scholarly journals Transformerless Quasi-Z-Source Inverter to Reduce Leakage Current for Single-Phase Grid-Tied Applications

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 312 ◽  
Author(s):  
Woo-Young Choi ◽  
Min-Kwon Yang
Keyword(s):  
Leakage Current ◽  
Power Efficiency ◽  
High Performance ◽  
Single Phase ◽  
Power Devices ◽  
Common Mode Voltage ◽  
Control Scheme ◽  
Frequency Components ◽  
The Common ◽  
Current Reduction

The conventional single-phase quasi-Z-source (QZS) inverter has a high leakage current as it is connected to the grid. To address this problem, this paper proposes a transformerless QZS inverter, which can reduce the leakage current for single-phase grid-tied applications. The proposed inverter effectively alleviates the leakage current problem by removing high-frequency components for the common-mode voltage. The operation principle of the proposed inverter is described together with its control strategy. A control scheme is presented for regulating the DC-link voltage and the grid current. A 1.0 kW prototype inverter was designed and tested to verify the performance of the proposed inverter. Silicon carbide (SiC) power devices were applied to the proposed inverter to increase the power efficiency. The experimental results showed that the proposed inverter achieved high performance for leakage current reduction and power efficiency improvement.

scholarly journals Forced stack sleep transistor (FORTRAN): A new leakage current reduction approach in CMOS based circuit designing

2021 ◽  
Vol 34 (2) ◽  
pp. 259-280
Author(s):  
Sankit Kassa ◽  
Neeraj Misra ◽  
Rajendra Nagaria
Keyword(s):  
Low Power ◽  
Leakage Current ◽  
Power Efficiency ◽  
High Performance ◽  
Low Voltage ◽  
Full Adder ◽  
Leakage Power ◽  
Modes Of Operation ◽  
Power Circuit ◽  
Current Reduction

Reduction in leakage current has become a significant concern in nanotechnology-based low-power, low-voltage, and high-performance VLSI applications. This research article discusses a new low-power circuit design the approach of FORTRAN (FORced stack sleep TRANsistor), which decreases the leakage power efficiency in the CMOS-based circuit outline in VLSI domain. FORTRAN approach reduces leakage current in both active as well as standby modes of operation. Furthermore, it is not time intensive when the circuit goes from active mode to standby mode and vice-versa. To validate the proposed design approach, experiments are conducted in the Tanner EDA tool of mentor graphics bundle on projected circuit designs for the full adder, a chain of 4-inverters, and 4- bit multiplier designs utilizing 180nm, 130nm, and 90nm TSMC technology node. The outcomes obtained show the result of a 95-98% vital reduction in leakage power as well as a 15-20% reduction in dynamic power with a minor increase in delay. The result outcomes are compared for accuracy with the notable design approaches that are accessible for both active and standby modes of operation.

scholarly journals Leakage Current Reduction in Single-Phase Grid-Connected Inverters—A Review

2020 ◽  
Vol 10 (7) ◽  
pp. 2384 ◽  
Author(s):  
Adyr A. Estévez-Bén ◽  
Alfredo Alvarez-Diazcomas ◽  
Gonzalo Macias-Bobadilla ◽  
Juvenal Rodríguez-Reséndiz
Keyword(s):  
Leakage Current ◽  
Harmonic Distortion ◽  
Clean Energy ◽  
Photovoltaic Module ◽  
Common Mode ◽  
Advantages And Disadvantages ◽  
Common Mode Voltage ◽  
The Common ◽  
Ac Converters ◽  
Current Reduction

The rise in renewable energy has increased the use of DC/AC converters, which transform the direct current to alternating current. These devices, generally called inverters, are mainly used as an interface between clean energy and the grid. It is estimated that 21% of the global electricity generation capacity from renewable sources is supplied by photovoltaic systems. In these systems, a transformer to ensure grid isolation is used. Nevertheless, the transformer makes the system expensive, heavy, bulky and reduces its efficiency. Therefore, transformerless schemes are used to eliminate the mentioned disadvantages. One of the main drawbacks of transformerless topologies is the presence of a leakage current between the physical earth of the grid and the parasitic capacitances of the photovoltaic module terminals. The leakage current depends on the value of the parasitic capacitances of the panel and the common-mode voltage. At the same time, the common-mode voltage depends on the modulation strategy used. Therefore, by the manipulation of the modulation technique, is accomplished a decrease in the leakage current. However, the connection standards for photovoltaic inverters establish a maximum total harmonic distortion of 5%. In this paper an analysis of the common-mode voltage and its influence on the value of the leakage current is described. The main topologies and strategies used to reduce the leakage current in transformerless schemes are summarized, highlighting advantages and disadvantages and establishing points of comparison with similar topologies. A comparative table with the most important aspects of each converter is shown based on number of components, modes of operation, type of modulation strategy used, and the leakage current value obtained. It is important to mention that analyzed topologies present a variation of the leakage current between 0 to 180 mA. Finally, the trends, problems, and researches on transformerless grid-connected PV systems are discussed.

scholarly journals Research on an Improved Single-Phase Unisolated Grid-Connected Photovoltaic Inverter

2021 ◽  
Vol 23 (2) ◽  
pp. 123-130
Author(s):  
Baoge Zhang ◽  
Deyu Hong
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Current Problem ◽  
Input Voltage ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Voltage Clamping ◽  
The Common ◽  
Simulation Results ◽  
Inverter Topology

An improved single-phase unisolated grid-connected photovoltaic inverter topology is proposed to solve the common mode leakage current problem of unisolated grid-connected photovoltaic inverters. By analyzing the topology structure and voltage clamping principle of the improved inverter, the topology can maintain the same low input voltage as the full-bridge inverter, and ensure that the common-mode voltage in the continuation mode is clamped to the midpoint voltage of the bus, so as to effectively reduce the common-mode leakage current caused by the common-mode voltage suspension in the continuation mode. Moreover, the common-mode leakage current of the improved topology is smaller than that of the traditional H6-2D topology at similar conversion efficiency. The simulation results on MATLAB /Simulink platform show that the topology is feasible and effective.

scholarly journals A Novel Inverter Topology for Single-Phase Transformerless PV System

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Haiyan Cao
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
High Efficiency ◽  
Low Cost ◽  
Experimental Tests ◽  
Pv System ◽  
Common Mode ◽  
Common Mode Voltage ◽  
The Common ◽  
Inverter Topology

Transformerless photovoltaic (PV) power system is very promising due to its low cost, small size, and high efficiency. One of its most important issues is how to prevent the common mode leakage current. In order to solve the problem, a new inverter is proposed in this paper. The system common mode model is established, and the four operation modes of the inverter are analyzed. It reveals that the common mode voltage can be kept constant, and consequently the leakage current can be suppressed. Finally, the experimental tests are conducted. The experimental results verify the effectiveness of the proposed solution.

A Single-Phase Five-Level Transformer-Less PV Inverter for Leakage Current Reduction

2021 ◽  
pp. 1-1
Author(s):  
Xiaonan Zhu ◽  
Hongliang Wang ◽  
Wenyuan Zhang ◽  
Hanzhe Wang ◽  
Xiaojun Deng ◽  
...  
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Pv Inverter ◽  
Current Reduction

scholarly journals A New Single-Phase Transformerless Current Source Inverter for Leakage Current Reduction

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1633 ◽  
Author(s):  
Xiaoqiang Guo ◽  
Jianhua Zhang ◽  
Jiale Zhou ◽  
Baocheng Wang
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Current Source ◽  
Current Source Inverter ◽  
Current Reduction

scholarly journals An Efficient H7 Single-Phase Photovoltaic Grid Connected Inverter for CMC Conceptualization and Mitigation Method

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1440 ◽  
Author(s):  
Mehrdad Mahmoudian ◽  
Eduardo M. G. Rodrigues ◽  
Edris Pouresmaeil
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Pulse Width Modulation ◽  
Reactive Power ◽  
Negative Impact ◽  
Harmonic Distortion ◽  
Common Mode ◽  
Safety Issues ◽  
Common Mode Voltage ◽  
Circuit Components

Transformerless inverters are the economic choice as power interfaces between photovoltaic (PV) renewable sources and the power grid. Without galvanic isolation and adequate power convert design, single-phase grid connected inverters may have limited performance due to the presence of a significant common mode ground current by creating safety issues and enhancing the negative impact of harmonics in the grid current. This paper proposes an extended H6 transformerless inverter that uses an additional power switch (H7) to improve common mode leakage current mitigation in a single-phase utility grid. The switch with a diode in series connection aims to make an effective clamp of common mode voltage at the DC link midpoint. The principles of operation of the proposed structure with bipolar sinusoidal pulse width modulation (SPWM) is presented and formulated. Laboratory tests’ performance is detailed and evaluated in comparison with well-known single-phase transformer-less topologies in terms of power conversion efficiency, total harmonic distortion (THD) level, and circuit components number. The studied topology performance evaluation is completed with the inclusion of reactive power compensation functionality verified by a low-power laboratory implementation with 98.02% efficiency and 30.3 mA for the leakage current.

Triangular Defects Reduction and Uniformity Improvement of 4H-SiC Epitaxial Growth in a Planetary Reactor

2018 ◽  
Vol 924 ◽  
pp. 104-107
Author(s):  
Wei Li Lu ◽  
Jia Li ◽  
Yu Long Fang ◽  
Jia Yun Yin ◽  
Zhi Hong Feng
Keyword(s):  
Epitaxial Growth ◽  
Leakage Current ◽  
High Throughput ◽  
High Voltage ◽  
High Performance ◽  
Etching Process ◽  
Power Devices ◽  
High Quality ◽  
Recent Advances

High quality SiC Epilayers are essential for the development of high performance power devices. Killer defects such as triangular defects could cause leakage current paths within the high voltage SiC devices. This paper reports on the recent advances in 4H-SiC epitaxial growth toward high-throughput production in a commercial planetary reactor. The triangular defects are suppressed by the optimized pre-etching process, and the physics behind was investigated. The doping and thickness uniformities of the intra-wafer and wafer-to-wafer have also been improved.

scholarly journals A Five-Level Converter in a Three-Level Mode for Common-Mode Leakage Current Suppression in PV-Generation Systems

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2382
Author(s):  
Aleksey V. Udovichenko ◽  
Sergey V. Brovanov ◽  
Evgeny V. Grishanov ◽  
Svetlana M. Stennikova
Keyword(s):  
Leakage Current ◽  
Pulse Width Modulation ◽  
Renewable Energy Sources ◽  
Multilevel Converter ◽  
Generation System ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Modulation Mode ◽  
The Common ◽  
Pv Generation

Power generation systems (PGSs) based on renewable energy sources are finding ever-widening applications, and many researchers work on this problem. Many papers address the problem of transformerless PGSs, but few of them aimed at conducting research on structures with multilevel converter topologies as part of a PGS. In this paper a grid-tied transformerless PV-generation system based on a multilevel converter is discussed. There are common-mode leakage currents (CMLCs), which act as a parasitic factor. It is also known that common-mode voltage is the main cause of the common-mode leakage current in grid-tied PV-generation systems. This paper considers the space vector pulse-width modulation (PWM) technique, which is used to suppress or reduce common-mode leakage current. The proposed PWM technique with the reduction of common-mode leakage current for a generation system based on the multilevel converter controlled with a PWM technique was verified experimentally. The experimental results accurately confirmed the mathematical model and the compensation achieved without errors. In the experiment, there was an approximately six-fold decrease in the common-mode leakage current (10.3 mA in rejection mode and 61 mA in non-rejection current). This can lead to the elimination of CMLC in a multilevel semiconductor converter only by changing the modulation mode. This suggests the possibility of using these devices as part of transformerless generation systems. Suppression of CMLC can only be carried out by changing the PWM algorithm. Both considered topologies can implement this mode of operation. The proposed converter has a higher efficiency up to a frequency multiplicity of 2000.

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