IEEE Summary Paper

Modeling Motor Loads for Voltage Sag and Recovery

John KueckDmitry Kosterov

John UndrilJoseph Eto

This report breaks down each LCM motor class into categories of motor type based on protection response

• Joe Eto to provide introduction on:– Load response to voltage transients– Overview of FIDVR– Electronic loads

Estimates of Typical motor protection response are given for the following motor types

• Adjustable speed drives• Large motors over 250 HP• Three phase motors under 250 HP, NEMA Design B• Single Phase Air Conditioners• Single Phase Appliances• Rooftop Air conditioners• Chiller Motors larger than 250 HP

Discussion of Motor Terminal Voltage and Stall

• Voltage, torque and regeneration• Failure to accelerate load• NEMA design letters• Starting schemes

John Undril to prepare section on the effect of point on wave

on motor stall.

Energy efficient motors

• Lower breakdown and pull up torque• Higher locked rotor current• Lower inertia

Contactors, Solenoids and Ice Cube Relays

• Predominant mode for de-energizing motors• Range in voltage sensitivity• 3 wire control• Ice cube relays can drop out at 70% V in one

cycle, they are ubiquitous

Dmitry to prepare section on time frame of interest, perfect load behavior and problematic load

behavior, why it matters, and what we would like loads to act like

for grid stability.