1、BSI Standards Publication Technical Guidelines for Radial HVDC Networks PD CLC/TR 50609:2014National foreword This Published Document is the UK implementation of CLC/TR 50609:2014. The UK participation in its preparation was entrusted to Technical Committee GEL/8, Systems Aspects for Electrical Ener
2、gy Supply. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published
3、by BSI Standards Limited 2014 ISBN 978 0 580 83555 1 ICS 29.240.01 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 March 2014. Amendments/corrigenda issued
4、 since publication Date Text affected PUBLISHED DOCUMENT PD CLC/TR 50609:2014 TECHNICAL REPORT CLC/TR 50609 RAPPORT TECHNIQUE TECHNISCHER BERICHT February 2014 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elekt
5、rotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2014 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. CLC/TR 50609:2014 E ICS 29.240.01 English version Technical Guidelines for Radial HVDC Netwo
6、rks Directives techniques pour les rseaux HVDC radiaux Technischer Leitfaden fr radiale HG- Netze This Technical Report was approved by CENELEC on 2013-12-09. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Est
7、onia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. PD CLC/TR 50609:20
8、14CLC/TR 50609:2014 2 Contents Page Foreword 7 0 Introduction 8 0.1 The European HVDC Grid Study Group . 8 0.2 Technology . 9 0.2.1 Converters 9 0.2.2 DC Circuit . 9 0.2.3 Technological Focus of the European HVDC Grid Study Group 10 1 Scope . 12 2 Terminology and abbreviations 12 2.1 General 12 2.2
9、Terminology and abbreviations for HVDC Grid Systems used in this report 12 2.3 Proposed Terminology by the Study Group 13 3 Typical Applications of HVDC Grids 14 3.1 The Development of HVDC Grid Systems 14 3.2 Planning Criteria for Topologies . 15 3.2.1 General 15 3.2.2 Power Transfer Requirements 1
10、6 3.2.3 Reliability 17 3.2.4 Losses . 19 3.2.5 Future Expansions. 21 3.3 Technical Requirements 21 3.3.1 General 21 3.3.2 Converter Functionality 22 PD CLC/TR 50609:2014 3 CLC/TR 50609:2014 3.3.3 Start/stop Behaviour of Individual Converter Stations 23 3.3.4 Network Behaviour during Faults 24 3.3.5
11、DC-AC Interface Requirements 25 3.3.6 The Role of Communication . 26 3.4 Typical Applications Relevant Topologies . 27 3.4.1 General 27 3.4.2 Radial Topology . 27 3.4.3 Meshed Topology 29 3.4.4 HVDC Grid Systems Connecting Offshore Wind Power Plants 29 3.4.5 Connection of a wind power plant to an ex
12、isting HVDC VSC link 30 4 Principles of DC Load Flow. 31 4.1 General 31 4.2 Structure of Load Flow Controls 31 4.2.1 General 31 4.2.2 Converter Station Controller 31 4.2.3 HVDC Grid Controller 32 4.3 Converter Station Control Functions . 34 4.3.1 General 34 4.3.2 DC Voltage (U DC ) Stations . 34 4.3
13、.3 Active Power (P DC ) and Frequency (f) Controlling Stations 34 4.4 Paralleling Transmission Systems . 35 4.4.1 General 35 4.4.2 Paralleling on AC and DC side . 35 4.4.3 Paralleling on the AC side 35 4.4.4 Steady-State Loadflow in Hybrid AC/DC Networks 36 PD CLC/TR 50609:2014CLC/TR 50609:2014 4 4.
14、5 Load Flow Control 38 4.5.1 DC Voltage Operating Range 38 4.5.2 Static and Dynamic System Stability . 39 4.5.3 Step response 39 4.6 HVDC Grid Control Concepts 40 4.6.1 General 40 4.6.2 Voltage-Power Droop Together with Dead Band 45 4.6.3 Voltage-Current Droop 48 4.6.4 Voltage-Power Droop Control of
15、 the HVDC Grid Voltage . 54 4.7 Benchmark Simulations of Control Concepts . 57 4.7.1 Case Study . 57 4.7.2 Results 58 4.7.3 Conclusions . 60 4.7.4 Interoperability . 61 5 Short-Circuit Currents and Earthing 61 5.1 General 61 5.2 Calculation of Short-Circuit Currents in HVDC Grid Systems . 61 5.3 Net
16、work Topologies and their Influence on Short-Circuit Currents . 63 5.3.1 Influence of DC Network Structure 63 5.3.2 Influence of Line Discharge 66 5.3.3 Influence of Capacitors . 67 5.3.4 Contribution of Converter Stations 69 5.3.5 Methods of Earthing 72 5.4 Secondary Conditions for Calculating the
17、Maximum/Minimum Short-Circuit Current . 73 5.5 Calculation of the Total Short-Circuit Current (Super Position Method) 74 PD CLC/TR 50609:2014 5 CLC/TR 50609:2014 5.6 Reduction of Short-Circuit Currents 75 6 Principles of HVDC Grid Protection . 76 6.1 General 76 6.2 HVDC Grid System . 77 6.3 AC/DC Co
18、nverter 78 6.3.1 General 78 6.3.2 DC System 79 6.3.3 HVDC Switchyard. 80 6.3.4 HVDC System without Fast Dynamic Isolation . 80 6.3.5 HVDC System with Fast Dynamic Isolation 80 6.4 DC Protection 81 6.4.1 General 81 6.4.2 DC Converter Protections . 81 6.4.3 Protective Shut Down of a Converter 83 6.4.4
19、 DC System Protections . 84 6.4.5 DC Equipment Protections . 84 6.5 Clearance of Earth Faults 84 6.5.1 Clearance of a DC Pole-to-Earth Fault . 84 6.5.2 Clearance of a Pole-to Pole Short Circuit . 85 6.5.3 Clearance of a Converter side AC Phase-to-Earth Fault . 85 7 Functional Specifications 85 7.1 G
20、eneral 85 7.2 AC/DC Converter Stations . 86 7.2.1 DC System Characteristics . 86 7.2.2 Operational Modes. 89 7.2.3 Testing and Commissioning . 95 PD CLC/TR 50609:2014CLC/TR 50609:2014 6 7.3 HVDC breaker . 96 7.3.1 System Requirements . 96 7.3.2 System Functions 96 7.3.3 Interfaces and Overall Archit
21、ecture . 96 7.3.4 Service Requirements . 96 7.3.5 Technical System Requirements . 96 Annex A (informative) HVDC Grid Control Study 99 Annex B (informative) Fault Behaviour of Full Bridge Type MMC 106 B.1 Introduction 106 B.2 Test Results 106 B.3 DC to DC Terminal Faults 106 B.4 DC Terminal to Ground
22、 Faults 107 B.5 Conclusion 107 Bibliography . 119 PD CLC/TR 50609:2014 7 CLC/TR 50609:2014 Foreword This document (CLC/TR 50609:2014) has been prepared by CLC/TC 8X “System aspects of electrical energy supply”. Attention is drawn to the possibility that some of the elements of this document may be t
23、he subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CENELEC by the European Commission and the European Free Trade Association. This document was already sent out within
24、CLC/TC 8X for comments and the comments received were discussed within CLC/TC 8X/WG 06 and were incorporated in the current document as far as appropriate. PD CLC/TR 50609:2014CLC/TR 50609:2014 8 0 Introduction 0.1 The European HVDC Grid Study Group Existing power systems in Europe have been develop
25、ing for more than 100 years to transmit the power, generated mainly by fossil and nuclear power plants to the loads. Climate change, limited fossil resources and concerns over the security of nuclear power are drivers for an increased utilization of renewable sources, such as wind and solar, to real
26、ize a sustainable energy supply. According to the geological conditions, the location of large scale renewable energy sources is different to the location of existing conventional power plants and imposes new challenges for the electric power transmission networks, such as extended transmission capa
27、city requirements over long distances, load flow control and system stability. The excellent bulk power long distance transmission capabilities, low transmission losses and precise power flow control make High Voltage Direct Current (HVDC) the key transmission technology for mastering these challeng
28、es, in particular for connection of offshore wind power plants to the onshore transmission systems. While the power system reinforcement is already underway by a number of new point-to-point HVDC interconnections, the advantages offered by multiterminal HVDC systems and HVDC grids become more and mo
29、re attractive. Examples are grid access projects connecting various wind power plants or combining wind plants with point-to-point transmission, e.g. in the North and Baltic Seas. Multiterminal projects are already in execution and there is planning for pan-European HVDC grids. In this document, mul
30、titerminal HVDC systems and HVDC grids are referred to as HVDC Grid Systems. To become reality, HVDC Grid Systems need, in addition to the necessary political framework for cross country system design, construction and operation, competitive supply chains of equipment capable of operating together a
31、s an integrated system. This marks a significant change in the HVDC technology market. While today - with very few exceptions a HVDC transmission system has been provided by a single manufacturer, future HVDC Grid Systems will be built step by step composed of converters and HVDC substations supplie
32、d by different manufacturers. Interoperability will thus become a fundamental requirement for future HVDC technology. Common understanding of basic operating and design principles of HVDC Grid Systems is seen as a first step towards multi vendor systems, as it will help the development for the next
33、round of European multiterminal projects. Furthermore, it will prepare the ground for more detailed standardization work. Based on an initiative by the DKE German Commission for Electrical, Electronic and Information Technologies, the European HVDC Grid Study Group has been founded in September 2010
34、 to develop “Technical Guidelines for first HVDC Grids”. The Study Group has the following objectives: to describe basic principles of HVDC grids with the focus on near term applications; to develop functional specifications of the main equipment and HVDC grid controllers; to develop “New Work Item
35、Proposals” to be offered to CENELEC for starting standardization work. CIGR SC B4, CENELEC TC8x and ENTSO-E and “Friends of the Supergrid” are involved at an informative level with the results of the work. Members affiliated with the following companies and organizations have been actively contribut
36、ing to the results of the Study Group achieved so far: 50 Hz Transmission, ABB, ALSTOM, Amprion, DKE, PD CLC/TR 50609:2014 9 CLC/TR 50609:2014 TransnetBW, Energinet.dk, ETH Zurich, National Grid, Nexans, Prysmian, SEK, Siemens, TenneT and TU Darmstadt. As a starting point the Study Group has been in
37、vestigating typical applications and performance requirements of HVDC Grid Systems. This information helps elaborating the basic principles of HVDC networks, which are described in the following clauses: Clause 3, Typical Applications of HVDC Grids; Clause 4, Principles of DC Load Flow; Clause 5, Sh
38、ort-Circuit Currents and Earthing; Clause 6, Principles of HVDC Grid Protection. From the technical principles described, functional specifications for the main equipment of HVDC networks are derived and summarized in Clause 7. 0.2 Technology 0.2.1 Converters HVDC transmission started more than 60 y
39、ears ago. Today, the installed HVDC transmission capacity exceeds 200 GW worldwide. The vast majority of the existing HVDC links are based on so-called Line- Commutated-Converters (LCC). LCC today are built from Thyristors. The power exchange of such converters is determined by controlling the point
40、on-wave of valve turn-on, while the turn-off occurs due to the natural zero crossing of valve current forced by the AC network voltage. That is why LCC rely on relatively strong AC systems to provide conversion from AC to DC and vice versa. With so-called Voltage Sourced Converters (VSC), a differen
41、t type of converters has been introduced to HVDC transmission slightly more than a decade ago. VSCs today utilize Insulated Gate Bipolar Transistors (IGBT) as the main switching elements. IGBTs have controlled turn-on as well as turn-off capability making the VSCs capable of operating under weak AC
42、system conditions or supplying power systems where there is no other voltage source, also referred to as passive networks. The evolution of VSC transmission was started with so-called Two-Level converters at the end of the 1990s and has commenced to Three Level Converters and further to Modular Mult
43、ilevel Converters (MMC) which have made their break-through in the mid to late 2000s. All MMC type converters apply the same principle of connecting a number of identical converter building blocks in series. However, at the present time there are basically two types of such building blocks: referred
44、 to as Half-Bridge (HB) and Full- Bridge (FB) modules. Other converter equipment which have been proposed for HVDC Grid applications, such as DC/DC converters, load flow controllers, etc. are not discussed in this document. 0.2.2 DC Circuit Similar to AC networks, HVDC transmission systems can be di
45、stinguished by their network topologies as radial and/or meshed networks and with respect to earthing in effectively grounded and isolated systems. Both aspects influence the design criteria and the behaviour of the HVDC system. PD CLC/TR 50609:2014CLC/TR 50609:2014 10 Radial and Meshed Topologies:
46、In radial systems, there is not more than one connection between two arbitrary nodes of the network. The DC voltages of the converter stations connected to each end of a line solely determine the power flow through that line, for example in Figure 1-1, station C is radially connected with station D.
47、 In meshed systems, at least two converter stations have more than one connecting path. Without any additional measures the current through a line will then be determined by the DC voltages of the converter stations as well as the resistances of the parallel connections. In Figure 1-1, the DC circui
48、t connecting stations A, B and C forms a meshed system while C and D is a radial connection. A HVDC Grid System having a meshed topology can be operated as a radial system if parallel connections are opened by disconnectors or breakers. A B C DFigure 1-1 Example of an HVDC Grid System having a meshe
49、d and radial structure Earthing: DC circuits can be effectively grounded if one DC pole is connected to earth through a low ohmic branch. Such systems are also referred to as asymmetrical Monopoles or just “Monopoles”. Two Monopoles of opposite DC voltage polarity are often combined into so-called bipolar systems or just “Bipoles”. Isolated DC circuits do not have a low ohmic connection to ground on the DC side. These configurations are also referred to as “Symmetrical Monopoles”. 0.2.3 Technological Focus of the European HVDC Grid Study Group Va
