Investigation of the Use of Rogowski Coils for Power Direction Relays in Fast Automatic Bus Transfer

Currently, devices for fast automatic bus transfer (FABT) are widely used. The reaction time of the FABT algorithms is on the order of 4-:-10 ms, which is why the behavior of starting, approving and blocking organs, for example, power direction relays (PDR) in transient modes, is very important for them. The paper investigates the behavior of the PDR when using signals from Rogowski coils (RC) and electromagnetic current transformers (CT), taking into account the possible saturation of the magnetic circuit, when modeling emergency modes. The PDR study was performed using the Simulink simulation environment of the Matlab software package. Hodographs of the PDR vector for internal and external circuits are constructed, which show the advantage of using signals received from the RC, including at saturation of CT. Based on the conducted research, the conclusion is made about the advantages of using RC for FABT. The successful operation of FABT devices with the use of RC on a real object has also been demonstrated.