Single‐phase common mode transformer‐less soft‐switching grid‐connected inverter with eliminated leakage current

2019 ◽  
Vol 47 (6) ◽  
pp. 838-861
Author(s):  
Mehdi Tofigh Azary ◽  
Mehran Sabahi ◽  
Ebrahim Babaei
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Soft Switching ◽  
Common Mode ◽  
Grid Connected Inverter

scholarly journals Dual‐buck full‐bridge grid‐connected inverter with common‐mode leakage current elimination

2018 ◽  
Vol 54 (2) ◽  
pp. 93-95 ◽  
Author(s):  
Yunzhong Dai ◽  
Shengxian Zhuang ◽  
Wenzhu Li ◽  
Luhang Jiang
Keyword(s):  
Leakage Current ◽  
Common Mode ◽  
Grid Connected Inverter

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.

scholarly journals Three-Phase Transformerless Inverter for Photovoltaic Grid Connected System with Zero Common Mode Noise

2021 ◽  
Vol 19 ◽  
pp. 137-142
Author(s):  
K. Karam ◽  
◽  
M. Badawi El Najjar ◽  
M. El Hassan
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Common Ground ◽  
Phase System ◽  
Common Mode ◽  
Overall Design ◽  
Modulation Technique ◽  
Pv Inverter ◽  
Three Phase ◽  
Major Factors

The pervasion of transformerless grid connected photovoltaic (PV) inverters has triggered the concerns of many researchers since it can induce power quality problems. In these types of applications, the generation of common mode (CM) leakage current is one of the major factors that affects the reliability of the overall design. In single-phase systems, the concept of the common ground between the PV negative terminal and the neutral point of the grid is the only topology that “totally” cancels this CM noise. However, none of the existing three-phase inverter techniques is able to totally remove it. Therefore, this paper proposes a three-phase PV inverter based on the concept applied in the single-phase system in order to achieve, for the first time, a zero CM noise in three-phase grid-connected PV applications. The proposed inverter is simulated with a PV array, appropriate modulation technique, corresponding inverter controller, and a three-phase Y-connected alternating current (AC) grid voltage. The simulation of the overall system is done using Matlab/Simulink software. As compared with results of existing three-phase topologies, this is the only three-phase transformerless PV inverter technique that offers generation of multilevel output, total elimination of leakage current flow, simple inverter structure, and uncomplicated modulation technique.

scholarly journals Current Source AC-Side Clamped Inverter for Leakage Current Reduction in Grid-Connected PV System

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1296 ◽  
Author(s):  
Li ◽  
Wang ◽  
San ◽  
Guo
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Current Source ◽  
Electrolytic Capacitor ◽  
Modulation Method ◽  
Switching Frequency ◽  
Pv System ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Single Phase Inverter

For the grid-connected photovoltaic inverters, the switching-frequency common-mode voltage brings the leakage current, which should be eliminated. So far, many kinds of single-phase inverters have been published for this purpose, but most of them are the conventional voltage-type ones, which have the disadvantages of poor reliability due to the DC-link electrolytic capacitor and the risk of short-through of the bridge switches. To solve this technical issue, a novel current source inverter with AC-side clamping is proposed to mitigate the switching-frequency common-mode voltage. Meanwhile, a novel modulation method is proposed for the new single-phase inverter to achieve low-frequency operation of the main switches, which reduces the switching losses. Finally, the proposed method is implemented on the TMS320F28335DSP + XC6SLX9FPGA digital hardware platform. Also, the performance comparisons are done with the traditional solution. The results prove the proposed solution.

scholarly journals Research on common-mode leakage current for a novel non-isolated dual-buck photovoltaic grid-connected inverter

2018 ◽  
Vol 15 (12) ◽  
pp. 20180400-20180400 ◽  
Author(s):  
Yunzhong Dai ◽  
Zichao Guan ◽  
Rongfei Zhang ◽  
Shengxian Zhuang ◽  
Yan Wang
Keyword(s):  
Leakage Current ◽  
Common Mode ◽  
Grid Connected Inverter
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