A Three Phases Z-Source Inverter Topology

2013 ◽  
Vol 712-715 ◽  
pp. 1746-1750
Author(s):  
Ji Ying Shi ◽  
Shuang Dong ◽  
Wen An Liu
Keyword(s):  
Research Focus ◽  
Third Harmonic ◽  
Soft Start ◽  
Voltage Stress ◽  
Injection Control ◽  
New Type ◽  
Start Process ◽  
Inverter Topology ◽  
Source Structure ◽  
Lower Voltage

Now Z-Source inverter is replacing traditional inverter and becoming a research focus. But traditional Z-source inverters bring high voltage stress both in DC input and the Z-source network, which restricts its wide application. In order to solve this problem, a new type Z-source structure with third harmonic injection control strategy is proposed in this paper. The principle and operation models are analyzed. Compared with traditional boost-type Z-Source topologies, the proposed topology offers lower voltage stress, whats more, soft-start strategy can be implemented to suppress the inrush surge arising in the start process. Finally, simulation results demonstrate the good performance of the proposed inverter.

scholarly journals A novel single-phase PWM asymmetrical multilevel inverter with number of semiconductor switches reduction

2019 ◽  
Vol 10 (3) ◽  
pp. 1133
Author(s):  
S. Kakar ◽  
S. M. Ayob ◽  
N. M. Nordin ◽  
M. S. Arif ◽  
A. Jusoh ◽  
...  
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Multilevel Inverter ◽  
Semiconductor Switches ◽  
Voltage Stress ◽  
Gate Driver ◽  
Inverter Topology ◽  
Sinusoidal Pulse Width Modulation ◽  
Lower Voltage ◽  
Fundamental Module

In this paper, a new asymmetrical multilevel inverter topology (MLI) is proposed with the objectives of using decreased number of semiconductor switches, dc voltage sources, gate driver circuits and dc links. The structure of presented MLI is very simple and modular. The fundamental module of this structure consists of nine semiconductor switches (eight unidirectional and one bidirectional) and four asymmetrical configured DC sources (ratio of 1:2), which can generate 13-level output voltage. To validate the design, a Matlab-Simulink based model is developed. For this paper, a Sinusoidal Pulse Width Modulation (SPWM) is deployed as the switching strategy of the proposed MLI. The circuit model is simulated under pure resistive and inductive loads. It will be shown that the circuit performs well under both loads. Comparison with traditional MLIs and other recently introduced MLIs will be conducted to show the superiority of the proposed MLI in terms of reduced number of devices and lower voltage stress across the switches.

scholarly journals Engineering of Ti:Sapphire Lasers for Dermatology and Aesthetic Medicine

2021 ◽  
Vol 11 (22) ◽  
pp. 10539
Author(s):  
Aleksandr Tarasov ◽  
Hong Chu
Keyword(s):  
Excimer Laser ◽  
Technical Solution ◽  
Generation Process ◽  
Aesthetic Medicine ◽  
Third Harmonic ◽  
Ti:Sapphire Laser ◽  
Tattoo Removal ◽  
Ti:Sapphire Lasers ◽  
New Type ◽  
Laser Devices

This review describes new engineering solutions for Ti:Sapphire lasers obtained at Laseroptek during the development of laser devices for dermatology and aesthetic medicine. The first device, PALLAS, produces 311 nm radiation by the third harmonic generation of a Ti:Sapphire laser, which possesses similar characteristics to excimer laser-based medical devices for skin treatments. In comparison to excimer lasers, Ti:Sapphire laser services are less expensive, which can save ~10% per year for customers compared to initial excimer laser costs. Here, the required characteristics were obtained due to the application of a new type of diffraction grating for spectral selection. The second device, HELIOS-4, based on the Ti:Sapphire laser, produces 300 mJ, 0.5 ns pulses at 785 nm for tattoo removal. The characteristics of HELIOS-4 exceed those of other tattoo removal laser devices represented in the medical market, despite a simple and inexpensive technical solution. The development of the last laser required the detailed study of a generation process and the investigation of the factors responsible for the synchronization of the generation in Ti: Sapphire lasers with short (several millimeters) cavities. The mechanism that can explain the synchronization in such lasers is suggested. Experiments for the confirmation of this concept are conducted and analyzed.

Dynamic transmission of oil film in soft-start process of HVD considering surface roughness

2018 ◽  
Vol 70 (3) ◽  
pp. 463-473 ◽  
Author(s):  
Fangwei Xie ◽  
Jie Zhu ◽  
Jianzhong Cui ◽  
Xudong Zheng ◽  
Xinjian Guo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Friction Pair ◽  
Maximum Temperature ◽  
Force Model ◽  
Content Type ◽  
Oil Film ◽  
Soft Start ◽  
Viscous Torque ◽  
Start Process

Purpose The purpose of this paper is to study the dynamic transmission of the oil film in soft start process of hydro-viscous drive (HVD) between the friction pairs with consideration of surface roughness, and obtain the distribution law of temperature, velocity, pressure, shear stress and viscous torque of the oil film. Design/methodology/approach The revised soft-start models of HVD were derived and calculated, including average Reynolds equation, asperity contact model, load force model and total torque model. Meanwhile, a 2D model of the oil film between friction pair was built and solved numerically using computational fluid dynamics (CFD) technique in FLUENT. Findings The results show that the maximum temperature gradually reduces from the intermediate range (z = 0.5 h) to the inner side of the friction pair along the direction of oil film thickness. As the soft-start process continues, pressure gradient along the direction of the oil film thickness gradually changes to zero. In addition, tangential velocity increases and yet radial velocity decreases with the increase of the radius. Originality/value In this paper, it was found that the viscous torque calculated by the numerical method is smaller than that by the CFD model, but their overall trend is almost the same. This also demonstrates the effectiveness of the numerical simulation.

Experimental Study on Piezoresistivity and Magnetoresistivity of Magnetorheological Elastomers

2010 ◽  
Vol 37-38 ◽  
pp. 444-447 ◽  
Author(s):  
Wei Qiang Ye ◽  
Yi Min Deng ◽  
Wei Wang
Keyword(s):  
Smart Materials ◽  
Magnetic Field Intensity ◽  
Nickel Content ◽  
Applied Pressure ◽  
Hysteresis Phenomenon ◽  
Magnetorheological Elastomer ◽  
Research Focus ◽  
Magnetorheological Elastomers ◽  
New Type ◽  
Low Magnetic Field

As a new type of smart materials, magnetorheological elastomer (MRE) has become a hot current research focus. However, the piezoresistivity and magnetoresistivity of MRE have not been well studied. In this paper, this was done by using a test rig developed by the authors. The experimental results showed that the conductivity of the MRE responded sensitively to the applied pressure, and a linear relationship between the resistivity of the MRE and the applied pressure can be observed within a certain range. Besides, the sensitivity of piezoresistivity is different among different ratios of metal content, and it becomes more obvious when using the nickel content. And, the magnetoresistivity of MRE is not obvious in a range of low magnetic field intensity, and there is also no hysteresis phenomenon about magnetoresistivity.

scholarly journals A REDUCED SWITCH THIRTEEN LEVEL INVERTER FOR PHOTOVOLTAIC APPLICATIONS

2021 ◽  
pp. 71-75
Author(s):  
Mr.A.VinothKumar ◽  
Dr.S.Vijayabaskar ◽  
Ms.C.Selsiya
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Pulse Width Modulation ◽  
Power Converters ◽  
Renewable Energy Sources ◽  
Photovoltaic Applications ◽  
Multi Level ◽  
Photo Voltaic ◽  
Inverter Topology ◽  
Lower Voltage

The demand for clean and sustainable energy has prompted research into all types of renewable energy sources, including solar energy generated by photovoltaic systems. We suggest a new multi level inverter topology in this paper. This paper looks at a PV-based 13-level multi level inverter with fewer switches. The most gainful power converters for high power applications and modern applications with fewer switches are multi level inverters. PWM methodology is used to manage the proposed topology. The proposed topology has one of the highest efficiency and lower voltage THD. The inverter produces output voltage in thirteen levels: Vdc, Vdc/2, Vdc/3, Vdc/4, Vdc/5, Vdc/6, 0, -Vdc, -Vdc/2, -Vdc/3, -Vdc/4, -Vdc/5 and -Vdc/6. The validity of the proposed inverter is verified through simulation. KEY WORDS: Pulse Width modulation (PWM), Photo Voltaic (PV) Source.

Wye-delta winding configuration for brushless operation of a wound field synchronous machine

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1165-1172
Author(s):  
Muhammad Ayub ◽  
Asif Hussain ◽  
Ghulam Jawad Sirewal ◽  
Byung-il Kwon
Keyword(s):  
Harmonic Component ◽  
Synchronous Machine ◽  
Induced Voltage ◽  
Element Analysis ◽  
Magnetomotive Force ◽  
Third Harmonic ◽  
Harmonic Currents ◽  
Drive Circuit ◽  
Inverter Topology ◽  
Circulating Currents

This manuscript proposes a wye-delta winding configuration for brushless operation of a wound field synchronous machine (BL-WFSM). In existing third harmonically excited BL-WFSM topologies, the additional third harmonic component of the stator magnetomotive force (MMF) was produced by an extra thyristor drive circuit or by utilizing an additional inverter. In the proposed single inverter topology, the stator winding is divided into two coil sets: the wye coil and delta coil. Triplen harmonic currents are produced owing to the delta coils set and start to circulate in the delta coils. This triplen harmonic circulating currents produce a triplen harmonic pulsating MMF in the airgap. The additional triplen harmonic pulsating MMF induces voltage in the rotor harmonic winding. This induced voltage in the harmonic winding is used to excite the rotor field. A 2D finite element analysis is performed, and the simulation results confirmed the operation principle of the proposed brushless topology.

A Novel Asymmetrical Reduced Switch Nine-Level Inverter

2019 ◽  
Vol 29 (08) ◽  
pp. 2050117
Author(s):  
Madan Kumar Das ◽  
Akanksha Sinha ◽  
Kartick Chandra Jana
Keyword(s):  
Phase Structure ◽  
Output Voltage ◽  
Bridge Circuit ◽  
Multilevel Inverter ◽  
Effective Technique ◽  
Experimental Prototype ◽  
Three Phase ◽  
Voltage Stress ◽  
Simulation Results ◽  
Inverter Topology

A novel asymmetrical nine-level inverter topology using only six switches along with its generalized structure are presented in this paper. The proposed reduced switch multilevel inverter topology makes use of a lower total standing voltage for a required output voltage as compared to the existing ones. One of the major advantages of the proposed multilevel inverter over other existing topologies is that, the circuit can be extended to a higher-level inverter, by cascading a few proposed inverter modules and can also be extended to the three-phase structure very easily, thereby making the inverter structure simple. In addition to this, the proposed inverter module does not require any additional H-bridge circuit to obtain the negative voltage levels for AC voltage, resulting in reduced voltage stress on the switches. This paper also incorporates an effective technique to determine the total standing voltage as well as the switching and conduction losses of the inverter. The MATLAB/Simulink based proposed nine-level as well as an 81-level inverters are modeled and the simulation results are presented. An experimental prototype of nine-level inverter using six switches is developed and tested to validate the simulation results.

Research of Li-Ion Battery’s Equalizer Circuit Based on TL431

2014 ◽  
Vol 651-653 ◽  
pp. 1056-1059
Author(s):  
Hao Ming Zhang ◽  
Hong Li ◽  
Lian Soon Peh
Keyword(s):  
System Performance ◽  
Lithium Battery ◽  
Li Ion Battery ◽  
Discharge Time ◽  
Large Power ◽  
Power Battery ◽  
New Type ◽  
Li Ion ◽  
The Difference ◽  
Lower Voltage

Li-ion battery, as a new type of energy storage equipment, has small size, large power density, high individual voltage, low rate of self-discharging and small self-resistance etc. It substitutes the traditional power battery in AGV.In practical process, due to the difference of battery cells, after a period of charge-discharge time, the upper and lower voltage limits of every unit of batteries become various, seriously affecting the system performance. The idea of upper and lower equalizer is released for this case. Then, a further research is made on the equalizer circuit of li-ion battery. The experiment result proves the correctness of design on several types of lithium battery equalizer circuit.

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