Electrocon International (United States)

Consumers Power Company, an investor-owned, combination (gas and electric) utility serving customers throughout most of Michigan's lower peninsula, is in the process of adding a 345/138 kV autotransformer bank, rated 300 MVA self-cooled, to one of its substations. Before a system modification of this scale can be completed, protective relay settings throughout the area must be reviewed. Consumers Power Company's experience using the coordination graphics module to review settings for the planned system change and determine new settings to provide the required coordination is reported. The coordination analysis of overcurrent and distance devices is described. >

A new user interface has been developed for the EMTP (the ElectroMagnetic Transients Program developed at the Bonneville Power Administration). This interface uses the concept of to allow the interactive graphic assembly of complex simulations in an organized, user-friendly manner. These modules are defined formally, with each consisting of a and an part. The visible part describes the function the module performs and the terminal points that enable it to be connected to other modules. The internal part describes how the module is constructed. Two types of module internal parts are distinguished: atomic and composite. Atomic modules are mapped directly into EMTP card images. Composite modules consist of interconnectioons of other modules.