PWM regenerative rectifiers: state of the art

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.

Global Journal of Research In Engineering, 2016

Harmonic distortion is a huge problem for the power systems. But harmonic distortion can be controlled using some unique methods with the utility systems. This paper discusses the impact of using 12- pulse and 24-pulse rectifier circuit. The 24-pulse topology is generally more expensive, but produces the least Input current harmonics. In this paper pulsemultiplication technique is used to mitigate the harmonic distortion from the input line current. Phase-shifting transformers are used to produce 24-pulse from 12- pulse. A comparison between 12-pulse and 24-pulse rectifier also shown in this paper. Operation of the circuits is verified through computer simulations.

Proceedings Particle Accelerator Conference, 1995

European Transactions on Electrical Power, 2009

This paper presents an innovative method for reducing current distortion on the AC side of 12-pulse series-connected line-commutated AC/DC rectifiers. Furthermore, the overlap conduction of thyristors is completely eliminated. The methodology involves an accurate shaping of the DC current by using two self-commutated switches. This DC-current shaping is reflected back into the shaping of the AC input currents, which become pure sine waves. Rectifying operation is possible with a simple control circuit, which is able to deal with both rapid load variations and failures in the self-commutated switches. HVDC application of this innovative method is briefly examined, together with experimental results showing both the steady state and transient behavior of the technology by using a 380-V 20-kVA 50-Hz laboratory prototype.

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.

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.

IEEE Access

A novel autotransformer configuration for 24-pulse rectification is proposed that not only maintains the desired power quality but also enables a reduction in autotransformer equivalent power capacity, therefore lowering cost, volume, and weight of the overall 24-pulse rectification system. The significances of the proposed autotransformer configuration are easier implementation and have reduced windings per autotransformer core limb contrary to the established topology. The topology of the novel autotransformer is such that one of the four 3-phase rectifiers draws current directly from the input power supply instead of the autotransformer; hence, the power load on the autotransformer is significantly reduced. Higher pulse rectification systems are needed to be investigated, because they comply with the stringent power quality standards defined by IEEE-519. The performance of the novel topology is compared with the well-established 24-pulse rectification system where the proposed system exhibits superior characteristics evaluated regarding power quality and simplicity. In this paper, the performance of both 24-pulse power converters is assessed through MATLAB simulations and validated through experimental prototypes.