IEEE Power & Energy Magazine - November/December 2016 - 70

To prepare for future events, Hydro-Québec has developed
and maintained a strong expertise in the simulation
of geomagnetic disturbances.
stalled to monitor voltage harmonic
distortion at different substations
(mostly 735 kV and at interties).
The system uses synchrophasor
technology to provide real-time
voltage harmonics to the system
control center (scc). another
system, called doGme, monitors
even harmonic distortion at four
735-kV substations and provides
real-time conditions to the scc.
This system is complementary to
the voltage distortion monitoring
system, smda, and provides a redundant measurement not based
on synchrophasor technology.

System Control Center
Real-Time Measurements

information from the smda and
doGme systems provide real-time
information to the system operators at the scc. in addition, the
four-point voltage asymmetry measuring system, which only
produced informational data, was adapted so that it would also
trigger an alarm when certain asymmetry limits were reached
or exceeded. over the years, this system has been extended and
modified to include voltage harmonics from synchrophasors at
ten 735-kV substations while four more points have been added
to measure only even harmonics. Today, these 14 voltage harmonics measurements provide an oversight of real-time geomagnetic conditions on the hydro-Québec power system.

figure 10. An example of a series compensator installation at the Périgny 735-kV
switching station (662 MVar). (Courtesy of Lisa Vo Van, Hydro-Québec.)

lower than the permissible values, according to standards relating to the transformers. The maximum heating occurs in the
flitch plates, which are used to maintain the mechanical rigidity
of windings and could have a temporary impact on the mechanical strength of the transformer. however, the test lasted for one
full hour at 75 a per phase, while important Gic flows usually
last for under 5 min. it was concluded that transformer heating
was not a major concern for the specific design of 735-kV transformers used on the hydro-Québec system.

Geomagnetic Disturbance Monitoring
and Operating Procedures
Monitoring Systems
system operators require sufficient and timely information on the actual geomagnetic disturbance condition on
the power system. providing geomagnetic monitoring was
an important post-event objective and was achieved by the
implementation of three monitoring systems: couTeL,
smda, and doGme, shown in Figure 9.
couTeL is an offline Gic monitoring system installed at
five 735-kV substations to measure Gic flows and both voltage and current harmonics. a real-time system, smda, was in70

ieee power & energy magazine

New Operating Strategies

new system operating strategies for geomagnetic storm conditions were implemented and updated over the years. based on
a forecasted alert of the planetary k-index (Kp) above eight
Kp > 8 or when real-time measurements of even harmonic
distortion is greater than 2.2-2.6%, geomagnetic operating
conditions come into force. The power system is placed in a
secure operating state by taking the following actions:
✔ putting back in service series compensation
✔ adjusting maintenance planning
✔ limiting the transit on the transmission system to preserve an operating margin taking into account the current configuration of the power system
november/december 2016

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2016