This paper presents work on the control strategy and algorithm for automatic voltage control (AVC) of cascaded hydroelectric power stations with multiple units and large capacities. Under the conditions that no dynamic voltage problems are considered, a method intended primarily to monitor and control steady state voltage and reactive power situation of cascaded hydroelectric power stations is proposed. A computer program based on the proposed approach is described. The numerical simulations in an off-line environment on a practical system demonstrate that the processing speed and the accuracy are completely acceptable in a practical project.