CYMDIST (CAM) is an add-on module to CYMDIST designed to study the impact of single forced or planned outages on the electrical distribution system. It finds the optimal switching plan to restore electrical power to priority customers and to recover the maximum possible load in the affected areas.

This module is fully integrated with CYMDIST and assumes the initial starting state (loading and connectivity) to be defined by the active study in CYMDIST. Restrictions may be set on selected switching devices so they are not considered in the switching plan. Contingencies may be set at the substation, circuit or component level, meaning that you may study the impact of losing a transformer-bank in the substation or simply simulate a damaged component on the main feeder.

The optimal selection criteria and priority path of CYMDIST (CAM) is defined by a ranking-based search method that handles multiple objective functions. In order to define the relative importance of each objective for your particular case, a weight is assigned to each of the following objectives:

• Minimize the Number of Switching operations
• Maximize the Total Load Restored
• Maximize Feeder Spare Capacity
• Maximize Component Spare Capacity
• Minimize Restoration Path (Distance)

The best switching plan is selected from all the alternatives (based on customer count, priority of the customers, and number of operations required) while ensuring that the user-defined constraints are respected, such as there are no abnormal conditions (overloading of equipment and voltage violations) on the system. The program provides a report that identifies the weak points on the feeders (limiting components) and the total customers exposed beyond these points. This allows you to modify the components and replay the simulation without the limiting components.

The restoration mode provides the options to either pick-up the un-served customers through "switching" (switching plan) or through "repair". The main difference is that the "repair" option does not transfer load to the adjacent circuit. Instead, it uses the "cold load" pick-up factors of the different type of loads in order to suggest a two-step sequence to restore the customers without power. For both options, the proposed switching plan is shown graphically and you may replay (undo/redo) the proposed scheme and make modifications if desired.

The proposed switching plan may be saved in a study file for later replay, and a detailed customizable report is generated for in-depth analysis.