Distribution automation requires a deep knowledge of the system to where it is applied. For this, a proper handling of analysis techniques is very important. Distribution system analysis is a part of a broader concept referred to as power system analysis. In distribution system analysis only some fields of the overall picture are studied, and, of course, those referring mainly to feeders and radial systems. The main topics to be analyzed correspond to the modeling of the elements, the analysis of load flows for ring and radial systems, and short circuit conditions. Load flows are applied for different applications involving not only the analysis of power flows and voltage regulation but also feeder reconfiguration and loss reduction. Short circuit as always is essential in sizing equipment and protective relay setting. Studies of transient and small signal stability are not usually conducted at distribution levels and therefore will not be considered in this book.

Chapter Contents:

• 3.1 Electrical circuit laws
• 3.1.1 Ohm's law
• 3.1.2 Kirchhoff's voltage law
• 3.1.3 Kirchhoff's current law
• 3.2 Circuit theorems
• 3.2.1 Thévenin's theorem
• 3.2.2 Star/delta transform
• 3.2.3 Superposition theorem
• 3.3 Power AC circuits
• 3.4 PU normalization
• 3.5 Load flow
• 3.5.1 Formulation of the load flow problem
• 3.5.2 Newton-Raphson method
• 3.5.3 Type of buses
• 3.5.4 Application of the Newton-Raphson method to solve load flows
• 3.5.5 Decoupling method
• 3.6 Radial load flow concepts
• 3.6.1 Theoretical background
• 3.6.2 Distribution network models
• 3.6.3 Nodes and branches identification
• 3.6.4 Illustration of nodes and branches identification
• 3.6.5 Algorithm to develop radial load flow
• Proposed exercise

Inspec keywords: power distribution protection; relay protection; power distribution control; load flow; short-circuit currents; voltage control

Other keywords: power flow analysis; feeder reconfiguration; voltage regulation; analysis techniques; sizing equipment; transient stability; signal stability; power system analysis; ring systems; loss reduction; distribution automation; distribution system analysis; radial systems; protective relay setting; short circuit conditions; load flow analysis

Subjects: Voltage control; Power system control; Power transmission, distribution and supply; Distribution networks; Control of electric power systems; Power system protection