Model of a sychronous machine with four windings. The transformer voltage terms are neglected if neglectTransformerTerms=true. The model parameters refer directly to internal physical parameters such as inductances and resistances.
The model is taken from the theory manual of the Eurostag software. For consistency with the base class OnePortACdq, however, the currents ifPu, idPu and iqPu are all assumed to be positive entering, while the Eurostag manual assumes them to be all positive leaving. Therefore, all the current and fluxes have an opposite sign in the Park equations.
This model is in fact equivalent to the model described in Kundur, Power Systems Stability and Control, Chapter 3, except for the current sign conventions, which in that case are assumed to be positive entering for the rotor winding and positive leaving for the direct and quadrature stator axes. The correspondance of the parameter symbols is given in the table, all parameters are in p.u. referred to the machine rated values.
| PowerGrids | Kundur | Meaning |
|---|---|---|
| raPu | Ra | Armature resistance |
| rDPu | R1d | Resistance of the direct axis damper |
| rfPu | Rfd | Resistance of the excitation windings |
| rQ1 | R1q | Resistance of the quadrature axis 1st damper |
| rQ2 | R2q | Resistance of the quadrature axis 2nd damper |
| MdPu | Lad | Direct axis mutual inductance |
| MqPu | Laq | Quadrature axis mutual inductance |
| LdPu | Ll | Direct axis stator leakage |
| LqPu | Ll | Quadrature axis stator leakage |
| LDPu | L1d | Direct axis damper leakage |
| LQ1Pu | L1q | Quadrature axis 1st damper leakage |
| LQ2Pu | L2q | Quadrature axis 2nd damper leakage |
| LfPu | Lfd | Excitation winding leakage |
| mrcPu | Lfld-Lad | Canay's mutual inductance |
Two different choices of base excitation voltage are available
Types.ExcitationPuType.nominalStatorVoltageNoLoad: 1 p.u. of excitation voltage gives 1 p.u. of air-gap stator voltage at no-load conditionsTypes.ExcitationPuType.Kundur: base voltage as in Kundur, Power Systems Stability and Control, Chapter 3. Note that in this case, typical p.u. values are less than 0.001