No abstract available

[en] A simulation study is performed for the purpose of determining the transient stability characteristics of superconducting alternators. This simulation is compared with an equal area criterion method. It is found that superconducting machines have good transient stability characteristics, that field forcing is not particularly helpful nor necessary. It is also found that the equal area criterion is useful for computing critical clearing times, if voltage behind subtransient reactance is held constant. (U.S.)

[en] The relationship between stiffness and sizes of the foundation arises much trouble to the designer because of the conflicting solution they require. The dynamic behavior studies of the foundations show the interest of the low fundamental frequency foundation. However, classical solutions, valuable for 3000rev/mn running speed machineries, are not suitable for large 1500 rev/mn running speed turbo-generator of nuclear power plants. A new design chosen by Electricite de France is dealt with

[en] Modern air-cooled turbo-generators are simply constructed and thus inexpensive in comparison with hydrogen-cooled ones; in addition to this, they require little maintenance. These machines have a high degree of availability for immediate starting. The authors outline the development up to present-day machines, which are constructed for outputs of up to approx. 170 MVA. (orig.)

[en] BBC build turbo-generators with full liquid cooling for large nuclear power stations. The stator and rotor are cooled with water and the laminated core with oil. The rotor and stator space which are separated by an air-gap cylinder, contain nitrogen. The author describes the cooling principle and construction features. (orig.)

No abstract available

No abstract available

[en] Turbo-alternators are the primary producers of electric pFwer. The units in service today comprise models from post-war years of production and, to some extent, from pre-war years as well. By statistical evaluation of incidents of damage notified over the past three years, it is nevertheless possible to ascertain from the overall spectrum of these units certain focal points of damage, these being of course influenced to some degree by the trend of developments over the years. Examples of such focal points are, in the case of the stator, the windings - where mechanical influences such as electric power and electrical insulation defects are the primary cause of damage - and, in case of the inductor, the exciter windings and conductors - where grounding and winding short circuiting occurs - and also the area around the end ring and rotor end. The focal points of damage thereby ascertained are dealt with here in detail. The author goes into the physical-technical problems present in each case, showing how these were solved in the individual units concerned and what damage nevertheless occurred. Remedial measures are, where possible, elucidated and - on the basis of experience gained from the overall volume of damage - indications furnished on the consequences and/or unit risk exposure to be expected in individual cases. (orig.)

[en] In the operational supervision of turbines, vibration readings have two functions to fulfill - firstly, in indicating critical vibration for the purposes of damage prevention and, secondly, in assessing the mechanical condition of the rotor and bearings (damage diagnosis). Direct measuring of the shaft undulation is the most indicative method. Several manufacturers of measuring devices offer highly developed shaft vibration reading systems. On the basis of examples drawn from actual turbine operations - and, in particular, on the basis of damage incidents - the authors show the possibilities and limitations of shaft vibration readings. Qualitative assessment criteria rank in the foreground. The problem of furnishing boundary values is also dealt with. Measuring equipment serving the protection of a turbo-set by indicating critical vibration for the purposes of damage prevention incurs little expense in relation to the value of the machinery itself. The equipment for assessing the mechanical condition of the rotor and bearings, on the other hand, incurs greater financical outlay, but is in the majority of cases justified in view of the cost of operational interruptions caused by unscheduled, forced shut-downs, as well as in view of the availability factor involved. By means of ambulant vibration analyses carried out by a specially trained team of experts at regular intervals, in the case of breakdowns and prior to and following inspections, gaps in the monitoring system can be closed to a certain degree. Details are furnished on the conducting of such measurement readings by the Allianz Centre for Technology and on initial results. (orig.)

[en] The paper describes the 'design review' technique and its applications to the manufacture of turbogenerators for power stations. It is stated that one benefit arising from design review is its use for design verification, and reference is made to the CEGB standard QA-2 (Quality Assurance) defining design verification. (U.K.)