Fuzzy risk based method for optimal placement of protection devices in distribution networks with DG

Lots of methods have been presented for designing a protection system for distributed networks included DG up to now. But, the simplicity in configuration of distribution networks and expensive costs needed for changing this configuration causes these methods not to be used in practice in the most countries of the word. This is because a wide area communication network is needed to protect a distribution networks so that operation of DGs in island mode can be achieved. This type of communication networks is also very expensive. So, presenting a method for allocation of protective devices in distribution network without changing the configuration and only by increasing, decreasing, or relocating the protective devices can be a good solution for distribution networks. In this paper, a risk analysis and fuzzy calculation combined method is used for optimal placement of protective devices in distribution networks. In this method fuzzy calculation is used for modeling in uncertainties of distribution networks and risk analysis is used for optimization of the protection system's configuration.