Distribution systems analysis employs a set of techniques to simulate, analyse, and optimise power distribution systems. Combined with automation, these techniques underpin the concept of the smart grid. In recent years, distribution systems have been facing growing challenges, due to increasing demand as well as the rising shares of distributed and volatile renewable energy sources.For this new edition, the chapters of the first edition have been revised and updated, and the topics of distribution system analysis and distribution automation combined. Coverage includes smart grid, load flow analysis, determination of optimal topology, voltage control and capacitor application, power quality and harmonics in distribution systems, distribution system restoration, numerical relaying and distribution feeder protection, distributed generation and microgrid technology.New material related to renewable energy and microgrids are included, and maturity models and evaluation of smart grid projects are presented, along with material on the transition to the new distribution system technologies.