Accurate harmonic state estimation is an important basis for controlling harmonic problems in power grid. To solve the problem that phasor measurement unit (PMU) is difficult to satisfy observability condition and power quality monitoring device (PQMD) time scale is asynchronous. Taking PMU sampling time as estimation time

a PMU/PQMD hybrid harmonic state estimation method based on adaptive modification of measurement data is proposed in this paper. Designed to obtain accurate harmonic state quantities. First

the optimization factor is introduced into the statistical data of PQMD

the harmonic data of PQMD is characterized as bounded uncertainty variable

and the hybrid harmonic measurement set of PMU and PQMD is constructed. Secondly

a hybrid harmonic state estimation model is established with the minimum normalized residual sum of squares as the optimization objective. Subsequently

the linear programming algorithm is used to simplify the state estimation model into a convex optimization model

and the internal point method is used to solve the problem. The harmonic data of PQMD is adaptively corrected by optimization factor during the solution process to enhance the accuracy of state estimation. Finally

the feasibility and superiority of the proposed method are verified in IEEE standard system.