Small signal stability analysis for a turbine-generator unit connected to an HVDC system

The rapidly growing complexity and increasing size of power system networks with a large number of interconnections have exposed the system to various contingencies that may lead the system to steady-state, dynamic or transient instability. It is thus vital for a power system to be able to maintain the load-generation balance under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a disturbance such that the system frequency remains within its operating range. Conventional methodologies in assessing power system transient or small-signal stabilities, such as Time Domain Approach, Extended Equal Area Criterion, Direct method of Lyapunov Function and Transient Energy Function are employed. Eigenvalues analysis, participation factor analysis and transient security assessment using transient security index have been used as the assessment tools in this thesis for evaluating the power system stability.