Studies on Risk-Based Security Assessment of Power System Voltages of 330kV 41-Bus Transmission Grid in Nigeria

Abstract

Researchers, system operators, engineers, and utility owners are working hard to fully utilise power system installed facilities in response to rising energy demand, which is posing security challenges for power systems. As a result, this paper uses risk-based security assessment to address the problem of power system security. A linearized risk-based method which uses fast decoupled load flow algorithm was used to assess the low voltage security of power systems. The method is based on the concept of risk, which considers both the likelihood of occurrence and the severity of the contingency. Risk is decomposable and can be decomposed by perverting the conditions that make the network risky. It requires the probability of voltage distribution, the probability of contingency and severity function to evaluate the impact of the contingency. The proposed method was illustrated on a real power system, the simulation model of the Nigerian 41 bus 330kV transmission grid network for calculating the risk indices of three simulated contingencies at various rates of occurrence. The calculated risk indices show that as the rate of occurrence increases, risk indices increase.  This means that contingencies with a high incidence rate but little effect have a higher or equal chance than contingencies with a large impact but occur infrequently. As a result, system operators, technicians, and engineers must quickly identify, investigate, and propose solutions to mitigate their effects on the network and improve service delivery.