The basic theory of the single phase transformer has been described, including the derivation of parameters, the modelling of magnetisation non-linearities and its numerical implementation in a form acceptable for electromagnetic transients programs. The need for advanced models has been justified, and a detailed description made of UMEC (the Unified Magnetic Equivalent Circuit), a general transformer model developed for the accurate representation of multi-phase, multi-winding arrangements. UMEC is a standard transformer model in the latest version of PSCAD/EMTDC. The rotating machine modelling based on Park's transformation is reasonably standard, the different implementations relating to the way of interfacing the machine to the system. A state variable formulation of the equations is used but the solution, in line with EMTP philosophy, is carried out by numerical integrator substitution. The great variety of rotating machines in existence precludes the use of a common model and so the electromagnetic transient programs include models for the main types in current use, most of these based on general machine theory.

Chapter Contents:

• 7.1 Introduction
• 7.1 Introduction
• 7.2 Basic transformer model
• 7.2 Basic transformer model
• 7.2.1 Numerical implementation
• 7.2.1 Numerical implementation
• 7.2.2 Parameters derivation
• 7.2.2 Parameters derivation
• 7.2.3 Modelling of non-linearities
• 7.2.3 Modelling of non-linearities
• 7.3 Advanced transformer models
• 7.3 Advanced transformer models
• 7.3.1 Single-phase UMEC model
• 7.3.1 Single-phase UMEC model
• 7.3.1.1 UMEC Norton equivalent
• 7.3.1.1 UMEC Norton equivalent
• 7.3.2 UMEC implementation in PSCAD/EMTDC
• 7.3.2 UMEC implementation in PSCAD/EMTDC
• 7.3.3 Three-limb three-phase UMEC
• 7.3.3 Three-limb three-phase UMEC
• 7.3.4 Fast transient models
• 7.3.4 Fast transient models
• 7.4 The synchronous machine
• 7.4 The synchronous machine
• 7.4.1 Electromagnetic model
• 7.4.1 Electromagnetic model
• 7.4.2 Electro-mechanical model
• 7.4.2 Electro-mechanical model
• 7.4.2.1 Per unit system
• 7.4.2.1 Per unit system
• 7.4.2.2 Multi-mass representation
• 7.4.2.2 Multi-mass representation
• 7.4.3 Interfacing machine to network
• 7.4.3 Interfacing machine to network
• 7.4.4 Types of rotating machine available
• 7.4.4 Types of rotating machine available
• 7.5 Summary
• 7.5 Summary
• References
• References

Inspec keywords: EMTP; power system simulation; machine theory; equivalent circuits; power transformers

Other keywords: multiwinding arrangements; UMEC; electromagnetic transients programs; PSCAD/EMTDC; rotating machine modelling; transformer model; magnetisation non-linearities modelling; machine theory; Park's transformation; multiphase arrangements; single phase transformer; numerical integrator substitution; state variable formulation; Unified Magnetic Equivalent Circuit; EMTP philosophy

Subjects: a.c. machines; d.c. machines; Transformers and reactors; Power engineering computing