Hospital Transformer Failure Transient Investigation
By: Tom Grebe, Principal Consultant
tgrebe@enernex.com
865-770-4880
Power system apparatus, such as transformers, switchgear, and cables may be exposed to various types of transients. High-frequency transients and very steep overvoltages may cause problems for electrical equipment because they can cause local overstressing of the insulation system. Vacuum circuit breaker (VCB) openi...
Multiple Prestriking Phenomenon in High Voltage Transmission Substations: Modeling and Simulation
Published via IEEE Xplore
Authors
Sarina Adhikari, EnerNex
Chandra Pallem, EnerNex
David Mueller, EnerNex
Tom Grebe, EnerNex
Bob Zavadil, EnerNex
Kevin Little, Transmission Technical Support, Duke Energy
Abstract
This paper presents the prestriking and re-striking phenomenon caused by switching disconnect switches in a high-volta...
25-year industry veteran recognized for overall advancement of the power industry
October 04, 2016 09:00 AM Eastern Daylight Time
KNOXVILLE, Tenn.--(BUSINESS WIRE)--EnerNex, an electric power research, engineering and consulting firm, announces Co-founder and Executive Vice President Robert Zavadil has received the 2016 Wayne E. Knabach Award for Excellence in Power.
Zavadil has worked on electric power system issues for wind generation for over 25 ye...
At the 2016 IEEE PES Switchgear Committee Meeting in Hilton Head, South Carolina, the Transient Limiting Inductor Applications in Shunt Capacitor Banks technical report was awarded the IEEE PES Technical Committee Prize Paper Award presented to Roy Alexander, Lucas Collette, Tom Grebe, Halim Malaj, and Joe Meisner by the Switchgear Committee of the IEEE Power and Energy Society.
Transient Limiting Inductor Applications ...
Geomagnetic Disturbances and the Grid
Harmonics Studies Needed to Assess Vulnerabilities
By David Mueller, Director of Energy Systems Studies
Fortnightly Magazine - July 2016
On March 13, 1989, a geomagnetic disturbance, GMD, caused by solar activity affected bulk power systems in North America.
The most serious impact led to the shutdown of static compensators on a network essential to control of Hydro Québec's grid. This caused v...
Power System Transient Studies Using EMTP-RV
By: Tom Grebe, Principal Consultant
tgrebe@enernex.com
865-770-4880
Published via Electric Energy Online | June 2016
Power system transients that are caused by utility switching operations or lightning strikes to electric facilities have significant potential to damage equipment or disrupt operation. High frequency transients have been recognized for quite some time as a thr...
Booth exhibit set to showcase tools and techniques necessary to address transmission and distribution design for a modern grid
April 25, 2016 11:20 AM Eastern Daylight Time
KNOXVILLE, Tenn.--(BUSINESS WIRE)--EnerNex, an electric power research, engineering and consulting firm, announced today its involvement in the IEEE Power and Energy Society’s Transmission and Distribution Conference and Exposition in Dallas, May 2-5, 2016.
EnerNex Chairman and CTO E...
Utility Capacitor Bank Switch Failure Investigation
By: Tom Grebe, Principal Consultant
tgrebe@enernex.com
865-770-4880
Power system apparatus, such as switchgear, capacitor banks, and surge arresters may be exposed to various types of transients. Transients from restrikes during vacuum switch opening may cause problems for electrical equipment because they can cause local overstressing of the insulation system and exceed su...
Utility Capacitor Bank Studies
By: Tom Grebe, Principal Consultant
tgrebe@enernex.com
865-770-4880
Recent and upcoming power plant retirements are resulting in a need to reinforce our transmission systems. One measure being adopted is to install additional reactive power in the form of capacitor banks that often require detailed harmonic or transient simulation studies to assure a successful design.
The analysis of utilit...
March 11, 2014 01:00 PM Eastern Daylight Time
KNOXVILLE, Tenn.--(BUSINESS WIRE)--EnerNex announced today two recent personnel additions to the firm within the power systems consulting team.
Tom Grebe joins EnerNex as a Principal Consultant and will be responsible for extending EnerNex’s already extensive power systems engineering study practice. Tom’s experience as an engineer at an electric utility and as an engineering consultant has made him an expe...
