The protection of nonlinear and sensitive loads can be achieved economically through series compensation-based dynamic voltage restorer. The effective voltage compensation by dynamic voltage restorer depends on the controller used for voltage sag detection. In this paper, the sag detection of dynamic voltage restorer employing feed-forward control and synchronous reference frame control are compared. The efficiency of sag detection of these controls in dynamic voltage restorer for in-phase compensation of balanced sags with PWM-based injection of compensation voltage is analyzed. Comparisons on the performance of the controllers are shown clearly using Matlab/Simulink-based simulated results. © Springer Nature Singapore Pte Ltd. 2018.