scholarly journals Parallel Resonant DC Link Inverter for Thermoacoustic Power Generation

2014 ◽  
Vol 8 (1) ◽  
pp. 379-389
Author(s):  
Ma Li Li ◽  
Xia Jia Kuan
Keyword(s):  
Pulse Width Modulation ◽  
Short Circuit ◽  
Parameter Design ◽  
Generation System ◽  
Circuit Structure ◽  
Working Principle ◽  
Mathematical Equations ◽  
Dc Bus ◽  
Bus Voltage ◽  
Zero Voltage

A new parallel resonant soft-switching DC link inverter which can deal with the output power from thermoacoustic energy generation system is proposed. Auxiliary resonant unit is added to DC link to make DC bus voltage decreased to zero periodically, which realized all switches with zero voltage operation of in the inverter. The time of the duration for the DC bus zero voltage has nothing to do with the load current. The same bridge arm in the inverter is not made instantaneous short circuit and controlled reliably. Random duration of zero voltage was obtained through the on-off instant control of the auxiliary switch. Various flexible pulse width modulation strategies can be applied in the softswitching inverter. The topology structure is put forward and the circuit working principle is analyzed in this paper. The equivalent different working modes are analyzed and the mathematical equations are given. The principle of parameter design is put forward according to the circuit structure. The experiment is carried out and through it the validity and correctness of the theoretical analysis is proved.

Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Dead Time ◽  
Control Method ◽  
Short Circuit ◽  
Two Phase ◽  
Zero Crossing ◽  
Time Control ◽  
Bus Voltage ◽  
Current Zero

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

scholarly journals Short-Circuit Current Calculation and Harmonic Characteristic Analysis for a Doubly-Fed Induction Generator Wind Turbine under Converter Control

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2471 ◽  
Author(s):  
Jing Li ◽  
Tao Zheng ◽  
Zengping Wang
Keyword(s):  
Wind Turbine ◽  
Analytical Model ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Induction Generator ◽  
Doubly Fed Induction Generator ◽  
Stator Current ◽  
Dc Bus ◽  
Bus Voltage ◽  
Doubly Fed

An accurate calculation of short-circuit current (SCC) is very important for relay protection setting and optimization design of electrical equipment. The short-circuit current for a doubly-fed induction generator wind turbine (DFIG-WT) under excitation regulation of a converter contains the stator current and grid-side converter (GSC) current. The transient characteristics of GSC current are controlled by double closed-loops of the converter and influenced by fluctuations of direct current (DC) bus voltage, which is characterized as high order, multiple variables, and strong coupling, resulting in great difficulty with analysis. Existing studies are mainly focused on the stator current, neglecting or only considering the steady-state short-circuit current of GSC, resulting in errors in the short-circuit calculation of DFIG-WT. This paper constructs a DFIG-WT total current analytical model involving GSC current. Based on Fourier decomposition of switch functions and the frequency domain analytical method, the fluctuation of DC bus voltage is considered and described in detail. With the proposed DFIG-WT short-circuit current analytical model, the generation mechanism and evolution law of harmonic components are revealed quantitatively, especially the second harmonic component, which has a great influence on transformer protection. The accuracies of the theoretical analysis and mathematical model are verified by comparing calculation results with simulation results and low-voltage ride-through (LVRT) field test data of a real DFIG.

scholarly journals Investigation of short-circuit failure mechanisms of SiC MOSFETs by varying DC bus voltage

2018 ◽  
Vol 57 (7) ◽  
pp. 074102 ◽  
Author(s):  
Masaki Namai ◽  
Junjie An ◽  
Hiroshi Yano ◽  
Noriyuki Iwamuro
Keyword(s):  
Short Circuit ◽  
Failure Mechanisms ◽  
Dc Bus ◽  
Bus Voltage

scholarly journals Novel approach for SVPWM of two-level inverter fed induction motor drive

2020 ◽  
Vol 11 (4) ◽  
pp. 1750
Author(s):  
Olwi A. Elkholi ◽  
Mohamed A. Enany ◽  
Ahmed F. Abdo ◽  
Mahmoud Eid
Keyword(s):  
Induction Motor ◽  
Pulse Width Modulation ◽  
Frequency Converter ◽  
Harmonic Distortion ◽  
Motor Drives ◽  
New Approaches ◽  
Novel Approach ◽  
Three Phase ◽  
Dc Bus ◽  
Bus Voltage

<p class="Abstract">Due to their better DC bus utilization and easier digital realization, Space Vector Pulse Width Modulation (SVPWM) scheme is the most widely used PWM scheme. Also two level inverter is the traditional frequency converter because it has fewer components and is lower complex to control, but on the other hand it generates higher harmonic distortion. This paper presents the realization of novel SVPWM approaches applied to the three phase induction motor drives. Specifically various schemes are based on using more combinations of step operation in each cycle to approximate the reference vector, such as 24 and 48 step operations in each cycle. The basic principle of conventional SVPWM with different modulation index M is presented. The switching sequences of new approaches are described. The modulation signals waveforms, DC bus voltage utilization, De-rated motor torque, standard error of average torque, voltage and current harmonic of new approaches are analyzed by the MATLAB/SIMULINK software. The results confirms that 48 step SVPWM approach is the best compared to other approaches.</p>

scholarly journals Performance Evaluation of a Semi-Dual-Active-Bridge with PPWM Plus SPS Control

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 184 ◽  
Author(s):  
Ming Lu ◽  
Xiaodong Li
Keyword(s):  
Pulse Width Modulation ◽  
Secondary Phase ◽  
Effective Control ◽  
Zero Voltage Switching ◽  
Dual Active Bridge ◽  
Light Load ◽  
Control Scheme ◽  
Working Principle ◽  
Secondary Side ◽  
Zero Voltage

In this paper, a semi-dual-active-bridge (S-DAB) DC/DC converter with primary pulse-width modulation plus secondary phase-shifted (PPWM + SPS) control for boost conversion is analyzed in detail. Under the new control scheme, all effective operation modes are identified at first. Then, the working principle, switching behaviour, and operation range in each mode are discussed. Compared with conventional secondary phase-shifted control, PPWM + SPS control with two controllable phase-shift angles can extend the zero-voltage switching (ZVS) range and enhance control flexibility. In addition, an effective control route is also given that can make the converter achieve at the global minimum root-mean-square (RMS) current across the whole power range and avoid the voltage ringing on the transformer secondary-side at a light load. Finally, a 200 W prototype circuit is built and tested to verify correctness and effectiveness of theoretical results.

Investigation into Short-Circuit Ruggedness of 1.2 kV 4H-SiC MOSFETs

2008 ◽  
Vol 600-603 ◽  
pp. 1123-1126 ◽  
Author(s):  
Yukiyasu Nakao ◽  
Shoyu Watanabe ◽  
Naruhisa Miura ◽  
Masayuki Imaizumi ◽  
Tatsuo Oomori
Keyword(s):  
Power Electronics ◽  
High Temperatures ◽  
Gate Voltage ◽  
Small Difference ◽  
Short Circuit ◽  
System Requirements ◽  
Dc Bus ◽  
Bus Voltage

The shout-circuit ruggedness of prototype 1.2kV SiC MOSFETs has been investigated. The short-circuit measurements were carried out at 25 °C and 125 °C with a dc bus voltage of 800 V and an on/off state gate voltage of +20/-10 V. The small difference in tfail between 25 °C and 125 °C indicates that the destructive breakdown occurs at temperatures much higher than 125 °C. The temperature at destructive breakdown estimated from the Wunsch-Bell formula is about 1400 °C. At such high temperatures, intrinsic carriers are increased markedly and generated heat leads to the destructive breakdown. tfail of all the SiC-MOSFETs studied is longer than 10 μs, meaning that the short-circuit ruggedness satisfies system requirements. These results show that the SiC-MOSFETs are promising for power electronics applications.

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