Capacitance, dc Voltage Utilizaton, and Current Stress: Comparison of Double-Line Frequency Ripple Power Decoupling for Single-Phase Systems

2017 ◽  
Vol 11 (3) ◽  
pp. 37-49 ◽  
Author(s):  
Haiyu Zhang ◽  
Xiao Li ◽  
Baoming Ge ◽  
Robert S. Balog
Keyword(s):  
Single Phase ◽  
Double Line ◽  
Dc Voltage ◽  
Line Frequency ◽  
Current Stress ◽  
Power Decoupling ◽  
Phase Systems

scholarly journals Power Decoupling of a Single Phase DC-AC Dual Active Bridge Converter Based on an Integrated Bidirectional Buck/Boost Stage

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2746 ◽  
Author(s):  
Jiatu Hong ◽  
Mahinda Vilathgamuwa ◽  
Jian Yin ◽  
Yitao Liu ◽  
Jianchun Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Electrolytic Capacitor ◽  
Voltage Source ◽  
Double Line ◽  
Decoupling Method ◽  
Line Frequency ◽  
Dual Active Bridge ◽  
Power Decoupling ◽  
Dc Current ◽  
Frequency Power

In single phase DC-AC systems, double-line-frequency power ripple appears at the DC side inherently. Normally a large electrolytic capacitor can be used to reduce the power ripple at the DC side. But there are several problems with this method as it decreases the power density and reliability of the converter. In addition, a double-line-frequency current ripple appears in case a voltage source serves at the DC side, which is undesired in specific applications. This paper proposes a single phase DC-AC DAB (dual active bridge) converter with an integrated buck/boost stage for power decoupling purpose under low power condition. The proposed active power decoupling method is able to completely eliminate the double-line-frequency power ripple at the DC side. Therefore, a constant DC current can be obtained for requirements in specific DC-AC applications.

scholarly journals A Novel Power Decoupling Control Method to Eliminate the Double Line Frequency Ripple of Two Stage Single-Phase DC-AC Power Conversion Systems

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 931
Author(s):  
Saghir Amin ◽  
Hyun-Hwa Lee ◽  
Woojin Choi
Keyword(s):  
Single Phase ◽  
Control Method ◽  
Power Conversion ◽  
Decoupling Control ◽  
Two Stage ◽  
Double Line ◽  
Line Frequency ◽  
Front End ◽  
Ac Power ◽  
Power Decoupling

In two-stage single-phase inverters, inherent double line frequency ripple is present at both the input and output of the front-end converter. Generally, large electrolytic capacitors are used to eliminate this double line frequency ripple. It is well known that low frequency ripple shortens the lifespan of capacitors. Hence, the system reliability can get worse. In order to eliminate the double line frequency ripple, additional hardware combined with an energy storage device is required in most of the methods developed so far. In this paper, a novel power-decoupling control method is proposed to eliminate the double line frequency ripple at the front-end converter of two-stage single phase DC/AC power conversion systems. The proposed control algorithm is composed of two loops, a ripple compensation loop and an average voltage control loop, and no extra hardware is required. Since the proposed method does not require information from the phase-locked-loop (PLL) of the inverter, it is independent of inverter control. In order to verify the validity and feasibility of the proposed algorithm a 5 kW Dual Active Bridge (DAB) DC/DC converter and a single-phase inverter are implemented. The effectiveness of the proposed method is verified through the simulation and experimental results.

scholarly journals Classification of Three-Phase Grid-Tied Microinverters in Photovoltaic Applications

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2929
Author(s):  
Ahmed Shawky ◽  
Mahrous Ahmed ◽  
Mohamed Orabi ◽  
Abdelali El Aroudi
Keyword(s):  
Single Phase ◽  
Double Line ◽  
Line Frequency ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Pv Module ◽  
Three Phase ◽  
Power Point ◽  
Pv Grid

Microinverters are an essential part of the photovoltaic (PV) industry with significant exponential prevalence in new PV module architectures. However, electrolyte capacitors used to decouple double line frequency make the single-phase microinverters topologies the slightest unit in this promising industry. Three-phase microinverter topologies are the new trend in this industry because they do not have double-line frequency problems and they do not need the use of electrolyte capacitors. Moreover, these topologies can provide additional features such as four-wire operation. This paper presents a detailed discussion of the strong points of three-phase microinverters compared to single-phase counterparts. The developed topologies of three-phase microinverters are presented and evaluated based on a new classification based on the simplest topologies among dozens of existing inverters. Moreover, the paper considers the required standardized features of PV, grid, and the microinverter topology. These features have been classified as mandatory and essential. Examples of the considered features for classifications are Distributed Maximum Power Point Tracking (DMPPT), voltage boosting gain, and four-wire operation. The developed classification is used to identify the merits and demerits of the classified inverter topologies. Finally, a recommendation is given based on the classified features, chosen inverter topologies, and associated features.

scholarly journals Development of a DC-Side Direct Current Controlled Active Ripple Filter for Eliminating the Double-Line-Frequency Current Ripple in a Single-Phase DC/AC Conversion System

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4772
Author(s):  
Ying-Chieh Chen ◽  
Liang-Rui Chen ◽  
Ching-Ming Lai ◽  
Yuan-Chih Lin ◽  
Ting-Jung Kuo
Keyword(s):  
Energy Source ◽  
Steady State ◽  
Single Phase ◽  
Current Control ◽  
Control Loop ◽  
Double Line ◽  
Line Frequency ◽  
Conversion System ◽  
Current Ripple ◽  
Frequency Current

The objective of this paper is to propose an active ripple filter (ARF) using the patented DC-side direct current control for eliminating the double-line-frequency current ripple in a single-phase DC/AC conversion system. The proposed ARF and its control strategies can not only prolong the usage life of the DC energy source but also improve the DC/AC system performance. At first, the phenomena of double-line-frequency current ripple and the operation principle of the ARF are illustrated. Then, steady-state analysis, small-signal model, and control loop design of the ARF architecture are derived. The proposed control system includes: (1) a DC current control loop to provide the excellent ripple eliminating performance on the output of the DC energy source; (2) a voltage control loop for the high-side DC-bus voltage of the ARF to achieve good steady-state and transient-state responses; (3) a voltage feedforward loop for the low-side voltage of the ARF to cancel the voltage fluctuation caused by the instability of the DC energy source. Finally, the feasibility of the proposed concept can be verified by the system simulation, and the experimental results show that the nearly zero double-line-frequency current ripple on the DC-side in a single-phase DC/AC conversion system can be achieved.

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