This example illustrates the possibility of SIMSEN to simulate complex HVDC networks including power plants, 12-pulse thyristors converters, filters, SVC and all the control and regulation devices. Both rectifier and inverter of the HVDC are modeled with all the semiconductors. Three-windings transformers are also taken into account on both sides of the HVDC. They allow the 30° phase shifting for 12-pulse operation.
The rectifier and inverter regulation is completely modeled, especially the extinguishing angle regulation of the inverter.
Simulation results show the behavior of the HVDC after a three-phase short circuit at the rectifier AC grid (power plants).
For large and complex networks, SIMSEN offers the possibility to add, replace or remove components without restarting the simulation from zero.
This great advantage allows the study of networks including a large number of electrical components.
The user can build his example step by step by adding elements and stabilizing the circuit again.
Once the system is stabilized, the user can add circuit breakers (or other elements) and define faults to be simulated.
Once done, it is possible to continue the simulation with the saved initial conditions.
For this example, it is possible to analyze the fault recovery after a short circuit at the rectifier AC grid.
In this goal, the regulation contains special functions like VDCOL (Voltage Dependant Current Order Limitation). These functions allow a smooth recovery of the HVDC.