Evaluation of Double-Line-Frequency Power Flow in Solid-State Transformers

2021 ◽

pp. 119-126

Author(s):

Bharat Bhushan Khare ◽

Rajeev Shankar Pathak ◽

Sanjeev Sharma ◽

Vinod Kumar Singh

Keyword(s):

Solid State ◽

Smart Grid ◽

Energy Distribution ◽

Power Flow ◽

Electric Energy ◽

Global Market ◽

Transformer Oil ◽

Solid State Transformer ◽

Solid State Transformers ◽

Compact Size

According to future renewable electric energy distribution and management (FREEDM) system, solid state transformers play an important role in smart grid technologies. They have several advantages over conventional transformers such as bi-directional power flow, light in weight, compact size, etc. They also compensate the environmental issues which are created due to transformer oil. Because of various advantages over traditional transformer, SST is preferred widely at the present time. So in this chapter, the various architectures, needs, and applications of solid state transformers are discussed. The global market of SST has continuously improved because it has several applications and benefits.

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Single-Phase Z-Source\/Quasi-Z-Source Inverters and Converters: An Overview of Double-Line-Frequency Power-Decoupling Methods and Perspectives

IEEE Industrial Electronics Magazine ◽

10.1109/mie.2018.2825479 ◽

2018 ◽

Vol 12 (2) ◽

pp. 6-23 ◽

Cited By ~ 12

Author(s):

Yushan Liu ◽

Baoming Ge ◽

Haithem Abu-Rub ◽

Frede Blaabjerg

Keyword(s):

Single Phase ◽

Double Line ◽

Line Frequency ◽

Power Decoupling ◽

Frequency Power

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PV Micro-Inverter Topology Using LLC Resonant Converter

Energies ◽

10.3390/en12163106 ◽

2019 ◽

Vol 12 (16) ◽

pp. 3106 ◽

Cited By ~ 4

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.

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Solid-State Transformers: Fundamentals, Topologies, Applications, and Future Challenges

Sustainability ◽

10.3390/su14010319 ◽

2021 ◽

Vol 14 (1) ◽

pp. 319

Author(s):

Saniya Khan ◽

Khaliqur Rahman ◽

Mohd Tariq ◽

Salman Hameed ◽

Basem Alamri ◽

...

Keyword(s):

Solid State ◽

Power Flow ◽

Control Strategies ◽

Low Frequency ◽

Origin And Evolution ◽

Solid State Transformers ◽

The Future ◽

Future Challenges ◽

Converter Topologies ◽

And Control

Solid-state transformers (SSTs) have emerged as a superior alternative to conventional transformers and are regarded as the building block of the future smart grid. They incorporate power electronics circuitry and high-frequency operation, which allows high controllability and enables bi-directional power flow, overcoming the limitations of conventional transformers. This paper presents a detailed analysis of the solid-state transformer, expounding the fundamentals, converter topologies, applications, and future challenges of the SST in a systematic manner. The paper discusses the necessity of improved replacement of the low-frequency transformers (LFTs) and presents the configuration of SST. It presents SST fundamentals in individual stages and explores its origin and evolution. The basic topologies, their specifications, and control strategies are also described. The applications of SST as a replacement of LFTs are discussed along with recent applications. The future challenges for real-time implementation of SSTs are explored, and research directions are proposed.

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

Energies ◽

10.3390/en11102746 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2746 ◽

Cited By ~ 1

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.

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