Harmonic voltage of the bus of concern in the power grid is the joint contribution of all harmonic sources. When the main harmonic sources are known to the system

how to distinguish the responsibility of these harmonic sources has important significance. This paper firstly establishes the multiple linear regression models. When the coefficient matrix is pathological

using the least squares regression will lead to a wrong solution. Therefore

this paper proposes a method called ridge estimation. When the harmonic current data is abnormal or there is a certain correlation

ridge estimation can avoid drawing the wrong solution if the model is pathological. Simulation results show that this method is feasible and can get a better result than the least squares method when the coefficient matrix is pathological.