Sensitivity analysis of load-damping, generator inertia and governor speed characteristics in hydraulic power system frequency regulation

Maintaining the balance of generation and load is the most important factor in a power system for frequency regulation. Recently, controllable load and renewable energy are integrated increasingly in power grid. In practice, this may have substantial impact on system frequency response (SFR). This paper investigates the effect of load-damping, generator inertia and governor speed characteristics on system frequency using typical SFR model with hydraulic generation. Theoretic analysis based on transfer functions shows that the frequency deviation under variable load-damping, generator inertia and governor speed coefficients is relatively small and bounded when the power system is essentially stable; while the frequency deviation can be accelerated when a power system is unstable after disturbance. Multiple-machine cases are also included in the analysis with verifications by simulation studies. The conclusion can be useful for system operators for decision-making of frequency regulation or load control.