This thesis addresses the problem of frequency control in a power system composed of several non-synchronous AC areas connected by a multi-terminal HVDC grid. For this system, we propose three control schemes, two for primary frequency control and one for secondary frequency control. Based on remote measurements of the other areas' frequencies, the first control scheme modifies the power injections from the different AC areas into the DC grid so as to make the system collectively react to load imbalances. This collective reaction allows each individual AC area to downscale its primary reserves. The second control scheme has the same objective with the first one, but acts on the DC voltages of the HVDC converters. In particular, it modifies the DC voltage of each converter based on the frequency deviation of the AC area it is connected to. The last control scheme aims at restoring the frequencies and the power exchanges to their nominal or scheduled values in the aftermath of a power imbalance. It can be combined with the other two control schemes. Theoretical studies reveal the stability properties of the three control schemes. Simulation results on a benchmark power system with five AC areas confirm their good performance.
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:tel-00783519 |
| Date | 03 October 2011 |
| Creators | Dai, Jing |
| Publisher | Supélec |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | English |
| Detected Language | English |
| Type | PhD thesis |
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