Power Transmission Division Link between power generation and distribution

Transcription

1 Power Transmission Division Link between power generation and distribution Seite 4

2 High Voltage Substations Schemes, Devices and Types of AIS Installation Content Link between power generation and distribution Transmission and distribution network Typical substations feeders and their devices Circuit configurations Design criteria of HV substations Types of HV substations Note: All topics are only referring to the substation design without control-, protection and other auxiliary systems! Seite 5

3 Transmission of electrical Energy From Power Plant to Consumer Power Generation Power Plant Power Transmission e.g. Overheadline 420 kv Power Distribution Overheadline / Cable z.b. 36 kv Power Transmission Step-up Substation e.g. 20/420 kv Power Distribution Step-down Substation e.g 420/123/36 kv Power Distribution e.g. Cable, 420/230 V Power Consumer Industry / Households e.g. 420/230 V Medium Voltage High Voltage Medium Voltage Low Voltage Seite 6

4 Voltage Levels Transmission and Distribution Low Voltage LV High Voltage HV Medium Voltage MV 30 kv (36 kv) 20 kv (24 kv) 10 kv (12 kv) 690 V 6kV (7,2 kv) 400 V 230 V Extra High Voltage EHV 150 kv (170 kv) 132 kv (145 kv) 110 kv (123 kv) 52 kv (66 kv) Ultra High Voltage UHV 500 kv (550 kv) 380 kv (420 kv) 220 kv (245 kv) 1200 kv 1100 kv 800 kv There is not strict rule or standard defining Low-, Medium- and High Voltage levels. Seite 7

5 Principle of anetwork Connection from Generation to Consumer 380 kv Network grid Power Plant 110 kv Substation Due to renewable energy sources power plants are more and more decentralized! 20 kv Substation 10 kv Substation 0,4 kv Seite 8

6 Typical Network elements Generator Shunt Reactor Bus Coupler Power Transformer Busbar Circuit breaker Current-limiting reactor Cable Netstation M Motor Overhead Line Charging currentlimitation reactor Filter Consumer Seite 9

7 Network configuration Radial-line connection Meshed network Radial network Seite 10

8 High Voltage Substation Definitions Substations (S/S) are node points in the transmission and distribution networks of electrical energy in all voltage levels up to 1100 kv (1200 kv planning stage). Asubstation is the entirety of all devices (switchgear, control, protection and measuring equipment) and auxiliary systems necessary to ensure the reliable operation. Predominate task is the connection and isolation of overhead lines, cables, gasinsulated lines and transformers. Substation types are related to the function in the network: S/S attached to power station Interconnection S/S Step-up /step-down S/S Seite 14

9 High Voltage substation Definitions The voltage level depends on the power and short-circuit capacity and the distance. Distributionnetworks are operated predominantly up to 145 kv. Power transmission systems and ring mains around urban areas operate in all voltage levels above, depending on local conditions. Over very large distances, extra high powers are also transmitted by highvoltage direct-current systems. Substations can be air-insulated (AIS) and gas-insulated (GIS) and installed indoors and outdoors. Seite 15

10 High Voltage substation Definitions The starting point for planning asubstation is its single-line diagram. This indicates: Electrical substation data Circuit configuration Number and type of feeders Location and designation of feeders Associated devices and their designation Feeders are in- and outgoing lines or cables and connection to transformers, reactors and filters, which are connected to the busbar. Seite 16

11 High Voltage substation Typical feeder Busbar (BB) Busbar disconnecting switch Circuit breaker Current transformer Outgoing disconnecting switch Earthing switch Line trap Voltage transformer Surge arrester Seite 17

12 High Voltage substation Typical feeder Busbar BB Central node point for power accumulation and distribution Spatial arrangement of rigid and flexible conductors Number of busbar is one factor for operational flexibility and availability Sectionalizing of busbar is increasing the flexibility. Individual sections can operate independently Abusbar failure can leads to aoutage of the substation Seite 18

13 High Voltage substation Typical feeder Circuit breaker CB Most important device within aswitchgear feeder, because the CB is controlling the load flow from and to the busbar Capability of making, carrying and breaking currents under normal conditions (rated current) and under abnormal conditions (short circuit current) Ability of single- or triple auto-enclosures, depending on feeder type Seite 19 Types available: Live tank CB interrupter unit compartment is on line potential Dead tank CB interrupter unit is on earth potential

14 High Voltage substation Typical feeder Disconnecting switch DS Isolating of substation parts (safety reasons) by performing an isolating distance in the open position Capability of opening and closing negligible current (< 0,5A) Capability of carrying currents under normal and abnormal conditions Worldwide more than 10 different types. Mostly used: Centre break DS, Double-break DS, Vertical break DS, Pantograph DS Seite 20

15 High Voltage substation Typical feeder Current transformer CT Transforming the high primary currents to measurable values (1 A, 5A) Galvanic isolation between high voltage on primary side and earth potential of secondary facilities Supply input data for control, protection and measuring facilties and systems with specific core types Types: oil-insulated and gas-insulated Seite 21

16 High Voltage substation Typical feeder Earthing switch ES For earthing and short-circuiting acc. to safety regulations Discharging of switched-off lines and cables Capable to carry short-circuit currents in closed position Types: Freestanding earthing switches,mounted to post insulators ES Built-on earthing switches to disconnecting switches DS/E Seite 22

17 High Voltage substation Typical feeder Line trap LT Necessary by power line carrier system (PLC) to filter frequencies Has to be used together with capacitors or capacitive voltage transformers Types: standing and suspension type Seite 23

18 High Voltage substation Typical feeder Voltage transformer VT, CVT Transforming the high primary voltage to measurable values (e.g. 110 V) Galvanic isolation between high voltage on primary side and earth potential of secondary facilities Supply input data for control, protection and measuring facilties andd systems Types: inductive (VT) and capacitive (CVT) Seite 24

19 High Voltage substation Typical feeder Surge arrester SA Protection of important equipment, particularly transformers, from atmospheric overvoltage and switching overvoltage Considering certain protection zone limitations Types: Porcelain and Composite housings Seite 25

20 High Voltage substation Typical for in-/outgoing feeder types Cable feeder Overhead line Transformer feeder feeder BB 1 BB 1 BB 2 BB 2 M M M M M M Seite 26

21 Circuit configurations Types of coupler feeder 2BB -Coupler 3BB -Coupler M M Coupler feeder increase the flexibilty and allows agroup operation. Beispiel: UW Reuter, Berlin Seite 27

22 Circuit configurations Types of busbar sectionalzer 1SS -Sectionlizer 2SS -Sectionalizer M M M M Sectionalizer devide the busbar in sections and increase the flexibilty. Seite 28

23 Circuit configurations Types of coupler 2BB -Bus-tie coupler 2BB -Bus-tie and bus coupler BB1 A BB1 B BB1 BB2 BB2 A BB2 B M M M M Seite 29

24 Circuit configurations Types of bus coupler 3BB Sectionalizer in combination with bus-tie and coupler Beispiel: UW Reuter, Berlin Seite 30

25 Circuit configuration Selecting criteria The type of the substation depending on the function in the network requires different consideration of the following criteria: Security Response of the substations configurationby internal and external faults Availability Considering the reliability of installed equipment (reliability calculation) Flexibility Ability to rearrangethe feeders and split up the substation Seite 31 Accessibility Ability to keep feeders/devices energized during maintaining high voltage components

26 Circuit configurations Overview of classical types Single Busbar Single busbar with transfer busbar Double Busbar Double BusbarwithBypass disconnector Three Busbar One and a half Circuit Breaker configuration Two Circuit breaker configuration Ringbusbar 1 BB 1BB/TB 2 BB 2BB / Bypass 3BB 1,5 CB 2CB RBB Seite 32

27 Selected Circuit configurations Single busbar (1 BB) Double busbar (2 BB) One and half Circuit breaker (1,5 CB) Triple busbar (3 BB) Seite 33

28 Circuit configurations Single busbar (1 BB) M M Field of application Step-down substations HV /MV-network Industrial areas Wind parks Features Little switching flexibility Limited availability in case of busbar and disconnector maintanance and failure In case of extension the whole substation has to be shut-down Sample isthespecial form of a single busbar, the H-configuration Alternative: Additional busbar sectionalizer and bus-tie coupler increase the flexibility and allows agroup operation. Seite 34

29 Circuit configurations Single busbar with transfer busbar (1 BB/TB) Field of application Step-down substations HV /MV-network Features Improved switching flexibility than 1BB With the Bypass-Disconnector and the transfer busbar the Coupler CB can substitute any other CB Improved availability in case of busbar and disconnector maintenance and failure Little security against busbar faults Sample is the special form of a single busbar, the H-configuration Seite 35

30 Circuit configurations Double busbar (2 BB) Alternative: Coupler feeder in combination with sectionalizer increases the flexibility Field of application Network nodes, power plants, Large substations meshed networks Features High system security High flexibility and availability for meshed networks Interrupted power supply during maintenance of CB or CT Busbar maintenance with shut downof the feeders Uninterrupted supply by failing of one busbar with coupler Sample is the special form of a single busbar, the H-configuration Seite 36

31 Circuit configurations Triple busbar (3 BB) Field of application Network nodes, power plants, Large substations meshed networks Features High system security Higher flexibility andavailability for meshed networks than 2BB Interrupted power supply during maintenance of CB or CT Busbar maintenance with shut downof the feeder Uninterrupted supply by failing of one busbar with coupler Sample isthespecial form of a single busbar, the H-configuration Seite 37

32 Circuit configurations One and half Circuit breaker (1,5 CB) Field of application Network nodes, power plants Large substations with high loads Not in meshed networks Features High system security High availability due to additional CB Uninterrupted power supply during maintenance of CB or CT All devices capable full BB load Uninterrupted power supply by failing of one BB Sample is the special form of a single busbar, the H-configuration Seite 38

33 Circuit configurations Double busbar Two-Circuit breaker (2 CB) Field of application Network nodes, power plants, Large substations with high loads Features Highest system security and availability dueto2nd CB High flexibility Uninterrupted supply by failing of 1 busbar Uninterrupted power supply during maintenance of CB Busbar maintenance with shut downof Sample isthespecial the feeder form of a single busbar, the H-configuration Seite 39

34 Circuit configurations Ringbusbar (RBB) Field of application Smaller Distribution S/S Features Maximumsecurity against BB faults (no busbar) Minimum outage for maintenance Uninterrupted power supply during maintenance of CB Capability of device for double feeder current Not easy to extend Sample isthespecial form of a single busbar, the H-configuration Seite 40

35 Our High Voltage Substation Solutions Gas-Insulated Substations Air-Insulated Substations Gas-Insulated Switchgear GIS Highly Integrated Switchgear HIS Switchgear Bay SIMOBREAKER SIMOVER Dead Tank Switchgear Bay Seite 41

36 Gas-Insulated Switchgear Product Portfolio Rated short-breaking current (ka) 63 8DN9 8DQ1 8DR DN Seite Rated voltage (kv)

37 High Voltage Substation AIS Arrangements 500 kv 110 kv 380 kv 220 kv Seite 43

38 High Voltage Substation Basic requirements Electrical Requirements Nominal System voltage Rated voltage Rated current, feeder and busbar Rated frequency Short-circuit current Short duration power frequency withstand voltage Rated lightning impulse withstand voltage Rated switching impulse withstand voltage Creepage distance Minimum clearances Seite 44

39 High Voltage Substation Basic requirements Environmental and siteconditions Ambient temperature (min /average /max) Seismic conditions Wind Altitude Pollution level Available space Existing transmission lines Seite 45

40 High Voltage Substation Basic standards (IEC) IEC IEC Power installations exceeding 1kV AC Part 1 Common Rules Insulation coordination Part 1: Definitions, principles and rules IEC Insulation coordination Part 2: Application guide IEC Short-circuit currents Calculation of effects Part 1 Definitions and calculation methods IEC/TR IEC IEC Guide for the selection of insulators in respect of polluted conditions Common specification high-voltage switchgear and controlgear standards Instrument transformers IEC High-voltage switchgear and controlgear -Part 100 High-voltage alternating-current circuit-breakers IEC High-voltage switchgear and controlgear -Part 102 Alternating current disconnectors and earthing switches IEC High-voltage switchgear and controlgear -Part 203 Gas-insulated metal-enclosed switchgear for rated voltages > 52 kv DIN EN Operation of electrical installations Seite 46

41 High Voltage Substation AIS Arrangements Air-insulated substation arrangement means the physical arrangement of high voltage devices for realization of an electrical circuit configuration with all the additional necessary components. The name of the arrangement is derived from: Type and arrangement of busbar disconnector Arrangement of the fields Number of Circuit-Breakers Seite 47

42 High Voltage Substation AIS Arrangements Circuit configuration Single busbar (1 BB) H-Configuration Double busbar (2BB) 11/2Circuit breaker configuration (special solution of 2 BB) Arrangement Single busbar Double busbar H-Arrangement In-line arrangement Centre-tower arrangement Diagonal arrangement 11/2 Circuit breaker arrangement (special solution of 2BB) Ring configuration Ringarrangement There is no preferred substation arrangement. All arrangements have under certain conditions advantages and also disadvantages. Seite 48

43 High Voltage Substations 1BB H-Arrangement H-Arrangement -Substation with2 overhead lines und 2transformers and abusbar sectionalizer respectively bus tie. Solutions with 2or CB s are also possible. Used in the 110 kv level Seite 49

44 High Voltage Substations 1BB H-Arrangement Design: Simple and clear arrangement Less material Space saving Few gantries Devices: Live tank CB Centre break disconnectors Tubular busbar Seite 50

45 High Voltage Substations 2BB In-line arrangement Siemens calls this design Kiellinien arrangement Busbar disconnectors are in-line under the busbar phases. Mainly used in110 kv level, but also for 220 kv a low cost solution Seite 51

46 High Voltage Substations 2BB In-line arrangement Design: Clear arrangement Less gantries with tubular busbar High bay width Less bay depth Devices: Live tank CB Centre break disconnectors, inline Tubular busbar Seite 52

47 High Voltage Substations 2 BB Centre tower arrangement This arrangement is called medium-high or classical arrangement. Voltage level mainly 220 kv Seite 53

48 High Voltage Substations 2BB Centre tower arrangement Design: Small bay width Simple by-passing of the circuitbreaker current transformers Combination High effort for the gantries 3levels of conductors Devices: Live tank CB Centre break disconnectors, sideby-side arrangement Strained busbar Seite 54

49 High Voltage Substations 3 BB Diagonal arrangement Diagonal arrangement because of the location of disconnecting switches under the busbar. Typical for German transmission network Seite 55

50 High Voltage Substations 3 BB Diagonal arrangement Design: Small bay depth and width Less gantries Complete isolation of BB Expensive pantograph disconnectors Devices: Live tank CB Pantograph disconnectors, diagonal arranged Tubular busbar Seite 56

51 High Voltage Substations 1,5 Circuit breaker arrangement For power transmission substation above 220 kv Sample 500 kv diameter Seite 57

52 High Voltage Substations 1,5 Circuit breaker arrangement Design: Alot of equipment Alarge number of gantries Big of space requirement Devices: Live tank CB Vertical break/centre break /Double break disconnectors Strained/tubular busbar Seite 58

53 High Voltage Substations 1,5 Circuit breaker arrangement Step-down distribution substation 1,5 CB arrangement with Dead tank Circuit breaker Sample 220 kv Seite 59

54 High Voltage Substations 1,5 Circuit breaker arrangement Design: Alot of equipment Alarge number of gantries Big of space requirement Devices: Live tank CB Vertical break/double break disconnectors Strained busbar Seite 60

55 High Voltage Substations need reliable High Voltage Devices The substation basic requirements Electrical data Environmental and site conditions together with requirements from the substation design Load data Phase distance are input data for the design of High Voltage Devices. Seite 61

56 High Voltage Substations Thank you for your attention! Seite 62