A disturbance source location method on the low frequency oscillation with time-varying steady-state points

The low frequency oscillation is a serious threat to security and stability of a power grid. How to locate the disturbance source accurately is an important issue to low frequency oscillation disposal. Existing methods have poor adaptability to the low frequency oscillation with time-varying steady-state points because of the limitations in the location criterion derivation. A disturbance source location method on a low frequency oscillation with good generality is presented in the paper. Firstly, the reasons why the steady-state points are time-varying on a low frequency oscillation are analyzed. Then, based on the energy function construction form, the branch transmission energy is decomposed into state energy, reciprocating energy and dissipation energy by mathematical derivation. The flow direction of the dissipation energy shows the source and destination of the disturbance energy, and the specific location of a disturbance source can be identified according to its flow direction. Meanwhile, to meet the needs of energy calculation, a recognition method on the electrical quantities steady-state points is also presented by using the cubic spline interpolation. Simulation results show the correctness of the derivation and analysis on energy structure in the paper, and the disturbance source can be located accurately according to the dissipation energy.