Voltage sag compensation with minimum energy injection by use of a micro‐SMES

This paper presents a method to compensate voltage sags with minimum energy injection for a series‐connected voltage restorer using a micro‐SMES. A circuit for extracting the fundamental symmetrical components from sag voltages and a minimum energy injection algorithm is described. Simulations of voltage sag compensation have been carried out using PSCAD/EMTDC for various faults. The simulation results confirm the validity of the proposed method and show the possibility of reducing the size of energy storage devices. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 70–80, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10047     

Configuration of a voltage sag compensator by use of a micro‐SMES and experimental results

A voltage sag compensating using a micro‐SMES is presented. Based on previous works, we have carried out experiments for voltage sag compensation on the laboratory‐built system in order to validate the proposed minimum energy injection voltage sag compensation algorithm. To improve the compensating performance of the system, two‐degree‐of‐freedom voltage control is proposed. In this paper, the circuit configuration and feedback voltage control system of the compensator are described and the experimental results are reported. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(2): 84–92, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10267     

Corrosion Fatigue Study of 6061 Aluminum Alloy: The Effect of Coatings on the Fatigue Characteristics

Metallurgical and Materials Transactions A - This study proposes a method for protecting 6061 aluminum alloy from corrosion fatigue. Corrosion fatigue can reduce fatigue strength at the endurance...     

Control of fault current limiter by series‐connected voltage sag compensator

This paper describes a control scheme of fault current limiter by series voltage injection. The current limiter proposed in this study is based on the use of a SMES‐based series‐connected voltage sag compensator, which has been previously studied by the authors, for controlling fault current caused by short circuit on the load side. An algorithm for fast discriminating between power system voltage sag and load‐side short circuit is proposed for the equipment to correctly function either for voltage sag compensation or for fault current limiting purpose. Furthermore, a new control strategy based on output voltage phase control of the series compensator is proposed for current limiting with good waveform characteristics and low active power absorption. Experimental results demonstrated the validity of the proposed strategy. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(2): 64–72, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20128