Voltage fluctuation and flicker are becoming more and more serious, which need necessary detection and further management. An improved algorithm designed for detecting voltage flicker parameters has been proposed. The method transformed voltage flicker signal model into a sum of series exponential signal model. Two matrices were constructed and combined into a matrixpencil. Thus, the nonlinear problem was converted into a linear problem. Not only voltage amplitude and frequency but also phase information of voltage flicker can be extracted through the method. Moreover, due to the difficulty of modal order determination in the noise environment, a method of Hankel matrix rank estimation was put forward to determine modal order accurately. Voltage flicker experiments were taken in the noise background. The results show that the proposed method is superior in computational accuracy, order determination and anti-noise capability. As a result, the method could contribute a new idea for the voltage flicker signal parameter extraction
