Prioritizing the Restoration of Network Transformers Using Distribution System Loading and Reliability Indices

Operation risk assessment of active distribution networks considering probabilistic uncertainties of distributed generators‐loads and power management of VRB ESSs

“…Therefore, EENS and SI are appropriately used as the risk assessment index to evaluate the operational risk of ADNs in this paper. Generally, the expected value of EENS can be calculated by (13) where L mum represents the peak loads during one year. The failure state s of ADNs is determined by the random failure of distribution lines and transformers k which is composed of the planned outage failure k,p and the aging failure k,r .…”

“…On the other hand, large numbers of studies are focused on the construction of risk assessment indexes for ADNs with the penetration of photovoltaic units or WTGs and VRB ESSs. In [13], the indexes of system average interruption frequency index (SAIFI), customer average interruption frequency index and system average interruption duration index (SAIDI) were comprehensively used to reflect the indexes of energy loss rate ELR and user loss rate CLR for the risk assessment of ADNs considering the penetration of DGs. In [14,15], risk indexes such as voltage violation, load curtailment and frequency response adequacy were used to analyse power system security for operation planning under high penetration of wind power generation.…”

Prioritization of network transformers in electrical distribution system by considering social welfare index

“…When transformer T70 is out of service, the number of transformers which bear additional load (NT) is 38. Probability values of transformers and feeders can be computed by their transformer failure rates and feeder failure rates respectively through curve fitting method [1].…”

“…Priority can be given to the transformers based on the number of customers affected. Prioritizing the network transformers can be done by using a risk index [1] algorithm for mesh type distribution networks at the time of normal loading conditions. Transformer outages may happen due to overload of an equipments or tank leakages or damage in protection or due to maintenance etc.…”

“…Even though by providing sufficient data to the contingency tools as mentioned above, no tools can able to prioritize the return of network transformers. So by using risk index [1], priority can be provided to the transformers in normal loading conditions. In the case of emergency conditions, priority of the transformers may not be possible as per risk index terms.…”