This teaching and practical book, developed from many years of lecture experience, describes the most important calculation methods for three-phase networks in a systematic manner. The highly advantageous node-oriented representation runs like a common thread throughout the book. Key focuses include calculations using symmetrical components in the frequency domain based on the classical nodal method, and calculations using space phasor components in the time domain based on the new extended nodal method. For calculating various fault conditions (short circuits and interruptions), a new universal method called the fault matrix method is introduced, which can be applied equally to both symmetrical components and space phasor components. Numerous worked examples and MATLAB program codes complement the discussions.