SEL Power System Model

This project will create a mathematical model of an industrial facility's electrical power system. Schweitzer Engineering Laboratories will donate equipment to this project. The SEL control hardware in conjunction with a Real Time Digital Simulator (RTDS) will simulate faults and load shedding for this industrial power model.

Design Task
Create an industrial power system model with utility inter-tie using RSCAD and Runtime software. Utility and generators will be connected to buses with various loads. The model will be limited by the size and processing power of the Real Time Digital Simulator (RTDS).

The power system will be comprised of the following components:
 * Combustion Gas Generator
 * Steam Turbine Generator
 * Utility Power
 * Variable Speed Drive (VSD)
 * Synchronous Motor
 * Induction Motor
 * Exciter
 * Governor
 * Transformer

Each component will be validated then simulated with RTDS. Once everything is validated, the components will be connected into one system. The system will be validated and controls will be added.

An SEL Real-Time Automation Controller (RTAC) will be used for the control algorithms. This piece of equipment will be connected to the RTDS and RSCAD equipped computer.

Detailed Specifications
Industrial Power System

Single Line Diagram Created with RSCAD software

System Monitoring and Manual Controls

Single Line Diagram Created in RSCAD Runtime software

Control Algorithm

The algorithm measures six system parameters:
 * Imported power
 * Power consumed by the loads
 * Utility breaker status
 * Voltage amplitude
 * Phase angles
 * System electrical frequency

These analog signals are fed into functions that output a binary signal to indicate if the system might need to shed load to maintain stability. There are two paths that can trigger load shedding. If the utility breaker opens or imported power goes below a certain threshold, the system checks to make sure that adequate local generation is available to carry the loads. If there is not enough local generation the load shedding algorithm is triggered. This path can act very rapidly, but does not measure all possible failure modes. The second path to trigger load shedding measures voltage, phase balance, and system frequency and triggers load shedding if any are outside normal operating parameters. This second branch typically has a much slower response time than is necessary to prevent system failure in the case of a sudden loss of power.

Project Learning

 * Components need to be validated before the whole system is assembled
 * Make sure the block diagram models being used are consistent
 * Industry standard for controls communication (IEC 61850)
 * Sometimes the parameters the client provides are not the parameters needed