march 13, 1989 to present - ieee web hostingewh.ieee.org/cmte/substations/scm0/pittsburgh... ·...

GMD Experience

March 13, 1989 to Present

Presentation for FirstEnergy

System Operations May 2011 Transmission System Assessment: Summer 2011

2FirstEnergy Presentation

IEEE/PES Substation Committee

April 29, 2013

Geo-Magnetic Disturbances

March 13, 1989

• Transformer - 500/138kV Auto

– Abnormal sounds observed.

– Removed from service due to

high combustible gas

readings.

– Paint discolored due to tank

heating.

– Analysis was subject of a

paper presented at IEEE PES

Summer meeting on

7/29/1989.

• Ten 138kV shunt capacitor

banks tripped.

• All are located in northern

Virginia or central Maryland

in or near areas of low Earth

conductivity.

Area of capacitor tripping





April 29, 2013


Analysis of Transformer Currents – March 13, 1989





April 29, 2013


Capacitor Bank Trips – March 13, 1989

• Ten 138kV grounded-

wye shunt capacitor

banks tripped.

– Unbalance protection

schemes operated due to

high harmonic current

flow in the bank neutrals.

– Thermal damage to

neutral current

transformers and

secondary circuitry.





April 29, 2013


Mitigation Measures – Post 1989

Following the March, 1989 event, the following was done:

– DC neutral current monitoring was installed on all EHV

autotransformers in the Potomac Edison area and on selected

transformers in the other, non-igneous rock areas.

– Protection circuitry changes to allow system operators to enable

sudden pressure and gas accumulator tripping of the EHV

transformers.

– Capacitor protection control circuitry was modified to allow system

operators to disable the neutral unbalance protection.

– Filtered (60Hz) and normal unfiltered (RMS) current transducers

were added to provide real-time readings of capacitor neutral

fundamental and harmonic current.

– Operating procedures were put in place for the operators’ use during

periods of high GIC currents.





April 29, 2013


Mitigation Measures – Post 1989

Locations with Transformer

Neutral GIC Monitoring

Locations with Capacitor

Neutral Current Monitoring

Area of capacitor tripping





April 29, 2013


GIC Observations - 1990

Relative GIC magnitudes recorded - 1990

Average response of all disturbances

1-22-1990 to 4-14-1990

1

23

4

1-T1 2-T1 2-T2 3-T1 4-T1 4-T2 4-T3 4-T4 4-T5

Area of Igneous Rock Geology





April 29, 2013


Transformer Tripping due to gas accumulation 2001-2004Substation 1 now with three Autotransformers - Only one (different from 1989

event) trips due to gas accumulation during GIC activity.

11-5-2001 11-24-2001

10-30-2003 11-6-2004





April 29, 2013


Recent GMD Activity - 4/23/2012Comparison of GIC recorded at 4 different locations

1 2

34





April 29, 2013


Recent GMD Activity - 4/23/2012

Location 2 RMS Current

Location 1 RMS Current





April 29, 2013


FirstEnergy GMD Activities

• EPRI Participation

– Geomagnetic Disturbance Project

• Regular attendance on GMD monthly conference calls.

– Sunburst Project

• Installation of Sunburst nodes.

• Working to make non-Sunburst GIC monitoring data available.

• Regular attendance on Sunburst monthly conference calls.

• Attendance at annual meetings.

• NERC

– Attendance at NERC GMD workshop





April 29, 2013



• System Operations

– Operating Procedures

• Transformer neutral currents are continuously monitored through Scada and alarm at 10 amps DC.

• 138kV Grounded-Wye capacitor bank RMS and 60Hz neutral currents are monitored through Scada at select locations.

• FE works with PJM to Identify that a GMD event is in progress :

– Change the system configuration – reduce loading on susceptible transformers.

– Remove susceptible capacitor neutral unbalance protection from service.

– Enable EHV transformer sudden pressure and gas accumulator tripping.

– Place reactive sources into service.





April 29, 2013


FirstEnergy GMD Activities Monitoring Equipment

FirstEnergy GIC MonitoringSunburst GIC Monitoring

FirstEnergy and Sunburst GIC Monitoring

Capacitor Neutral Current Monitoring





April 29, 2013



• Engineering Activities

– Upgrade all older style capacitor neutral unbalance protection

to microprocessor over-current relays.

• Eliminates the need to remove unbalance protection during periods of

high harmonic currents.

– Investigate the use of substation microprocessor relays and

Digital Fault Recorders to monitor the Var consumption of

EHV transformers during periods of high GIC flow.

– Identify protection equipment that is subject to misoperation

as a result of GIC.





April 29, 2013



• Transmission Planning

– Create model to identify locations where high GIC

currents can be expected.

– Perform analysis using PSLF GIC add-on

• Identify maximum transformer reactive consumption due to GIC

– Perform loadflow and dynamics simulations to identify:

• Identify buses with voltages below Planning Criteria limits due to

increased transformer reactive loading associated with GIC and

misoperation of protective equipment (base case, N-1 and

common mode contingencies).

• Evaluate impact on reactive margins.





April 29, 2013


Questions?

march 13, 1989 to present - ieee web hostingewh.ieee.org/cmte/substations/scm0/pittsburgh... ·...

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