Conventional optimal power flow studies neglect the effect of temperature on resistance for simple calculation. However, the branch resistance changes with the change of temperature. Thus, the optimal power flow (OPF) should consider the temperature effect for accurate calculation. Moreover, contingency cases should be considered to ensure system security. Accordingly, the security-constrained temperature-dependent optimal power flow (SCTDOPF) emerges as a critical and practical issue in power systems. To deal with the SC-TDOPF problem, this study suggests a hybrid method, namely pseudo-gradient based particle swarm optimization and differential evolution method (PGPSO-DE). The suggested PGPSO-DE method is applied to the standard IEEE 30 bus system under normal condition as well as
contingency condition. The findings have shown that the PGPSO-DE method provides better solution quality than other studied optimization methods. Consequently, the PGPSO-DE method proves its effectiveness in solving the complex SC-TDOPF problem