Centralized versus distributed state estimation for hybrid AC/HVDC grid

Abstract

The need of transmission grid expansion has drawn the attention towards high voltage DC (HVDC) as a solution. This brings new challenges for power system control application such as state estimation that are originally designed for AC power system. This papers studies centralized and distributed architectures for hybrid AC/HVDC state estimator (SE). Furthermore, the benefit of having bad data detection (BDD) and deploying phasor measurement units (PMU) in the state estimation are investigated. The method used for the SE is the weighted least square (WLS) method. The SE will be developed based on the power grid model ‘The CIGRE B4 DC Grid Test System’. The results of the tests show that the addition of BDD and PMU improved the error of the estimated values. Furthermore the distributed architecture offered slightly less accurate AC values than the centralized.