Doctoral Dissertations

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Engineering Science

Major Professor

Yilu Liu

Committee Members

Seddik Djouadi, Lin Zhu, Evangelos Farantatos


In this dissertation, the impacts of WADCs on system transient stability are investigated, including system separation prevention under large disturbances and tie-line power transfer limit enhancement with consideration of a three-phase fault on one of the two tie-lines. The full Saudi power grid model in PSS/e is reduced for the real-time simulation on the Real-Time Digital Simulator (RTDS), and thus the developed WADCs can be tested in a controller hardware-in-the-loop environment in the future. The RTDS model is validated by comparing the full PSS/e model and the reduced PSS/e model under different contingencies. The WADCs are designed using a measurement-driven approach. The system separation prevention and tie-line power transfer limit by these WADCs are demonstrated by the real-time simulations on the RTDS. Moreover, the performance of the developed WADC was validated on the HIL test setup under different scenarios, including measurement error/noise, constant and stochastic time delay, consecutive and stochastic data package loss, and multiple PMUs as a backup. The experiment results demonstrate that the developed WADC can provide sufficient damping to suppress the targeted oscillation mode. Meanwhile, with multiple WADCs, the system separation after a large amount generation trips can be prevented. Also, the transfer limit of the tie-line can be further enhanced. The WADC performance will be evaluated under realistic operating conditions, including communication uncertainties and measurement error. The CompactRIO system was used to implement the WADC. The CompactRIO system is a general-purpose controller provided by National Instruments (NI) for prototyping. Using a hybrid TSAT-RTDS simulation, a HIL testing platform was built to imitate realistic conditions with several communication network uncertainties and impairments. The hardware WADC was tested in the HIL setup, where several auxiliary function modules were implemented within the WADC. The WADC viwas validated during testing to ensure satisfactory performance under realistic operating conditions. The impacts of the higher PV penetration on the rotor angle stability and interarea oscillations are also investigated. It has been known that the inter-area oscillations are significantly affected by the increasing amount of PV generation since the system inertia is reduced. The impacts of WADCs on small-signal stability and system transient stability are investigated when the SEC system is integrated with high PV penetration. The marginal generation trip and tie-line power transfer limit enhancement considering a three-phase fault on one of the major tie-line.

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