DC microgrid for household applications

• Main Author: Ong, Ruskin Zhi Sheng
• Other Authors: Wang Peng
• Format: Theses and Dissertations
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/75983
• Institution: Nanyang Technological University

The rise in popularity of DC microgrids for households worldwide was mainly attributed to the ease of DC power injection [1-3] and energy savings from an AC-DC conversion stage [2-8]. While there was research carried out on DC microgrids, none were set up in Singapore [7-12]. Therefore, a lab-scale DC microgrid was implemented at the Marine Energy Testbed (METB) in Nanyang Technological University (NTU), Singapore. Moreover, DC-based household loads such as LED lights, fan, fridge and air conditioner were connected to observe the transient and steady state response of the DC microgrid. Components used in the dissertation were also discussed: bidirectional interlinking converter (BIC) and DC Transformer (DCT). Key findings included the verification of controlled power flow direction in the proposed AC-DC interlink and implementation of standalone DC microgrid with DC household loads. Apart from the breakdown of communication link with the DCT at higher reference current values, no major power quality issues were observed throughout the experiments. This dissertation was organized into 6 chapters. Chapter 1 listed the background, motivation, literature review, objectives and major contributions while chapter 2 detailed the circuitry design and control theories used for the BIC and DCT. Chapter 3 discussed the 3 modes of operation by a DCT in a standalone DC microgrid while chapter 4 reviewed the proposed AC-DC interlink for a grid-connected DC microgrid. Chapter 5 discussed and showcased the experimental results. Finally, chapter 6 concluded the dissertation with recommendations for similar studies in the future.