Electric power systems have become much more complex in the past years, owed to distributed generation and the intermittency of renewables. This complexity makes power systems potentially more vulnerable. However, use of information technology also helps in detecting errors and problems, and in preventing and correcting them.

This is the second edition of the comprehensive introduction to protection of electrical power systems using computer-based methods (i.e. digital relays). The new edition offers a thorough revision and update, and comprehensive additional material. Chapters treat the mathematical background of protection algorithms, sinusoidal-wave-based algorithms, Walsh function and S-Transform-based techniques, least squares and differential equation-based techniques, travelling wave-based protection, protection of transformers, digital line differential protection, a comparison between digital protection algorithms, and importantly, protection of networks with distributed generation including renewable resources.

Written for researchers in electrical engineering and power engineering, in industry, utilities and universities, and for advanced students, the treatment is logically structured, covering mathematics and principles for the development and implementation of the major algorithms underlying different protection techniques. These techniques can be applied to protection of generator transformers, lines, switchgear and cable circuits: the main components of transmission and distribution systems with and without integrated distributed energy sources including renewables.