Investigating the Impact of Real-Time Thermal Ratings on Power Network Reliability

Real-Time Thermal Rating (RTTR) is a smart-grid technology that allows electrical conductors to operate at an enhanced rating based on local weather conditions. RTTR also provides thermal visibility of the network, making system operators aware if the actual rating drops below the static seasonal rating. This paper investigates how using these enhanced variable ratings affects power network reliability. A methodology has been developed to assess network reliability with variable conductor ratings. The effect of failures and uncertainties in the RTTR system are also considered, and the effect of the correlation between conductor ratings due to common weather conditions is built into the model. State sampling and sequential Monte Carlo simulations are used to estimate the reliability of the RBTS 6-bus test network. At low loading levels, the RTTR appears to reduce network reliability but actually illustrates occasions when the existing ratings are being unknowingly infringed. For higher loading, the network reliability is significantly improved by the use of RTTR, with reductions in loss of load expectation of up to 67%.