Subido por Juan Saldaña

3BHS883924 E01 RevA MV Drives-Safety - Arc Resistant Design

Anuncio
—
MV Drives – Main Protection and Personnel Safety
2021/03 – 3BHS883924
Arc Resistant Design
—
Introduction
Electrical failures and arc faults
Bolted Short Circuits
Arc Faults
– Bolted short circuits are caused by a breakdown of a component
that ends in a solid conductive electrical connection
– Arc Faults are caused by a breakdown of the insulation
– Due to low resistance of the fault, only a low energy is absorbed
into the fault
 Thermal stress is limited (short term)
– The low impedance short circuit causes potentially high short
circuit currents
– Short circuit currents flow through ionized air, called an arc
 As a primary effect, high energy is released, causing a
pressure, sound and heat wave
 Harmful gases and particles represent a secondary danger
 High mechanical stress on the components in the short circuit
path (magnetic field)
There is no immediate safety risk
– Probability of occurrence is related to the reliability of the
electrical components.
– Typical MTBF of the power circuit is in the range 15 – 30 years
October 4, 2021
Slide 2
There is an immediate safety risk
Probability of occurrence is very low
Choosing clearance and creepage distances in
accordance to relevant standards reduces risks of
occurrence
—
ABB MV Drives
Main protection and safety barrier
Main circuit breaker (MCB/ICB)
– Major protection device of the frequency converter
– See important safety note 3BHS230517
– Maximum opening time is critical
Short circuit occurs
Open and / or trip command is set at the
frequency converter control output
No further damage of frequency converter
No hazard to personnel
Max. protection trip time
Max. safety trip time
October 4, 2021
Slide 3
Max. protection trip time:
Max. safety trip time:
Maximum opening time that ensures
minimum HW damage inside the drive in
case of bolted short circuit
Maximum opening time that ensures* no
personnel safety risks due to arcing in
the converter section
Minimize HW damage
Minimize safety risk
* “ensure” means: converter meets relevant standards for drives or product is classified as arc fault resistant
—
Arc Fault Safety
ABB’s approach - the 4 safety classes
•
•
CLASS
I
CLASS
II
CLASS
III
CLASS
IV
protection based on arc prevention
protection based on arc resistant
cabinet structure
protection based on external arc
fault limitation and elimination
fast arc elimination
Design of insulation systems in
accordance with relevant IEC and
NEMA standards to prevent arcs
and provide personnel safety
Class I is not a certified arc resistant
design, it is mainly focusing on arc
fault prevention
•
•
•
The cabinet is designed to
withstand the pressure of an arc
flash
Arc fault is contained in the cabinet
or guided through pressure relief
vents
The drive will face severe damage
after an event
•
•
HV Fuses are applied externally to
the drive in order to limit the arc
fault current to less than half cycle
of the fundamental AC frequency (<
10ms in case of 50Hz supply)
This method is only used to reach
arc resistant designs for MV drives
connected without external drive
transformer to the mains
(integrated transformer solutions
and DTL solutions)
•
•
•
This is an ABB patented method,
ABB MV drives “protection firing”
system. The arc fault is detected
and converted into a non severe
bolted short circuit
For an even faster detection and
elimination an optical ABB arc fault
detection system is available
Provides highest level of personal
safety and the equipment remains
undamaged and can be immediately
restarted after inspection and
elimination of the arc ignition cause
Arc resistant design
IAC Certified according IEC62271-200 / IEC 62477-2
October 4, 2021
Slide 4
—
Safety Requirements
Standards with
arc resistant design requirements
Standards without
arc resistant design requirements
Relevant standards for MV drives
Switchgear
IEC
NEMA
UL
IEC 62271-200
High-voltage switchgear and controlgear
IEC 62477-2
Safety requirements for power electronic converter
systems and equipment
IEEE C37.20.7
none
IEEE Guide to test metal-enclosed switchgear
UL347
Medium-Voltage AC Contactors, Controllers, and
Control Centers
- Presently there is no relevant standard
released for arc resistant design of MV
drives
- ABB and other companies have applied
switch gear standards.
- IEC and IEEE are very similar
October 4, 2021
Power Electronic Converters
Slide 5
UL347 (a)
Medium Voltage Power Conversion Controllers
- A new IEC standard relevant for MV
drives has been released
- This standard will be relevant in IEC and
(likely) also in NEMA world
- The standard allows to reuse the
certifications according switchgear
standards
Drives
IEC
IEC 61800-5-1
Safety requirements, Electrical, thermal and energy
IEC 61800-5-1
Safety requirements, Electrical, thermal and energy
none
- This are most relevant standards for MV
(and LV) drives safety requirements
- Future revision will reference to IEC
62477 (-1 for LV) and (-2 for MV) for arc
resistant design
—
Migrating from IEC 62271-200 to IEC 62477-2
Definition
•
•
IEC 62477-2
Safety requirements for power electronic converter systems
and equipment – Part 2 defines an internal arc classification
(IAC) system for MV Drives
Future revision of MV (and LV) safety requirement standard will
reference IEC 62477-2 for MV Drives arc resistant design,
classification and test
•
IEC 62477-2 describes 6 internal arc fault safety concepts
•
Test results based on IEC 62271-200 performed prior to release
date of IEC 62477-2 can be transferred
•
Rated arc fault current and arc fault duration are listed on the
IAC rating plate along with the accessibility types for each
classified side of the equipment.
October 4, 2021
Slide 6
* PPE – Personal protective equipment
Concept/Measure
Product property
Test
Required
Specific prevention:
1. Arc-prohibiting design
2. Active protection
3. Passive protection
1) no arc possible, arc
would not start on its own
2) arc is not bridging different
power Sources
Avoid damage:
Stop the arc evolving
Withstand damage:
Yes
Yes
Withstand the full arc
(pressure wave, heat, gas)
Yes
4. Distance
Limit the area of damage
Yes
5. Housing
-
No
6. Wear PPE
-
No
—
Migrating from IEC 62271-200 to IEC 62477-2
Comparison ABB’s approach - the 4 safety classes
CERTIFIED SAFE FOR PERSONNEL
ACC. TO IEC 62271-200:IAC AFLR
CLASS
III and II
CLASS
I
2
Active protection
3
Passive protection
4
Distance
5
Housing
6
Wear PPE
N/A
ARC
PREVENTION
+
FAST ELIMINATION
ARC
PREVENTION
+
PROTECTION OR
ELIMINATION
ARC
PREVENTION
ARC
PREVENTION
USAGE OF PROPER
PPE MANDATORY
NO ARC POSSIBLE,
ARC NOT START
ON ITS OWN
BASED ON
PROTECTION
FIRING AND/OR
FAST DETECTION
BASED ON ARC
RESISTANT
ENCLOSURE OR
BASED ON HVFUSES
BASED ON
RESISTANT
ENCLOSURE
BASED ON DESIGN
ACC. TO
IEC 60146-1-1
IEC 61800-4
N/A
NONE
NEGLIGIBLE
MODERATE
SEVERE
SEVERE
SEVERE
1
Arc-prohibiting
design
CONCEPT/MEASURE
PERSONNEL SAFETY BASED
ON
EQUIPMENT DAMAGE IN
CASE OF ARC
October 4, 2021
CLASS
IV
Slide 7
* PPE – Personal protective equipment
—
Arc Fault Safety
Arc resistant design
Equipment is called “arc resistant” in case it has passed
certification tests in accordance with IEC 62477-2 or IEC 62271200 / IEEE C37.20.7 if test performed prior to IEC 62477-2 release
date
Test
– Test equipment is surrounded with highly flammable cotton
– Ignition of an arc inside the cabinet (place with highest
probability)
– Maximum arc rating current is feed into the arc for a defined
time
Test criteria
– Multiple criteria per standard
– During the test duration: no damages or any burning signs are
allowed to be recorded in the cotton
October 4, 2021
Slide 8
IEC standard defines IAC (Internal Arc Classification) for
equipment passing the tests
Examples:
FLRTB, means the equipment is safe from front (F), left side (L), right side (R),
top side (T), bottom side (B), Black cretonne 150 g/m2 cotton indicator
(AA.5.2.2) at d m distance (2b), associated protection is required (APR),
special condition (SC)
—
Arc Fault Safety
Different parts of the drive system sees different max currents
Main
power line
Input
section
Input
transformer
Rectifier
DC-link
Inverter
Output filter
Motor
50
M
Network
short circuit
Converter internal short circuit is limited
by transformer & filter
Barrier
transformer impedance limits short
circuit current/power
October 4, 2021
Slide 9
* Only relevant for sync bypass
Motor / Network*
short circuit
Barrier
filter impedance limits short circuit
current/power
—
Arc Fault Safety
Basis for arc current ratings and times
Main
power line
Input
section
Input
transformer
Rectifier
DC-link
Inverter
Output filter
Motor
Main
power line
50
Input
section
Input
transformer
Rectifier
DC-link
Inverter
Output filter
50
M
M
Maximum currents
Maximum currents
– Worst case arc fault reached when all transformer secondary systems are feeding into an arc
in parallel
– Integrated transformer and DTL versions are directly connected to the mains.
– Maximum arc fault current is mainly defined by main transformer impedance, secondary
voltage and number of secondary systems
Time
– The arc resistance time has to be sufficient to guarantee safe interruption of fault current.
– The products have been rated for times in a range of 250ms – 500ms, which is sufficient for:
•
The protection relay of the main circuit breaker can detect the fault current and open the
breaker
•
In case the breaker doesn’t open, the breaker on the next upper level can still be opened
– Those products are therefore exposed to full short circuit current rating of the supply at the
primary side of the transformer or decoupling inductor
Time
– Since the short circuit rating of the supply can be extremely high, ABB offers arc resistant
design for this products only in combination with an external current limiting fuse located in
the feeder line
– The current limiting fuse will limit the short circuit current to half cycle of the fundamental
frequency, at 50Hz < 10ms. Tests are done with minimum 10ms
The external current limiting fuse only protects in case of arc faults at the primary side of the transformer.
The secondary side arc faults are handled the same way as for external transformer solutions. Therefore, a second IAC rating is provided for those products.
October 4, 2021
Motor
Slide 10
—
ABB MV Drives
Arc resistant design offering
Product
ABB
class
Concept /
Measure**
IAC Rating
Third body
certificate
Availability in
DriveSmart
ACS1000a and w
I
4.
none
-
default
ACS1000a
II
3.
5kA / 0.5s
12123Ra
option
ACS1000w
II
3.
6kA / 0.5s
15kA / 0.5s
11075Ra
11077Ra
option
C+ (Reinforce
Cabinet)
ACS2000 DFE IEC
I
4.
None
II
3.
15kA / 0.45s
15114Ra
option
IV
2.
18kA / 0.5s
15114Ra
option
I
4.
none
-
default
II
3.
3.5kA / 0.5s
12035Ra
option
I
4.
none
-
default
ACS5000w FS1, 2 & 3
IV
2.
19kA / 0.5s
12116Ra/11176Ra
default
ACS5000w FS4
IV
2.
28kA / 0.5s
11176Ra
default
ACS6000 / ACS6080
II
3.
20kA/ 0.5s
09067Ra
option
IV
2.
20kA / 0.5s
1202 Bm-1
default
(protection firing
only)
IV
2.
50kA / 0.5s
1202 Bm-2
option
I
4.
none
-
default
II
3.
23kA / 0.5s
11011Ra/2196-19
option (*)
ACS2000 AFE IEC
ACS5000a
MEGADRIVE-LCI
October 4, 2021
Slide 11
default
Products with integrated transformer:
Product
ABB
class
Concept /
Measure**
IAC AFLR Rating
Third body
certificate
Availab
ility in
DriveS
mart
ACS580MV
I
4.
none
-
default
ACS1000i
I
II
III
4.
3.
3.
13021Ra/13023Ra
13017Ra
default
option
option
I
4.
None
-
Default
III + II
3.
15kA/50kA for 0.45s/0.02s
15114Ra/15115Ra
option
III + IV
3. + 2.
18kA/50kA for 0.5s/0.02s
15114Ra/15115Ra
Option
ACS2000 DTL
I
4.
none
-
default
ACS5000i
I
4.
none
-
default
ACS2000 DFE IEC
.
.
none
.
6kA/20kA for 0.5s/0.1s
6kA/20kA/50kA for 0.5s/0.1s/0.01s
– Integrated transformer solutions from ABB are available up to 7MVA. For this
power range it is common approach to use «fused contactors» as MCBs
Therefore in many cases the external current limiting fuse is already
available.
– Attention: fuses within the drive as part of the optional integrated “fused
line-side contactor” do not replace external fuses. The fuse has to be external
FS: Frame Size
(*) Power cable entry from top is not compatible with the “arc resistant” design. Reason is that the space on top is limited (cable entry,
pressure relieve flaps & fans). In case this combination is required a Cplus needs to be issued. Depending on the type of LCI it might be required to increase the size of the terminal unit. Minimum ceiling height: 3.5m!
** Definition according to IEC 62477-2
Descargar