scholarly journals DC traction power substation using eighteen-pulse rectifier transformer system

2021 ◽  
Vol 12 (4) ◽  
pp. 2284
Author(s):  
Chuen Ling Toh ◽  
Chee Wei Tan
Keyword(s):  
Simulation Study ◽  
Harmonic Distortion ◽  
Phase Shifting ◽  
Dc Voltage ◽  
Grid Current ◽  
Power Substation ◽  
Research Findings ◽  
Distortion Index ◽  
Current Ripple ◽  
Traction Power

<span lang="EN-US">Twelve-pulse rectification system had been widely integrated in today’s DC traction power sub-station (DC-TPSS). This configuration had successfully mitigated low order harmonic distortion. As some research findings had confirmed that the dc voltage and current ripple factors may further minimize by increasing the number of rectification pulses to 18, 24, or 36. This paper had presented a simulation study to investigate the prospect of implementing an eighteen-pulse rectification system in a DC-TPSS. The theory of phase-shifting transformer used to produce an 18-pulse rectifier is presented with simulation verification. Simulation result shows that 3.69% of grid current distortion index is recorded without installing any filters. In addition, the dc voltage and current ripple may also be further reduced for about 30% compared to a conventional twelve-pulse rectification system.</span>

scholarly journals Design a nine-level modular multilevel converter for DC railway electrification system

2020 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Chuen Ling Toh ◽  
P. C. Ooi
Keyword(s):  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Modular Multilevel Converter ◽  
Centralized Control ◽  
Multilevel Converter ◽  
Power Substation ◽  
Harmonic Voltage ◽  
Traction Power

<p>A recuperating converter is highly demanded in traction power substation to deliver the braking energy generated by a traction vehicle. Conventional voltage source inverter had been implemented in the traction power station. However, large ac line filters must be installed to improve the quality of ac voltages and currents. This paper proposes to install a nine-level Modular Multilevel Converter (MMC) as a recuperating converter. The main aim is to eliminate the need of ac line filters while producing good quality of ac voltage and current waveforms. The MMC is designed and modelled using MATLAB/Simulink Simulation tool. A centralized control of balancing all the sub-module capacitor voltage level is proposed with Third Harmonic Voltage Injection Level Shifted Pulse Width Modulation (THVI-LSPWM) technique. The simulation results prove that with the application of MMC, good quality of ac voltages and currents are being produced. The Total Harmonic Distortion indexes are found less than 3.5 % without using any ac line filters in the system. In addition, the classic DC link capacitance has also being eliminated. </p>

scholarly journals Power quality of dual two-level inverter fed open end winding induction motor

2020 ◽  
Vol 18 (2) ◽  
pp. 688
Author(s):  
Hayder Ali Mohamed ◽  
Hanan Mikhael D. Habbi
Keyword(s):  
Induction Motor ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Current Signal ◽  
Space Vector Pwm ◽  
Dc Voltage ◽  
Common Mode Voltage ◽  
Voltage Quality ◽  
Open End Winding

<p><span>This paper presents the minimization of the total harmonic distortion (THD) of the current signal for open-end winding induction motor by using dual two-level inverter. In order to obtain a good value of THD, the space vector PWM has been used for switching the dual two-level inverter to improve the output voltage quality, gets a low common mode voltage, reduce the execution time, and to save the memory capacity. The proposed scheme uses two different DC voltage source with two two level inverter in order of minimizing the number of components. As well as it is an important to utilize the energy which increases the application of dual inverter in microgrids. All simulation results are obtained using Matlab/Simulink. </span></p>

Simulation and Analysis of Novel Extendable Multilevel Inverter Topology

2019 ◽  
Vol 28 (06) ◽  
pp. 1950089 ◽  
Author(s):  
V. Thiyagarajan ◽  
P. Somasundaram ◽  
K. Ramash Kumar
Keyword(s):  
Single Phase ◽  
Harmonic Distortion ◽  
Multilevel Inverter ◽  
Voltage Waveform ◽  
Dc Voltage ◽  
Switching Losses ◽  
Comparison Results ◽  
Symmetrical Condition ◽  
Gate Driver ◽  
Inverter Topology

Multilevel inverter (MLI) has become more popular in high power, high voltage industries owing to its high quality output voltage waveform. This paper proposes a novel single phase extendable type MLI topology. The term ‘extendable’ is included since the presented topology can be extended with maximum number of dc voltage sources to synthesize larger output levels. This topology can be operated in both symmetrical and asymmetrical conditions. The major advantages of the proposed inverter topology include minimum switching components, reduced gate driver circuits, less harmonic distortion and reduced switching losses. The comparative analysis based on the number of switches, dc voltage sources and conduction switches between the proposed topology and other existing topologies is presented in this paper. The comparison results show that the proposed inverter topology requires fewer components. The performance of the proposed MLI topology has been analyzed in both symmetrical and asymmetrical conditions. The simulation model is developed using MATLAB/SIMULINK software to verify the performance of the proposed inverter topology and also the feasibility of the presented topology during the symmetrical condition has been validated experimentally.

Harmonic Current Distortion Using the Linear Quadratic Regulator for a Grid-Connected Photovoltaic System

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Oscar Andrew Zongo ◽  
Anant Oonsivilai
Keyword(s):  
Control Strategies ◽  
Harmonic Distortion ◽  
Linear Quadratic Regulator ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Linear Quadratic ◽  
Grid Current ◽  
Harmonic Currents ◽  
Low Pass ◽  
Low Pass Filters

This paper presents a comparison between a proportional-integral controller, low pass filters, and the linear quadratic regulator in dealing with the task of eliminating harmonic currents in the grid-connected photovoltaic system. A brief review of the existing methods applied to mitigate harmonic currents is presented. The Perturb & Observe technique was employed for maximum power point tracking. The PI control, low pass filters, and the linear quadratic regulator are discussed in detail in terms of their control strategies. The grid current was analyzed in the system with all three of the controllers applied to control the voltage source inverter of the solar photovoltaic system connected to the grid through an L filter and LCL filter and simulated in MATLAB/SIMULINK. The simulation results obtained have proven the robustness of the linear quadratic regulator over other methods. The technique lowers the grid current total harmonic distortion from 7.85% to 2.13%.

scholarly journals A New Modular Multilevel Inverter Based on Step-Up Switched-Capacitor Modules

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 524 ◽  
Author(s):  
Aryorad Khodaparast ◽  
Erfan Azimi ◽  
Ali Azimi ◽  
M. Ebrahim Adabi ◽  
Jafar Adabi ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Low Frequency ◽  
Multilevel Inverter ◽  
Voltage Source ◽  
Switched Capacitor ◽  
Level Control ◽  
Dc Voltage ◽  
Bipolar Voltage

A new structure of switched capacitor multilevel inverter (SCMLI) capable of voltage boosting and with self-balancing ability is introduced in this article. This advantage is the result of a step by step rise of capacitor voltages in each module, supplied by just one DC voltage source. The proposed topology generates a sinusoidal output waveform with a magnitude several times greater than the input one. Higher output staircase AC voltage is obtained by applying a nearest level control (NLC) modulation technique. The most significant features of this configuration can be mentioned as: fewer semiconductor devices, remarkably low total harmonic distortion (THD), desirable operating under high /low frequency, high efficiency, inherent bipolar voltage production, easy circuit expansion, ease of control and size reduction of the circuit thanks to utilizing neither bulky transformer nor inductor. Moreover, the proposed SCMLI is comprehensively surveyed through theoretical investigation and a comparison of its effectiveness to recent topologies. Eventually, the operating principle of a 25-level prototype of the suggested SCMLI is validated by simulation in the MATLAB SIMULINK environment and experimental results.

scholarly journals Traction Power Substation Load Analysis with Various Train Operating Styles and Substation Fault Modes

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2788
Author(s):  
Zhongbei Tian ◽  
Ning Zhao ◽  
Stuart Hillmansen ◽  
Shuai Su ◽  
Chenglin Wen
Keyword(s):  
Power Supply ◽  
Normal Operation ◽  
Supply Network ◽  
Power Network ◽  
Power Load ◽  
Power Substation ◽  
Railway Traction ◽  
Train Operation ◽  
The Impact ◽  
Traction Power

The simulation of railway systems plays a key role in designing the traction power supply network, managing the train operation, and making changes to timetables. Various simulation technologies have been developed to study the railway traction power network and train operation independently. However, the interactions between the load performance, train operation, and fault conditions are not fully understood. This paper proposes a mathematical modeling method to simulate the railway traction power network with a consideration of a multi-train operation, driving controls, under-voltage traction, and substation fault modes. The network voltage, power load demands, and energy consumption according to the existing operation are studied. The hotspots of the power supply network are identified based on an evaluation of the train operation and power demand. The impact of traction power substation (TPSS) outage and a short circuit on the power supply network have been simulated and analyzed. The simulation results have been analyzed and compared with those of a normal operation. A case study based on a practical metro line in Singapore is developed to illustrate the power network evaluation performance.

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