scholarly journals ± 180° Discontinuous PWM for Single-Phase PWM Converter of High-Speed Railway Propulsion System

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1550
Author(s):  
Min-Sup Song ◽  
In-Ho Cho ◽  
Jae-Bum Lee
Keyword(s):  
High Speed ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
High Capacity ◽  
Half Cycle ◽  
Temperature Deviation ◽  
High Speed Railway ◽  
Switching Losses ◽  
Switching Dynamics

As high-capacity alternating current/direct current (ac/dc) power conversion systems, single-phase pulse-width modulation (PWM) converters used in high-speed railway propulsion systems adopt high-voltage Insulated-Gate Bipolar Transistors (IGBTs) as switching elements. Due to their high breakdown voltage characteristics, the switching dynamics are inferior to those of low-voltage IGBTs and switching losses are more dominant than conduction losses despite operating at relatively low switching frequencies of hundreds to several kHz. To solve this problem, this paper proposes ± 180° discontinuous PWM (DPWM) suitable for a single-phase circuit. With the simple addition of offset voltages, the proposed DPWM method can be implemented easily and switching losses can be reduced by half by clamping the switching legs of the H-bridge converter to the positive or negative dc rail during every half cycle. In addition, temperature deviation between the power stacks can be minimized by using selective application of clamping modes. The validity and effectiveness of the proposed DPWM are verified through simulations and experiments of a prototype converter.

Improving the Efficiency of High-Speed AC Contact Suspension

2021 ◽  
Vol 5 (5) ◽  
pp. 39-43
Author(s):  
Maksim V. SHEVLYUGIN ◽  
◽  
Daria V. SEMENOVA ◽  
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Single Phase ◽  
New Technologies ◽  
Alternating Current ◽  
Rolling Stock ◽  
New Materials ◽  
High Speed Railway ◽  
Electric Rolling Stock ◽  
Electrified Railways

When developing a high-speed contact suspension for railways electrified with alternating current, it is important to ensure that the electric rolling stock passes the neutral insert without turning off the current and without reducing the speed of movement. The article provides an analysis of previously developed devices in the field of power supply of electrified railways of single-phase alternating current, in which an attempt was made to pass an electric rolling stock of a neutral insert without disconnecting the load. The device of isolating coupling of a catenary and a neutral insert for high-speed railway lines electrified on alternating current is described. In this case, the passage of the neutral insert is carried out under current and braking of the electric rolling stock will not occur. Among other things, to improve the efficiency of high-speed contact suspension for railways electrified with alternating current, it is proposed to use new materials and new technologies that can be used in the device of insulating coupling of the catenary

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

scholarly journals Research on Safety Technology for High-Speed Interruption for Mining Flameproof Movable Substation

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 934
Author(s):  
Yanwen Wang ◽  
Le Wang ◽  
Sven G. Bilén ◽  
Yan Gao
Keyword(s):  
Solid State ◽  
High Speed ◽  
Single Phase ◽  
Low Voltage ◽  
Short Circuit ◽  
Rate Of Change ◽  
Simulation Experiments ◽  
Gas Detonation ◽  
Ultra High Speed ◽  
Short Circuit Fault

Due to the working condition of low-voltage cabling from the mining flameproof movable substation to the loads of the mining face being poor, it is easy to cause various external mechanical damages to the cable sheaths. Furthermore, a single-phase earth leakage fault or short-circuit fault can occur when the low-voltage cable sheaths are damaged, and electric sparks caused by these faults can lead to a gas explosion. As the gas detonation time caused by the above faults is usually more than 5 ms, the high-speed interruption solid-state switch which controls the cables must cut off the current within 3 ms. This requires the action time of the solid-state switch to be less than 1 ms, and at the same time, the sampling and calculation time of the relay protection must be less than 2 ms. Based on these problems, this paper proposes the use of a high-speed solid-state circuit breaker (SSCB) topology at the neutral point of transformer, and analyzes the conduction mechanism and shut-off mechanism of the current of the SSCB. It presents an ultra-high-speed algorithm based on pattern recognition of single-phase earth leakage fault protection, and an ultra-high-speed algorithm of short-circuit fault which is based on the rate-of-change of the current. Finally, through computer simulation experiments and semi-physical simulation experiments, the feasibility of the above three technologies is verified to ensure that when a single-phase earth leakage fault or short-circuit fault occurs in the low-voltage cable, the solid-state switch which is installed in the mining flameproof movable substation will cut off the current within 3 ms.

Real-Time Database System Implementation of Railway Signal Power Source Remote Monitoring

2011 ◽  
Vol 128-129 ◽  
pp. 961-964
Author(s):  
Zhi Jian Qu ◽  
Li Liu
Keyword(s):  
Power Supply ◽  
Remote Monitoring ◽  
High Speed ◽  
Low Voltage ◽  
Signal Power ◽  
High Speed Railway ◽  
Railway Traffic ◽  
Power Failure ◽  
Railway Signal ◽  
Real Time Database

Railway signal is a key technology for high-speed railway，which is the foundation to keep the high-speed train line. Railway signal power is the automatic blocking of railway lines and 10kV lines transform into 380V power through after the power supply for railway signals. Signal power as the railway traffic signal of the power supply, it belongs to the first level of power system load. Its 10kV high voltage side stik up by the major of electric, 380V low voltage side maintenance by the signal major. When the signal power failure, often occur shirk responsibilities between the different majors, in order to define the responsibilities of the accident better, which need automation remote monitoring for main railway lines of the railway signal power and scheduling control as soon as possible[1-3].

scholarly journals Design and Simulation of a Single Phase Four Level Neutral Point Clamped Inverter

2019 ◽  
Vol 8 (2) ◽  
pp. 5285-5287
Keyword(s):  
Normal Mode ◽  
Pulse Width ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Reference Signal ◽  
Neutral Point ◽  
Half Cycle ◽  
Adjustment Strategy ◽  
Four Levels ◽  
Sinusoidal Pulse Width Modulation

In this paper, sinusoidal pulse width adjustment strategy for single stage four levels neutral point clamped inverter is proposed disposed of normal mode voltage. Sinusoidal pulse width modulation is much of the time utilized in modern applications. The gating sign are created by contrasting a sinusoidal reference signal and a triangular bearer sign of recurrence. The quantity of heartbeats per half-cycle relies upon the transporter recurrence

scholarly journals SINGLE PHASE REDUCED ORDER AC-AC RESONANT- FREQUENCY CONVERTER

2021 ◽  
Vol 9 (06) ◽  
pp. 663-672
Author(s):  
Anukriti Sharma ◽  
◽  
Navdeep Singh ◽  
Keyword(s):  
Resonant Frequency ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Frequency Converter ◽  
Simulation Software ◽  
Reduced Order ◽  
Zero Voltage Switching ◽  
Switching Losses ◽  
Zero Current Switching ◽  
Zero Current

This paper presents the performance analysis of proposed circuit of Single-Phase Reduced Order AC-AC Resonant Frequency Converter. AC-AC converter is minimized number of switches for multi-operation and resonant converter is converter work on the principle of ZCS (Zero Current Switching) and ZVS (Zero Voltage Switching) combining both topology, which provide better output with reduce THD and switching losses. A mathematical modeling is done for proper value of used parameters in converter. The output of converter is improved by applying Modulation technique in this converter we are using Trapezoidal Pulse Width Modulation (TPWM) for the better performance and control. THD of the converter is calculated by using MATLAB simulation software. MATALB simulation of AC –AC Resonate Frequency Converter is done by using MOSFET as switch.

scholarly journals Multilevel level single phase inverter implementation for reduced harmonic contents

2021 ◽  
Vol 12 (1) ◽  
pp. 314
Author(s):  
Taha Ahmed Hussein
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Switching Losses ◽  
Simulink Simulation ◽  
Harmonic Elimination ◽  
Single Phase Inverter ◽  
System Frequency ◽  
Cascaded Multilevel Inverter ◽  
Electronic Switches

<p>Selective harmonic elimination technique SHE is adopted in this work to reduce the harmonic contents in single phase cascaded multilevel inverter. The firing instants for the electronic switches MOSFETs in the inverter are calculated off line for five level to thirteen level inverter. An Arduino microcontroller is programmed to cope with different topologies of the multilevel inverter. The implemented multi-level (MLI) inverter results are compared with Simulink simulation program and are found very close to each other. SHE technique works at system frequency (50 Hz or 60 Hz) and the switching losses are very small. The sinusoidal pulse width modulation SPWM requires a carrier frequency not less 20 times the system frequency so SHE approach is found to be superior compared with SPWM. Also, SHE technique shows significant reduction in THD as the number of levels increased. Results for the output voltages and currents along with their frequency spectrum are shown and compared with traditional SPWM.</p>

scholarly journals Resonant Converter with Soft Switching and Wide Voltage Operation

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3479 ◽  
Author(s):  
Bor-Ren Lin
Keyword(s):  
Output Voltage ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Resonant Converters ◽  
Resonant Converter ◽  
Switching Loss ◽  
Voltage Range ◽  
Power Diodes ◽  
Switching Losses ◽  
In Series

A new DC/DC resonant converter with wide output voltage range operation is presented and studied to have the benefits of low switching losses on active devices and low voltage stresses on power diodes. To overcome serious reverse recovery losses of power diodes on a conventional full-bridge pulse-width modulation converter, the resonant converter is adopted to reduce the switching loss and increase the circuit efficiency. To extend the output voltage range in conventional half-bridge or full-bridge resonant converters, the secondary sides of two diode rectifiers are connected in series to have wide output voltage operation. The proposed converter can be either operated at one-resonant-converter mode for low voltage range or two-resonant-converter mode for high voltage range. Thus, the voltage rating of power diodes is decreased. Experiments with the design example are given to show the circuit performance and validate the theoretical discussion and analysis.

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