Load Characteristic Model: BRAKE

 

Any inservice load which has a BRAKE model assigned to it will cause a validation error and prevent any simulation from running.

Note that the actual MW and Mvar of the respective load in the power flow case are ignored.

Added in Version 19, build on January 13, 2016

This model represents a braking resistor such as the Chief Joseph Braking resistor. This model has 5 input parameters (ZmwStart, ZmvarStart, ZmwEnd, ZmvarEnd, and Tinsert). When a load with this characteristic is Closed during a simulation, it will start as a constant nominal impedance represented by ZmwStart + jZmvarStart. It will than linearly change into a constant nominal impedance represented by ZmwEnd + jZmvarEnd over a time of Tinsert seconds. Tinsert seconds after the load is closed in, the model will automatically trip the load again. The figure below depicts this. During validation, if the load record to which this stability model is assigned is inservice, a validation error will occur which prevents you from running transient stability. The expectation is that the braking resistor will be represented by an OPEN load which has zero MW and zero Mvar in the power flow case, however the actual MW and Mvar in the power flow case are ignored.”

Example:

Model Equations and/or Block Diagrams

Parameters:

ObjectFieldSummary

Field Name Description

ZmwStart The initial resistance in the units of MW. This will represent the load MWs that the brake would be at 1.0 per unit voltage.
ZmvarStart The initial reactance in the units of Mvar. This will represent the load Mvars that the brake would be at 1.0 per unit voltage.
ZmwEnd The final resistance in the units of MW. This will represent the load MWs that the brake would be at 1.0 per unit voltage.
ZmvarEnd The final reactance in the units of Mvar. This will represent the load Mvars that the brake would be at 1.0 per unit voltage.
Tinsert Time in seconds that the brake remains inserted after being activated.