Maximum Boost Control for 7-level Z-source Cascaded H-Bridge Inverter

Author(s):  
R. Palanisamy ◽  
K. Vijayakumar

This paper proposes maximum boost control for 7-level z-source cascaded h-bridge inverter and their affiliation between voltage boost gain and modulation index. Z-source network avoids the usage of external dc-dc boost converter and improves output voltage with minimised harmonic content. Z-source network utilises distinctive LC impedance combination with 7-level cascaded inverter and it conquers the conventional voltage source inverter. The maximum boost controller furnishes voltage boost and maintain constant voltage stress across power switches, which provides better output voltage with variation of duty cycles. Single phase 7-level z-source cascaded inverter simulated using matlab/simulink.

Author(s):  
Lambu Rushi Reddy

Some industrial applications require high step-up and step-down voltage gain. The transformer less buck-boost converter has high voltage gain than that of traditional buck-boost converter without extreme duty cycles. A transformer less buck-boost converter with simple structure is obtained by inserting an additional switched network into the traditional buck-boost converter. The two power switches of the buck-boost converter operate synchronously. The operating principles of the buck-boost converter operating in continuous conduction modes are presented. A new buck- boost converter is presented by providing a feedback to the converter. By this, constant output voltage can be maintained under varying load conditions in both buck and boost operation. The output voltage of 40V (step—up mode)/8V (step down mode) is obtained with input voltage 18V and the outcomes are approved through recreation using PSIM MODEL.


Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 282 ◽  
Author(s):  
Nagaraja Sulake ◽  
Ashok Devarasetty Venkata ◽  
Sai Choppavarapu

This paper presents an optimized single-phase three-level boost DC-link cascade H-bridge multilevel inverter (TLBDCLCHB MLI) system to generate a seven-level stepped output voltage waveform for photovoltaic (PV) applications. The proposed TLBDCLCHB MLI system is obtained by integrating a three-level boost converter (TLBC) with a seven-level DC-link cascade H-bridge (DCLCHB) inverter. It consists of a TLBC, level generation unit (LGU) and phase sequence generation unit (PSGU). When compared with traditional boost converter-fed multilevel inverter systems, the proposed TLBDCLCHB MLI system requires a single DC source, fewer power switches and gate drivers. Reduction in the switch count and number of DC sources makes the system cost effective and requires a smaller installation area. Pulse generation for the power switches of an LGU in a DCLCHB inverter is accomplished by providing proper conducting angles that are generated by optimized conducting angle determination (CAD) techniques. In this paper two CAD techniques i.e., equal-phase CAD (EPCAD) and step pulse wave CAD (SPWCAD) techniques are proposed to evaluate the performance of the proposed system in terms of the total harmonic distortion (THD) and the quality of the stepped output voltage waveform. The proposed system has been modeled and simulated using MATLAB/SIMULINK software. Results are presented and discussed. Also, a prototype model of a single-phase TLBDCLCHB MLI system is developed using a field-programmable gate array (FPGA)-based pulse generation with a resistive load and its performance is analyzed for various operating conditions.


Author(s):  
Jeevan Naik

<span>In this paper, a design and control for the buck-boost converter, i.e., 1-plus-D converter with a positive output voltage, is presented, which combines the 1-plus-D converter and the synchronous rectified (SR) buck converter. By doing so, the problem in voltage bucking of the 1-plus-D converter can be solved, thereby increasing the application capability of the 1-plus-D converter. Since such a converter operates in continuous conduction mode inherently, it possesses the nonpulsating output current, thereby not only decreasing the current stress on the output capacitor but also reducing the output voltage ripple. Above all, both the 1-plus-D converter and the SR buck converter, combined into a buck–boost converter with no right-half plane zero, use the same power switches, thereby causing the required circuit to be compact and the corresponding cost to be down. Furthermore, during the magnetization period, the input voltage of the 1-plus-D converter comes from the input voltage source, whereas during the demagnetization period, the input voltage of the 1-plus-D converter comes from the output voltage of the SR buck converter.</span>


2021 ◽  
Vol 2 (2) ◽  
pp. 44-53
Author(s):  
GENNADY S. MYTSYK ◽  
◽  
ZAW HTET HEIN ◽  

The recent interest of developers of new technology in studying a structural and algorithmic synthesis (SAS) of voltage source inverters (VSI) for solar power plants (SPP) is stemming from a growing need to solve problems in connection with the revealed new possibilities of converting energy flow (from DC to AC) with better energy efficiency by reducing the depth of its pulse modulation. This problem is solved by using more rational structural and algorithmic solutions. It is shown that for SPPs for a capacity of about 1 MW and more, it is more expedient to construct inverters based on the energy flow multichannel conversion principle. Given a limited power capacity of the transistor components, the application of this principle allows the problem to be solved in fact without using an output filter. The output voltage waveform is shaped using the energy flow pulse-amplitude modulation (PAM), and its M parts are summed in the output circuit by out using M winding transfilters (M-TF). The proposed method for carrying out combined SAS of single-phase voltage source inverters with multichannel conversion is considered, which consists in using an N-level single-phase VSI (N-SPVSI) in each of the M channels with the voltage levels optimized in terms of the minimum total harmonic distortion (THD). The resulting voltage of this class of single-phase inverters, designated as MxN-SPVSI, is formed by the corresponding phase shift of the channel voltages followed by summing the channel currents by M-TF. It is shown that the resulting output voltage levels are also close to their values optimized with respect to the minimum of the THD indicator. The results from a comparative analysis of two options — a single-channel 8-level inverter and a four-channel 8-level inverter are given. For the second option, only one intermediate voltage tap in the solar battery is required (instead of seven taps in the first option) along with modern transistor components that are available for practical implementation. In both options, the THD value less than 5% is obtained with almost no need of using an output filter. The presented results provide a certain information and methodological support for system designing of single-phase voltage source inverters as applied to the specific features of solar power plants. Three-phase inverters can be built on the basis of three single-phase inverters with galvanic isolation of the power sources for each phase.


Author(s):  
Shima Sadaf ◽  
Nasser Al-Emadi ◽  
Atif Iqbal ◽  
Mohammad Meraj ◽  
Mahajan Sagar Bhaskar

DC-DC power converters are necessary to step-up the voltage or current with high conversion ratio for many applications e.g. photovoltaic and fuel cell energy conversion, uninterruptible power supply, DC microgrid, automobile, high intensity discharged lamp ballast, hybrid vehicle, etc. in order to use low voltage sources. In this project, a modified SIBC (mSIBC) is proposed with reduced voltage stress across active switches. The proposed mSIBC configuration is transformerless and simply derived by replacing one diode of the classical switched inductor structure with an active switch. As a result, mSIBC required low voltage rating active switches, as the total output voltage is shared between two active switches. Moreover, the proposed mSIBC is low in cost, provides higher efficiency and required the same number of components compared to the classical SIBC. The experimental results are presented which validated the theoretical analysis and functionality, and the efficiency of the designed converter is 97.17%. The proposed mSIBC converter provides higher voltage conversion ratio compared to classical converters e.g. boost, buck-boost, cuk, and SEPIC. The newly designed configurations will aid the intermediate power stage between the renewable sources and utility grid or high voltage DC or AC load. Since, the total output voltage is distributed among the two active switches, low voltage rating switches can be employed to design the power circuit of the proposed converter. The classical boost converter or recently proposed switched inductor based boost converter can be replaced by the proposed mSIBC converter in real-time applications such as DC microgrid, DC-DC charger, battery backup system, UPS, EV, an electric utility grid. The proposed power circuitry is cost effective, compact in size, easily diagnostic, highly efficient and reliable.


Author(s):  
R. Palanisamy ◽  
A. Velu ◽  
K. Selvakumar ◽  
D. Karthikeyan ◽  
D. Selvabharathi ◽  
...  

This paper deals the implementation of 3-level output voltage using dual 2-level inverter with control of sub-region based Space Vector Modulation (SR-SVM). Switching loss and voltage stress are the most important issues in multilevel inverters, for keep away from these problems dual inverter system executed. Using this proposed system, the conventional 3-level inverter voltage vectors and switching vectors can be located. In neutral point clamped multilevel inverter, it carries more load current fluctuations due to the DC link capacitors and it requires large capacitors. Based on the sub-region SVM used to control IGBT switches placed in the dual inverter system. The proposed system improves the output voltage with reduced harmonic content with improved dc voltage utilisation. The simulation and hardware results are verified using matlab/simulink and dsPIC microcontroller.


Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 154
Author(s):  
Wei Yao ◽  
Jiamin Cui ◽  
Wenxi Yao

This paper presents a novel digital control scheme for the regulation of single-phase voltage source pulse width modulation (PWM) inverters used in AC power sources. The proposed scheme adopts two deadbeat controllers to regulate the inner current loop and the outer voltage loop of the PWM inverter. For the overhead of digital processing, the change of duty of PWM lags one carrier period behind the sampling signal, which is modeled as a first-order lag unit in a discrete domain. Based on this precise modeling, the deadbeat controllers make the inverter get a fast dynamic response, so that the inverter’s output voltage is obtained with a very low total harmonic distortion (THD), even when the load is fluctuating. The parameter sensitivity of the deadbeat control was analyzed, which shows that the proposed deadbeat control system can operate stably when the LC filter’s parameters vary within the range allowed. The experimental results of a 2kW inverter prototype show that the THD of the output voltage is less than 3% under resistive and rectifier loads, which verifies the feasibility of the proposed scheme. An additional advantage of the proposed scheme is that the parameter design of the controller can be fully programmed without the experience of a designer.


Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 394 ◽  
Author(s):  
Dai-Van Vo ◽  
Minh-Khai Nguyen ◽  
Duc-Tri Do ◽  
Youn-Ok Choi

A novel single-phase nine-level boost inverter is proposed in this paper. The proposed inverter has an output voltage which is higher than the input voltage by switching capacitors in series and in parallel. The maximum output voltage of the proposed inverter is determined by using the boost converter circuit, which has been integrated into the circuit. The proposed topology is able to invert the multilevel voltage with the high step-up output voltage, simple structure and fewer power switches. In this paper, the circuit configuration, the operating principle, and the output voltage expression have been derived. The proposed converter has been verified by simulation and experiment with the help of PSIM software and a laboratory prototype. The experimental results match the theoretical calculation and the simulation results.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2640 ◽  
Author(s):  
Xiang Lin ◽  
Faqiang Wang ◽  
Herbert H. C. Iu

Bridgeless power factor correction (PFC) converters have a reduced number of semiconductors in the current flowing path, contributing to low conduction losses. In this paper, a new bridgeless high step-up voltage gain PFC converter is proposed, analyzed and validated for high voltage applications. Compared to its conventional counterpart, the input rectifier bridge in the proposed bridgeless PFC converter is completely eliminated. As a result, its conduction losses are reduced. Also, the current flowing through the power switches in the proposed bridgeless PFC converter is only half of the current flowing through the rectifier diodes in its conventional counterpart, therefore, the conduction losses can be further improved. Moreover, in the proposed bridgeless PFC converter, not only the voltage stress of power switches is lower than the output voltage, but the voltage stress of the output diodes is lower than the conventional counterpart. In addition, this proposed bridgeless PFC converter features a simple circuit structure and high PFC performance. Finally, the proposed bridgeless PFC converter is analyzed and designed in the discontinuous conduction mode (DCM). The simulation results are presented to verify the effectiveness of the proposed bridgeless PFC converter.


2019 ◽  
Vol 29 (01) ◽  
pp. 2050004
Author(s):  
Sidharth Sabyasachi ◽  
Vijay B. Borghate ◽  
Santosh Kumar Maddugari

This paper presents a module for single-phase multilevel inverter topology. The proposed module generates maximum 21-level bipolar output voltage with asymmetric sources without H-bridge. This results in reduction in filter cost and size. The module can be cascaded for high voltage applications. The same arrangement of voltage source magnitudes in first module is maintained in the remaining cascaded modules. The proposed topology is suitable for the applications like electric vehicle and emergency services like residences and hospitality industries, etc. A set of comparisons between the proposed and recently published topologies are provided to differentiate between them. The topology is simulated and verified in MATLAB/SIMULINK. A hardware prototype is developed in the laboratory for experimental confirmation with various conditions.


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