A novel interval voltage control method considering interval power data and discrete control variables

•We approximated the RPOIU model using a first-order interval Taylor expansion [28] and employed the OSM to obtain more accurate ranges of the state variables in the ILAM process.•We replaced the positive-curvature quadratic penalty function employed in the standard LAM with a Gaussian penalty function [32], [33] and round-off method in the ILAM to accommodate discrete variables in the RPOIU model.•We compared the results obtained to solve the RPOIU model using the proposed method with those acquired using the LAM.