RTDS Testing Final Report

Lawrence Berkeley National Laboratories hired SEL Engineering Services to provide Model Power System (MPS) Testing Services for testing the dynamic behavior of single phase air conditioner motors at a distribution feeder level. The primary purpose of this project was to develop a custom single phase induction motor model in Real Time Digital Simulator (RTDS) and apply multiple instances of that model on a given distribution feeder to study the phenomenon of delayed voltage recovery.

The advantage to using RTDS over other modeling environments is that full flux linkages are modeled explicitly, providing more accurate results than other modeling software.

This project involves a dynamic model development and simulation study that supports a broader investigation of the effect of air conditioning and similar loads on the recovery of electric utility voltage after faults. The phenomenon of slow recovery of utility voltages is referred to as Fault Induced Delayed Voltage Recovery. From here onwards, this phenomenon will be referred as FIDVR.

This project is the result of conclusions made after extensive preliminary work which showed that it is necessary to represent both the electrical behavior of single phase capacitor motors and the driven loads in point-on-wave detail to obtain a faithful simulation of the test behavior of residential air conditioners. One of the major objectives of this project was to incorporate multiple instances of the detailed motor/load model into an electric power system simulation where these motors can be subjected to voltage disturbances that are seen in feeders experiencing the FIDVR phenomenon.