Study of delta/polygon-connected transformer-based 36-pulse ac-dc converter for power quality improvement

2012 ◽  
Vol 61 (2) ◽  
pp. 277-292 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Indices ◽  
Unity Power Factor ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling

Study of delta/polygon-connected transformer-based 36-pulse ac-dc converter for power quality improvementDesign of a delta/polygon-connected autotransformer based 36-pulse ac-dc converter is presented in this paper. The 36-pulse topology is obtained via two paralleled eighteen-pulse ac-dc converters each of them consisting of a nine-phase (nine-leg) diode bridge rectifier. For independent operation of paralleled diode-bridge rectifiers, two interphase transformers (IPT) is designed and implemented. A transformer is designed to supply the rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The proposed structure has been implemented and simulated using Matlab/Simulink software under different load conditions. Simulation results confirmed the significant improvement of the power quality indices (consistent with the IEEE-519 standard requirements) at the point of common coupling. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 4% for the proposed topology at variable loads.

Reduced Rating 30-pulse AC-DC Converter for Power Quality Improvement

2017 ◽  
Vol 6 (3) ◽  
pp. 199 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Power Quality ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Criteria ◽  
Motor Drives ◽  
Unity Power Factor ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling

This paper presents the design and analysis of a novel polygon connected autotransformer based 30-phase ac-dc converter which supplies Direct Torque Controlled Induction Motor Drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via three paralleled 10- pulse ac-dc converters each of them consisting of 5-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The proposed converter requires only three inter-phase transformers in the dc link that leads to the reduced kilovolt ampere rating, size, weight, and cost of the proposed rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current Total Harmonic Distortion (THD) is less than 3% for the proposed topology at variable loads.

scholarly journals Design and construction of a polygon-connected autotransformer-based 36-pulse AC-DC converter for power quality improvement in retrofit applications

2015 ◽  
Vol 63 (2) ◽  
pp. 353-362 ◽  
Author(s):  
R. Abdollahi
Keyword(s):  
Power Quality ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Criteria ◽  
Simulation Models ◽  
Unity Power Factor ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling

Abstract This paper presents the design and analysis of a polygon connected autotransformer based 36-phase AC-DC converter which supplies direct torque controlled induction motor drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via two paralleled eighteen-pulse AC-DC converters each of them consisting of nine-phase diode bridge rectifier. An autotransformer is designed to supply the rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The proposed structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 4% for the proposed topology at variable loads. A laboratory prototype of the proposed Polygon-Connected autotransformer-based 36-pulse AC-DC converter is developed and test results are presented to validate the developed design procedure and the simulation models of this AC-DC converter under varying loads

Design and Experimental Verification of 20-Pulse AC–DC Converter for Retrofit Applications and Harmonic Mitigation

2017 ◽  
Vol 26 (10) ◽  
pp. 1750147 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Power Quality ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Criteria ◽  
Simulation Models ◽  
Motor Drives ◽  
Unity Power Factor ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Point Of Common Coupling

This paper presents the design and analysis of a polygon-connected autotransformer based 20-pulse AC–DC converter which supplies direct torque-controlled induction motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via two paralleled 10-pulse AC–DC converters each of them consisting of five-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in such a way that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The proposed structure improves power quality criteria at AC mains and makes them consistent with the IEEE-519 Standard requirements for [Formula: see text]. Furthermore, near-unity power factor is obtained for a wide range of DTCIMD operations. A comparison is made between six-pulse and proposed converters from the viewpoint of power quality indices. Results show that input current total harmonic distortion (THD) is less than 8% for the proposed topology at variable loads. A laboratory prototype of the proposed polygon-connected autotransformer-based 20-pulse AC–DC converter is developed and test results are presented to validate the developed design procedure and the simulation models of this AC–DC converter under varying loads.

scholarly journals Pulse doubling in zigzag–connected autotransformer–based 12–pulse ac–dc converter for power quality improvement

2012 ◽  
Vol 63 (6) ◽  
pp. 357-364 ◽  
Author(s):  
Rohollah Abdollahi
Keyword(s):  
Power Quality ◽  
Output Voltage ◽  
Harmonic Distortion ◽  
Design Procedure ◽  
Quality Criteria ◽  
Wide Range ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling ◽  
Zero Sequence

This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

A Tapped Star Connected Autotransformer Based 24-Pulse AC-DC Converter for Power Quality Improvement in Induction Motor Drives

2006 ◽  
Vol 7 (4) ◽  
Author(s):  
Vipin Garg ◽  
Bhim Singh ◽  
G Bhuvaneswari
Keyword(s):  
Induction Motor ◽  
Power Quality ◽  
Motor Drives ◽  
Quality Indices ◽  
Induction Motor Drives ◽  
Harmonic Reduction ◽  
Bridge Rectifier ◽  
Power Quality Improvement ◽  
Point Of Common Coupling ◽  
Phase Angles

This paper presents the design, analysis and development of a novel tapped star connected autotransformer based twenty-four-pulse ac-dc converter for improving power quality at the point of common coupling (PCC) in vector controlled induction motor drives (VCIMD’s). A star connected autotransformer with four windings per phase at different phase angles is used to realize the proposed twenty-four-pulse ac-dc converter. The basic design equations are derived to calculate the number of turns in different windings for achieving the harmonic reduction in the proposed autotransformer. The design of autotransformer is further modified for making it suitable for retrofit applications to replace presently used 6-pulse diode bridge rectifier. The proposed 24-pulse ac-dc converter is able to eliminate up to 21st harmonics in the supply current along with the power factor improvement close to unity in the wide operating range of the drive. The effect of load variation on VCIMD is also studied to demonstrate the effectiveness of the proposed ac-dc converter. Different power quality indices on input ac mains and on dc bus for a VCIMD fed from a 12-pulse and a 24-pulse ac-dc converters are also given to compare their performance. Various tests are conducted on the developed prototype of proposed autotransformer based 24-pulse ac-dc converter. Different power quality indices are measured on developed 24-pulse ac-dc converter to validate the design and simulation model.

scholarly journals Power Quality Improvement through a UPQC and a Resonant Observer-Based MIMO Control Strategy

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6938
Author(s):  
Holman Bueno-Contreras ◽  
Germán Andrés Ramos ◽  
Ramon Costa-Castelló
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Control Strategy ◽  
Closed Loop ◽  
Mimo Systems ◽  
Control Strategies ◽  
Harmonic Distortion ◽  
Phase System ◽  
Coupling Effects ◽  
Power Quality Improvement

Performance degradation is, in general, regarded as a power quality problem. One solution to recover grid performance is through the application of a unified power quality conditioner (UPQC). Although these devices are multi-input/multi-output (MIMO) systems, the most common control strategies consist of two decoupled controllers, which neglect the coupling effects and add uncertainty to the system. For this reason, this paper proposes a multivariable resonant observer-based control strategy of a UPQC system. This method includes all significant coupling effects between this system and the grid. This strategy results in a stability-based compensator, which differs from recently proposed strategies that are based on signal calculation and cannot assure closed-loop stability. In addition, this paper introduces a simplified controller tuning strategy based on optimal conventional methods without losing closed-loop performance. It implies that the controller can be easily tuned, despite the complexity of the MIMO dynamic model. The UPQC with the resonant observer is verified on an experimental setup for a single-phase system, obtaining three relevant results for power quality improvement: (1) harmonics compensation tested with a total harmonic distortion limit of 5%; (2) sags and swells mitigation; and (3) power factor correction, achieving a unitary value on the grid side.

scholarly journals Fuzzy with Hysteresis Controller for Power-Quality Improvement of Grid Interconnected System

2020 ◽  
Vol 9 (3) ◽  
pp. 4059-4062
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Distribution Systems ◽  
Harmonic Distortion ◽  
Voltage Sag ◽  
Interconnected System ◽  
Logic Control ◽  
Unbalanced Voltage ◽  
Hysteresis Controller ◽  
Power Quality Improvement

The grid connected distribution systems are providing the energy to the load from the grid. During the period of energy transmission, the issues are occurred on the power quality in transmission line. In the power system, the power quality issues are occurred due to the following issues as instability of the system, voltage sag, harmonic distortion, over voltage, unbalanced voltage etc. In this paper, the power quality improvement is designed using the inverter which compensates the voltage and current when the fault occurred. This inverter is used to inject the power using a DC source. This improvement of power quality is controlled by the hysteresis controller with fuzzy logic control. The feedback is given to the controller which reduces the error from the system and provides the control variables to the inverter terms of switching gate signals.

scholarly journals Power Quality Improvement by Reduction of Total Harmonic Distortion (THD) using PWM Inverter

2020 ◽  
Vol 9 (2) ◽  
pp. 1641-1643
Keyword(s):  
Quality Improvement ◽  
Power Quality ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Nonlinear Loads ◽  
Pwm Inverter ◽  
System A ◽  
Power Quality Improvement ◽  
Simulation Results ◽  
And Performance

In this paper, a PWM inverter is proposed for improvement of power quality i.e., reduction of total harmonic distortion (THD). The power quality problems reduce the lifetime and performance of equipments. The proposed system reduces the THD which is generated from the nonlinear loads. Because presence of harmonics leads to problems like overheating, failure of insulation etc. Here the simulation results of the proposed system is studied using MATLAB SIMULINK. Using the system, a lower THD is achieved which shows the effectiveness of the system.

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