Fault control and restoration in a multi-feed power network

A control system for automatically reconnecting power to customers in a distribution automation multi-feed power network on a fault disconnecting customers in the network, comprising:

• at least two separate power sources, each power source comprising a power feed to the network, an auto-recloser switch, and means for connecting each power source for delivering power to at least some of the customers in the power network;
• a plurality of fault isolation switches for disconnecting customers positioned in series in said power network, each isolation switch comprising either an open or closed state and connected to a separate intelligent switch controller;
• means to allow the power network to be divided into sub-networks each of which connectable to a power source by providing a fault isolation switch in an open state;
• actuating means in each intelligent switch controller to actuate each isolation switch to either an open or closed state;
• fault detection means to determine if a fault exists in said power network and in the event a fault is detected in a sub-network, the auto-recloser switch trips each isolation switch to an open state to disconnect each customer in said sub-network;
• timing logic means within each intelligent switch controller for sequentially restoring power to each isolation switch on said intelligent switch controller determining a no fault condition at each isolation switch;
• identifying means within each intelligent switch controller to determine a fault condition at each isolation switch from said fault detection means and said timing logic means and, on identifying a fault at said isolation switch, means to isolate said fault by configuring said isolation switch open to a lockout state to disconnect customers associated with said isolation switch and means to keep each isolation switch open positioned in series thereafter from said power source in said sub-network;
• means within each intelligent switch controller, on identifying and isolating said fault, to implement a local control means to automatically after a predetermined period move said open fault isolation switch;
• the intelligent switch controller for said open fault isolation switch comprises means, to detect no voltage at one side of said open fault isolation switch for said predetermined period, closes the open fault isolation switch;
• said local control means has means to sequentially close each isolation switch kept open positioned in series from said open fault isolation switch until said fault is detected and said auto-recloser of the second power source trips each isolation switch in said other sub-network to an open state;
• timing logic means within each intelligent switch controller for sequentially restoring power to each open isolation switch and on said intelligent switch controller determining a no fault condition at each isolation switch from said other power source;
• and
• identifying means within each intelligent switch controller to determine said fault condition at an isolation switch and on identifying said fault, said local control means configures the isolation switch to an open lockout state to define a sub-network whereby a minimum number of customers are disconnected from said power sources in said power network.