Common Mode Voltage Reduction in a Single-Phase Quasi Z-Source Inverter for Transformerless Grid-Connected Solar PV Applications

Meraj, Mohammad; Rahman, Syed; Iqbal, Atif; Ben‐Brahim, Lazhar

doi:10.1109/jestpe.2018.2867521

Cited by 63 publications

(49 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another method is to use a decoupling circuit to disconnect the inverter from the grid [9][10][11][12][13][14][15]. The decoupling circuit technique has been described for single-phase transformerless inverter applications in [9].…”

Section: Introductionmentioning

confidence: 99%

“…Many efforts have also been made to develop transformerless inverters by applying decoupling circuits to the current source inverters [16,17]. To date, however, only a few studies [13][14][15] have been reported that apply decoupling circuits to ZS inverters. In [13], a symmetric ZS HERIC inverter was proposed.…”

Section: Introductionmentioning

confidence: 99%

“…It uses an additional two power switches for maintaining the common-mode voltage constant. In [14,15], a QZS HERIC inverter was suggested. It uses an additional two power switches and two power diodes for clamping the common-mode voltage.…”

Section: Introductionmentioning

confidence: 99%

“…It uses an additional two power switches and two power diodes for clamping the common-mode voltage. The inverters in [13][14][15] commonly have three distinct switching states, namely powering, freewheeling, and shoot-through states. During powering states, the inverter delivers the DC power into the grid.…”

Section: Introductionmentioning

confidence: 99%

“…During freewheeling states, the grid current circulates through extra power switches, which operate with the grid frequency. However, the previous inverters [13][14][15] have drawbacks such as (1) they still use the bipolar PWM for power switches in full-bridge inverter legs; and (2) they always need freewheeling states for every powering state and shoot-through state. These drawbacks increase the number of switching times for the power switches, causing high switching power losses.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

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

Choi

Yang

2019

Electronics

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Choi

Yang

2019

Electronics

View full text Add to dashboard Cite

show abstract

Single‐stage high reliability doubly grounded nonisolated PV grid‐connected inverter

Yao

2021

Int Trans Electr Energ Syst

View full text Add to dashboard Cite

Nonisolated PV grid-connected inverters are extensively used in renewable generation systems. However, there is a shoot-through issue in traditional voltage-source inverters and common mode leakage current (CMLC) in nonisolated PV inverters. In order to address the aforementioned problems, a single-stage high reliability doubly grounded nonisolated PV grid-connected inverter is presented. The inverter is composed of a buck converter and a buck-boost converter, which operates in the positive and negative half grid periods, respectively. Grounds of the grid and PV array are shorted to eliminate the CMLC. The sinusoidal pulse width modulation (SPWM) is adopted in the proposed inverter. The proposed inverter is a single-stage system in each half grid cycle. There is no CMLC in the proposed inverter. Voltage across all semiconductors is not affected by the intrinsic capacitors of them. In addition, the inverter does not have the shoot-through issue, which increases reliability of the inverter. Only one switch is high frequency operated in each half grid period, so efficiency of the inverter can be improved, which is 98.6%. Experimental results of a 250 W single-stage high reliability doubly grounded nonisolated PV grid-connected inverter confirm the theoretical analysis. The inverter can be used in the PV application with high reliability and no CMLC.

show abstract

Single input qZ‐source cascaded multilevel inverters : Analysis , design, and implementation

Guisso

Vargas

Faistel

et al. 2021

Int Trans Electr Energ Syst

View full text Add to dashboard Cite

The Single Input quasi-Z-Source Cascade Multilevel Inverter (SIqZS-CMI) has the ability to make use of a single DC input source and to share active power among all cascaded qZS modules. This unique feature, do not present in any other quasi-Z-Source (qZS) multilevel inverter in the literature, is accomplished by replacing one of its Z-impedance inductances by a coupled inductor. With this topology, it is possible to make use of a single low voltage PV string, favoring the use of small size residential rooftop systems. In addition, it simplifies the system grounding and the compliance with many Installation, Maintenance, and Safety Codes and Standards. The proposed control strategy enables high quality current injection into the grid, keeping the DC bus voltage regulation, ensuring precise power balancing with symmetric multilevel waveforms. Experimental results from a 5-level SIqZS-CMI prototype demonstrate the system's performance and its advantages.active power sharing, cascaded loop controller, cascaded multilevel inverter (CMI), DC-AC converter, grid-tied, photovoltaic (PV) power system, quasi-Z-source inverter (qZSI) | INTRODUCTIONRecently, Z-source and quasi-Z-source (qZS) multilevel inverters have been presented in literature. 1,2 These converters combine the advantages of cascaded multilevel inverters (CMIs) with the voltage gain provided by impedance-source List of Symbols and Abbreviations: C f , filter capacitor; C in(a,b) , input capacitor of module a and b; C 1(a,b) , capacitor 1 of module; C 2(a,b) , capacitor 2 of module; D 0(a,b) , duty-cycle of the ST; D 1(a,b) , module diode a and b; D 2(b) , module diode b; f grid , grid frequency; f s , switching frequency; i grid , grid current; i in , input current; i P , secondary winding current; I PN(a,b) , current drained from module a and a; L 1(a,b) , inductor 1 of module a and b; L 2(a,b) , inductor 2 of module a and b; L cf , converter-side inductor; L g , grid inductor; L gf , grid-side inductor; m (s), modulation index; N, turns-ratio; V a , module output voltage a; V b , module output voltage b; V grid , grid voltage; V PN(a,b) , module bus peak voltage a and b.;

show abstract

Common Mode Voltage Reduction in a Single-Phase Quasi Z-Source Inverter for Transformerless Grid-Connected Solar PV Applications

Cited by 63 publications

References 24 publications

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

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

Single‐stage high reliability doubly grounded nonisolated PV grid‐connected inverter

Single input qZ‐source cascaded multilevel inverters : Analysis , design, and implementation

Contact Info

Product

Resources

About