Maintenance vital to profitability

Paul Boughton

Deregulation of the energy markets is still increasing the competition among utilities and good operations and maintenance procedures are now key to maintaining profitability.

US development company Battelle says the losses associated with poor operation and maintenance cost industry billions of dollars each year. Companies that automate the process of diagnosing faults and performance degradation in equipment can also lower costs and increase profits by increasing the life-cycle of critical components.

The company has developed a generic automated diagnostic tool that uses existing instrumentation to assess the state of a plant and its relation to proper operating conditions. Using a combination of neural networks and fuzzy logic principlesthe diagnostician predictsidentifies and diagnoses degradation and faults in equipment according to customer needs. It can be applied to valvesheat exchangerscompressorsfiltersgeneratorsboilersand electrical equipment.

Ternathe owner of the main Italian transmission networkis one utility that is upgrading its management systems. As part of its Sicas Standard automation project for substationsit has contracted Siemens Power Transmission and Distribution to develop and install a new integrated substations automation system.

All functions plus the human interface and telecontrol gatewaysfit into a new concept that Terna has developedbased on the communication standard IEC 61850. Covering 40 bays and worth E4.6 millionthe master order will be executed over a period of three years.

IEC 61850 is the standard for a seamless communication solution for electric substations and the basis for decentralised power generation. It subsections cover protection and control; integration of innovative sensor and switch technologies; remote monitoring and fault diagnosis; asset management; and condition monitoring. It is a global standard that uses mainstream technologies such as EthernetTCP/IPObject modellingand XML.

With the Sicas Standard projectthe company aims not only to standardise functions and equipment in its substations but to improve plant management and unattended remote control. Terna expects multiple benefits from the application of communication standard IEC 61850 and a more efficient power system management.

Northern project

Further northABB has been selected by Energinet of Denmarkand StatnettNorwayto upgrade the control system of the 30-year-old Skagerrak 1&2 high voltage direct current (HVDC) link with a new ABB system called MACH 2. Samir Brikhohead of ABB’s Power Systems divisions says: “This will extend the link’s life by another 30 years.”

MACH 2 is distributed over an Ethernet LAN and enables control of the HVDC from process images; event recording; on-line help functions and direct access to plant documentation. It also provides alarm handling; remote control; access to standard applications such as e-mailword processingspreadsheetinternet; and automatic performance report generation.

Where internet access is requiredRunpower is a web enabled maintenance management software system from Runenergy specifically tailored for power generation facilities. It organises maintenance recordsfacilitates maintenance scheduling and provides quick reports which give immediate feedback on plant performance in support of operations and maintenance of power plants.

The software has been designed as an easy and cost effective way to manage power plant maintenance and monitoring. It records plant data; generates reports; provides built-in equipment lists ready for populating with site specific data; and schedules maintenance.

For a total viewcreation of an intelligent electricity grid promises utilities and their customers substantial advances in power reliability and enhanced services says the IntelliGrid Consortium.

The Consortium comprises electricity utilitiespublic agencies and equipment manufacturers. It will provide a process and tools to help design smart systems that will seamlessly integrate with other systems through a common data and communications link. The Consortium says this will enable organic growth of a smart electricity grid as opposed to the creation of a new monolithic system that could have a high probability of difficulty in implementation.

One of its tasks is to help develop automated meter readingwhich requires intelligent meters with a communication port. This will incorporate IEC 61850 principleswhich is an integral part of the IntelliGrid architecture.

Hardware

GE Energy has recently announced the availability of its D400 substation data managerwhich offers greater computing powermemory and future upgradability than other products in the industry today. Key applications for the D400 include intelligent electronic devices (IED) integrationnon-operational data managementnetwork security and SCADA system interfaces.

The D400 was developed to meet industry requirements for a securesubstation-gradedata-processing platform with easy to use configuration tools and a built-in human machine interface (HMI) that offers network security.

Other key features include automated fault record management; integrated HMI functionalitywhich eliminates the need for a PC in the substation; IEC 61131 control sequence programming; and IEC 61850 substation local area network support.
Dan Heintzelmanpresident of energy services for GE Energysays: “Our D400 substation data manager has four to ten times more computing power than traditional productswith larger memory and options for expansionincluding the acceptance of functional upgrades in the future.”

ABB offers a novel lifecycle health care service for high voltage installations called Doctor Switchgear. It aims to avoid unexpected outages or sudden re-investments. It is based on the company’s experienceparticularly with legacy switchgearand is supported by spare parts and upgrading services.

Carl Öhlenof ABB High Voltage Productssays the service protects any investment worldwide by extending equipment life expectancy and adapting old installations to meet modern standards.

He says that switchgear reliabilityespecially in surge arrestersis particularly important from both an operational and safety points of view. The service first assesses the installation based on a scorecard using predefined inspection criteria. From this a risk assessment is made which identifies installations to be investigated further. Finallynecessary work is then implemented.

ABB will assemble life extension kits consisting of new parts for retrofitting through to a complete refurbishment service including remanufacturingreplacement and installation of new units. A periodical check up completes the service. The policy of ABB is to maintain an inventory of emergency spare parts for immediate shipmentincluding parts from other manufacturers.

Interfacing

But all these operations and maintenance systems have to produce results and the most efficient way is for them to interface directly with field equipment. Eliminating the human interface saves timemoney and the possibility of human error butmost importantlyit frees off staff for those functions it is best atwhich is planning and managing.

A key piece of equipment is the automatic transfer switch (ATS) and Mike Carrmarketing manager of Generac Power Systemssays this is vital in emergency power systems and can be supplied in several different configurations to suit the application.
It will sense the presence or loss of utility powercommand the stand-by generator to start up or shut down and transfer the electrical load between its normal and standby power source. It can also be used to test run a genset periodically.
For applications that use paralleled generators as the standby power sourcemultiple ATS systems provide a convenient way to manage the load. In a paralleled generation systemload must be sequenced onto the generators to avoid overloading the first generator online. This requires the ATS to have an inhibit transfer option that will be interconnected with system load management.

The open transition transfer switch is the most common type of ATS and the least complexthough it is both mechanically and electrically interlocked. When transferring the electrical loadit functions in the break before make manner – that isit disconnects the load from the previous source before making connection with the new source.

Closed transition transfer switches (CTTS) eliminate momentary power interruption during planned transfers when both power sourcesthe utility supply and the generatorare present. The CTTS functions in the make before break mannerand is essential when an uninterrupted transition is important. Generac sells throughout the USA.
GE Zenith Controls says thatin critical applications such as hospitals and airportspower cannot be interrupted for maintenance of automatic transfer switches. In such circumstancesa bypass-isolation switch is essential and is often required by safety codes.
The company offers its ZBTS Series Bypass-Isolation Transfer Switches as the solution when interruption of power during service or testing is not acceptable. Consisting of two major modulesthe Automatic Transfer and the Bypass-Isolation Switchthe ZBTS Series offers rugged construction with a quick make/quick break manual load transfer handle and control interlock system which consists of both mechanical and electrical interlocks.

GE Zenith Controls’ ZTGD Series switches are built for delayed transition applications. These offer an adjustable time delay during transfer from one position to another. This is primarily for transfer of large motor or inductive loads and allows such loads to re-energise after transfer with only normal inrush starting currents.

The new Model SE expands the time-tested Series ZTG platform to serve more applications than ever before. This provides greater protection to critical loads against utility power outages and transient voltage disturbances. ZTGSE switches are equipped with GE’s next-generation embedded MX150 microprocessor panelwhich controls the operation and indicates the status of the transfer switch’s position and available sources.

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