Integrated Condition Monitoring for High Voltage Cables: Direct link to SCADA / substation automation

The intrinsic temperature measuring system DTS based on LIOS Technology’s design, with fibre optic sensors either installed within the power cable’s cross section (FIMT - Fibre in metal tube ) or attached to the exterior of the cable, makes it possible to record the temperature profile along an entire cable route continuously, and to pinpoint the exact location of hot spots within a metre.

Most commonly the measured temperature profile data is transmitted via standard interfaces from systems of the DTS as required, and be either displayed or further processed by PC, PLC or SCADA systems. As a result of the increasing demands placed on the ability to network and integrate measuring systems into management systems, LIOS offers network components that summarise DTS data from several DTS units and transport or convert it to the required network standards and protocols like Modbus, DNP3, IEC60870-5 or XML based data interfaces (e.g. POSC).

Equipped with the Embedded Communication Module (ECM) the Distributed Temperature Sensing (DTS) evaluation unit is accessible by Ethernet/ LAN, holds its own IP address and is compatible with DHCP.
The on-board storage facility of measurement data provides automatic buffering of network break downs. It can handle multiple protocols, so the DTS can be directly linked to PLC or SCADA systems and communicates in various industrial protocol standards providing measured data and customised alarm information.
Hereby, the evaluation unit communicates as a TCP /IP server with several clients.

Features of the embedded communication module of the LIOS DTS controller:

• Configuration and operation of the DTS via two independent channels:
  
  
  • RS232
  • Ethernet TCP/IP
  
  
• Onboard storage of measurement data
  
  
  • Buffers up to 72 hours of measurement data and initiates data transfer automatically after communication link was re-established
  • Individual file access to measurement data through CHARON_02 (onboard data storage 1 GB)
  
  
• Allows to operate individual Plug-In-Interfaces for customer specific protocol solutions
  
  
  • The DTS can communicate in parallel with its proprietary protocol and one or more customer specific protocols like DNP3, IEC60870-5-104, IEC61850, POSC WITSML, Modbus (Master/Slave) etc.
  • Individual assignments for protocols and client addresses (IP) possible
  
  
• Ethernet communication to and from clients with high bandwidth
• Module comes with built-in user configurable Firewall and enables reliable operation even in WAN’s
• Secure data transmission and individual authorisation according TLS- Standard (RFC 2246)

The most common industrial protocols used in electrical systems worldwide are introduced in the following section. However, also other protocol standards are available or can be implemented for the ECM. Please contact us in case of questions.

MODBUS
The MODBUS protocol was published by Modicon in 1979. It is a quite simple single master – multiple slave protocol widely used in general purpose SCADA applications. It provides binary (bit) and 16-bit integer data, but no floating point values, polled by the master, i.e. the slave cannot send data spontaneously. The protocol specification is openly published and royalty-free. In the DTS ECM, TCP/IP is used as transport layer.

IEC 60870-5
IEC 60870-5 provides a communication profile for sending basic Telecontrol messages between systems. It was developed by the IEC Technical Committee 57 (Working Group 03) as a protocol standard for Telecontrol, Teleprotection, and associated telecommunications for electric power systems. The result of this work is IEC 60870-5. The protocol provides inter alia bit, integer and floating point data with or without time stamps. Data is transmitted from controlled stations (slaves) either by polling or spontaneously. In the ECM the IEC 60870-5-104 companion standard, defining standard TCP/IP connections as transport layer, is used.

DNP3
DNP3 (Distributed Networking Protocol) is an open standard managed by the DNP User Group. Initially; the DNP3 protocol was developed by Westronic (now GE-Harris) in 1993. It is widely used in electrical systems worldwide, including North and South America, the UK, Southeast Asia, South Africa, Australia, and New Zealand. It has gained wider use beyond electrical utilities, e.g. for water supply as well. The DNP3 protocol is also referenced in IEEE Std. 1379-2000, which recommends a set of best practices for implementing modern SCADA Master-RTU/IED communication links.
The protocol provides bit, integer and floating point data and time stamps. Data is transmitted from the outstation (slave) either by polling or spontaneously. The ECM uses TCP/IP as transport layer, but even in this mode the DNP3 protocol additionally uses its own protocol stack for synchronisation and error checking. This provides extra security.

Condition Monitoring of high voltage cables: Turning information into extra capacity

Increasing demand for power is forcing power utilities to load power cables to their physical limit, and safety and efficiency concerns are making it more and more critical for operators to understand what is happening thermally both inside the cables themselves, and along the cable route.
Real Time Determination of Thermal Conditions along HV Power Cable Systems
During high-load conditions and under emergency circumstances (such as when a failure occurs in a segment of the grid and power must be shifted to other sections to compensate) it often becomes necessary to load cables right up to the limits permitted by the relevant regulations. In these operational situations, it must be ensured that maximum temperature limits are not exceeded. Due to the increasing complexity of the thermal relationships along cable routes, the ability to continuously measure the temperatures along the cable has proven invaluable, providing critical operational data to engineers, especially in the case of a system faults such as a hot spots that could result in cable failure if they are not corrected.
The intrinsic temperature measuring system DTS based on LIOS Technology’s design, with fibre optic sensors either installed within the power cable’s cross section (FIMT – Fibre in metal tube ) or attached to the exterior of the cable, makes it possible to record the temperature profile along an entire cable route continuously, and to pinpoint the exact location of hot spots within a metre. Since the measuring principle employed is purely optical, the presence of electromagnetic influences, which can result in false sensor signals in other technologies, does not affect the DTS unit.
Distributed temperature sensing is a powerful tool that allows the accurate rating of high voltage power cables in real time, and provides the following operating benefits:

• Reduce power outages or blackouts
• Ensure continuity of supply
• Activate hidden capacity reserves of existing assets
• React quickly to overload conditions
• Conduct precisely and in real-time load predictions as new sources of energy are added to the grid

The temperature profile data, in any desired form or format, can be transmitted via standard interfaces from systems of the OTS product series as required, and be either displayed or further processed by PC, PLC or SCADA systems. As a result of the increasing demands placed on the ability to network and integrate measuring systems into management systems, LIOS offers network components that summarise DTS data from several DTS units and transport or convert it to the required network standards and protocols like Modbus, DNP3, IEC60870-5 or XML based data interfaces.
Dynamic Cable Rating
LIOS also provides an integrated Real Time Thermal Rating (RTTR) package via a well defined interface between its DTS data visualisation software and a commercialised – the industry’s de facto standard – cable ampacity program based on IEC standardised methods (mainly IEC 60287 and IEC 60853). Dynamic rating software couples the accurate temperature data provided by the DTS unit to predictive functions of cable ratings, providing engineers with even more information upon which they can base distribution and load decisions. The result is dramatically more efficient transmission of power, fewer “brown-outs”, and decreased operating costs.

Electricity for all, the smart way – visit LIOS at Power Indonesia 2009

LIOS Technology GmbH- Linear Optical Sensors is pleased to invite you to attend Power Indonesia 2009 - the 14th International Power Generation, Transmission and Distribution Exhibition, taking place 14-17 October at the Jakarta International Expo, Kemayoran.

Booth number: A340

In cooperation with our partner Anugrah Mitra International & Anugrah Mira Nusantara we proudly present continuous and cost-effective monitoring solutions for the electric transmission and distribution grid, which are the essential success factors of Smart Grid implementations.

The LIOS DTS product line comprises a range of real-time fibre optic based linear temperature measuring devices (Distributed Temperature Sensing, DTS). LIOS offers Real Time Thermal Rating/ Dynamic Cable Rating (RTTR/ DCR) solutions for ampacity predictions of the power cable and overhead transmission line installation transparently integrated with its field proven DTS systems.

The Electric Indonesia Series 2009 provides a one stop shop for the major elements in the development of the country's electrical sector. For power generation, transmission and distribution Power Indonesia is South East Asia‘s most comprehensive exhibition.
This year over 600 companies from 34 countries will participate showing the huge potential in Indonesia’s Power and Electric Industries. Regional & National Pavilions from Taiwan, Korea, Germany, Czech Republic, Spain, Italy, Singapore, UK, and China will showcase the latest technology and equipment to help meet the countries huge demand for additional power.
Under its vision "Electricity for all", the Government is currently planning to increase power generation by 35,000MW by 2015 at an investment of over US$40Billion.

We look forward to seeing you in Jakarta!

Read more:

	For more information on Power Indonesia 2009 click here
	Distributed temperature monitoring of power cables