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Energy Sector / Power Transmission SolutionsEnergy Sector / Power Transmission Solutions

DC Control & Protection TrainingDC-Protection Functions – DC Busbar Protection

Page 2 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

DC C&P Training – DC-Protection Functions – DC Busbar Protection

DC Busbar Protection Overview

DC-Filter

IdCH

IdCNIdee1

Idee2

UdH

UdNIdLN

HSNBS

MRTB

IdSG

HSGS

IdLH

33

Uac

UsumY

3UsumD

IacY

IacD

HSNBS

Other Pole

MRSIdLN_op

IdMRS

Protection zone

Protection zone

Page 3 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

DC C&P Training – DC-Protection Functions – DC Busbar Protection

HV DC Busbar Differential Protection (87HV)

DC-Filter

IdCH

IdCNIdee1

Idee2

UdH

UdNIdLN

HSNBS

MRTB

IdSG

HSGS

IdLH

33

Uac

UsumY

3UsumD

IacY

IacD

HSNBS

Other Pole

MRSIdLN_op

IdMRS

Page 4 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

Protection Task Faults to ground or neutral within protection zone

Evaluation Principle Abs(IdLH – IdCH) > threshold

Initiated Sequences At rectifier: Converter Block to Pole Control At inverter: Converter Block to Pole Control, Bypass Pair Firing

Inhibit Retarded Protection Task for both stations if firing pulses are blocked: Opening of HSNBS ESOF to Pole Control

Typical settings Threshold = 0.25 p.u. Delay time = 10 ms

DC C&P Training – DC-Protection Functions – DC Busbar Protection

HV DC Busbar Differential Protection (87HV)

Page 5 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

DC C&P Training – DC-Protection Functions – DC Busbar Protection

Neutral DC Busbar Differential Protection (87LV)

DC-Filter

IdCH

IdCNIdee1

Idee2

UdH

UdNIdLN

HSNBS

MRTB

IdSG

HSGS

IdLH

33

Uac

UsumY

3UsumD

IacY

IacD

HSNBS

Other Pole

MRSIdLN_op

IdMRS

Page 6 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

Protection Task Faults to ground or high voltage within protection zone

Evaluation Principle Abs(IdLN – IdCN) > threshold, (2 stages)

Initiated Sequences ESOF to Pole Control Open AC circuit breaker Opening of HSNBS

Typical settings 1st stage: Threshold = 0.25 p.u.; Delay time = 50 ms 2nd stage: Threshold = 0.07 p.u.; Delay time = 500 ms

DC C&P Training – DC-Protection Functions – DC Busbar Protection

Neutral DC Busbar Differential Protection (87LV)

Page 7 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

DC C&P Training – DC-Protection Functions – DC Busbar Protection

DC Differential Back-Up Protection (87DCB)

DC-Filter

IdCH

IdCNIdee1

Idee2

UdH

UdNIdLN

HSNBS

MRTB

IdSG

HSGS

IdLH

33

Uac

UsumY

3UsumD

IacY

IacD

HSNBS

Other Pole

MRSIdLN_op

IdMRS

Page 8 April 2009Copyright © Siemens AG 2008. All rights reserved.

Energy Sector - Power Transmission SolutionsE T PS EN21

Protection Task Earth faults at HV or Neutral DC busbars or pole equipment

Evaluation Principle Abs(IdLH – IdLN) > threshold, (2 stages)

Initiated Sequences ESOF to Pole Control Open AC circuit breaker Opening of HSNBS

Typical settings 1st stage: Threshold = 0.25 p.u.; Delay time = 200 ms 2nd stage: Threshold = 0.07 p.u.; Delay time = 1000 ms

DC C&P Training – DC-Protection Functions – DC Busbar Protection

DC Differential Back-Up Protection (87DCB)