Towards a smart distribution transformer for smart grid

In this paper, a smart distribution transformer which addresses power quality issues in the electrical power distribution system is presented. The proposed system is comprised of a line frequency transformer connected to a power electronic converter that is `auto-connected' on the secondary side. The auto-connection is facilitated by the use of a high-frequency (HF) / medium frequency (MF) transformer. A simplified strategy to compensate for voltage sags, swells, and distortions on the grid side, by providing continuous ac voltage regulation, is discussed. When a voltage disturbance event occurs, the power electronic converter generates a compensating voltage, which is vector-added to the grid voltage in order to regulate the output voltage supplied to the load. The smart distribution transformer will satisfy the various needs of the present and future distribution smart grid such as improved availability, equipment protection, and resilience. This paper provides detailed analysis, simulation results and experimental results from a scaled down laboratory prototype rated 200 W are also presented to validate the operation of the proposed smart distribution transformer.

[1]  Prasad Enjeti,et al.  Analysis and design of electronic transformers for electric power distribution system , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[2]  S. Rajagopalan,et al.  Hybrid distribution transformer: Concept development and field demonstration , 2012, 2012 IEEE Energy Conversion Congress and Exposition (ECCE).

[3]  Byung-Moon Han,et al.  A new single-phase voltage sag/swell compensator using direct power conversion , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[4]  P. N. Enjeti,et al.  A new wind turbine generator / battery energy storage utility interface converter topology with medium-frequency transformer , 2013, 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition (APEC).

[5]  Richard S. Zhang,et al.  A grid simulator with control of single-phase power converters in D-Q rotating frame , 2002, 2002 IEEE 33rd Annual IEEE Power Electronics Specialists Conference. Proceedings (Cat. No.02CH37289).

[6]  Rolando Burgos,et al.  Review of Solid-State Transformer Technologies and Their Application in Power Distribution Systems , 2013, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[7]  J.M.A. Myrzik,et al.  Consequences of poor power quality - an overview , 2007, 2007 42nd International Universities Power Engineering Conference.

[8]  Deepak Divan,et al.  Dynamic sag correctors: cost effective industrial power line conditioning , 1999, Conference Record of the 1999 IEEE Industry Applications Conference. Thirty-Forth IAS Annual Meeting (Cat. No.99CH36370).

[9]  P.N. Enjeti,et al.  A low cost approach to provide ride-through for critical loads , 2001, APEC 2001. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.01CH37181).

[10]  Prasad Enjeti,et al.  Analysis and design of a new voltage sag compensator for critical loads in electrical power distribution systems , 2002 .

[11]  Raja Ayyanar,et al.  The design of power acceptability curves , 2002 .