Understanding Micrologic

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Understanding Micrologic
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Contents

• Range
• Protection against overloads
• Protection against short-circuits
• Protection against insulation faults
• Hardware
• Metering
• Others functions
• Monitoring and/or protection of loads
• Load shedding and reconnection
• Programmable controller
• Harmonic
• Asic and microprocessor self-protection

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MicrologicRange
Micrologic 6. 0 P
Measurement type version Current
protection type
Without
Measurement type
P
A
H
Current protection type
5.0 H 6.0 H 7.0 H
5.0 P 6.0 P 7.0 P
2.0 A 5.0 A 6.0 A 7.0 A
2 Distribution L, I 5 Selective L, S, I 6
Selective and ground fault L, S, I, G 7
Selective and earth leakage L, S, I, V
2.0
5.0
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Protection against overloadsphases
LT setting

• Long-time protection (i²t) of the phases and the
  neutral
• Protect against premature ageing of cables
• Adjustable setting range using rating plugs
• standard 0.4 - 1, low 0.4 - 0.8, High 0.8 -
  1, plug OFF
• Setting to within one Amp with keypad or via
  Communication

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Protection against risk of fire
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Protection against overloadsneutral conductor

• Neutral protection
• Adjustment
• by three position dial on the 4th pole 4P 3D,
  3DN/2, 4P 4D
• by keypad OFF, 1/2, Full, 1.6 (3 pole breaker
  only)
• Settings
• N/2 IrN 1/2 IrP, IsdN 1/2 IsdP, IiN IiP,
  IgN IgP
• 1.6N IrN 1.6 IrP, IsdN 1.6 IsdP, IiN IiP,
  IgN IgP
• Oversized neutral protection
• protection against 3rd-order harmonics summed up
  in the neutral conductor
• 3Pole breaker only

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Protection against overloads3rd harmonic in
neutral conductor
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Protection against overloadsIDMTL

• Long-time protection of the phases IDMTL type
  (Inverse definite minimum time lag)
• High voltage fuse
• Extremely inverse time
• Very inverse time
• Standard inverse time
• Definite time

Improvement of discrimination with HV
fuses Better protection of switchgears
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Protection against short-circuits

• Short-time protection
• For low impedance short-circuits (80 of faults)
• I²t ON to improve discrimination with downstream
  protection, inverse time protection up to 10Ir
• Instantaneous protection
• For solid short-circuits
• N1 and H1 breaker OFF position inhibits the
  instantaneous protection
• H2, H3 and L1 breaker OFF postion DIN value
  (shown on screen)
• RMS measurement with 20ms fixed time delay

ST pick-up
ST delay
Inst.
pick-up
Protection against risk of damage
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Protection against short-circuits Zone selective
interlocking (ZSI)

• Principle
• ZSI enables the control units to communicate with
  each other. The system is able to locate the
  short circuit or ground fault and clear it.
• Functionning
• ZSI allows the circuit breaker to ignore its
  preset delay when necessary. The fault is
  cleared by the nearest upstream circuit breaker
  with no intentional time delay.
• Advantages
• Faster tripping time without sacrificing
  coordination
• Limitation of system stress by reducing amount of
  let through energy.

Maximum 100 circuit breakers interconnected
whatever the configuration
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Protection against insulation faultsGround fault

• Ground fault protection
• Micrologic 6.0P
• Made mandatory by NEC
• Residual current Source Ground Return

Ig
Prevent risk of fire
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Protection against insulation faultsEarth
leakage
New

• Earth-leakage protection
• Micrologic 7.0P
• Mandatory per standards NFC 15100 and IEC 364
• In a TT system, protects property against low
  level fault currents
• In a TNS system, protects installations where
  long cables are installed

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Hardware Principle and power supply
ZSI
M2C/M6C
COM Module
ASIC Basic protection L S I G V
Microprocessor Additional functions (monitoring,
measurement, analyses...)
Synchronous Exchange data
Mitop
Air CT
Isolation
Plugs Calibre/ perform.
Optical coupling
Iron CT
Power supply
Trip unit power supply
Surplus

• Optional external 24V DC power supply for
• programmable contact power supply and
• when breaker is open
• Powers display,
• Identification, adjustments through Com module

Test kit
Standard Internal voltage sensor lt690v
or optional external voltage sensor for µP power
supply and measurement
24V DC BUS power supply
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MeteringPrinciple
Refresh
Sampling
544µs
1 s
1s Integration Instant. data
15 s (sliding) 5..60 min (fixed)
5 to 60 min Integration Demand data
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RMS measurement

• Sampling frequency
• 1838Hz
• One measurement point every 544µs
• 36 points per cycle
• RMS value calculation

20ms
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Others functionsPrinciple
Meter
Programmable Controller
Monitor
Logging Data Logs Historical Data
Maintenance Data
Instant. data
IRMS P Q S EP EQ
Min / Max
Max I1 Min f17
Thresholds (pickup dropout)
Demand
Iavg Pavg
Relay Activation M2C/M6C
Breaker trip Mitop
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Demand measurementsfixed or sliding window

• fixed window
• Measurement of active reactive and apparent power
• time intervals programmable between 5mn and 1h
• values are refreshed at the end of the time
  interval
• Sliding window
• Measurement of current and active reactive and
  apparent power
• time intervals programmable between 5mn and 1h
• values are refreshed every 15 sec

sliding
fixed
5mn to 1h
t
15s
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Power factor PF

• Power factor
• PF P/S P active powerS apparent
  powerNota cos ? P1/S1P1
  Fundamental active powerS1 Fundamental
  apparent power

apparent power S kVA
reactive power Q kvar
active power P kW
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Power factor PFSign convention
Reactive Power
Watts VArs P.F
Watts - VArs P.F -
Active Power
Active Power
Active Power
Watts VArs - P.F
Watts - VArs - P.F -
IEEE PF sign - Q sign(P/S)
IEEE altenate PF sign Q sign(P/S)
IEC PF sign sign(P/S)
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Monitoring and/or protection of loadsbased on
current, voltage, power, frequency

• Current and voltage unbalance

• Maximum current (per phases neutral)

• Minimum / maximum voltage

• Minimum / maximum frequency

• Reverse power

• Phases rotation

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Monitoring and/or protection of loads Principle
of operation
variable
T1
Activation threshold
Deactivation threshold
T2
t
Alarm generated by Micrologic
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Monitoring and/or protection of loads Current
unbalance ANSI 46

• Application
• Protect rotating machines (motors, generators)
  operating on balanced three-phase supplies
  against ageing and slowing
• Balance single-phase loads on three-phase
  distribution systems
• Detect phase loss
• Principle
• the function compares the current unbalance to
  the threshold previously set by the user, for a
  time greater than the time delay
• Example
• I1 2500A I2 4000A I 3 3400A
• Iaverage. 3300A
• Emax I1 - Iave. 800A
• DI Emax /Iaverage 24

I average
I1
I2
I3
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Monitoring and/or protection of loads Maximum
current per phase and N

• Application
• Obtain the maximum current demand in the presence
  of major load fluctuations (welding machines,
  crushers, hoists)
• Principle
• This function calculates the maximum demand value
  of the current in each Ph and Neutral over a
  sliding time interval.
• The interval can be adjusted between five
  minutes and one hour.
• The value is refreshed every 15s

I max demand
t1
t2
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Monitoring and/or protection of loads Voltage
unbalance ANSI 47
U average

• Application
• Protect loads against vibrations, temperature
  rise and premature ageing
• Principle
• The function compares the voltage unbalance to
  the threshold previously set by the user, for a
  time greater than the time delay.
• Example
• U12 330v
• U23 390v
• U31 10V
• U average. 243v
• Emax U31 - U average. 233v
• DU Emax /U average. 96

E max
U12
U23
U31
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Monitoring and/or protection of loads Minimum
voltage ANSI 27

• Application
• Protect motors against voltage drops resulting in
  loss of torque and a major increase in the
  current drawn by the motor
• Check the output voltage of a generator
• Principle
• The function is activated when one of the phase
  to phase voltages is below the threshold set by
  the user, for a time greater than the time delay.
• The function is desactivated when all 3 phase are
  above the threshold.

U12
U23
U31
Activation threshold U min
dectivation threshold U min
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Monitoring and/or protection of loads Minimum
voltage ANSI 27
U
U max activation threshold (maxi 1200V)
U min deactivation threshold
T2
T1
U min activation threshold (mini 100V)
100V
Alarm
t
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Monitoring and/or protection of loads Maximun
voltage ANSI 59

• Application
• Protect loads (motor and transformer) against
  abnormally high voltages that can result in
  irreversible damage
• Avoid saturation of transformers
• Principle
• The function is activated when one of the phase
  to phase voltages is above the threshold set by
  the user, for a time greater than the time delay
• The function is desactivated when all 3 phases
  are under the threshold

Activation threshold U max
deativation threshold U max
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Monitoring and/or protection of loads Maximum
voltage ANSI 27
U
1200V
T1
U max activation threshold (maxi 1200V)
T2
Deactivation threshold
U min activation threshold (mini 100V)
Alarm
t
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Monitoring and/or protection of loads Reverse
power ANSI 32P
t

• Application
• Protect diesel engines from generators operating
  as motors
• marine applications, generator sets
• Avoid power transfers between two
  parallel-connected sources
• Principle
• The function is activated when the active power
  flowing in the direction opposite set by the user
  is greater than the activation threshold for a
  time greater than the time delay.

Reconnection
Activation
Load shedding
Deactivation
Reverse power
P kW
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Monitoring and/or protection of loads Minimum
frequency ANSI 81

• Application
• Check the frequency of a generator
• Check the frequency across the terminals of a
  motor
• Avoid saturation of transformers following a drop
  in frequency
• Principle
• The function is activated when the frequency
  exceeds the set threshold for a time greater than
  the time delay

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Monitoring and/or protection of loads Minimum
frequency ANSI 81
F
F max activation threshold (maxi 540Hz)
T2
F min deactivation threshold
T1
F min activation threshold (mini 45Hz)
45Hz
Alarm
t
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Monitoring and/or protection of loads Maximum
frequency ANSI 81

• Application
• Check the frequency of a generator
• Check the frequency across the terminals of a
  motor
• Principle
• The function is activated when the frequency
  exceeds the set threshold for a time greater than
  the time delay

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Monitoring and/or protection of loads Maximum
frequency ANSI 81
F
540Hz
T1
F max activation threshold (maxi 540Hz)
T2
F max deactivation threshold
F min activation threshold (mini 45Hz)
Alarm
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Monitoring and/or protection of loads Phase
rotation
F2

• Application
• Avoid reversed rotation of motors
• Check on coupling between generator and
  distribution system (phase sequence)
• Principle
• The function compares the actual phase sequence
  with the selected sequence
• Alarm only
• Not available if the 400 Hz frequency is set

F1
F3
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Load shedding and reconnectionbased on current
t

• Application
• Ensure the continuity of service of priority
  circuits by disconnecting non-priority loads
• Principle
• The function is activated when the current
  exceeds the set threshold for a time greater than
  the time delay

reconnection
shedding
I
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Load shedding and reconnectionbased on power

P kW

• Application
• Ensure the continuity of service of priority
  circuits by disconnecting non-priority loads
• Principle
• The function is activated when the power exceeds
  the set threshold for a time greater than the
  time delay

10MW
Activation
Deactivation
100 kW
t
Alarm
shedding
reconnection
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Programmable controllerAlarms and relay outputs
with distinct thresholds
Activation
T1

• Alarm
• on supervisor via Com module
• activation and desactivation after a
  programmable time delay
• M2C or M6C relay outputs
• without latching gt follows the state of the
  alarm
• with temporary latching
• programmable from 1s to 6mn
• with permanent latching gt needs a resetting

Deactivation
T2
t
Alarm
Relays without latching
Relays with temporary latching
from 1s to 360s
possible Resetting
Relays with permanent latching
Reset
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Programmable controller Alarms and relay outputs
with identical thresholds

• Alarm
• on supervisor via Com module
• activation and desactivation after a
  programmable time delay
• M2C or M6C relay outputs
• without latching gt follows the state of the
  alarm
• with temporary latching
• programmable from 1s to 6mn
• with permanent latching gt needs to be reset

Activation/
T2
Deactivation
Alarm
Relays without latching
from 1s to 360s
Relays with temporary latching
possible resetting
Relays with permanent latching
Reset
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HarmonicDefinition

• A periodic signal is a combination of
• The original sinusoidal signal at the fundamental
  frequency
• Other sinusoidal signals (the harmonics) with
  frequencies that are whole-number multiples of
  the fundamental frequency
• A DC component, where applicable

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HarmonicOrigin and effects

• OriginHarmonics are caused by non linear loads
  such as
• Welding machines
• arc/induction furnaces
• Variable speed drive
• office equipment (computer, copy machine, neon
  lighting)
• EffectsThe flow of harmonics in distribution
  systems can cause serious problems such as
• Increased currents (oversized neutral)
• Additional losses and premature aging
• Disturbances to loads due to voltage harmonics
• Disturbances in communication networks

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HarmonicQuality indicators

• These indicators are the indispensable tools used
  to determine any required corrective action
• Measurement of the fundamental
• Phase displacement of the fundamental
• Harmonic distorsion THD
• cos ?, power factor
• K factor, crest factor
• Distorsion power, distorsion factor
• Amplitude spectrum up to order 31 st
• Displacement spectrum

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Harmonic Total Harmonic Distortion

• Current THD
• Current per phase
• Neutral current
• Voltage THD
• Phase to phase voltage
• Phase - Neutral voltage

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Harmonic Fast Fourier Transfert

• Current harmonics
• each phase plus neutral
• up to 31st order
• Voltage harmonics
• phase to phase
• phase to Neutral
• up to 31st order

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Harmonic Waveform capture (WFC)

• Triggered manually
• 4 cycles
• magnitude I 0- 1.5 In
• magnitude V 0- 690V
• 64 points /cycle
• Triggered on event (alarm gt 1s)
• 4 cycles (on supervisor)
• magnitude I 0- 1.5 In
• magnitude V 0- 690V
• 64 points /cycle
• triggered by a fault
• 11/13 cycles (50/60 Hz)
• magnitude I 0- 20 In
• magnitude V 0- 690V
• 18/15 points /cycle (50/60 Hz)
• WFC available through the COM option only

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Asic and microprocessor self-protection
ASIC
Self protection - temperature - power supply
deficiency
Data exchange reading
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Asic and microprocessor self-protection

• ASIC self protection
• resulting in a circuit breaker tripping
• excessive temperature gt120
• ASIC power supply deficiency (overvoltage)
• Indication
• LED Ap  ON 
• display of error code on LCD screen
• Events log recording gtsupervisor
• µP self protection
• never trip the circuit-breaker
• Memory check sum
• Time-out
• Detection by the µPro of a serial link failure
  between µP and the ASIC
• Indication
• Events log recording gtsupervisor (if
  communication still healthy)

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That s all for today !

• Isn t it simple and nice ?