Aspects of common-mode leakage current suppression in single-phase PV-generation systems

2017 ◽  
Author(s):  
Evgeny V. Grishanov ◽  
Sergey V. Brovanov
Keyword(s):  
Leakage Current ◽  
Single Phase ◽  
Common Mode ◽  
Pv Generation

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

2021 ◽  
Author(s):  
Aleksey Vyacheslavovich Udovichenko ◽  
Sergey Viktorovich Brovanov ◽  
Evgeny Valerievich Grishanov ◽  
Svetlana Mikhailovna Stennikova
Keyword(s):  
Leakage Current ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Renewable Energy Sources ◽  
Multilevel Converter ◽  
Generation System ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Conducting Research ◽  
Pv Generation

Power generation systems based on renewable energy sources are finding ever-widening applications and many researchers work on this problem. Many papers address the problem of transformerless structures, but few of them are aimed at conducting research on structures with multilevel converter topologies. In this paper a grid-tied transformerless PV-generation system based on a multilevel converter is discussed. There are common-mode leakage currents 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 engineering solutions for a generation system based on the multilevel converter controlled with a pulse-width modulation technique are verified by experiment.

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 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.

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 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.

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