Technical Specification for an Overhead Line Real …...purchase of the Overhead Line (OHL)...

Document Reference: CLNR-L149

Version: 1.0 Date of Issue: December 2014 1

Copyright Northern Powergrid (Northeast) Limited, Northern Powergrid (Yorkshire) Plc, 2014

Technical recommendation for the purchase of overhead line Real Time Thermal Rating systems

1 Purpose The purpose of this document is to set out and describe the technical requirements developed, that enabled the

purchase of the Overhead Line (OHL) Real-time Thermal Rating (RTTR) System applied on the Northern

Powergrid High and Extra High Voltage power distribution networks that were trialled on the Customer-Led

Network Revolution project.

2 Scope This recommendation details the technical requirements for all equipment to be used in the calculation of OHL

RTTR; including line-mounted sensors, remote weather stations and computing equipment (that may be

located in primary or secondary sub-stations, remote servers or control rooms).

The document applies to RTTR equipment at operating voltages:

High Voltage (>1000V, < 22kV as specified in ENA ER 43-3);

Extra High Voltage (≥ 22kV, < 132kV as specified in ENA ER 43-3);

This recommendation includes the interfacing requirements with a remote server. A summary table of the

supplier/product technical compliance is given in Appendix 1 & 2 for manufacturers to complete, detailing any

variation.

Manufacturers are encouraged to offer more than one option if they have a number of possible solutions. The

technical requirements detailed in the main body of this document are generic. Additional site specific data will

be discussed with the potential supplier.




Contents

1 Purpose ................................................................................................................................................1

2 Scope ...................................................................................................................................................1

2.1 Contents.........................................................................................................................................2

3 Technical Requirements ....................................................................................................................3

3.1 General ..........................................................................................................................................3

3.2 Equipment Mounting ......................................................................................................................4

3.3 Equipment Specification ................................................................................................................4

3.4 RTTR Model...................................................................................................................................5

3.5 Weather Measurement Device Outputs ........................................................................................7

3.6 Communication between System Components.............................................................................7

3.7 Safety .............................................................................................................................................8

4 References ...........................................................................................................................................9

4.1 External Documentation ................................................................................................................9

5 Definitions ......................................................................................................................................... 10

Appendix 1 – Schedule of Suppliers Technical Data ............................................................................ 11

Appendix 2 – Self Certification Conformance Declaration................................................................... 15

Appendix 3 – Addendum to Supplier Requirements ............................................................................ 18

Appendix 4 - Pre-commission testing, Routine Inspection and Maintenance requirements ........... 19

Appendix 5 - Technical Information Check List .................................................................................... 20

Appendix 6 – Schedule of Components ................................................................................................. 21

Appendix 7 – Electromagnetic Compatibility ........................................................................................ 22




3 Technical Requirements

3.1 General

The constituent components of an OHL RTTR system are:

On-line measurement devices

Local controllers

Weather stations

Communications hubs

RTTR calculation engines

Single weather stations and RTTR calculation engines should be capable of being used to support multiple sites.

All equipment intended for outdoor installation shall be environmentally tested to IP55 and all internal equipment to IP52 in accordance with BSEN 60529. All equipment should be capable of operating under conditions of shock and vibration normally encountered in service on UK distribution networks. The dimensions of all equipment should be specified by the suppliers. All equipment with a real-time clock should be capable of synchronisation with an Internet Engineering Task Force (IETF) standard Network Time Protocol version 4 (NTPv4) server.

3.1.1 On-line Measurement Devices

It must be feasible to install line-mounted equipment using approved live-line procedures at voltage levels where live-line working is permitted by DNO safety rules. Higher voltage levels will require an outage to install, but installation should be such that ladder access from towers is sufficient and scaffolding is not required.

The device shall have a backup battery, rechargeable from scavenged or renewable sources, and capable of providing no less than 48 hours backup power. The time to fully charge the battery shall be no more than 24 hours. The power source(s) adopted shall be sufficient and suitable to ensure that the battery is kept charged at all times under weather and loading conditions expected in the UK.

The device shall have sufficient on-board non-volatile storage for at least 40 minutes of readings at the maximum operating rate.

3.1.2 Weather Measurement Devices

If anemometers are used to record weather data whilst attached to poles or towers they shall be the electronic type mounted from the side of the structure with prevailing wind so as to avoid wind shading. The preferred distance from the pole shall be 10 pole diameters (where practicable).

3.1.3 Local Controller

The local controller shall have a backup battery, rechargeable from local renewable sources, and capable of providing no less than 48 hours of backup power. The time to fully charge the battery shall be no more than 8 hours.




3.2 Equipment Mounting

3.2.1 Line-Mounted Equipment

Equipment should be designed for attachment directly onto the overhead line conductors. Devices should be suitable for application onto conductors with conductor cross-section area ranging between 16mm

2 and

500mm2 depending on the specific line being rated. Further information should be sought on the specific line

construction, although flexibility in this regard would be very desirable.

Suppliers should provide details confirming that no corrosion issues will be created due to large variances in the electro-chemical series of the conductor and any metallic components within the installed device that have direct contact with the conductor.

3.2.2 Pole, Tower or Remote – Mounted Equipment

The equipment should be designed for permanent attachment to an appropriate wood pole through the use of M12 or M16 galvanized coach screws or mounted on steel towers. Where fixture is required to towers, this should be achieved through the use of bolted brackets or clamps that fit around existing steel members. Under no circumstances should the fixing require drilling of any tower members.

3.2.3 Substation Equipment

Where appropriate, equipment may be located in a substation. A standard 19” rack shall be used for housing the equipment in this case.

3.3 Equipment Specification

Table 1: Device technical specifications

Parameter Weather Measurement

Device On-line Measurement Device Local Controllers

Power supply From Local Controller Line current scavenge with battery

backup Solar Power with battery

backup

Backup battery endurance N/A 48 hours 48 hours

Backup battery re-charge time

N/A 24 hours 8 hours

Operating temperature -20°C to 40°C -20°C to 80°C -20°C to 40°C

Maintenance Annually > 3 years > 3 years

Lifetime >10 years >10 years >10 years

Maximum weight 25kg 8kg 25kg

Sampling rate 5 minute capability(user

configurable) 5 minute capability (user

configurable) 5 minute capability(user

configurable)

Operating voltage ≤50V AC

≤120V DC 0 to 220kV

≤50V AC

≤120V DC




Parameter Weather Measurement

Device On-line Measurement Device Local Controllers

UV stability Stable in accordance with BS

2782-5: method 22A Stable in accordance with BS 2782-5:

method 22A Stable in accordance with BS

2782-5: method 22A

Unit impact resistance 2 Joules 2 Joules 2 Joules

Humidity levels 0 – 100% 0 – 100% 0 – 100%

Mounting location Pole, Tower or Local Line Pole or Tower

Minimum operating line current

Not applicable 5% of full scale current Not applicable

Full Scale Current Not applicable 50% above the P27 ratings for the

line Not applicable

Fault withstand

(Line-size, Fault Current, Duration)

Not applicable

66kV, 20kA, 3s

33kV, 20kA, 2s

20kV, 10.1kA, 2s

11kV, 13.1kA, 2s

Not applicable

3.4 RTTR Model

3.4.1 RTTR Calculation Engines (Thermal Models)

The RTTR model is the software responsible for calculating the line-rating using parameters measured by the on-line measurement device and weather station. The model shall be based on one of the standard models listed in Table 2.

Table 2: Thermal Models

Thermal Models

IEC/TR 61597 Ed. 1.0 b:1995

IEEE 738-2006

CIGRE WR 22.12 : 2002 (or as updated)

It is recommended that the values that give the same rating as ENA ER P27 at the defining conditions are used, unless there is a compelling reason offered to the contrary. Parameters that should be fixed unless otherwise specified by the Network Operator are listed in




Table 3. It should be noted that absorptivity and emissivity will change with ageing assets for example; new Aluminium conductors have absorptivity of the order of 0.2 to 0.3. Old aluminium conductors have an absorptivity which approaches 0.9.




Table 3: Fixed Parameters

Fixed Parameters

Yaw Angle 12°

Corona heating 0

Evaporative cooling 0

Magnetic Heating 0

Solar gain 0

Absorptivity of conductor 0.9

Emissivity of conductor 0.8

Radial conductivity 4 W / m.K

Parameters used in the thermal models that depend upon the characteristics of the equipment from which measurements are taken will vary. These parameters are listed in Table 4 and shall be specified at each installation location. Other parameters for use within the model should be calculated or measured directly.

Table 4: Site Dependent Parameters

Parameters

Conductor Type and Size

Conductor Resistance @ 20°C per unit length

Temperature coefficient of resistance for conductor

Pole/Tower span and height above terrain

Minimum electrical clearance and conductor temperature at time of installation

Standard(s) that the line is designed to (e.g. design temperature, minimum clearance).

3.4.2 Weather Interpolation and Controlled Degradation

It is desirable that the calculation engine should be able to predict line temperature (and hence) ratings between weather measurement sites, both to reduce the number of weather measurement sites installed, and to enable the system to continue to operate (albeit with degraded accuracy) when one or more weather stations are not working. If offered, suppliers should provide practical trial evidence of their system’s efficacy and accuracy in performing such interpolation.




3.4.3 RTTR Model Outputs

A list of the outputs that the system should be able to send to a remote point is given in Table 5; these may be calculated or measured directly. All output parameters should be time-stamped with an accuracy of ±5 seconds and a precision of ±1 second. All time parameters are to be accepted and output in UTC. An option to convert to configurable local time zones for user interaction may be provided. Where additional outputs are available these should be specified by manufacturers. Health indicators should be provided. RTTR settings should be configurable, including:-

Changes in network configurations, for example a normally open-point is closed;

Changes in maximum and minimum ratings, types of component;

Change of settings – manufacturers should list the settings that are configurable.

Table 5: RTTR model outputs

Accuracy Precision Range Other

Ampacity Defined 1 A 0 → Max Rating Average over 5 min.

Conductor Current ±1% 1 A 0 → 150% of the P27 ratings for

the line Average over 5 min.

Conductor Temperature ±2 °C 1 °C -20 °C to 80 °C Average over 5 min.

Health Indicator NA NA NA Heartbeat/Handshake

3.5 Weather Measurement Device Outputs

The weather measurement device should provide the data listed in Table 6. The specification should be for an electronic anemometer which can cater for low wind speed and have device reliability. The device must be capable of measuring low wind speeds (between 0.05 and 0.5 m/s) accurately otherwise the ratings during low wind speeds will be unnecessarily pessimistic, restricting capacity and increasing call on load management systems. Where additional outputs are available these should be specified by manufacturers.

Table 6: Weather measurement device output


Ambient temperature ±1°C 0.1°C -20°C to 50°C Average over 5 min.

Wind Speed ±0.1 m/s 0.1 m/s 0-60 m/s Average over 5 min.

Wind direction ±2° 1° 0 - 359° N Average over 5 min.

3.6 Communication between System Components

All systems should be suitable to communicate with industry standard SCADA protocols; this should be via direct communication or by using an intermediate device. The preferred protocols are likely to be DNP3 or IEC 61850. In all cases the communications equipment must be compliant with the EMC requirements given in Appendix 7. The manufacturer will be required to agree the communications protocol and format of data with the purchasing Network Operator. For applications considering 3G and GPRS communications, roaming SIM card compliance is required.




3.7 Safety

Live line working is permitted on UK Distribution Networks, typically up to 33kV although limits do vary. This is

subject to suitable working practices being developed and the appropriate health and safety policies. Potential

suppliers should comply with their statutory obligations under the Construction (Design and Management)

Regulations 2007, in particular to avoid foreseeable risks to those involved in the installation and further use of

the equipment. A list of appropriate BS, ENA standards and guidelines are given at the end of this document;

these should be adhered and conformed to. Manufacturers should provide example procedures, method

statements and risk assessments to the Network Operator to facilitate the assessment of safe installation

procedures, for both live and dead installations.




4 References The products described within this recommendation should comply with the latest versions of the relevant International Standards, British Standard Specifications and all relevant Energy Network Association Technical Specifications (ENATS) current at the time of supply.

4.1 External Documentation

Reference Title

BS 215 Part 2: 1970 Aluminium stranded conductors for overhead power transmission

BS 2782:method 552A Methods of testing plastics — Optical and colour properties, weathering — Determination of changes in colour and variations in properties after exposure to

daylight under glass, natural weathering or laboratory light sources

BS 7884: 1997 Copper and copper cadmium stranded conductors for overhead electric traction and power transmission systems

BS EN 50183: 2000 Conductors for overhead lines – Aluminium-magnesium-silicon alloy wires.

BS EN 60801-2 : 1993 Electromagnetic compatibility for industrial-process measurement and control equipment. Electrostatic discharge requirements

BS EN 61000 Electromagnetic compatibility

BS EN 61000-4-2 :2009 Electrostatic Discharge Immunity test

BS EN 61000-4-3 :2006 +A2:2010 Testing and measurement techniques. Radiated, radio-frequency, electromagnetic field immunity test

BS EN 61000-4-4:2004-07 Testing and measurement techniques - Electrical fast transient/burst immunity test

BS EN 61000-6-2 :2005 Generic standards - Immunity standards for industrial environments.

BS EN 61000-6-3:2007 +A1:2011 Generic standards - Emission standards for residential, commercial and light-industrial environments

BSEN60529 Degrees of protection provided by Enclosures (IP Code)

ENA ER P27, 1986 Current operating guide for high voltage overhead lines in the UK distribution system.

IETF RFC 5905 Network Time Protocol Version 4: Protocol and Algorithms Specification

IETF RFC 5906 Network Time Protocol Version 4: Autokey Specification

IETF RFC 5907 Definitions of Managed Objects for Network Time Protocol Version 4

The supplier should provide with the tender full technical details of the equipment offered and should indicate any divergence from these standards or specifications.




5 Definitions

Term Definition

BS British Standard

CIGRE International Council on Large Electric Systems

DNO Distribution Network Operator

EMC Electromagnetic Compatibility

ENA Energy Networks Association

GPRS General Packet Radio Services (GPRS) is a packet-based wireless communication service that provides data rates from 56 up to 114 Kbps and continuous connection to the Internet for mobile phone and computer users.

GPRS is based on Global System for Mobile (GSM) communication system.

IEC International Electrotechnical Commission

IEEE Institute of Electrical and Electronics Engineers

IETF Internet Engineering Task Force, a standards organisation for the Internet

IP Ingress Protection

LAN Local Area Network

Minimum electrical clearance of conductor

A measurement of the smallest distance between the conductor and ground

NA Not Applicable

NTP Network Time Protocol (see IETF RFC 5905)

OHL Overhead line

Pole/Tower Span A measurement of the distance between the two poles/towers which support conductor.

RFC Request For Comment, a standardisation document issued by the IETF.

RTTR Real Time Thermal Ratings

Solar Irradiance A measure of how much solar power available at a given location. This irradiance varies throughout the year depending on the seasons. It also varies throughout the day, depending on the position of the sun in the sky,

and the weather (Measured in kWh/m2/day)

UTC Universal Coordinated Time, the international time standard with no seasonal changes to which all other time zones are referenced (aligned to GMT in UK winter).

UV Ultraviolet

WAN Wide Area Network




Appendix 1 – Schedule of Suppliers Technical Data The following Technical schedules must be completed by suppliers

Thermal Models (Table 2)

Thermal Models Conformity with, (Yes / No)

IEC/TR 61597 Ed. 1.0 b:1995

IEEE 738-2006

CIGRE WR 22.12 : 2002

Fixed Parameters (Table 3)

Fixed Parameters Conformity with, Yes / No

If no, please detail value used.

Wind speed < 2m/s Yaw angle to line is set at 12°

Corona heating 0

Evaporative cooling 0

Magnetic Heating 0

Global Solar Radiation 0

Absorptivity of conductor 0.9

Emissivity of conductor 0.8

Radial conductivity 4 W / m.K

Site Dependent Parameters (Table 4)

Parameter Value

Conductor Type and Size

Conductor Resistance @ 20°C per unit length

Temperature coefficient of resistance for conductor

Pole/Tower span and height above terrain

Minimum electrical clearance and conductor temperature at time of installation




Parameter Value

Standard(s) that the line is designed to (e.g. design temperature, minimum clearance).

RTTR Model Outputs (Table 5)


Ampacity

Conductor Current

Conductor Temperature

Health Indicator

Weather measurement device output (Table 6)


Ambient temperature

Wind Speed

Wind direction

Ability to accept expected Inputs

Input Comments

Change of settings - manufacturer should list the settings that are configurable.




Weather measurement devices - (Compliance with Table 1)

Parameter/Component Comments

Power supply

Ingress protection

Operating temp.

Maintenance

Lifetime

Maximum weight

Sampling rate

Operating Voltage

UV stability

Unit impact resistance

Humidity levels

Mounting location

On-line measurement devices - (Compliance with Table 1)


Power supply

Ingress protection

Operating temp.

Maintenance

Lifetime

Maximum weight

Sampling rate

Operating Voltage





UV stability


Humidity levels

Mounting location

Minimum operating current

Maximum operating conductor temperature

Fault withstand

(Fault Current, Duration)

Local controller (Compliance with Table 1)


Power supply

Ingress protection

Operating temp.

Maintenance

Lifetime

Maximum weight

Sampling rate

Operating Voltage

UV stability


Humidity levels

Mounting location




Appendix 2 – Self Certification Conformance Declaration

Supplier/Product Technical Compliance Grid (to be completed by the supplier for each variant offered).

The “on-line” measuring devices, weather stations and local controllers shall comply with the latest issues of the IEC’s and British Standards quoted within this specification.

Key elements from the above standards and this specification have been quoted to amplify and/or clarify the requirements of those Standards.

This check sheet identifies the particular clauses of the aforementioned Standards relevant to overhead-line RTTR systems.

The manufacturer shall declare conformance or otherwise, clause by clause, using the following levels of conformance declaration codes for each conductor.

Conformance declaration codes:

N/A = Clause is not applicable/ appropriate to the product

Cs1 = The product conforms fully with the requirements of this clause

Cs2 = The product conforms partially with the requirements of this clause

Cs3 = The product does not conform to the requirements of this clause

Cs4 = The product does not currently conform to the requirements of this clause, but the manufacturer proposes to modify and test the product in order to conform.

Note: Separate Self Certification Conformance Declaration sheets shall be completed For each product being offered. Manufacturer: Product Reference: Name: Signature: Date:

Instructions for completion

• When Cs1 code is entered no remark is necessary

• When any other code is entered the reason for non-conformance shall be entered

• Prefix each remark with the relevant ‘BS EN’ or ‘ENATS’ as appropriate




Specific requirements within this specification

Clause/Sub-clause Requirements Conformance Code Remarks

Table 1 Compliance with device technical specifications

Table 2 Compliance with one or more specified thermal model(s)

Table 3 Compliance with fixed parameters

Table 4 Compliance with site dependent parameters

Table 5 Compliance with RTTR model outputs

Table 6 Compliance with wind measurement device outputs




Electromagnetic Compatibility

Clause/Sub-clause Requirements Conformance

Code Remarks

BS EN 61000-6-3:2007

Emission standards for residential, commercial and light industrial environments.

BS EN 61000-6-2:2005 Immunity Standards – Immunity for industrial environments

BS EN 60801-2:1993 EMC for industrial-process measurement and control equipment – Electrostatic discharge requirements Min values Air – 4kV Contacts – 8kV

BS EN 61000-4-3:2002 EMC – Radiated, radio- frequency, electromagnetic field immunity test Min Values 27Mhz – 1Ghz @ 10V/m 80Mhz – 1Ghz @ 10V/m

IEC 61000-4-4:2004 EMC – Electrical fast transient/burst immunity test Min values +/- 1kV

BS EN 61000-4-6:2007 EMC - Immunity to conducted disturbances induced by radio frequency fields Min Values 150khz – 80Mhz @ 10V/m




Appendix 3 – Addendum to Supplier Requirements

Please indicate Packaging/delivery information

Details of how this product will be packaged and delivered shall be provided.

Please indicate dimensions of RTTR system components

Details of the individual RTTR system component dimensions shall be provided.

Please indicate options for location of the calculation engine

Details of how the calculation engine software can be hosted.

Project specific requirements

Any project specific requirements will be provided by the purchasing Network Operator for inclusion in this appendix.




Appendix 4 - Pre-commission testing, Routine Inspection and Maintenance requirements

Suppliers shall provide details of any recommended pre-commission testing or installation requirements.

Additionally suppliers shall also provide information regarding any periodic inspection or maintenance

requirements to be undertaken during the lifetime of their product.




Appendix 5 - Technical Information Check List The following information shall be provided by the supplier for technical review by the purchasing Network Operator. Additional information shall be provided if requested.

Requirement Provided (Y/N)

Appendix 1 – Completed technical schedules Appendix 2 – Completed self-certification conformance declaration Appendix 4 – Inspection and testing recommendations Appendix 7 – Electromagnetic compatibility Type test evidence Routine test plan (example) Packaging/delivery information




Appendix 6 – Schedule of Components

Item Description Price

1 Weather Measurement Devices

2 On-line measurement devices.

3 Local controllers

4

5

6




Appendix 7 – Electromagnetic Compatibility

Electromagnetic Compatibility Tests for equipment

All equipment shall be compatible with the following generic EMC standards:

• BS EN 61000-6-3: 2007 - Generic Emissions standard • BS EN 61000-6-2: 2005 - Generic Immunity standard • BS EN 61000-4-2: 1995 - Electrostatic discharge immunity Test ((Requirement Air 8kV, Contact 4kV) • BS EN 61000-4-3: 2006 Radiated radio Frequency, Electromagnetic Field Immunity. (Requirement

80MHz-1GHz @ 10V/m) • BS EN 61000-4-6: 2007 Immunity to conducted disturbances induced by radio frequency fields (Requirement 150kHz - 80MHz @ 10V/m) • BS EN 61000-4-4: 2004 Electrical Fast Transient/Bursts Immunity (Requirements +/- 1kV).

Technical Specification for an Overhead Line Real …...purchase of the Overhead Line (OHL)...

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