Abstract
The subsynchronous resonance (SSR) problem may become more serious with the continuous evolvement of a series-compensated power system. Consequently, the existing SSR mitigation scheme might no longer keep the system stable. This issue has been encountered by Shangdu Power Plant, where the deployed supplementary excitation damping controllers (SEDCs) that well stabilized the system before cannot maintain torsional stability after the recent change occurred in the power system. Therefore, a combined mitigation scheme of SEDC and generator terminal subsynchronous damping controller (GTSDC) is proposed in this paper to regain system stability. SEDC provides electrical damping by modulating the excitation voltage at the rotor side. Meanwhile, GTSDC can damp SSR via injecting super-synchronous and subsynchronous currents into the generator stator. Field tests have proven the effectiveness of this combined scheme in addressing the deteriorated SSR issue. Eigenvalue analysis indicates that the combined scheme can provide enough positive damping for the system under any operating condition. Thanks to the low investment of SEDC and the flexibility of GTSDC, this combined scheme provides an economical and scalable solution for SSR mitigation, especially when the target system changes constantly.
Original language | English |
---|---|
Article number | 7031968 |
Pages (from-to) | 769-776 |
Number of pages | 8 |
Journal | IEEE Transactions on Power Systems |
Volume | 31 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2016 |
Keywords
- Field test
- Fixed series capacitor (FSC)
- Generator terminal subsynchronous damping controller (GTSDC)
- Subsynchronous resonance (SSR)
- Supplementary excitation damping controller (SEDC)