QUESTION / CLARIFICATION QC-ENE-001 CO-ORDINATION BETWEEN NOTIFIED BODIES DIRECTIVES 96/48/EC AND 2001/16/EC ON THE INTEROPERABILITY OF THE TRANS-EUROPEAN HIGH-SPEED AND CONVENTIONAL RAILWAY SYSTEMS Issue 01 Date: 17/06/2009 Page 1 of 13 TITLE INTERPRETATION OF TSI REQUIREMENTS ON REGENERATIVE BRAKING ORIGINATOR DET NORSKE VERITAS DANMARK A/S SUBJECT RELATED TO TSI Energy:2002, clause 4.3.1.4 and Annex K DESCRIPTION AND BACKGROUND EXPLANATION It is not clear, whether or not the TSI requires feed-back of energy from the substation to the primary supplying net. Clause K.3 of Annex K concerning energy subsystem considerations states, that The adjudicating entity shall ask the power supply authority to accept the feedback of braking energy into the supply network, when energy cannot be absorbed by other railway consumers. This implies that if the infrastructure manager has asked the owner of the primary network to accept the feedback of energy, then despite the answer from the owner of the primary net the requirement of the TSI is fulfilled. If the answer is no, the possibility of feed-back of energy is not required, if the answer is yes, the possibility of feed-back is required. Clause K.4 of Annex K concerning assessment states, that The substation control and devices shall allow feed-back for energy to the supplying net This implies that in any case, the feed-back of energy from the substation to the primary net shall be possible. The Question is whether feed-back is required or not as stated in Clause K.4 or whether it is optional as described in K.3. These formulations are not clarified in the last version of the revision of the TSI. SUGGESTED RESOLUTION / INTERPRETATION In the case of new building or rebuilding of an energy subsystem including substation(s) for power supply or upgrading of existing substation(s) for power supply: If the owner of the primary net allows the feed-back of energy, it shall be possible to feed back energy from the substation to the primary net If the owner of the primary net does not allow the feed-back of energy, this does not need to be possible In the case of upgrading the energy subsystem of an existing line not including the substation(s) for power supply: The feed-back of energy from the substation to the primary net does not need to be possible ORGANISATION(S) REQUESTED TO RESPOND (E.G. TSI GROUP, RISC, ERA ETC.) TSI GROUP, ERA 15/10/2008 DATE OF AGREEMENT AT NB RAIL PLENARY MEETING QUESTION & CLARIFICATION
QUESTION / CLARIFICATION QC-ENE-001 CO-ORDINATION BETWEEN NOTIFIED BODIES DIRECTIVES 96/48/EC AND 2001/16/EC ON THE INTEROPERABILITY OF THE TRANS-EUROPEAN HIGH-SPEED AND CONVENTIONAL RAILWAY SYSTEMS Issue 01 Date: 17/06/2009 Page 2 of 13 RESPONSE FROM ORGANISATION ABOVE See document TECHNICAL OPINION ON NB-RAIL Q&C-ENE-001 ON REGENERATIVE BRAKING attached. QUESTION & CLARIFICATION
EUROPEAN RAILWAY AGENCY INTEROPERABILITY UNIT TECHNICAL OPINION ON NB-RAIL Q&C-ENE-001 ON REGENERATIVE BRAKING REFERENCE: IU-ENE-090511- TO DOCUMENT TYPE: TECHNICAL OPINION VERSION: 1.0 DATE: 11/05/2009 Name Edited by Reviewed by Approved by Stanislaw LIS Gianvittorio TAVOLA Andrzej Harassek Jean-Charles PICHANT Position Project Officer Adviser Head of Interoperability Unit Date & Signat. 11/05/2009 Page 1 of 13
AMENDMENT RECORD Version Date Section number Modification/description Author 1.0 11/05/2009 Stanislaw LIS Gianvittorio TAVOLA Version 1.0 Page 2/11
Table of Contents European Railway Agency 1. Introduction... 4 2. Abbreviations and references... 5 2.1 Abbreviations... 5 2.2 References... 5 3. General comments... 6 4. Regenerative braking in TSI ENE for AC systems... 7 5. Q&C by NB-RAIL... 9 6. ERA opinion... 11 Version 1.0 Page 3/11
1. INTRODUCTION The present document expresses the Agency opinion about a question and clarification issued by NB-RAIL. The subject is related to requirements for regenerative braking and their mandatory application. Version 1.0 Page 4/11
2. ABBREVIATIONS AND REFERENCES 2.1 ABBREVIATIONS Abbreviation AC CR DC EN ENE HS OCL TSI WP Definition Alternating Current Conventional Rail Direct Current European Standard Energy High Speed Overhead Contact Line Technical Specification for Interoperability Working Party 2.2 REFERENCES Ref. N Document Reference [1] Commission Decision 2002/733/EC concerning the technical specification for interoperability relating to the energy subsystem of the trans-european highspeed rail system referred to in Article 6 (1) of Directive 96/48/EC [2] [3] [4] [5] [6] Commission Decision 2008/284/EC concerning a technical specification for interoperability relating to the energy sub-system of the trans-european highspeed rail system EN 50388 Railway applications Power supply and rolling stock Technical criteria for the coordination between power supply (substation) and rolling stock to achieve interoperability Trans-European Conventional rail system. Subsystem ENERGY - Technical Specification of Interoperability QC-ENE-001: Interpretation of TSI requirements on regenerative braking Directive 2006/32/EC of the European Parliament and of the Council of 5 April 2006 on energy enduse efficiency and energy services and repealing Council Directive 93/76/EEC Last Issue 30/05/2002 06/03/2008 August 2005 January 2009 10/01/2008 27/04/2006 Version 1.0 Page 5/11
3. GENERAL COMMENTS The regenerative braking is the technical solution applying the physical phenomena that electric engines can behave as a consumer of energy in case of propelling mode (supply energy -> motor -> kinematic) and as a generator of energy in case of braking (kinematic -> generator - > supply energy). The regenerative braking is in line with the European policy to reduce the amount of energy consumed in transport (see also Dir. 2006/32/EC [6]). This is also strongly supported by operators of trains because it reduces energy consumption costs. This solution is widely used in AC traction supply systems. Current technologies allow producing energy during regenerative mode free from harmonics and other disturbances having impact on the quality of energy delivered by the supplier to other consumers. For these reasons regenerative braking for AC traction supply systems shall be mandatory for the infrastructure and the rolling stock and is considered as an important aspect of the target system. Version 1.0 Page 6/11
4. REGENERATIVE BRAKING IN TSI ENE FOR AC SYSTEMS The regenerative braking is considered as a basic parameter for energy subsystem. TSI ENE HS Commission Decision 2002/733/EC of 30/05/2002 [1] 4.3.1.4. Regenerative braking The AC energy supply systems shall be designed to permit the use of regenerative braking as a service brake able to exchange power seamlessly with other trains or with the primary network supplier. Reference is made to Annex K to this TSI. Train equipment shall allow the use of other braking systems where regenerative braking is not possible. The adjudicating entity can decide whether or not to accept regenerative braking on DC systems. The register of infrastructure as defined in Annex D to this TSI shall contain necessary information. Conformity assessment for fixed installations shall be carried out as specified in Annex K (K.4) to this TSI. For rolling stock conformity assessment shall be carried out as specified in the rolling stock TSI. Annex K 3. ENERGY SUBSYSTEM CONSIDERATIONS The energy subsystem has to be designed in such a way that regenerative braking can be used as a service brake. The adjudicating entity shall ask the power supply authority to accept the feedback of braking energy into the supply network, when the energy cannot be absorbed by other railway consumers. 4. ASSESSMENT The substation control and protection devices shall allow feed-back for energy to the supplying net. The connecting diagrams shall allow the assessment. Revised TSI ENE HS Commission Decision 2008/284/EC of 06/03/2008 [2] 4.2.4. Regenerative braking AC power supply systems shall be designed to permit the use of regenerative braking as a service brake, able to exchange power seamlessly either with other trains or by any other means. The substation control and protection devices in the power supply system shall allow regenerative braking. DC power supply systems are not required to be designed to permit the use of regenerative braking as a service brake. However, where it is permissible to do so, it shall be recorded in the Infrastructure Register. The fixed installations and their protection devices shall permit the use of regenerative braking unless the conditions described in EN 50388:2005 Version 1.0 Page 7/11
clause 12.1.1 occur. Conformity assessment for fixed installations shall be carried out according EN 50388:2005, clause 14.7.2. EN 50388:2005 [3] 14.7.2 Substation The substation control and protection devices shall allow feed-back energy to supplying net. The analysis of the connecting diagrams allows the assessment. Where required, combined system test shall be undertaken to verify correct operation of substation protection with regenerative traction unit on line. Resuming: In HS it is mandatory to design the AC system to allow feed-back of energy to the grid; Version 1.0 Page 8/11
5. Q&C BY NB-RAIL In general, in each version of TSI ENE, the design of the energy subsystem for AC traction supply shall allow the feed-back of energy during regenerative braking to the grid. The question raised by NoBo [5] is: It is not clear, whether or not the TSI requires feed-back of energy from the substation to the primary supplying net. Clause K.3 of Annex K {of Commission Decision 2002/733/EC [1] editor`s note} concerning energy subsystem considerations states, that The adjudicating entity shall ask the power supply authority to accept the feedback of braking energy into the supply network, when energy cannot be absorbed by other railway consumers. This implies that if the infrastructure manager has asked the owner of the primary network to accept the feedback of energy, then despite the answer from the owner of the primary net the requirement of the TSI is fulfilled. If the answer is no, the possibility of feed-back of energy is not required, if the answer is yes, the possibility of feed-back is required. Clause K.4 of Annex K concerning assessment states that The substation control and devices shall allow feed-back for energy to the supplying net This implies that in any case, the feed-back of energy from the substation to the primary net shall be possible. The Question is whether feed-back is required or not as stated in Clause K.4 or whether it is optional as described in K.3. These formulations are not clarified in the last version of the revision of the TSI. And the suggested resolution: In the case of new building or rebuilding of an energy subsystem including substation(s) for power supply or upgrading of existing substation(s) for power supply: If the owner of the primary net allows the feed-back of energy, it shall be possible to feed back energy from the substation to the primary net If the owner of the primary net does not allow the feed-back of energy, this does not need to be possible In the case of upgrading the energy subsystem of an existing line not including the substation(s) for power supply: The feed-back of energy from the substation to the primary net does not need to be possible The problem is focused on the second sentence of Annex K, point 3 in the TSI ENE HS 2002 (see text in 4 of this report), now repealed by the Commission Decision 2008/284/EC [2], which could create doubts: although the subsystem shall be designed to allow regenerative braking, the IM shall ask the power supply authority to accept the feedback of braking energy into the supply network, when the energy cannot be absorbed by other railway consumers. The position of NB-RAIL is to question the general requirement and give the possibility to the IM to design the subsystem according to the agreement he has Version 1.0 Page 9/11
with the supplier i.e. if the supplier does not accept the feed-back of energy the IM can built a new (upgrade) subsystem without provision for the feed-back of regenerated energy. Version 1.0 Page 10/11
6. ERA OPINION The problem was discussed during the meetings of the ENE WP (on 05/11/2008 and 16/12/2008) and also in NB-RAIL meeting of the ENE mirror group on (25/09/2008). The opinion of the WP strongly supports the general rule of accepting the feedback of regenerated energy to the grid by the supplier as a target system: this is a commonly used approach supported by European policy for energy efficiency. The cost of adaptation of substation to this function is limited to 1-2.5 k. The main reason why a supplier is not able to accept the energy coming back from the IM, is the quality of that energy. This happens especially when locomotives and substations are not equipped with filters eliminating disturbances on the fed-back energy. It is not a case for new installations and vehicles, designed according to current technologies and compatible with TSI. Taking all into account not acceptance of the regenerative braking shall be treated as an exceptional and temporary state. Considering the above mentioned aspects, ERA proposal which is as follow: the design of the subsystem for AC supply systems shall allow feed-back of energy to the grid during regenerative mode. A similar approach will be applied to the draft CR TSI ENE. Version 1.0 Page 11/11