scholarly journals Analysis of Three Phase 3-Level NPC Voltage Source Converter for AC-DC Conversion

2020 ◽  
Vol 06 (09) ◽  
pp. 144-148
Author(s):  
A Divya Teja and Dr. N Sambasiva Rao
Keyword(s):  
Power Quality ◽  
Power Flow ◽  
Reactive Power ◽  
Neutral Point ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Phase 3 ◽  
Control Techniques ◽  
Point Potential ◽  
Three Phase

The use of power electronic converters influences the generation of harmonics and reactive power flow in power system. Therefore, three-phase multilevel improved power quality AC-DC converters are gaining lot of popularity in power conversion applications. This work deals with critical problem of multilevel structure i.e neutral point potential (NPP) variation. In this paper, a simplified current controlled scheme is presented to ensure unity power factor operation. Neutral point potential (NPP) of three-phase, 3-level NPC AC-DC converter is controlled by modifying control signal in the controller using NPP regulator. An auxiliary circuit is being presented in this paper as an alternative option for controlling the neutral point potential of the converter. Comparison has been carried out between these control techniques in terms of power quality. A complete mathematical model is presented for better understanding of both techniques used for NPP control. The presented control techniques has been verified through simulation investigations and validated

Star/Hexagon Transformer Based Three-Phase Four-Wire DSTATCOM for Power Quality Improvement

2008 ◽  
Vol 9 (6) ◽  
Author(s):  
Bhim Singh ◽  
Jayaprakash Pychadathil ◽  
Dwarkadas Pralhaddas Kothari
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Distribution System ◽  
Distribution Systems ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Three Phase ◽  
Power Quality Improvement

A new topology of DSTATCOM (distribution static compensator) is proposed for power quality improvement in three-phase four-wire distribution systems. A three-leg VSC (Voltage Source Converter) is integrated with a star/hexagon transformer for the compensation of reactive power for voltage regulation or for power factor correction along with load balancing, elimination of harmonics currents and neutral current compensation. The star/hexagon connected transformer provides a path to the zero sequence current in a three-phase four-wire distribution system. In order to optimize the voltage rating of the VSC, the star/hexagon transformer is designed to have a suitable voltage rating for the secondary windings for integrating the three-leg VSC. This transformer connection provides the selection of 'off the shelf' VSC for this application and it also provides isolation for the VSC system. The performance of the proposed DSTATCOM system is validated through simulations using MATLAB software with its Simulink and Power System Block set (PSB) toolboxes.

scholarly journals Research on Control Method of Neutral Point Potential Balance of T-Type Three-level Inverter Based on PLECS

2021 ◽  
Vol 2087 (1) ◽  
pp. 012051
Author(s):  
ZhuoQun Liu ◽  
JunChi Ma ◽  
KaiXu Liu
Keyword(s):  
Electromagnetic Interference ◽  
High Efficiency ◽  
Reactive Power ◽  
Control Method ◽  
Balance Control ◽  
Neutral Point ◽  
Voltage Source ◽  
Point Potential ◽  
Capacitor Voltage ◽  
Inverter Topology

Abstract The T-type three-level inverter topology has the advantages of low electromagnetic interference, high efficiency, and low output harmonic content. This article combines constant power inverter, independent control of active and reactive power output, Analyzed and studied the neutral point potential balance control of the T-type three-level inverter topology. Through PI adjustment control on the amount of charge of the capacitor, the midpoint voltage of the capacitor is always maintained in a balanced state, and the fluctuation of the midpoint voltage is controlled within ±0.23%. This method can effectively avoid the influence of the difference of capacitance parameters on the DC side on the midpoint voltage. The PLECS software simulation verifies the reliability of the capacitor voltage equalization circuit under the condition of the voltage imbalance at the midpoint of the DC side voltage source supply capacitor voltage equalization.

Design and Performance of a PV-STATCOM for Enhancement of Power Quality in Micro Grid Applications

2017 ◽  
Vol 8 (3) ◽  
pp. 1408 ◽  
Author(s):  
Lakshman Naik P ◽  
K Palanisamy
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Reactive Power ◽  
Electrical Power ◽  
Test System ◽  
Green Energy ◽  
Integrated System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Power Demand

<p>The Green Energy sources (solar, wind) are performing a vigorous role to reach the electrical power demand. Due to the presence of non-linear loads, reactive loads in the distribution system and the injection of wind power into the grid integrated system results power quality issues like current harmonics, voltage fluctuations, reactive power demand etc. This paper mainly investigates the designing and satisfactory performance evaluation of solar farm as PV-STATCOM (Static Synchronous Compensator) for enhancement of power quality in grid tie system by using MATLAB environment (Simulink). The proportional and integral (PI) Controller and Hysteresis Current Controller (HCC) were effectively utilized to inject the desired current from voltage source converter (VSC) based PV-STATCOM at PCC for the mitigation of quality related problems in the proposed test system.</p>

A New Control Algorithm for Three-Phase, Four-Wire Unified Power Quality Conditioner (UPQC) in Distributing Systems

2012 ◽  
Vol 433-440 ◽  
pp. 6731-6736
Author(s):  
Chandrakant L. Bhattar ◽  
Vilas N. Ghate
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Control Algorithm ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Voltage Source ◽  
Voltage Source Inverter ◽  
Unified Power Quality Conditioner ◽  
Three Phase ◽  
Power Quality Conditioner

This paper presents the new control algorithm for three-phase, four-wire distributing system using unified power quality conditioner (UPQC). The UPQC, a combination of series and shunt active filter (AF) with common dc link, is one of the best solution towards the compensation of voltage sag, swell problems and also compensate voltage flicker/imbalance, reactive power, negative sequence current and maintain zero voltage regulation (ZVR) at the point of common coupling (PCC) on distribution system. The series AF is seen by using a three-phase, three leg voltage source inverter (VSI) and the shunt AF is of a three-phase, four leg voltage source inverter (VSI). The proposed model of the UPQC is developed in the MATLAB/SIMULINK environment and the simulation results prove the power quality improvement in the system.

Voltage Compensation with Interline Power Flow Controller (IPFC) Using Control Magnitude and Phase Angle Control

2014 ◽  
Vol 626 ◽  
pp. 184-189
Author(s):  
A.S. Monikandan ◽  
N. Kesavan Nair
Keyword(s):  
Phase Angle ◽  
Power Flow ◽  
Degrees Of Freedom ◽  
Reactive Power ◽  
Control Method ◽  
Transmission System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Flow Controller ◽  
Power Flow Controller

The Interline Power Flow Controller (IPFC) is a voltage-source-converter (VSC)-based flexible ac transmission system (FACTS) controller for series compensation in a multiline transmission system of a substation. The capability of injecting series voltages with controllable magnitude and phase angle makes it a powerful tool for better utilization of existing transmission lines in a multiline transmission system. IPFC is used to regulate active and reactive power flow in a multiline system, usually. In this paper, a control method for IPFC is proposed to control magnitude and phase angle of one sending bus of a substation. All degrees of freedom of IPFC and decoupled synchronous frame concept are used in the proposed control structure. Simulation results in Matlab/Simulink are presented to show the capability of IPFC in compensating the bus voltage.

scholarly journals Leaky-momentum control algorithm for voltage and frequency control of three-phase SEIG feeding isolated load

2021 ◽  
Author(s):  
Duli Chand Meena ◽  
◽  
Madhusudan Singh ◽  
Ashutosh K. Giri ◽  
◽  
...  
Keyword(s):  
Control Algorithm ◽  
Reactive Power ◽  
Frequency Control ◽  
Storage System ◽  
Operating Conditions ◽  
Control Technique ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Nonlinear Load ◽  
Three Phase

This paper dealt the implementation of a Leaky-Momentum Control Algorithm (LMA) for controlling a voltage source converter (VSC) to enhance the power quality of a three-phase self-excited induction generator (SEIG) used in a distributed generating system. This LMA technique operates the VSC to regulate voltage and frequency of SEIG within a permissible limit. The LMA control is implemented to reduce the higher demand of reactive power, harmonics distortions and balancing of loads under different operating conditions. During the electrical and mechanical dynamical conditions, the LMA technique is maintaining a constant voltage and frequency at point of common coupling (PCC). The proposed technique is a modified control technique of basic Leaky and Momentum Algorithms. This control has removed the drawbacks of Leaky and momentum algorithms. Moreover, it is observed that LMA performs better when there are uncertainties in input conditions. The whole system comprising SEIG, nonlinear load, voltage source converter and battery storage system is made in MATLAB /SIMULINK. It has shown promising performance under both dynamical state and steady state of the system.

scholarly journals Control Method of Four Wire Active Power Filter Based on Three-Phase Neutral Point Clamped T-Type Converter

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8427
Author(s):  
Dawid Buła ◽  
Grzegorz Jarek ◽  
Jarosław Michalak ◽  
Marcin Zygmanowski
Keyword(s):  
Power Flow ◽  
Reactive Power ◽  
Control Method ◽  
Active Power Filter ◽  
Active Power ◽  
Neutral Point ◽  
Laboratory System ◽  
Power Filter ◽  
Input Filter ◽  
Three Phase

An active power filter based on a three-level neutral point clamped T-type converter with LCL input filter is presented in the paper. The main goal of the paper is the analysis of a control system that ensures independent control of a current in each phase. The presented control method of the filter allows reactive power compensation and/or a higher harmonics reduction to be achieved in each phase independently, with the possibility of control tan (φ) coefficient. This allows the power flow between the phases to be minimalized and reduces the RMS values of filter currents without the need to balance grid currents. The analysis presents the possibility of an operation in different modes, which was verified by experimental results. The results have been obtained in a 20 ARMS laboratory system described in the paper. The results reveal relatively low power losses, which are a feature of the selected three-level T-type topology. Additionally, that topology, when compared to a two-level one, ensures the reduction in current ripples with the same parameters of passive components.

scholarly journals Smart Integration of a DC Microgrid: Enhancing the Power Quality Management of the Neighborhood Low-Voltage Distribution Network

Inventions ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 25
Author(s):  
Ahmed F. Ebrahim ◽  
Ahmed A. Saad ◽  
Osama Mohammed
Keyword(s):  
Power Quality ◽  
Power Flow ◽  
Reactive Power ◽  
Low Voltage ◽  
Distribution Network ◽  
Nonlinear Behavior ◽  
Electrical Equipment ◽  
Voltage Source ◽  
Voltage Distribution ◽  
Dc Microgrid

The fast development of the residential sector regarding the additional integration of renewable distributed energy sources and the modern expansion usage of essential DC electrical equipment may cause severe power quality problems. For example, the integration of rooftop photovoltaic (PV) may cause unbalance, and voltage fluctuation, which can add constraints for further PV integrations to the network, and the deployment of DC native loads with their nonlinear behavior adds harmonics to the network. This paper demonstrates the smart integration of a DC microgrid to the neighborhood low-voltage distribution network (NLVDN). The DC microgrid is connected to the NLVDN through a three-phase voltage source inverter (VSI), in which the VSI works as a distribution static compensator (DSTATCOM). Unlike previous STATCOM work in the literature, the proposed controller of the VSI of the DC smart building allows for many functions: (a) it enables bidirectional active/reactive power flow between the DC building and the AC grid at point of common coupling (PCC); (b) it compensates for the legacy unbalance in the distribution network, providing harmonics elimination and power factor correction capability at PCC; and (c) it provides voltage support at PCC. The proposed controller was validated by Matlab/Simulink and by experimental implementation at the lab.

scholarly journals An electronic solution for the direct connection of a three-phase induction generator to a single-phase feeder

2009 ◽  
Vol 20 (3) ◽  
pp. 417-426 ◽  
Author(s):  
Ricardo Q. Machado ◽  
Amílcar F. Q. Gonçalves ◽  
Simone Buso ◽  
José A. Pomilio
Keyword(s):  
Power Quality ◽  
Power Flow ◽  
Power Plants ◽  
Single Phase ◽  
Reactive Power ◽  
Induction Generator ◽  
Direct Connection ◽  
Hydro Power ◽  
Pwm Inverter ◽  
Three Phase

This paper proposes a solution for the direct connection of a three-phase induction generator to a single-phase feeder. This high power quality system is intended to be used in micro-hydro power plants applications with control of the water flow. It is employed to maintain the speed of the induction generator greater than its synchronous value. The difference between the generated power and the power consumed by the local load flows through the single-phase feeder. The power flow control is provided by a three-phase PWM inverter that additionally guarantees the local power quality. A system with good power quality must have sinusoidal and constant amplitude voltages, fixed frequency operation, balanced induction generator voltages and currents, harmonics and reactive power compensation. The paper describes the inverter control strategy, presents design criteria of the controllers, and shows experimental results.

scholarly journals Research on SVPWM Method and its Neutral Point Potential Control

2011 ◽  
Vol 2-3 ◽  
pp. 39-42
Author(s):  
Yan Liu ◽  
Xu Wang ◽  
Yan Xing
Keyword(s):  
Passive Control ◽  
Balance Control ◽  
Neutral Point ◽  
Superior Performance ◽  
Voltage Source ◽  
Effective Control ◽  
Potential Control ◽  
Point Potential ◽  
Voltage Vector ◽  
Three Phase

Neutral-point potential unbalance is an inherent problem of Neutral-point-clamped three-level PWM rectifiers. If the problem of neutral point can’t be controlled appropriately, the harm of input current will increase, and even the dc-link capacitor and switches will be destroyed. Thus domestic and foreign experts have done lots of research on the balance control of Neutral-point-clamed and put forward many effective control methods. This paper proposes a novel SVPWM strategy for the three-level neutral-point-clamped voltage source inverter, based on the particular disposition of all the redundant voltage vectors. The new modulation approach shows superior performance for the harmonic voltage and the control of neutral-point potential compared to the popular eight-stage centered SVPWM and realizes the balancing control of inverter neutral-point potential by modifying redundant small vectors pairs’ distribution factor accurately, only requiring the information of dc-link capacitor voltages and three-phase load currents, which is convenient to apply and is compatible of digital computer realization. The feasibility of the proposed control approach has been verified via simulation and experiment results. In the strategy of software control, domestic and foreign scholars propose numerous neutral point potential control schemes. When carrier modulation is used, the balance control is achieved by injecting zero-sequence component into the three-phase modulated wave. When space vector modulation methods are adopted, they can be divided into three categories: passive control, hysteresis control and active control. there is also a new algorithm based on the intrinsic relationship between SVPWMs for two—level inverters and three．1evel inverters．a novel SVPWM control algorithm is proposed for three．1evel．The dwell time of voltage vector for three-level inverter can be acquired from counterpart for two-level inverter by using a linear transformation．Aiming to analysis the output PWM sequence of three-level inverter, a novel classification standard of voltage vector is proposed．Based on evaluating the PWM sequences, a novel PWM sequence is given，that can reduce the total harmonics distortion of inverter output.

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