Abstracts - VGB PowerTech Journal 6/2009
High Frequency Deviations within the European Power System - Origins and Proposals for Improvement
Tobias Weißbach and Ernst Welfonder
The resulting higher power plant stress which has to be included in cost calculation for primary control, as well as the increasing amount of required secondary control energy are inevitably going to lead to higher control energy costs. Furthermore, a large part of the primary control reserve power is no longer available due to frequency deviations. The presented proposals for improvement include a two-stage complementary realisation of measures.
Effect of Increasing Wind Power Production on the Power Plant Operation in Germany
Harald Weber and Christian Ziems
Today, all over the world the number of installed wind turbines is increasing continuously. This causes more and more problems concerning the integration of the fluctuating wind power production into the existing electrical supply systems. To handle these problems the main aim for the future must be to guarantee the security of supply and the quality of electrical energy by taking the maximum advantage of the available wind potentials. Application strategies as well as thermal limits of current power plant engineering are analysed.
From Blackout towards a “Smart Grid” – Prospects of Power System Developments
Dietmar Retzmann, Dusan Povh and Dietrich Biester
The paper provides an overview about the large “blackouts” of interconnected electricity grids and measures for their avoidance are discussed. The avoidance of loop flows and voltage collapse as well as the elimination of stability problems are introduced together with the implementation of electrical firewalls. The benefits of HVDC (High Voltage Direct Current) and FACTS (Flexible AC Transmission Systems) for system enhancement are explained.
Integration in Power Control Systems as a Key for Higher Transparency and Security
Jörg Kinast
The need for higher efficiency, more flexible use of power generation capabilities and the demand for high availability results in process control systems that have to meet higher requirements than ever. Today, the focus is on the entire plant. This results in the application of integrated solutions in control technology. The integrated approach avoids double work as well as mistakes and offers more safety and transparency in daily routines.
Compliance with Grid Code Proofed by Simulations of the Transient Behaviour of Steam Turbines Connected to the Electrical Grid
Jens Rosendahl, Martin Bennauer, Heribert Werthes and Martin Lösing
The transient behaviour of large-scale steam turbine power plants is of major interest regarding voltage and grid frequency stability both for grid failures and for fast load changes. In order to comply with requirements of the Transmission Code 2007, the steam turbine controller has to meet highest demands. This paper specifies the steam turbine controller during abnormal operations like 3-phase short circuit and load rejection.
Fully Automatic and Self-learning Process Optimisation to Increase Efficiency of Large-scale Power Plants by Correlation of Data from the Process Control System with Optical and Acoustic Information
Alexander Carl Hanf
Economic necessities have led to new challenges for the operation of coal steam generators in large power plants. The strongly fluctuating quality, in particular of imported coal, design and coal-dependent uneven distribution of pulverised coal results in a sub-optimal combustion air distribution if classical control concepts are used. This has a direct negative impact on efficiency. By using a system package consisting of intelligent software and optical sensors for flame analysis and acoustic sensors for milling degree analysis, the fuel-/air-ratio for each burner and over the burner levels is optimised.
Optimisation of the PSC 7 Automation System in Plant II at Pfleiderer AG's Site in Gütersloh
Guido Niehaves and Stephan Gaerisch
Standard DIN 19222 Process Control and the VGB Guidelines VGB 170 B0 to B6 form the basis for the system architecture of process control in power plants and industrial generation facilities. There is a trend towards the development of open system architecture. This pertains to hardware as well as to software. The emphasis lies on system flexibility and long-term upgradeability. What is needed is the standardisation of the concepts, functions, interfaces and technologies. The benefits gained are high investment security and low costs due to technical continuity. Many tasks can be completed in a few steps when using a typical-based, power plant-specific library. The benefits of this approach are illustrated by an upgrading measure performed on a CHP plant – PCS 7 migration, integration of the boiler protection and burner control system and replacement of the turbine governor.
Opening up a New Era Power Plant Control Performance
Bernd Lamb, Klaus Wendelberger and Bernhard Meerbeck
In order to obtain smooth and stable boiler operation with a conventional control concept it was necessary to use the turbine as stabiliser for main steam pressure. The SPPA-P300 APC (Advanced process control)-based control structure no longer requires this kind of stabilisation. By using the APC, main steam pressure can be stabilised without influencing the turbine load set point. The electrical load can follow its set point with a very high accuracy. Still, the pressure control deviations are as small as they were before. Control performance will not degrade even if the dynamic response of the boiler changes due to wear and tear, fouling, changing coal quality or similar factors.
Heat Pipes - A Novel Cooling Principle for Generator Circuit Breakers
Dieter Braun, Giosafat Cavaliere, Kurt Dahinden and Martin Lakner
Generator circuit-breakers have to meet high requirements in terms of their current carrying and short-circuit current interrupting capability. An increase of the rated current of a given circuit-breaker can only be achieved by improving the heat transfer to the environment. The application of „heat pipes“ in generator circuit-breakers can effectively transfer heat across a large electrical potential.
Making the Most of Available Assets – How Intelligent Add-on Technology Helps to Upgrade Boiler Performance
Alexander Voß, Alexander Hlawenka, Michael Haug and Michael Schreiber
The efficiency and availability of a coal-fired power unit are mainly determined by the combustion and steam generation process. The add-on system EUcontrol optimises combustion process, limits emissions, increases boiler efficiency and reduces operating costs. It is able to target special problems like flame ball imbalances and slagging phenomena and to initiate appropriate measures.
Cooling Water and Heat Exchanger Materials – Aspect to be Considered in the Revised Version of the VGB Cooling Water Guideline
Frank-Udo Leidich and Hans-Günter Seipp
The VGB Guidelines entitled “Tubes for Condensers and Other Types of Heat Exchangers (R 106 L, Copper Alloys; R 113 L, Stainless Steel; R 114 L, Titanium)” will be revised. In the revised version of the cooling water guideline VGB-R 455 all aspects of material application, resulting from the activities in connection with the above guidelines, have to be highlighted. This has to be done against the background of the development of future power plants with an extended application range of heat exchangers, as well as the worldwide development of market, manufacturers and power plant operators in view of the procurement, availability and delivery time of high-quality semi-finished products.
Continuous Acid Dew Point Measurement in Coal-fired Power Plants
Holger Födisch, Jörg Schulz, Petra Schengber and Gabriele Dietrich
The reduction of flue gas losses is one option to increase power plant efficiency. The target is the optimised low waste gas temperature. When applying lignite and other high-sulphur fuels the temperature of the flue gas is mainly determined by the acid dew point. Temperature of the flue gas system is to amount some 10 to 20 K above the assumed acid dew point. The acid dew point measuring system AMD 08 is able to detect the real acid dew point in a quasi-continuous way. Thus, it is possible to deliberately decrease waste gas temperature.
Element Analysis in Mineral Oils with X-Ray Fluorescence – An Easy Task?
Jürgen Wess
Determination of element concentrations and additives in lubricating oils is among the most important analyses in power plant analytics. Methods for analysing debris and the efficiency of additives have been developed. X-ray fluorescence spectrometry (XRF) established quickly in this field. The unknown mineral oil matrix, influences by additive elements and the complex geometry of the excitation in the sample have to be taken into account. A new approach for solving these tasks will be introduced and applied. A significant improvement in accuracy is obtained.