Embed Size (px)
Citation preview
Dr. Richard Candy
Corporate Specialist
Eskom – Transmission - System Operator
South Africa
This paper discusses the steps that Eskom and the Space Science Directorate of the South African
National Space Agency (SANSA) are taking to monitor the effects of solar flares and coronal mass
ejections on South Africa and Eskom’s interconnected power system in particular.
Impact of space weather on the
Eskom interconnected power system
When the charged partials, in the
Coronal Mass Ejection cloud, strike
the Earth’s magnetic field they
interfere with the many aspects of
earth’s technology such as satellites,
power lines, pipe lines, railway lines
and radio communications.
Nearly every day, solar storms releases a billion-ton burst of electrons and protons as solar winds.
Coronal mass ejections (CME) travel away from the Sun at speeds between 300 and 3000 km/s.
Introduction The number of sunspots increase and decrease and peak every 11
years during the 22 year cycle. The North and South poles swop
over at the peak of the cycles. The sun rotates every 27 days.
Each sunspot is assigned a unique number.
How Sun Spots and Coronal
Mass Ejections Form
Coronal Mass Ejection
NASA's Solar Dynamics Observatory
recorded this parting shot during the
late hours of 6th May 2014.
http://www.spaceweather.com/
This plume of plasma, propelled away
from the sun's surface by an M-class
explosion in the sunspot's magnetic
canopy, is as tall as a dozen planet
Earths.
CMEs are characterized by three major
components:
• Speed
• Density
• Direction
Note, not all storms are geo effective!
A coronal mass ejection (CME) is a massive
burst of solar wind and magnetic fields rising
above the solar corona or being released
into space.
The ACE satellite
Located at L1, ACE has a prime
view of the solar wind, interplanetary
magnetic field and higher energy
particles.
A Space Weather event is heralded with an X-Ray
burst which takes 8 and half minutes to reach us. On
average it takes 18 hours for the CME to reach Earth
and we typically have 45 minutes warning of the
actual intensity once the CME passes the Advanced
Composition Explorer (ACE) satellite
http://www.swpc.noaa.gov/ace/EPAM_7d.html
Solar wind
speed: 345.1 km/sec
density: 8.2 protons/cm3
Monitoring Coronal
Mass Ejections
The two STEREO (Solar TErrestrial RElations
Observatories) satellites are used by NOAA on a daily
basis to ensure the best possible forecasts of how
space weather will effect the earth.
Solar Dynamics
Observatory (SDO)
The SDO satellite investigates how the Sun's magnetic
field is generated and structured how the stored
magnetic energy is converted and released into the
heliosphere and geospace in the form of solar wind.
CME’s and
Earth
The Earth’s magnetic field draws the majority of the charged particles from the CME towards the
north and south poles where they interact with Earth’s magnetosphere-ionosphere and produce
high altitude currents in millions of amperes in the ionosphere. We call them electrojets.`
There are three well-known ways in which CMEs impact Earth:
1. Creates eletrojects above the poles
2. Direct penetration of the magnetosphere and ionosphere
3. CME slowly stretches the Earth’s magnetic field away from Earth
Historic Storms The biggest solar storm on record happened in September
1859, during a solar maximum. The storm has been
dubbed the Carrington Event, after British astronomer
Richard Carrington.
From our observations the manner in which
the Hydro Quebec crash occurred in 1989,
we see that the network suffered a slow
voltage collapse, possibly due to the
consumption of a large amount of reactive
power in the south of the network.
Hydro-Quebec Blackout, March 13 1989
Around 2:44 AM, we lost 7 SVCs (possibly
due to incorrect harmonic tripping) in less
than 1 minute. 8 seconds later, several
lines tripped.
The storm was the largest solar flare to
target the Earth in decades, the 3rd largest
since 1989.
From October 19 to November 5, there
were 17 major flares.
During the event, GIC currents, exceeding
300 amps, were reported flowing in the
Swedish power system.
29 October 2003, “Halloween”
Hydro-Quebec confirms that the March 13 blackout
was caused by the strongest magnetic storm ever
recorded.
We lost the 9,450 MW in 25 seconds.
Southern African
impacts
South Africa is a mid-latitude country and is not normally
subjected to the influence of the southern auroral electrojet.
However during severe space weather events the southern
auroral has been seen to move as far up as Cape Town.
In addition the equatorial ring current, which lies directly over
the northern part of South Africa, can have a significant impact
on the top of the country where the new power stations are
being built.
Magnetometers The fluctuations of the geomagnetic fields on the
Earth’s surface are measured using a Fluxgate
vector magnetometer. The device consists of
three sense winding and three drive windings for
each of the three axes (X,Y, Z).
On March 13-14 of 1989, the Earth
experienced a geomagnetic storm with a
magnitude of 500 nT/min.
What CMEs do to us
In all cases, coronal matter
in a CME consists of
charged particles, whose
intensity, speed and
direction are constantly
changing. Wherever there
is an electric circuit and a
changing magnetic field, a
current will flow in it.
Earth surface potential is a function of
storm intensity and earth conductivity
Transformer Half Wave Saturation
Semi-saturation of the core causes:
• Rapid heating of the transformer yoke plates
• Increased var demand causes voltage problems
• Generator var demand can increase significantly
• Harmonics cause incorrect protection operation –
loss of Cap Banks when you need them most.
“Electric Fields, GIC Flow, and Transformer Response” - Antti Pulkkinen (EPRI)
Eskom and SANSA
Response
Eskom with assistance from the Space Science
Directorate of the South African National Space
Agency are working together on the following topics:
Installing
magnetotelluric
sensors
Dedicated
Communications
Link
Installing Hall Effect sensors on the Transformer Neutrals
The GIC Calculation
Process
During December last year two Potch University
graduates developed a Matlab GIC calculation
model using the real time power system network
state and magnetometer data from SANSA.
Solar
Flare CME
Interaction with Earth’s
Magnetic Field dB
dt
Maxwell Equations & Earth Model
Grid Model
Space
GIC
Earth
AB(x) = B(x) – A(x) and AB(y) = B(y) – A(y)
Vy = dBx/dt.AB(y) and Vx = dBy/dt.AB(x)
Induced voltage = V(a-b) = Sin(θ).(Vx + Vy).Area
I (GIC) = Induced voltage / R (DC)
Key Indicator is the Volts/km value
G a b
d e
y1
y2
y4
x1 x2 x3
-24.95
α
A(x,y)
H
By
f
c
x4
D(x,y)
C(x,y)
J(x,y)
y3
Bx
g h i
F
B(x,y)
α
-38.10
δ
K(x,y)
-25.25
𝐵𝑥
𝑑𝑡
α
By
Bx
𝐵𝑥
𝑑𝑡
By
Bx
M(x,y)
ϴ
y
x
NOAA prediction On the 1st October the NOAA predicted a storm as
follows: “Forecasters estimate a 45% chance of polar
geomagnetic storms on Oct. 2nd when a CME is
expected to hit Earth's magnetic field
The CME arrived in the early hours of the
2nd as predicted by NOAA.
SANSA
Magnetometers
20-May-14 18
Tsumeb
Keetmanshoop
Hartbeeshoek
Hermanus
Matimba & Medupi
Power stations
Koeberg
Power station
The South African National Space Agency has
access to four magnetometers, two units in
Namibia (Tsumeb and Keetmanshoop) and
two in South Africa (Hartbeeshoek and
Hermanus)
GOES data compared to
Matimba response
Matimba unit 6 nutral current compared
with GOES magnetometer 2nd October
Geostationary Operational
Environmental Satellite
12200
12250
12300
12350
12400
12450
12500
0:0
6:0
0
0:2
0:0
0
0:3
4:0
0
0:4
8:0
0
1:0
2:0
0
1:1
6:0
0
1:3
0:0
0
1:4
4:0
0
1:5
8:0
0
2:1
2:0
0
2:2
6:0
0
2:4
0:0
0
2:5
4:0
0
3:0
8:0
0
3:2
2:0
0
3:3
6:0
0
3:5
0:0
0
4:0
4:0
0
4:1
8:0
0
4:3
2:0
0
4:4
6:0
0
5:0
0:0
0
5:1
4:0
0
5:2
8:0
0
5:4
2:0
0
5:5
6:0
0
6:1
0:0
0
6:2
4:0
0
6:3
8:0
0
6:5
2:0
0
7:0
6:0
0
7:2
0:0
0
7:3
4:0
0
7:4
8:0
0
8:0
2:0
0
8:1
6:0
0
8:3
0:0
0
8:4
4:0
0
8:5
8:0
0
9:1
2:0
0
9:2
6:0
0
9:4
0:0
0
9:5
4:0
0
10
:08
:00
10
:22
:00
10
:36
:00
10
:50
:00
11
:04
:00
11
:18
:00
11
:32
:00
11
:46
:00
Hartbeesthoek HAR_x-8
-6
-4
-2
0
2
4
0:0
0:0
0
0:1
1:0
0
0:2
2:0
0
0:3
3:0
0
0:4
4:0
0
0:5
5:0
0
1:0
6:0
0
1:1
7:0
0
1:2
8:0
0
1:3
9:0
0
1:5
0:0
0
2:0
1:0
0
2:1
2:0
0
2:2
3:0
0
2:3
4:0
0
2:4
5:0
0
2:5
6:0
0
3:0
7:0
0
3:1
8:0
0
3:2
9:0
0
3:4
0:0
0
3:5
1:0
0
4:0
2:0
0
4:1
3:0
0
4:2
4:0
0
4:3
5:0
0
4:4
6:0
0
4:5
7:0
0
5:0
8:0
0
5:1
9:0
0
5:3
0:0
0
5:4
1:0
0
5:5
2:0
0
6:0
3:0
0
6:1
4:0
0
6:2
5:0
0
6:3
6:0
0
6:4
7:0
0
6:5
8:0
0
7:0
9:0
0
7:2
0:0
0
7:3
1:0
0
7:4
2:0
0
7:5
3:0
0
8:0
4:0
0
8:1
5:0
0
8:2
6:0
0
8:3
7:0
0
8:4
8:0
0
8:5
9:0
0
9:1
0:0
0
9:2
1:0
0
9:3
2:0
0
9:4
3:0
0
9:5
4:0
0
10
:05
:00
10
:16
:00
10
:27
:00
10
:38
:00
10
:49
:00
11
:00
:00
11
:11
:00
11
:22
:00
11
:33
:00
11
:44
:00
11
:55
:00
Avg QP dc Amps
-100
-50
0
50
100
150 1
2:05
:00
AM
12:
20:0
0 AM
12:
35:0
0 AM
12:
50:0
0 AM
01:
05:0
0 AM
01:
20:0
0 AM
01:
35:0
0 AM
01:
50:0
0 AM
02:
05:0
0 AM
02:
20:0
0 AM
02:
35:0
0 AM
02:
50:0
0 AM
03:
05:0
0 AM
03:
20:0
0 AM
03:
35:0
0 AM
03:
50:0
0 AM
04:
05:0
0 AM
04:
20:0
0 AM
04:
35:0
0 AM
04:
50:0
0 AM
05:
05:0
0 AM
05:
20:0
0 AM
05:
35:0
0 AM
05:
50:0
0 AM
06:
05:0
0 AM
06:
20:0
0 AM
06:
35:0
0 AM
06:
50:0
0 AM
07:
05:0
0 AM
07:
20:0
0 AM
07:
35:0
0 AM
07:
50:0
0 AM
08:
05:0
0 AM
08:
20:0
0 AM
08:
35:0
0 AM
08:
50:0
0 AM
09:
05:0
0 AM
09:
20:0
0 AM
09:
35:0
0 AM
09:
50:0
0 AM
10:
05:0
0 AM
10:
20:0
0 AM
10:
35:0
0 AM
10:
50:0
0 AM
11:
05:0
0 AM
11:
20:0
0 AM
11:
35:0
0 AM
11:
50:0
0 AM
Matimba Units 1 to 6 2nd OCtober 2013
MATMB .UNIT .UNIT_1 .MVAR MATMB .UNIT .UNIT_2 .MVARMATMB .UNIT .UNIT_3 .MVAR MATMB .UNIT .UNIT_4 .MVARMATMB .UNIT .UNIT_5 .MVAR MATMB .UNIT .UNIT_6 .MVAR
Matimba Mvar, GIC and
Magnetometer response.
20-May-14 20
Unit 6 GIC Current
Haartibeesthook Magnetometer reading
Units 1 – 6 Mvars
The magnetometer dB/dt trace indicates
that there were two strong impacts starting
at 2 o’clock and again at 5 o’clock in the
morning.
-8
-6
-4
-2
0
2
4
0:0
0:0
0
0:1
1:0
0
0:2
2:0
0
0:3
3:0
0
0:4
4:0
0
0:5
5:0
0
1:0
6:0
0
1:1
7:0
0
1:2
8:0
0
1:3
9:0
0
1:5
0:0
0
2:0
1:0
0
2:1
2:0
0
2:2
3:0
0
2:3
4:0
0
2:4
5:0
0
2:5
6:0
0
3:0
7:0
0
3:1
8:0
0
3:2
9:0
0
3:4
0:0
0
3:5
1:0
0
4:0
2:0
0
4:1
3:0
0
4:2
4:0
0
4:3
5:0
0
4:4
6:0
0
4:5
7:0
0
5:0
8:0
0
5:1
9:0
0
5:3
0:0
0
5:4
1:0
0
5:5
2:0
0
6:0
3:0
0
6:1
4:0
0
6:2
5:0
0
6:3
6:0
0
6:4
7:0
0
6:5
8:0
0
7:0
9:0
0
7:2
0:0
0
7:3
1:0
0
7:4
2:0
0
7:5
3:0
0
8:0
4:0
0
8:1
5:0
0
8:2
6:0
0
8:3
7:0
0
8:4
8:0
0
8:5
9:0
0
9:1
0:0
0
9:2
1:0
0
9:3
2:0
0
9:4
3:0
0
9:5
4:0
0
10
:05
:00
10
:16
:00
10
:27
:00
10
:38
:00
10
:49
:00
11
:00
:00
11
:11
:00
11
:22
:00
11
:33
:00
11
:44
:00
11
:55
:00
Avg QP dc Amps
Koeberg Mvar Response and
Hermanus MT data
-80
-60
-40
-20
0
20
40
60
80
100
Tim
e
12:
15:0
0 AM
12:
35:0
0 AM
12:
55:0
0 AM
1:1
5:00
AM
1:3
5:00
AM
1:5
5:00
AM
2:1
5:00
AM
2:3
5:00
AM
2:5
5:00
AM
3:1
5:00
AM
3:3
5:00
AM
3:5
5:00
AM
4:1
5:00
AM
4:3
5:00
AM
4:5
5:00
AM
5:1
5:00
AM
5:3
5:00
AM
5:5
5:00
AM
6:1
5:00
AM
6:3
5:00
AM
6:5
5:00
AM
7:1
5:00
AM
7:3
5:00
AM
7:5
5:00
AM
8:1
5:00
AM
8:3
5:00
AM
8:5
5:00
AM
9:1
5:00
AM
9:3
5:00
AM
9:5
5:00
AM
10:
15:0
0 AM
10:
35:0
0 AM
10:
55:0
0 AM
11:
15:0
0 AM
11:
35:0
0 AM
11:
55:0
0 AM
Koeberg Units 1 and 2 Mvar response2nd October 2013
KOEBG .UNIT .UNIT_1 .MVAR KOEBG .UNIT .UNIT_2 .MVAR
2nd October 2013 CME Impact
GIC Mitigation Extract from the
NERC 2012 Special Reliability Assessment Interim
Report: Effects on Geomagnetic Disturbances on the
Bulk Power System – February 2012
Phase 1 – Asses the base line risk
1. Improve understanding of the severity of solar storms
2. Understand the transformer risk
3. Understand the power system behaviour during solar storms
Phase 2 – Perform Technical and programmatic analysis
1. Development of transformer and Power System DC models
2. Use the models to understand the vulnerabilities in the power system
3. Evaluate the effect of network configuration changes on GIC flows
4. Create a list of approaches to eliminate the GIC effects in terms of costs and associated risks
5. Install monitoring devices and control room visualization tools to display the real time impacts of GICs
6. Replace risky transforms with more robust ones
Phase 3 – Develop an Integrated Solution
1. Determine the optimum combination of countermeasures at the lowest cost to the system security
Phase 4 – Implement solutions and adjust system procedures
1. Apply approaches and track performance
2. Update processes as new information becomes available.
US and Canada response action to Space weather notification
Network operators in the US and Canada when notified of impending solar storms have the following response
K=5: cancel all outages
K>7: return all Mvar devices
Questions
