the potential of a single-phase 11-level CHB inverter. For switching the IGBT devices, sinusoidal pulse width modulation (SPWM) is applied. Moreover, the fuzzy logic control (FLC) is introduced to improve the power quality. FLC reduce the THD via finding the appropriate set of IGBT switch signals. To show the improvement in the operation and reduction in the complex harmony signal effects of the CHB 11-level inverter, the proposed system is designed in Matlab/Simulink software. Finally, the results show that the dynamic behavior of the FLC is much better than the traditional proportional integral derivative (PID) controller.

Chaotic Modeling of Ferroresonance with Single-Phase Open in a Three-Phase System and Its Fractional-Order Control

2021 ◽  
Vol 31 (08) ◽  
pp. 2150118
Author(s):  
Ali̇ Durdu ◽  
Yilmaz Uyaroğlu
Keyword(s):  
Power Systems ◽  
Fractional Order ◽  
Chaotic System ◽  
Single Phase ◽  
Duffing Oscillator ◽  
Phase System ◽  
Fractional Order Control ◽  
Practical Applications ◽  
Mathematical Expressions ◽  
Three Phase

In this study, a chaos-theoretic method is proposed to model the case of ferroresonance that can occur under nominal conditions in power systems, and the factors that determine the types of ferroresonance to occur are examined. In the ferroresonance chaotic system modeled in Matlab environment, the length of the transmission line and the breaker capacities in the circuit are fixed and its relationship with the transformer efficiency is investigated. In the proposed chaotic modeling, considering the situations that may occur in practical applications, the ferroresonance situations that occur when the single-phase remains open in the three-phase system are examined. In the study, ferroresonance, which occurs when one phase is open in a three-phase system, is analyzed by considering the situations that may happen during practical implementations. The similarity between the mathematical expressions obtained from the systems that create ferroresonance and Duffing oscillator is evaluated. In the chaotic system, fundamental ferroresonance, subharmonic ferroresonance, and chaotic ferroresonance situations are created depending on the transformer loss. Additionally, ferroresonance that occurs when the chaotic system is of fractional-order is analyzed, and it is observed that results of ferroresonance with different fractional-order values are not different. The results show that transformer loss is a significant element to determine the type of ferroresonance in power transformers. Also, when the chaotic system is operated in the fractional-order setting, the ferroresonance cases that occur are re-examined, and it is observed that the system can exit from the chaotic situation and prevent the formation of ferroresonance when fractional-order control is applied. According to the results, the fractional-order method can be used to control ferroresonance.

Research on a New Array-Manifold of Single Vector Hydrophone

2014 ◽  
Vol 955-959 ◽  
pp. 899-910
Author(s):  
Bo Le Ma ◽  
Jing Fang Cheng ◽  
Chao Ran Zhang
Keyword(s):  
Signal Processing ◽  
Minimum Variance ◽  
Signal Classification ◽  
Beam Forming ◽  
Noise Power ◽  
Complex Data ◽  
Music Algorithm ◽  
Multiple Signal Classification ◽  
Minimum Variance Distortionless Response ◽  
Vector Hydrophone

For the purpose of improving the signal processing of single vector hydrophone, this paper combined two velocity signals as two complex data, so as to change array-manifold of single vector hydrophone. Taking two-dimension single vector hydrophone as an example, this paper compared the capability of signal processing of new array-manifold single vector hydrophone with old one from conventional beam-forming(CBF) ,minimum variance distortionless response (MVDR) and multiple signal classification (MUSIC). As for CBF, the analysis indicates, the capability of spatial filtering of new array-manifold could improve 0.51db and the HPBW of new array-manifold will be smaller than old array-manifold. When the noise power is 0, the HPBW of new array-manifold will be narrower than old array-manifold 19.26°. As for MVDR, the capability of signal processing of new array-manifold is the same as old array-manifold. In MUSIC algorithm, the value measuring angle resolution shows the superiority of the new array-manifold- angle resolution. Simulation and measured data proved the better performance of the method presented by this paper.

Sensitivity of Induction Motor under Symmetrical Voltage Sags and Interruption

2014 ◽  
Vol 875-877 ◽  
pp. 1923-1928 ◽  
Author(s):  
Surya Hardi ◽  
Ismail Daut ◽  
Ismail Rohana ◽  
Muhd Hafizi
Keyword(s):  
Power Systems ◽  
Distribution Systems ◽  
Single Phase ◽  
Induction Motors ◽  
Short Circuit ◽  
Inrush Current ◽  
Voltage Sags ◽  
Three Phase ◽  
Nominal Voltage ◽  
Transmission And Distribution

Voltage sags and interruption are one of most important of power quality problems. They can influence performance of equipment such as induction motors. They are generally caused by short circuit faults in transmission and distribution systems which propagate in entire of power systems. When their appear at a motor terminal, its effects are the speed and the torque will decrease to a level lower than values of the normal and even the motor become stall if magnitude of the voltage sags and duration exceed certain limit. The voltage can return to nominal voltage after end of the voltage sag and interruption. The motor will experience re-acceleration to normal condition is accompanied by large inrush current. A study on induction motors was carried out to confirm these effects. Single-phase and three-phase of small induction motors were used for investigating the effects caused by symmetrical voltage sags and interruption through experimental and simulation.

scholarly journals Fault Ride-Through Capability Enhancement for Microinverter Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sajad Arab Ansari ◽  
Amir Reza Mizani ◽  
Siamak Ashouri ◽  
Javad Shokrollahi Moghani
Keyword(s):  
Power Systems ◽  
Single Phase ◽  
Low Voltage ◽  
Pv Systems ◽  
Low Voltage Ride Through ◽  
Fault Ride Through ◽  
Three Phase ◽  
Future Challenges ◽  
Wind Power Systems ◽  
Conduction Mode

Due to the fast growth of single-phase grid-connected photovoltaic (PV) systems, the existing grid codes are expected to be modified to guarantee the availability, quality, and reliability of the electrical system. Therefore, the future single-phase PV systems should become smarter and support low voltage ride-through (LVRT) capability, which are required for three-phase wind power systems. In this paper, the operation principle of a flyback inverter in a low-voltage ride-through operation is demonstrated in order to map future challenges. The steady state performance of the flyback inverter under voltage rise and drop conditions at boundary conduction mode (BCM) and discontinues conduction mode (DCM) is studied theoretically. The simulation results of the flyback inverter for various grid faults are presented to verify the theoretical analyses. The results indicate the fact that the flyback inverter at BCM condition can provide LVRT capability for photovoltaic microinverter applications in distributed generation (DG) systems, even though it does not need any auxiliary control branches and any limitations in components design.

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