When an isolated power system experiences a serious disturbance or heavy load trip, the system frequency may drop and even collapse if the total generating power does not supply the system demand sufficiently. Since an isolated power system possesses a lower inertia and comes with limited reserves, the load shedding becomes an important strategy to restore system frequency. The initial rate of change of frequency is useful to detect an overload when the disturbance happens. This paper presents a method to determine the load shedding criteria by detecting the initial rate of change of frequency with modification from the maximum frequency change at the last step to satisfy system dynamics simultaneously. Numerical simulations show that the proposed method helps determine the amount of shedded load and trip them promptly in order to avoid over- or under-shedding. By these results, the feasibility of the proposed method in power system applications is demonstrated.
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering