Generation and propagation of harmonics in power system feeders containing nonlinear transformers and loads.

摘要

The problem of modifying the harmonic power flow analysis to permit the inclusion of nonlinear anisotropic transformers, so far neglected in power flow studies, constitutes the objective of this thesis.;A new approach for the determination of ;The computed ;Finally, the large-signal nonlinear model of transformers is used to develop a harmonic load flow algorithm capable of simulating nonlinear transformers situated within power systems and to compute their iron-core and copper losses by modifying an existing harmonic load flow algorithm. The convergence properties are similar to the harmonic load flow algorithm with linear transformers. A simple example consisting of a linear load, a full-wave bridge rectifier and an anisotropic transformer with linear loads is examined. Computed and measured losses of a single-phase circuit consisting of a linear load and a 1 kVA anisotropic transformer show good agreements.;The main contributions of this thesis are: (1) A large-signal nonlinear model of anisotropic transformers for nonsinusoidal operations. (2) A harmonic load flow algorithm capable of simulating nonlinear transformers. (3) A methodology which is general enough that it can be applied to other anisotropic transformers (e.g., large distribution transformers) in computing their losses or optimizing their designs.