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 PV Micro-Inverter Topology Using LLC Resonant Converter

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3106 ◽  
Author(s):  
Hiroki Watanabe ◽  
Jun-ichi Itoh ◽  
Naoki Koike ◽  
Shinichiro Nagai
Keyword(s):  
Conversion Efficiency ◽  
Power Converter ◽  
Electrolytic Capacitor ◽  
Resonant Converter ◽  
Double Line ◽  
Line Frequency ◽  
Point Tracking ◽  
Llc Resonant Converter ◽  
Frequency Power ◽  
Micro Inverter

In this paper, a DC–single-phase AC power converter with an LLC resonant converter is presented for a photovoltaic (PV) micro-inverter application. This application requires the leakage current suppression capability. Therefore, an isolated power converter is usually combined for DC/AC systems. The LLC resonant converter is the one of the isolated power converter topologies, and it has good performance for conversion efficiency with easy control. On the other hand, a double-line frequency power ripple has to be compensated for in order to improve the performance of the maximum power point tracking (MPPT). Therefore, a bulky electrolytic capacitor is usually necessary for the power converter. However, the electrolytic capacitor may limit the lifetime of the micro-inverter. This paper introduces the PV micro-inverter with a LLC resonant converter. In addition, the active power decoupling circuit is applied in order to compensate the double-line frequency power ripple by the small capacitor in order to eliminate the electrolytic capacitor. Finally, the transformer design is considered in order to reduce the transformer losses. As a result, the conversion efficiency of the LLC converter is improved by 1% when the litz wire has many strands.

scholarly journals Active Power Decoupling Design of a Single-Phase AC–DC Converter

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 841 ◽  
Author(s):  
Mingjie Qiu ◽  
Ping Wang ◽  
Huakun Bi ◽  
Zhishuang Wang
Keyword(s):  
Single Phase ◽  
Control Method ◽  
Active Power ◽  
Second Order ◽  
Voltage Source ◽  
Decoupling Method ◽  
Power Decoupling ◽  
Phase Converter ◽  
Dc Bus ◽  
Bus Voltage

The second-order ripple power of single-phase converter causes second-order ripple voltages on the DC bus. For eliminating second-order ripple components, passive power decoupling methods including DC bus electrolytic capacitors have some shortcomings, such as low power density and poor stability of converters. Thus, an active power decoupling method based on a single-phase converter is proposed in this paper. The control method, taking single-phase voltage source pulse width modulation (PWM) rectifier (single-phase VSR) as the basic converter and adopting a buck-boost power decoupling circuit, introduces second-order ripple of DC bus voltage into a power decoupling circuit. The ripple acts as compensation of the phase deviation between the command value and the actual value of the second-order ripple current. Therefore, estimation of the second-order ripple current is more accurate, the power decoupling circuit absorbs the second-order ripple power behind the H-bridge more completely, and the DC bus voltage ripple is effectively suppressed accordingly. Finally, experimental results of the single-phase VSR are given to verify the validity of the proposed method.

scholarly journals Active Power Decoupling Topology for Single Phase Bridge Inverter based on Buck-Boost Convertor

2019 ◽  
Vol 9 (2) ◽  
pp. 156-161
Keyword(s):  
Single Phase ◽  
Power Conversion ◽  
Voltage Source ◽  
Decoupling Method ◽  
Dc Voltage ◽  
Power Semiconductor ◽  
Dc Power ◽  
Power Decoupling ◽  
Increasing Demand ◽  
Stage 1

Increasing demand of power has led to exploration of non-conventional sources of energy. Solar energy has been the most exploited source of energy in this regard. Effectiveness of power utilization depends on the power conversion from AC to DC. Further improvement in utilization of DC power depends on the DC-DC conversion steps involved. The planned methodology offers a study of power decoupling method while no further power semiconductor are used for a DC to 1-ɸ AC device. 1-ɸ voltage source bridge inverters have primarily two drawbacks, that's reduction in DC voltage usage and disparity in power among the incoming and outgoing sides. These difficulties have been looked upon and a topology has been implemented that uses just a film capacitance beforehand buck-boost convertor that is linked to the voltage-source bridge inverter. Reenactment and preliminary outcome confirmed the credibility of the planned power decoupling technique on the 2-stage 1-ɸ bridge inverter by buck-boost convertor.

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.

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