Monograph, The University of Auckland, New Zealand, 1999, pg. 224Analytical modeling of HVDC systems has been a difficult task without a to-date reported model convenient for serious analysis of practically reported HVDC stability problems. In order to cover the frequency range f<100Hz, and to cater for different model requirements, three different HVDC-HVAC models are developed in this Thesis: Detailed linear-continuous model, simplified linear continuous model and linear discrete model.
Detailed HVDC-HVAC system model is intended for small signal analysis of HVDC-HVAC interactions and resulting stability problems. It demonstrates good response matching against PSCAD/EMTDC simulation, where the CIGRE HVDC Benchmark model is used as the test system. All model variables (states) and parameters have physical meaning, and the model consists of modules, which reflect actual physical subsystems. Simplified HVDC-HVAC system dynamic model is developed as a fourth order dynamic model, which is less accurate but more convenient for the analysis, than the detailed model. The model proves to be reliable for controller design for mitigation of composite resonance and for the study of non-linear effects in HVDC systems. The developed linear discrete model is primarily intended for the system analysis at frequencies close to 100Hz on DC side of HVDC system. A new approach in modeling of TCR/TCSC, based on the same principles for HVDC modeling, is presented in this book.CONTENTS:
Analytical modeling of HVDC-HVAC systems
Modeling of TCR and TCSC
Analysis of non-linear effects in HVDC systems
Composite resonance on HVDC systems
Control of second harmonic oscillations on DC side of an HVDC system
Analysis of HVDC-HVAC interactions
Stability analysis of HVDC control loops
HVDC operation with weak receiving AC systems
Conclusions
Apendix
Literature
