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The tissues of the medial arm as a donor site for perforator flap design have several advantages. However, they are relatively underused with limited reports, partly due to unreliable perforator anatomy. Therefore, we aimed to review our preliminary experience using indocyanine green (ICG) angiography to design and elevate preexpanded pedicled brachial artery perforator (BAP) flaps for regional reconstruction. All patients underwent soft tissue reconstructions using a preexpanded BAP flap in two or three stages. ICG angiography was used to localize perforators during both expander insertion and flap elevation. The pedicle was divided at the third stage 3 weeks following flap elevation for head and neck cases. Sixteen patients underwent reconstructions of the head and neck (n = 13) or shoulder/trunk (n = 3) using 14 perforator-plus and 2 propeller BAP flaps. In total, 50 perforators were identified using ICG imaging, all of which were appreciable during both expander placement and flap elevation. Thirty-five perforators were directly visualized during flap elevation, and an additional 15 perforators were not explored but incorporated into the flap. All flaps survived without necrosis, and the donor sites healed uneventfully without complications. The medial arm provides thin and pliable skin for the resurfacing of regional defects with relatively minimal donor-site morbidity. With the assistance of ICG angiography, perforators of the brachial artery can be reliably identified, facilitating the preexpansion and elevation of pedicled BAP flaps for use in head–neck and trunk reconstruction.

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When a large amount of wind power is connected to the power grid, certain control methods need to be taken for wind turbines (WTs) so that WTs can respond to system frequency changes and maintain system frequency stability. Based on the frequency control method of a single doubly fed induction generator, a deloading power coordinated distribution method for frequency regulation by wind farms considering wind speed differences is proposed to better utilize the wind farm frequency regulation ability. A reasonable distribution of the deloading power of a wind farm for participation in grid frequency regulation to better utilize the wind farm frequency regulation ability. A quantitative calculation formula for the wind speed, total deloading power and single WT deloading power is established by using a variable parameter deloading power coordinated distribution coefficient based on the wind speed. The deloading power is distributed according to the wind speed of the WT units to adapt to the wind speed distribution differences between WTs in cluster wind farms and fully utilize the wind farm frequency regulation ability. A typical doubly fed induction generator (DFIG) wind farm is used as a simulation case. The experimental results show that the control strategy can distribute the output of each WT, improve the frequency response of the wind farm and enhance the frequency stability of the system. INDEX TERMS Frequency regulation, wind farm, deloading power coordinated distribution, rotor kinetic energy control, deloading control.

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