Study of Harmonic Content Elimination with Three Phase PWM Rectifier and Phase Controlled Rectifier (original) (raw)
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IJERT-Application Of PWM Rectifiertechnology For Harmonic Reduction In Smart Grid
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/application-of-pwm-rectifiertechnology-for-harmonic-reduction-in-smart-grid https://www.ijert.org/research/application-of-pwm-rectifiertechnology-for-harmonic-reduction-in-smart-grid-IJERTV1IS7215.pdf The present focus of every power system is theadoption of renewable energy.But this generated output from renewable energy is difficult to control and may cause frequency and local voltage fluctuations which calls for grid modernization.Smart grid is a systemthat reduces effect of mass adoption of renewable energy. This calls for methods to improve quality of power being transmitted and hence a major concern of harmonic reduction comes to play. The three phase thyristerized rectifiers are used for AC to DC conversion which results in harmonics being produced. This study shows the variation of power factor and output voltage with respect to firing angle for three phase thyristerized rectifier. Calculations are made to predict that the level of disturbance in power factor is considerable and must be mitigated. So are the harmonics produced which needs to be controlled. It's hence a proposed theory that PWM rectifier technology is one way of reducing harmonics in smart grid system.
Harmonics Analysis of Input Current of 3-Phase PWM Rectifier
Andalas Journal of Electrical and Electronic Engineering Technology, 2021
Rectifier is a non-linier load that causes harmonic distortion in the power system. Pulse-width modulation (PWM) method is an effective method in pressing the magnitude of harmonics in a rectifier application, it provides an almost sinusoidal input current. However, the variation of loads that supplied by a rectifier cause the harmonics that arise can still beyond the applicable standard. The amount of harmonics in the operating range of a rectifier need to be identified to determine the filter on the input side. In this research article, 3-phase PWM rectifier was designed with hysteresis current control technique using PSCAD software simulation. Harmonic compensation was carried out by applying an active filter based on P-Q theory to reduce the harmonic distortion that occurs in the input current, thus giving a low total harmonic distortion (THD) value. Based on the simulation, 3-phase PWM rectifier operation starting at a power level of 150 kW, giving a THD value above 5-10% by t...
Harmonic reduction in a three-phase rectifier with sinusoidal input current
International Journal of Power and Energy Systems, 2003
This article proposes a new approach to reduce harmonics generated by a three-phase diode rectifier. The proposed approach uses the input filters, six controllable switches, high-frequency isolation transformer, and the three-phase diode rectifier. The switching of the controllable switches is modulated by a novel pulse-width modulation (PWM) implemented in an XC4006 field programmable gate array (FPGA). This approach realizes sinusoidal input current waveforms with low electromagnetic interference and arbitrary output voltage. The output voltage can be controlled by variation of the modulation index in the range (0 ≤ M ≤ 0.98). The experimental results to compare performance between with and without the proposed approach are carried out to confirm its feasibility. http://ieeexplore.ieee.org/xpls/abs\_all.jsp?arnumber=1047184&tag=1
—Compared with the traditional two-level or three level unidirectional rectifier, VIENNA rectifier is the favorite choice for its advantage such as only half numbers of the switches, simple structure, high power density and ability to realize unity power factor with appropriate control strategy. Vienna rectifier is a kind of power converter with complicated operating constraints. Thus, it is difficult to control with conventional control strategies, especially during transients or under low power factor operation. This paper presents the design of a modified Vienna rectifier for three phase power factor correction (PFC) under R load, also presents a new control scheme system for three phase modified Vienna rectifier which is supposed to control the DC output voltage and almost pure sinusoidal three phase input current to gain almost unity power factor. For switching pulse of the switch in each phase, eight control signals are used, the signals d1a, d1b and d1C are used to determine the positive and negative half-cycle of the current. The simulation of proposed system has been done using MATLAB simulation software. The propose topology provides almost ripple free input current, lower input current THD which is found to be about 3% and improved power factor up to 0.99.
Digital implementation of harmonics reduction of three-phase boost rectifier
2010
The line currents of three-phase diode bridge rectifier suffer from high THD. This THD is higher than IEEE standards. Injection of six harmonic components to the control signal of the boost converter connected to the three-phase diode bridge rectifier reduces the THD of the utility line current. In this paper a digital implementation of injecting six harmonic to the control signal of three-phase boost rectifier is shown. The digital implementation is carried out by using FPGA. In this study a sin-wave and a triangle-wave with six times the fundamental frequency and variable amplitude are digitally generated in the FPGA. Each signal is added to the dc control signal component of boost converter to be compared with digitally generated saw-tooth. The simulation and experimental results show that the THD of the utility line currents depends on the amplitude and phase-shift of the six-order component injected to the control signal of the boost converter and the angle of input three-phase voltage.
Comparative Study of Pulse Width Modulated and Phase Controlled Rectifiers
International Journal of Engineering Research and, 2015
Fixed DC voltage is one of the very basic requirements of the electronics' circuits in modern systems. Thus, single phase diode or thyristor rectifiers are commonly used in many industrial applications where we require a highpower DC supply or an intermediate DC link of AC/AC converters. The benefits include simple structure, high safety and most importantly, low cost. However, it is reasonable to assume that a price is to be paid for these benefits. The major drawback is the power system harmonics that these bridge rectifiers introduce within a system. The economic advantage that these systems enjoy can be nullified overnight if stricter harmonic standards are implemented. With this in mind, there is an increased interest in active filters and schemes like PWM that can counter these. The less prominent (but important from the consumers' point of view) issues include low power factor, voltage distortion, heating of transformer cores etc. A single standard scheme that can work for all applications is an ideal yet impractical solution. Thus, different schemes that have been introduced need to be compared so that it is easier to choose whichever fits best with the task at hand.
MITIGATION OF HARMONICS USING THYRISTOR BASED 12 PULSE VOLTAGE SOURCE PWM RECTIFIER
IJRET, 2012
Three-phase thyristor rectifiers have been used in industries for obtaining a variable dc voltage, but they have a problem of including large lower-order harmonics in the input currents. For high-power applications, a 12-pulse configuration is useful for reducing the harmonics, but it still includes the (12m ± 1) th (m: integer) harmonics. In order to further reduce the harmonics, this paper proposes to supply a ramp wave voltage at the input of a 12-pulse phase-controlled rectifier. Theoretical investigation to reduce harmonics is presented, and a strategy to control the regulated voltage and unity power factor at input side based on 12 pulse modulation technique. This paper discuss the impact of using 3-phase and 12-pulse rectifier circuit commonly found in unity power factor at input ac mains and regulate output voltage. The 12-pulse topology is known to be more expensive, but produce the least input current harmonics. However, the latter statement is completely true under balanced line conditions. In practice, the lines are inherently unbalanced. Hence, the question of whether the 12-pulse rectifier will indeed perform better in terms of the harmonics injected to the line is still under on-going discussions. This presents the modelling and simulation of both rectifier topologies to compare their input current and regulated output voltage harmonics. The rectifiers are modelled using the MATLAB/SIMULINK simulation model and several common cases conditions will be simulated to compare their harmonic levels.
Experimental studies of power converters rectifiers, their performance with different loads and their analysis is included in this research. These results are laboratory based in which controlled and uncontrolled rectification (FW, 1-& 3-) are observed with different loads (R, R-L) with their output rectified waveforms. Software models are developed, bases on the attained parameters in order to compare their precision with laboratory models and the final harmonics and total harmonic distortion produced by the power rectifier converters due to non linear loads are concluded.
Design and Implementation of PWM Rectifier with Power Factor Control
2019
1ME-Power Electronics and Drives, Department of Electrical and Electronics Engineering, Government College of Technology, Coimbatore, Tamil nadu, India 2Assistant Professor, Department of Electrical and Electronics Engineering, Government College of Technology, Coimbatore, Tamil nadu, India ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract This paper analyzes the principle of the PWM rectifier, with a variable unity power factor control method of the PWM rectifier. Controller used closed-loop PI control, which inner uses single-phase input current control method controlled by power factor and controls the output DC voltage of rectifier. Voltage phase detection methods proposed could eliminate the affection of the voltage harmonics on phase detection accuracy. The results of the simulation and experiment verify the feasibleness and effectiveness of the tactic.
IJERT-Comparative Study of Pulse Width Modulated and Phase Controlled Rectifiers
International Journal of Engineering Research and Technology (IJERT), 2016
https://www.ijert.org/comparative-study-of-pulse-width-modulated-and-phase-controlled-rectifiers https://www.ijert.org/research/comparative-study-of-pulse-width-modulated-and-phase-controlled-rectifiers-IJERTV4IS120537.pdf Fixed DC voltage is one of the very basic requirements of the electronics' circuits in modern systems. Thus, single phase diode or thyristor rectifiers are commonly used in many industrial applications where we require a high-power DC supply or an intermediate DC link of AC/AC converters. The benefits include simple structure, high safety and most importantly, low cost. However, it is reasonable to assume that a price is to be paid for these benefits. The major drawback is the power system harmonics that these bridge rectifiers introduce within a system. The economic advantage that these systems enjoy can be nullified overnight if stricter harmonic standards are implemented. With this in mind, there is an increased interest in active filters and schemes like PWM that can counter these. The less prominent (but important from the consumers' point of view) issues include low power factor, voltage distortion, heating of transformer cores etc. A single standard scheme that can work for all applications is an ideal yet impractical solution. Thus, different schemes that have been introduced need to be compared so that it is easier to choose whichever fits best with the task at hand.