Simulation of DAB for HVDC transmission

Figure 6.10 shows the simplified schematic of the simulated HVDC DAB system, which in this schematic form is equal to the back-to-back test system. Figure 6.10 DAB transmission system investigated in simulations. The simulation result for the DAB transmission system of Figure 6.10 is shown in this section. All power references are positive from left to right, see Figure 6.10. The data for the DAB converters are given in Table 6.1. The transformer short circuit resistance Rsc and self-inductance...

Load flow and short circuit calculations

DC power system analysis in terms of load flow and short circuit calculations is investigated in 26 . Numerous source models i.e. battery charger, rectifier and generator models are given. Also connector models for load flow and short circuit calculations are investigated. Loads and branches are modeled. According to 26 , the present standards in the year 1996 are not complete and need further work. In 3 , the methods of the IEC draft standard Calculation of short circuit-currents in dc...

VSC based HVDC

Controle Hvdc Vsc

HVDC Light trademark of ABB 19 and HVDC Plus trademark of Siemens are basically extensions of the IGBT back-to-back converter, operating at higher power and voltage levels and with an intermediate cable between the converters. Even though this might seem as small step from a development point of view it has resulted in numerous new patents. The main reason is that the development of VSC based HVDC has forced the limits of power electronic converter technology. For example, IGBT valves...

Publications

The results presented in this thesis regard DC bus voltage control and fault detection and clearance, found in Chapters 3, 4, 5 and 7. The main results of these chapters are also presented in P. Karlsson and J. Svensson, DC Bus Voltage Control for Renewable Energy Distributed Power Systems, IASTED Power and Energy Systems Conference, PES 2002 Conf. Proc, Marina del Rey, CA, USA, May 13-15, 2002, pp. 333-338. P. Karlsson and J. Svensson, Fault Detection and Clearance in DC Distributed Power...

DC bus voltage droop control

Droop Control

In common voltage droop control, the bus voltage decreases linearly as the output current, or in some cases power, for the converter increases, in order to give stable operation Figure 3.4 . This, of course, results in a stationary error in the voltage level. Figure 3.4 Steady state droop characteristic. The controller structure for DC bus voltage control is shown in Figure 3.5. A proportional P controller is used for the droop scheme, similar to the PI-controller derived in 6 for back-to-back...

DC bus voltage control

Two different DC bus voltage control schemes are investigated. One of the methods, referred to as the communication or master slave method, strongly relies on fast communication between the source and load converters. The output power, with sign, is calculated for each of the converters. Information on total output power is fed forward to the converters. One of the converters, the master, is responsible for controlling the DC bus voltage. Feed forward of the total output power allows for high...