Auto-Reclosure; Synchro-Check & Voltage Check

Topic:

REL316*4 Technology and Solutions Protection and Substation Automation

Auto- Reclosure; Synchro- Check & Voltage Check

RE.316_ AR_Syn / 2003-10-01 / RW

© ABB Switzerland Ltd. - 1

BASICS

ABB

REL316*4

Auto Reclosure; Synchro- & Voltage Check

Objectives

RE.316_AR_Syn / 2003-10-01 / RW


Auto Reclosure (79)

Rules / Facts

Important Settings

Supervision of the breaker (CB memory)

the four AR cycles

Function of the operating time

Examples

Substations with single busbar or multiple busbar

1 1/2 breaker scheme

Maser / Follower scheme

Line Protection Interfaces

ABB

REL316*4

Auto Reclosure; Synchro- & Voltage Check

Objectives

RE.316_AR_Syn / 2003-10-01 / RW


Synchro Check (25) & Voltage Check (27/59)

Auto Reclosure interfaces

3-pole tripping with 3-pole AR

1-pole tripping with 1-pole AR

Operating Modes

Synchronism Monitoring

Application Example

Voltage Selection

ABB

REL316*4

Auto Reclosure (79)

Application

Load

SYSTEM

TRIP LP

TRIP LP

SYSTEM

AR Close CB

AR Close CB

RE.316_AR_Syn / 2003-10-01 / RW


SYSTEM

SYSTEM Load

ABB

REL316*4

79 - Rules / Facts

On several auto-reclosing cycle, only the first cycle can be single pole tripping with fast auto-reclosing Following auto-reclosing cycles must be three phase tripping and reclosing The line protection must provide single phase trip for the first fault, following faults must be tripped three phase RE.316_AR_Syn / 2003-10-01 / RW


The closing command always goes to all three phases

ABB

REL316*4

79 - Rules / Facts

No synchro check is needed for fast single phase reclosing (Sychro-check by-pass) The system will not loose synchronity: 3 of 4 conductors (2 phases and ground) are still in service During the pause time the line still transmits more than 50% of the maximum power

RE.316_AR_Syn / 2003-10-01 / RW


If AR is not ready for a single cycle, the tripping circuit must be prepared or switched to 3-phase tripping Reasons for AR not ready: - AR blocked or switched off - AR blocked with t inhibit after reclosing (CB recovery time) - Fast AR dead time expired - No 1- pole AR permitted

ABB

REL316*4

79 - Rules / Facts

During the 1-pole dead time (one pole from the breaker is open) all other functions who react on unsymmetry and have a shorter tripping time then t-dead-1P-setting must be blocked Example: - Directional earth fault with tripping scheme POTT

RE.316_AR_Syn / 2003-10-01 / RW


- Pole discrepancy protection

ABB

REL316*4

79 - Important Settings

RE.316_AR_Syn / 2003-10-01 / RW


1-pole dead time (t dead 1P) 3-pole dead time (t dead 3P) Operating time (t oper) Discrimination time (t discrim.1P, t discrim.3P) Blocking time (t AR Block)

One pole opens and closes after t-dead -1P Typical dead time: 0.3 – 0.5 s in high voltage systems All 3 pole open and close after t-dead-3P Typical dead time: 0.5 s – sev. minutes Prevents an AR for a long during fault (eg. in the 2nd zone) Decision about 1-pole AR, 3 pole AR or definitive trip after evolving fault Prolongation of the AR blocking after a manual close command or after close command from the control system

ABB

REL316*4

79 - Important Settings

Inhibit time (t inhibit)

RE.316_AR_Syn / 2003-10-01 / RW


Close pulse duration (t close)

Blocking of the AR for 5 ….. 180 s after an unsuccessful AR attempt.t inhibit is also called recovery time. The breaker needs time to be ready for a new AR cycle Must be long enough to make sure the breaker closes properly. The close pulse is reset direct after an unsuccessful AR attempt.

ABB

REL316*4

79 - Supervision of the breaker (CB memory)

Breaker position: (CB open)

Close open (CO ready)

RE.316_AR_Syn / 2003-10-01 / RW


Open-Close-Open (CB ready)

Open circuit breaker blocks the AR device. During a running AR cycle the position of the breaker is not interrogated. This prevents under all circumstances an AR for a switched off CB The breaker is able to switch on to a fault and to open again. This information is interrogated direct before re-closing The breaker is able to do a complete AR cycle This input is not interrogated during a running AR cycle.

If the AR function operates two breakers the supervision signals are needed from both breakers.

ABB

REL316*4

79 – four AR cycles

Why several AR cycles? First AR:

Second AR:

RE.316_AR_Syn / 2003-10-01 / RW


Third AR:

Fourth AR:

With the opening of the breaker the voltage which supplies the arc is switched off ⇒ the arc will extinguish The dead time is set as short as possible. So the line can be back in normal service as fast as possible. If the arc is not extinguished with the first AR attempt (tree, bamboo) a second attempt with a longer dead time will be started (2nd and 3rd attempt are 3-phase cycles) This attempt is just an automatic voltage check One side will be switched on. An immediate trip occurs if the fault is still present. The opposite station will only reclose if the line was successful energized from the own station (Synchro- & V - Check) normally not applied in high voltage systems

ABB

REL316*4

79 - Function of the operating time t-oper

Supervision of the fault duration is important in distance protection

Fault duration < operating time Example: Trip in zone 1 initates an AR cycle

Fault duration > operating time Example: Trip in a higher zone stops the a fast AR cycle Starting

Starting

Tripping

Tripping Operating time Discrimination time

Discrimination time

On pulse Dead time Q0 Ph R

t dead 1P

Definitive trip

RE.316_AR_Syn / 2003-10-01 / RW


Q0 Ph S Q0 Ph T

t dead 3P Q0 Ph R Q0 Ph S Q0 Ph T

Normal setting: t-oper < t2 of distance protection The operating time prevents AR for faults in higher zones ⇒ faults outside of the own line.

ABB

REL316*4

79 - Examples

AR Mode: fast AR 1 / 3 - pole Example: - fast AR successful

Fault:: 1- phase Fault

Starting 1-phase Tripping 1-pole Discrimination time On - pulse

RE.316_AR_Syn / 2003-10-01 / RW


Dead time fast AR 1-pole,

Q0 Phase R Q0 Phase S Q0 Phase T

fast AR 1-pole

ABB

REL316*4

79 - Examples

AR Mode: fast AR 1 / 3 - pole and slow AR Fault: 1- phase fault Example: - fast AR not successful, - slow AR successful

Starting 1-phase Tripping 1-pole Discrimination time 1-pole On-pulse, interrupted with second tripping Dead time fast AR 1-pole, Starting 1-phase Tripping 3-pole

Discrimination time 3-pole

RE.316_AR_Syn / 2003-10-01 / RW


Dead time slow AR Q0 Phase R Q0 Phase S Q0 Phase T

LAR fast AR 1-pole

ABB

REL316*4

79 - Examples

AR Mode:fast AR 1 / 3 - pole, followed by a long dead time Example: - fast AR not successful; - slow AR not successful

Fault: 1- phase fault

Starting 1-phase Tripping 1-pole Discrimination time 1-pole On-pulse, interrupted with second tripping Dead time 1-pole,

Starting 1-phase Tripping 3-pole


Starting Tripping 3-pole

RE.316_AR_Syn / 2003-10-01 / RW


Dead time 3-pole Q0 Phase R Q0 Phase S Q0 Phase T

fast AR 1-pole

slow AR

Definitive tripping

ABB

REL316*4

79 - Examples

Mode: fast AR 1 / 3 - pole and slow AR Fault: 1- phase fault Example: - Evolving fault before expiring of discrimination time - fast AR not successful, slow AR successful Starting 1-phase Tripping 1-pole Discrimination time 1-pole Dead time 1-pole, interrupted with 2nd fault before expiring of 3-pole discrimination time Starting 1-phase(other phase) Tripping 3-pole Discrimination time 3-pole On-pulse, interrupted with tripping Dead time fast AR 3-pole Starting 1-phase

RE.316_AR_Syn / 2003-10-01 / RW


Tripping 3-pole


Dead time slow AR Q0 Phase R Q0 Phase S Q0 Phase T

fast AR 1-pole interrupted

fast AR 3-pole

Slow AR

ABB

REL316*4

79 - Examples

AR mode: fast AR 1 / 3 - pole and slow AR Fault: 1- phase fault Example: - Evolving fault after expiring of discrimination time of fast AR - Definitive tripping

Starting 1-phase Tripping 1-pole Discrimination time 1-pole

RE.316_AR_Syn / 2003-10-01 / RW


Dead time 1-pole, interrupted with 2ten fault after expiring of 3-pole discrimination time

Q0 Phase R Q0 Phase S Q0 Phase T

fast AR 1-pole interrupted

ABB

REL316*4

79 - Substations with single busbar or multiple busbar Standard - solution Main 1

Bus I

Main 2

Bus II AR

3

Trip 1

RE.316_AR_Syn / 2003-10-01 / RW


Main 2

Close Trip 2

“Cheap” - solution

AR Main 1

3

Main 1

Main 1

Main 2

3

Trip 1

Main 2 AR 3

Close Trip 2

ABB

REL316*4

79 - 1 1/2 breaker scheme

Main 1

Main 2

Main 1

Main 2

Bus A Bus A - CB

Q0 A

AR

Center - CB

Q0 C

AR

RE.316_AR_Syn / 2003-10-01 / RW


Bus B - CB

Q0 B Bus B

AR

AR

AR

AR

AR

AR

AR

“Diameter” All breakers are closed during normal service

Each CB next to a line needs an AR function.

ABB

REL316*4

79 - Master / Follower scheme

1 1/2 breaker scheme Q0 A

AR A CB image M

Q0 C

AR C

RE.316_AR_Syn / 2003-10-01 / RW

CB image


The Master re-closes after the set dead time

Line

The Follower re-closes only after successful re-closing of the Master. In case the master is not ready for an ARcycle a signal will be send to the follower. The follower will now re-close in the set dead time.

ABB

REL316*4

79 – Line Protection Interfaces

RE.316*4

Trip CB 3P

Start SOTF

CondBlkAR

RE.316_AR_Syn / 2003-10-01 / RW

ZExtensionAR

Trip 3-Pol ZExtension

Close CB

Trip CB 3P 1PolAR


Trip CB

Auto-reclosure function CO ready

Trip CB

Start

CB ready

Start RST

CB open

HEST 965 010 C

ABB

REL316*4

25; 27/59 – Auto Reclosure Interfaces

RE.316_AR_Syn / 2003-10-01 / RW


25 27/59

the Auto Reclosure is able to send a closing command if the Permit to close Signal is active

ABB

REL316*4

27/59 – Voltage Check

The Voltage Check is required to detect if the Bus / Line is

RE.316_AR_Syn / 2003-10-01 / RW


Live or Dead !!!

ABB

REL316*4

27/59 - 3-pole tripping with 3-pole AR

Check of only one phase to phase voltage for the busbar and the line is enough

RE.316_AR_Syn / 2003-10-01 / RW


Q0

V Bus bar

VLine

Synchro- & voltage-check

ABB

REL316*4

27/59 - 1-pole tripping with 1-pole AR

On the busbar the check of one phase to phase voltage is enough On the line the check of all three phase to ground voltage is recommended

RE.316_AR_Syn / 2003-10-01 / RW


Q0

Vbus bar

vLine

Synchro- & Voltage-check

ABB

REL316*4

25; 27/59 – Operating Modes

RE.316_AR_Syn / 2003-10-01 / RW


Selectable Operating Modes

(bus dead AND line dead)

the Permit to close Signal is active, if the Conditions are fulfiled

ABB

REL316*4

25 – Synchro Check

The Synchro Check is required to detect if in case of a Live Bus & Live Line

RE.316_AR_Syn / 2003-10-01 / RW


the grid is synchronized or not !!!

ABB

REL316*4

25 – Synchronism Monitoring fBusbar = ωBusbar /2 π fLine = ωLine /2 π

∆V

∆f = fBusbar - fLine = fSchlupf <

VLine

VBusbar

RE.316_AR_Syn / 2003-10-01 / RW


ωBusbar

ωLine

0.10 Hz

VBusbar > 80% Un VLine >

80% Un

∆V <

20% Un

∆ϕ <

∆ϕ

15°

SETTINGS

ABB

REL316*4

25 – Application Example

RE.316_AR_Syn / 2003-10-01 / RW


Feeder Connected to a double busbar

ABB

REL316*4

25 – Voltage Selection

• Only one phase to phase voltage is used for the synchro-check Reasons: • A three phase measuring is not needed because the synchro-check is only needed for 3-phase faults

RE.316_AR_Syn / 2003-10-01 / RW


• For 1-phase AR the synchro-check is bypassed • Phase to ground voltage should not be used. The natural zero sequence voltage disturbs in the medium voltage system the sychro-check measuring

ABB

RE.316_AR_Syn / 2003-10-01 / RW


ABB

Auto-Reclosure; Synchro-Check & Voltage Check

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