# An investigation of AC/DC load flow analysis using Newton's method and extensions

Singh, Birendra Nath (1983) An investigation of AC/DC load flow analysis using Newton's method and extensions. Masters thesis, Memorial University of Newfoundland. [English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version
Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.

• [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

## Abstract

In this thesis AC/DC load flow problem is formulated on the basis of the conditions established by realistic systems. The nonlinear AC/DC load flow equations, thus formulated, are solved first by using the Newton-Raphson technique. The method is then extended to using the alpha-modified quasi second order Newton-Raphson (alpha-M.Q.S.O.N.R.) iterative method by including the second order terms of the Taylor series. -- The AC/DC load flow equations are developed in rectangular form. Only one equation per converter station is necessary. For one HVDC link, two rows and two columns (with only eight elements) are added to the AC Jacobian matrix of the Newton-Raphson procedure. Suitable algorithms are proposed to obtain the solution. -- The proposed algorithms are extensively tested on four different test systems. With the Newton-Raphson method, computations for all test systems converged in three iterations. The effect of DC link resistance, and initial guesses for voltages and converter angles on the performance of the Newton-Raphson technique is also investigated. The performance of the alpha-modified quasi second order Newton-Raphson method is analyzed for a range of alpha values. The convergence rate with the alpha-modified quasi second order Newton-Raphson method varies with the value of alpha chosen. In three of the four test systems, the convergence performance of the alpha-modified quasi second order Newton-Raphson method for certain alpha values is better than that of the Newton-Raphson method.

Item Type: Thesis (Masters) http://research.library.mun.ca/id/eprint/7965 7965 Bibliography: leaves 86-88. Engineering and Applied Science, Faculty of 1983 Submission Electric current converters View Item