Modified Z-Network DC-DC Converter with Lower Capacitor Voltage Stress

2018 ◽  
Author(s):  
Punit Kumar ◽  
Bhavana Jangid
Keyword(s):  
Voltage Stress ◽  
Capacitor Voltage

scholarly journals Modified Space Vector Modulated Z Source Inverter with Effective DC Boost and Lowest Switching Stress

2010 ◽  
Vol 7 (1) ◽  
pp. 70 ◽  
Author(s):  
S. Thangaprakash ◽  
A. Krishnan
Keyword(s):  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Strategies ◽  
Input Voltage ◽  
Duty Ratio ◽  
Space Vector ◽  
Voltage Vector ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Full Utilization

 This paper presents a modified control algorithm for Space Vector Modulated (SVM) Z-Source inverters. In traditional control strategies, the Z-Source capacitor voltage is controlled by the shoot through duty ratio and the output voltage is controlled by the modulation index respectively. Proposed algorithm provides a modified voltage vector with single stage controller having one degree of freedom wherein traditional controllers have two degrees of freedom. Through this method of control, the full utilization of the dc link input voltage and keeping the lowest voltage stress across the switches with variable input voltage could be achieved. Further it offers ability of buck-boost operation, low distorted output waveforms, sustainability during voltage sags and reduced line harmonics. The SVM control algorithm presented in this paper is implemented through Matlab/Simulink tool and experimentally verified with Z-source inverter prototype in the laboratory. 

scholarly journals Double Sliding-Surface Multiloop Control Reducing Semiconductor Voltage Stress on the Boost Inverter

2020 ◽  
Vol 10 (14) ◽  
pp. 4912
Author(s):  
Oswaldo López-Santos ◽  
Germain García
Keyword(s):  
Sliding Mode ◽  
Operation Conditions ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Balance Technique ◽  
Dynamic Performances ◽  
Semiconductor Voltage ◽  
Multiloop Control ◽  
Mathematical Operations ◽  
Harmonic Balance Technique

Sliding-mode control (SMC) has been successfully applied to boost inverters, which solves the tracking problem of imposing sinusoidal behavior to the output voltage despite the coupled or decoupled operation of both boost cells in the converter. Most of the results reported in the literature were obtained using the conventional cascade-control structure involving outer loops that generate references for one or two sliding surfaces defined using linear combinations of inductor currents and capacitor voltages. As expected, all proposed methods share the inherent robustness and insensitivity to the uncertainties of SMC, which are the reasons why one of the few comparison criteria between them is the simplicity of their implementation that is evaluated according to the required measurements and mathematical operations. Furthermore, the slight differences between the obtained dynamic performances do not allow a clear distinction of the best solution. This study presents a new SMC approach applied to a boost inverter in which two boost cells are independently commutated. Each of these boost cells integrates an outer loop, enforcing the tracking of harmonic-enriched waveforms to the capacitor voltage. Although this approach increases by two the number of measurements and requires multiloop controllers, it allows effective alleviation of the semiconductor voltage stress by reducing the required voltage gain. A complete analytical study using harmonic balance technique allows deducing a simplified model allowing to obtain a PI controller valid into to the whole set of operation conditions. The several simulation results completely verified the potential of the control proposal and the accuracy of the employed methods.

High‐performance quasi‐Z‐source inverter with low capacitor voltage stress and small inductance

2015 ◽  
Vol 8 (6) ◽  
pp. 1061-1067 ◽  
Author(s):  
Liqiang Yang ◽  
Dongyuan Qiu ◽  
Bo Zhang ◽  
Guidong Zhang
Keyword(s):  
High Performance ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Small Inductance

scholarly journals A Step Up/Down Power-Factor-Correction Converter with Modified Dual Loop Control

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 199 ◽  
Author(s):  
Yi-Hung Liao
Keyword(s):  
Output Voltage ◽  
Thermal Stresses ◽  
Voltage Regulation ◽  
Loop Control ◽  
Turn On ◽  
Control Scheme ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Zero Voltage ◽  
Positive Half

A step up/down AC/DC converter with modified dual loop control is proposed. The step up/down AC/DC converter features the bridgeless characteristic which can reduce bridge-diode conduction losses. Based on the step up/down AC/DC converter, a modified dual loop control scheme is proposed to achieve input current shaping and output voltage regulation. Fewer components are needed compared with the traditional bridge and bridgeless step up/down AC/DC converters. In addition, the intermediate capacitor voltage stress can be reduced. Furthermore, the top and bottom switches still have zero-voltage turn-on function during the negative and positive half-line cycle, respectively. Hence, the thermal stresses can also be reduced and balanced. Simulation and experimental results are provided to verify the validity of the proposed step up/down AC/DC converter and its control scheme.

scholarly journals LC Impedance Source Bi-Directional Converter with Reduced Capacitor Voltages

Electronics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1062
Author(s):  
Dogga Raveendhra ◽  
Rached Dhaouadi ◽  
Habibur Rehman ◽  
Shayok Mukhopadhyay
Keyword(s):  
Boost Converter ◽  
Lower Number ◽  
Modulation Scheme ◽  
Matlab Simulink ◽  
Number Of Components ◽  
Test Conditions ◽  
Bidirectional Converter ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Continuous Current

This paper proposes an LC (Inductor and Capacitor) impedance source bi-directional DC–DC converter by redesigning after rearranging the reduced number of components of a switched boost bi-directional DC–DC converter. This new converter with a conventional modulation scheme offers several unique features, such as a) a lower number of components and b) reduced voltage stress on the capacitor compared to existing topologies. The reduction of capacitor voltage stress has the potential of improving the reliability and enhancing converter lifespan. An analysis of the proposed converter was completed with the help of a mathematical model and state-space averaging models. The converter performance under different test conditions is compared with the conventional bi-directional DC–DC converter, Z-source converter, discontinuous current quasi Z-source converter, continuous current quasi Z-source converter, improved Z-source converter, switched boost converter, current-fed switched boost converter, and quasi switched boost converter in the Matlab Simulink environment. MATLAB/Simulink results demonstrate that the proposed converter has lesser components count and reduced capacitors’ voltage stresses when compared to the topologies mentioned above. A 24 V to 18 V LC-impedance source bi-directional converter and a conventional bidirectional converter are built to investigate the feasibility and benefits of the proposed topology. Experimental results reveal that capacitor voltage stresses, in the case of proposed topology are reduced by 75.00% and 35.80% in both boost and buck modes, respectively, compared to the conventional converter circuit.

scholarly journals Wide Range Series Resonant DC-DC Converter with a Reduced Component Count and Capacitor Voltage Stress for Distributed Generation

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2051
Author(s):  
Abualkasim Bakeer ◽  
Andrii Chub ◽  
Andrei Blinov ◽  
Jih-Sheng Lai
Keyword(s):  
Distributed Generation ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Maximum Efficiency ◽  
Half Cycle ◽  
Wide Range ◽  
Voltage Stress ◽  
Capacitor Voltage ◽  
Output Side ◽  
Boost Rectifier

This paper proposes a galvanically isolated dc-dc converter that can regulate the input voltage in a wide range. It is based on the series resonance dc-dc converter (SRC) topology and a novel boost rectifier. The proposed topology has a smaller number of semiconductors than its SRC-based existing topologies employing an ac-switch in the boost rectifier. The proposed dc-dc converter comprises only two diodes and one switch at the output side, while the existing solutions use two switches and two diodes to step up the voltage. The proposed converter boosts the input voltage within a single boosting interval in the positive half-cycle of the switching period. In addition, the resonant current in the negative half-cycle is sinusoidal, which could enhance the converter efficiency. The resonant capacitor voltage is clamped at the level of the output voltage. Therefore, the voltage stress of the capacitor could significantly reduce at various input voltage and power levels. This makes it perfect for distributed generation applications such as photovoltaics with wide variations of input voltage and power. The converter operates at the fixed switching frequency close to the resonance frequency to obtain the maximum efficiency at the nominal input voltage. The zero-voltage switching (ZVS) feature is achieved in the primary semiconductors, while the diodes in the output-side rectifier turn off at nearly zero current switching. The mathematical model and design guidelines of the proposed converter are discussed in the paper. The experimental results confirmed the theoretical analysis based on a 300 W prototype. The maximum efficiency of the converter was 96.8% at the nominal input voltage, and the converter has achieved a wider input voltage regulation range than that with the boosting cell comprising an ac-switch.

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