Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : THD


A Review of Control Technique Applied in Shunt Active Power Filter (SAPF)

Ayad M. Hadi; Ekhlas M. Thjeel; Ali K. Nahar

Engineering and Technology Journal, 2022, Volume 40, Issue 8, Pages 140-149
DOI: 10.30684/etj.v40i8.2116

In recent years, electronic transformers and electronic devices (nonlinear loads) have increased. These loads are the source of harmonics (non-sinusoidal and distorted waves) and the interactive force that affects the performance of the power system network. Also, it badly affects the power factor and electrical energy on the scales of efficiency and quality. For this reason, a system called “Active Power Filters” has been adopted. It provides an effective alternative to traditional LC passive power filters. It can improve network performance by treating and reducing harmonics, improving power factor and quality, avoiding resonance between the filter and the network, and reducing reactive power. This paper presents a study on the shunt active power filters device and how to connect it to the distribution network and A review of the bathing control strategies in the methods of calculating current and power, methods of controlling the PWM device, the most prominent techniques for improving the PID control system, and the most prominent algorithms applied in that to improve the safety performance of the  Shunt  Active Power Filter (SAPF) on the one hand and to demonstrate the ability of different systems to compensate for THD on the other hand. APF performance fluctuates from one control strategy to another. It reduced (THD) between 0.9% and 13% in several control techniques applied with PWM. The aim of this paper is to illustrate the techniques applied to control the performance of the "Shunt Active Power Filter" to reduce THD

Performance Analysis of Three Phase Cascaded Multilevel Inverter (CMLI) for Induction Motor Drives

Shatha k. Baqir

Engineering and Technology Journal, 2013, Volume 31, Issue 13, Pages 2531-2547

Traditional high-frequency pulse width modulation (PWM) inverters for motor drives
have several problems associated with their high switching frequency which produces
high voltage change (dv/dt) rates. Multilevel inverters solve these problems because their
devices switch at the fundamental frequency. The concept of multilevel voltage source
inverter is explained. In this paper the cascade inverter is a natural fit for induction motor
drives because of the high VA ratings possible and it uses several levels of separate equal
dc voltage sources which would be available from batteries or fuel cells. The switching
angles of switch devices are determined by optimized harmonic stepped waveform
(OHSW) technique to reduce the output harmonics of cascade multilevel inverter (CMLI)
for induction motor is proposed, as a result the efficiency of system has improved.
Simulation results show the superiority of this inverter over 2-level inverter and were
carried out using ORCAD package.

Performance Study of a Modified Sine Wave Inverter

Jamal A. Mohammed

Engineering and Technology Journal, 2010, Volume 28, Issue 2, Pages 399-415

This paper presents the performance of a modified sine wave voltage source
inverter with duty cycle. Evaluation of quality factors like the Total Harmonic
Distortion THD of the output voltage for various values of switching-on angle α
indicates that the minimum harmonic distortion occurs at α=23.2180, where the
THD is 28.96%, about 60% of that of the square wave. The 3rd harmonic is about
12.61% of the fundamental, and about third of the square wave.
The current paper, illustrates the inverter waveforms and how different types
of loads behave when operating from them. Therefore, the THD of the output
current depends on the load types. Results of typical load types are presented.
No heavy filters or complex timing circuits are necessary; therefore, the
resulting inverter is smaller, lighter weight, and simpler, implying greater
reliability and lower cost. These advantages invite a closer look at inverter-motor
systems. Variations in induction motor performance may occur when the motor is
driven from a modified sine wave inverter rather than a sine wave source.

Modeling and Implementation of Space Vector PWM Driver of 3-Phase Induction Motor

Fadhil Abbas Hassan; Majid K. Al-Khatat

Engineering and Technology Journal, 2009, Volume 27, Issue 10, Pages 2113-2131

This research proposes the design, simulation, and implementation of a
three-phase induction motor driver, using voltage-fed Space Vector Pulse Width Modulation technique (SVPWM), which is an advance and modern technique. The SVPWM provides maximum usage of the DC link. A MATLAB/SIMULINK program is prepared for simulating the overall drive system which include; voltage-fed space vector PWM inverter model and three-phase induction motor model. A practical model is designed by imitate the conceptions of TMS320 (DSP) microcontroller. This practical model is completely implemented and exact results are obtained. The worst state of the harmonics content of the voltage and current (no-load condition) are analyzed. This analysis shows high reduction in the dominant harmonics and very low total harmonic distortion (THD) when SVPWM is used (less than 5%), compared to (more than 20%) in square wave. Experimental and simulation results have verified the superior performance and the effectiveness in reduction the harmonic losses and switching losses.

A High Quality Output Voltage for HEPWM of Single Phase AC Motor Drive

Mohammed K. Edan; Ali H. Jabbar; Jamal A. Mohammed

Engineering and Technology Journal, 2009, Volume 27, Issue 5, Pages 898-912

provide the exact on-line solution to the optimal PWM problem. The proposed
algorithm optimization technique is applied to a 3-level unipolar single-phase inverter to
determine optimum switching angles for eliminating low order harmonics while maintaining
the required fundamental voltage to drive single-phase induction motor with high quality.
The proposed HE method contributes to the existing methods because it not only generates
the desired fundamental frequency voltage, but also completely eliminates any number of
harmonics. It provides high quality sine-wave output voltage on the induction motor
terminals with very low THD.
The high quality sinusoidal output voltage produced by the inverter at different number
of switching angles is presented. The complete solutions for 3-level unipolar switching
patterns to eliminate the 3rd and 5th harmonics are given. Finally, the unipolar case is again
considered where the first 14 harmonics are eliminated.