scholarly journals E-Type Asymmetric Multilevel Inverter Based Transformer less Traction Drive

To overcome the limitations of conventional multilevel inverter such as of more no. of power semiconductor switches, large no. of capacitors, more switching loss etc. , a new topology of Envelope type (E-type) MLI is used. This E-type Module has some preferable features like reduced no. of components and low switching frequency. This E-type asymmetric converter uses four unequal DC sources and ten switches to generate 13 level of output voltage. SHE modulation technique is used to achieve high quality output voltage with low harmonic content. This E-type converter configuration will be used in transformer less traction drive. Nowadays Induction motors are used as electric drives for most of the electric railways. A transformer less connection is used for feeding Induction motor. This converter-inverter configuration will convert single phase AC voltage to DC and again this DC voltage will be converted into three phase AC. The output of the E-type Multi level inverter will be used to drive the Induction motors.

Author(s):  
B. Jyothi ◽  
M. Venu Gopala Rao

Now a day’s many industrial applications requires high power. Some other appliances may require intermediate power either more or less depending upon their operation. With these consequences, MULTI LEVEL INVERTERS are introduced in 1975.for above intermediate voltage applications. The name MULTI LEVEL began with the three-level converter.By enormous advancement in power semiconductor switches, in electric drives increasing the phase number greater than the conventional three phase especially in locomotives, naval, aerospace, and electrical vehicles industry has many advantages than three phase. In this view, here five phase VSI has developed. This paper aims at comparing the performance of conventional two level inverter Diode clamped and Capacitor clamped topologies of 5-phase multilevel inverter (3-level) using sinusoidal pulse width modulation. SPWM is highly economical, has more efficiency, controllability. These circuits are analyzed by using simulation software package such as MATLAB.


2019 ◽  
Vol 16 (2) ◽  
pp. 422-427
Author(s):  
S. Karthikeyan ◽  
K. Lakshmi ◽  
S. Sivaranjani ◽  
J. Karthika ◽  
T. Nandhakumar

Multilevel inverters are mainly used in high power and medium voltage applications to reduce the required voltage rating of the power semiconductor switching devices. Nowadays multilevel inverters are also preferred for various applications regardless of the power ratings because they can essentially realize lower harmonics with lower switching frequency and lower electromagnetic interference (EMI). However, it has some disadvantages such as increased number of components, complex Pulse Width Modulation control method, and voltage balancing problem. In this paper a new topology of cascaded multilevel inverter using reduced number of switches is introduced resulting in higher output voltage levels. There era five series connected H-bridges and the DC voltage is given in the ratio n0: n: n3:2n2:10n. The output voltage having 123 levels is obtained (61 positive voltage levels, 61 negative voltage levels and zero voltage levels). Reduced Total Harmonic Distortion (THD) makes them useful for electric vehicle, FACTS and has given option for various power applications. The proposed topology results in reduction of cost and has simplicity of control system. Therefore, the overall cost and complexity are greatly reduced particularly for higher output voltage levels.


Author(s):  
Jingwen Chen ◽  
Hongshe Dang

Background: Traditional thyristor-based three-phase soft starters of induction motor often suffer from high starting current and heavy harmonics. Moreover, both the trigger pulse generation and driving circuit design are usually complicated. Methods: To address these issues, we propose a novel soft starter structure using fully controlled IGBTs in this paper. Compared to approaches of traditional design, this structure only uses twophase as the input, and each phase is controlled by a power module that is composed of one IGBT and four diodes. Results: Consequently, both driving circuit and control design are greatly simplified due to the requirement of fewer controlled power semiconductor switches, which leads to the reduction of the total cost. Conclusion: Both Matlab/Simulink simulation results and experimental results on a prototype demonstrate that the proposed soft starter can achieve better performances than traditional thyristorbased soft starters for Starting Current (RMS) and harmonics.


2021 ◽  
Vol 17 (1) ◽  
pp. 1-13
Author(s):  
Adala Abdali ◽  
Ali Abdulabbas ◽  
Habeeb Nekad

The multilevel inverter is attracting the specialist in medium and high voltage applications, among its types, the cascade H bridge Multi-Level Inverter (MLI), commonly used for high power and high voltage applications. The main advantage of the conventional cascade (MLI) is generated a large number of output voltage levels but it demands a large number of components that produce complexity in the control circuit, and high cost. Along these lines, this paper presents a brief about the non-conventional cascade multilevel topologies that can produce a high number of output voltage levels with the least components. The non-conventional cascade (MLI) in this paper was built to reduce the number of switches, simplify the circuit configuration, uncomplicated control, and minimize the system cost. Besides, it reduces THD and increases efficiency. Two topologies of non-conventional cascade MLI three phase, the Nine level and Seventeen level are presented. The PWM technique is used to control the switches. The simulation results show a better performance for both topologies. THD, the power loss and the efficiency of the two topologies are calculated and drawn to the different values of the Modulation index (ma).


2020 ◽  
Vol 11 ◽  
pp. 11-17
Author(s):  
Gabriel Nicolae Popa ◽  
Corina Maria Diniș

Low-voltage three-phase induction motors are most often used in industrial electric drives. Electric motors must be protected by electric and/or electronic devices against: short-circuit, overloads, asymmetrical currents, two-phase voltage operation, under-voltage, and over-temperature. To design the electronic protection currents, voltages and temperature must be measured to determine whether they fall within normal limits. The electronic protection was design into low capacity PLC. The paper presents the designs and analysis of complex electronic protection for general purpose low-voltage three-phase induction motors. The electronic protection has Hall transducers and conversion electronic devices for AC currents to DC voltages, AC voltages to DC voltage, temperature to DC voltage, a low capacity PLC, switches, motor’s power contactors, and signalling lamps has been developed. Experiments with complex electronic protection, for different faults are presented. The proposed protection has the advantages of incorporating all usual protections future for the low-voltage three-phase induction motors.


2008 ◽  
Vol 128 (3) ◽  
pp. 244-250
Author(s):  
Kenji Amei ◽  
Kenji Teshima ◽  
Youhei Tanizaki ◽  
Takahisa Ohji ◽  
Masaaki Sakui

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 268 ◽  
Author(s):  
Ali Shojaei ◽  
Bahram Najafi ◽  
Hani Vahedi

In this paper the standalone operation of the modified seven-level Packed U-Cell (MPUC) inverter is presented and analyzed. The MPUC inverter has two DC sources and six switches, which generate seven voltage levels at the output. Compared to cascaded H-bridge and neutral point clamp multilevel inverters, the MPUC inverter generates a higher number of voltage levels using fewer components. The experimental results of the MPUC prototype validate the appropriate operation of the multilevel inverter dealing with various load types including motor, linear, and nonlinear ones. The design considerations, including output AC voltage RMS value, switching frequency, and switch voltage rating, as well as the harmonic analysis of the output voltage waveform, are taken into account to prove the advantages of the introduced multilevel inverter.


Author(s):  
G. Vijaykrishna ◽  
Y. Kusumalatha

This paper examines how a Reversing voltage multilevel inverter (RVMLI) strategy is enforced to develop multilevel inverter fulfilment. This approach has been used SPWM-PD technique to regulate the electrical inverter. It desires numerous less range of carrier signals to deliver gate pulses of switches. Increasing within the levels during this strategy aid in reduction of output voltage harmonics expeditiously and improves power quality at output of the electrical inverter. It wants a lowered quantity of total switches, which is in a position to decreases of switching losses in this process. The Three-phase reversing voltage multilevel inverter of 7- level and 9- level is accomplished for R-load and R-L load and Three Phase Induction Motor. A reversing voltage multilevel inverter of 7- level and 9- level simulation is intended and developed. Mat lab/Simulink outcome is awarded to validate the proposed scheme.


Author(s):  
Chinnapettai Ramalingam Balamurugan ◽  
S.P. Natarajan ◽  
T.S. Anandhi

The multi level inverter system is habitually exploited in AC drives, when both reduced harmonic contents and high power are required. In this paper, a new topology for three phase asymmetrical multilevel inverter employing reduced number of switches is introduced. With less number of switches, the cost, space and weight of the circuit are automatically reduced. This paper discusses the new topology, the switching strategies and the operational principles of the chosen inverter. Simulation is carried out using MATLAB-SIMULINK. Various conventional PWM techniques that are appropriate to the chosen circuit such as PDPWM, PODPWM, APODPWM, VFPWM and COPWM are employed in this work. COPWM technique affords the less THD value and also affords a higher fundamental RMS output voltage.


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