Research on illed-conditioned equations in tracking thevenin equivalent parameters with local measurements

This paper analyzes the local measurements based ill-conditioned Thevenin equivalent parameters equations and proposes methods to obtain precise solutions of the equations. In the general Thevenin equivalent parameters linear equations, we derive the analytical formula, therefore we can obtain precise solutions directly. In the least squares Thevenin equivalent parameters linear equations, in order to get precise solutions, a method based on Schmidt's orthogonalization transformation is presented; and the method has clear expressions, straightforward algorithm, and easiness of programming but also an excellent precision, which is not lower than general orthogonalization transformation methods. Simulations on a real system of Jiangsu Province show the methods are feasible and effective.