Control strategy without phase-locked loop based on power estimation and natural frame for single-phase cascaded H-bridge converter. - Zhao Zhang; Yanming Chen; Daliang Yang; Fannie Kong; Jinbao Liu; Dashuai Shao; Zuwen Peng; Zheng Li; Sencai Zeng; Mingkai Zhao (Int. J. Circuit Theory Appl., 2022)