Showing papers on "Forced outage published in 1994"

Reliability/availability guarantees of gas turbine and combined cycle generating units

Abstract: This paper is an updated and revised version of the 1992 ASME paper 92-GT-208 "Reliability measurements for Gas Turbine Warranty Situations" It recognizes that reliability performance is receiving significant and increasing attention in the bid requests for new gas turbine generating units. Reliability guarantees backed by liquidated damages clauses are becoming more the rule rather than the exception. But the power generation industry does not have a universally accepted set of reliability measurements and the more commonly used measurements are not always used appropriately neither are they sufficiently refined for the warranty situation. This paper is intended to provide the guidance, structure and refinement needed for meaningful reliability measurements and reliability warranties. Four key areas of reliability measurement: starting reliability, running reliability, availability and equivalent availability are discussed. Within each of these areas there is the flexibility and the need to adapt the measurement system to the varied operating regimes and philosophies encountered such as: peaking vs. continuous service, limited scopes of supply, different levels of maintenance intensity, chargeable vs. nonchargeable outage events and emotional/political/optical acceptability (i.e. 3% forced outage factor vs. 40% forced outage rate). Warranty structuring rationale and suggested contract language are provided to address such needs as a rigorous and explicit operating log, certification of data, measurement uncertainty, assurance of readiness and risk assessment. >

Frequency of transmission line outages in Canada

Abstract: Frequent transient and sustained forced outages of transmission equipment can significantly affect the performance of industrial and commercial power systems and the processes they control. A knowledge of the primary causes (e.g., adverse weather, defective equipment, etc.) of transmission line sustained and transient forced outages and which physical components of a transmission line (e.g., line conductors, structure, hardware, etc.) are affected is essential for designing and maintaining reliable transmission systems. Historical transmission reliability data provides the ability to predict the performance of various transmission line configurations and assess the impact of forced outages on industrial and commercial power systems. When no historical voltage sag data is available, historical transmission line reliability statistics can be used to predict the voltage sag activities at a particular site. This paper presents a summary of the Canadian Electrical Association's Equipment Reliability Information System statistics on the forced outage performance characteristics of transmission equipment for Canadian utilities for the period 1988-1992. The paper reveals the structure of the database and relevant summary data necessary for the application of these reliability methodologies. >

Alarming device during maintenance of elevator

Abstract: PURPOSE: To prevent a worker from colliding with the top of an elevator shaft or a balancing weight by informing the worker on a car of the possible danger based on the operation of an upper forced outage switch of the car or a switch to detect the approach of the balancing weight to the car during the maintenance and inspection of the elevator CONSTITUTION: An elevator control panel 8 controls the operation of a car 4 based on the operation of a manual operation switch 8 arranged on the upper part of the car 4 by a worker 1 during the maintenance and inspection of an elevator The elevator control panel 8 regulates the upper limit position of the car 4 based on the operation of an upper forced outage switch 2 arranged in an elevator shaft The approach of a balancing weight to the car 4 is detected by upper and lower proximity detecting switches 11, 12 respectively On the other hand, a device 13 to inform the worker 1 of the potential danger is arranged on the upper part of the car 4 The operation stopping control by the upper forced outage switch 2 is released during the maintenance and inspection, and the alarming device 13 is operated by the upper forced outage switch 2 or the respective switches 11, 12 COPYRIGHT: (C)1995,JPO

Dynamic phenomena in island power systems

Abstract: The paper deals with dynamic phenomena in island power systems. Most of the large disturbances that initiate the dynamic processes in the power system are caused by forced outages of generating units. The paper presents two large disturbances in the Israeli island power system: simultaneous forced outage of 3 large generating units and a large scale load rejection. An island power system must preserve sufficient measures to cope with disturbances of the kind mentioned above. The main measures are the load shedding system and the operational spinning reserve margin. The paper demonstrates the relations between the spinning reserve margin and the dynamic response of the power system. The paper also deals with the economic value of preserving a certain spinning reserve level.