Probabilistic Security Analysis of Optimal Transmission Switching

Abstract

Optimal transmission switching (OTS) optimizes simultaneously the generation dispatch and the topology of a power system. It has been shown that taking some transmission lines out of service can significantly reduce the operating cost of the system while respecting the traditional deterministic security criterion of operational reliability. However, topology modifications could adversely affect probabilistic security metrics. The operational reliability of a power system can be translated into a cost by multiplying the expected energy not served by the value of lost load. This paper therefore explores whether it is possible to maintain a positive economic balance with OTS when considering not only the cost of generation but also the expected socio-economic cost of disruptions in the supply. This is done in two steps: the computation of an secure OTS and then the calculation of a probabilistic estimate of the operational reliability of the OTS solution. Based on the results obtained with two test systems, it is shown that OTS tends to significantly degrade probabilistic measures of security. It is thus not obvious that OTS can lead to a positive economic balance, even when security is enforced. Consequently, a probabilistic security analysis should be performed before implementing an OTS solution.Index Terms-Operational reliability, power system economics, power system security, transmission switching, value of lost load.

Resiliencia de Sistemas Eléctricos de Potencia mediante la Conmutación de Líneas de Transmisión – Estado del arte

“…Una solución de conmutación de transmisión, no necesariamente es óptima, pues una modificación de la topología podría afectar las métricas de la seguridad probabilística del sistema, por ende antes de implementar una solución OTS debe realizarse un análisis de seguridad probabilística, [32]; Determinar el conjunto óptimo de líneas a conmutar trae consigo una enorme carga computacional, debido a las formulaciones matemáticas y a las variables binarias que se añaden al modelo, por ende debe tratarse de desarrollar un algoritmo de corte plano que genere desigualdades válidas y variables fijas, [33].…”

Integrated generation and transmission maintenance scheduling by considering transmission switching

“…The proposed IMSwTS model and the decomposition method are tested on modified IEEE 24-bus reliability test system (RTS). 38,39 The modified IEEE 24-bus RTS has 32 generation units and 39 transmission lines, which is depicted in Figure 1. The switchable lines are L1, L5, L12, L15, L16, L18, L24, L32, L34, and L36.…”

Congestion Risk-Averse Stochastic Unit Commitment with Transmission Reserves in Wind-Thermal Power Systems

“…The formal effort is straightforward and effective in mitigating wind power uncertainty; however, it requires a huge amount of capital investment, as well as other operation and maintenance costs relating to the equipment [14]. To circumvent such a problem, a less expensive approach to congestion management is achieved by modifying the network topology with transmission switching [15]. In [16], different types of DR programs are explored to evaluate their impacts on the reliability of the wind integrated power system.…”