Degree of Fault Tolerance as a Comprehensive Parameter for Reliability Evaluation of Fault Tolerant Electric Traction Drives

This paper describes a new approach and methodology of quantitative assessment of the fault tolerance of electric power drive consisting of the multi-phase traction electric motor and multilevel electric inverter. It is suggested to consider such traction drive as a system with several degraded states. As a comprehensive parameter for evaluating of the fault tolerance, it is proposed to use the criterion of degree of the fault tolerance. For the approbation of the proposed method, the authors carried out research and obtained results of its practical application for evaluating the fault tolerance of the power train of an electrical helicopter

Korkeataajuisten 65nm CMOS LC oscillaattoreiden käyttö kelojen hyvyysarvon todentamisessa

High quality factor inductors are essential for the design of low phase noise LC oscillators which play an important role in the transceivers of wireless communication devices. The reception capabilities of a radio frequency receiver are to great extent defined by the phase noise performance of the local oscillator. It is therefore important for modern single chip fully integrated transceiver design that high quality inductors are available and well modeled. In this work we investigate the possibility of evaluating the quality factor of an inductor by the phase noise it generates when used in a reference oscillator. A differential CMOS LC oscillator is designed for inductor test benching. The designed oscillator is fabricated on a 65nm CMOS process with two different inductor designs with simulated quality factors of 7.4 and 10.2. The overall combined silicon area of the two oscillators including inductors and probing pads is 680μm by 510μm. The oscillation frequencies are dictated by the designed inductors and were measured 3.04GHz and 4.56GHz. The oscillators achieve a phase noise of -125dBc/Hz and -124dBc/Hz at 1MHz offset with 14mW and 16mW power dissipation respectively. An oscillator phase noise model is fitted to the measured phase noise data of both oscillators and the model parameters are compared. The received quality factors for the designed inductors are 8.2 ± 0.8 and 10.8 ± 0.6 respectively. It was found that the measured phase noise is in good agreement with the results predicted by the model and the relative quality factor can, with certain limitations, be estimated through relative phase noise measurements

Mechanische Unkrautregulierung in der Saatreihe von Soja

Organic cropping of soya beans mainly depends on the successful control of weeds. Hoeing in between the crop rows can be effective but the mechanical control of weeds within the crop row is difficult. Objective of this study was to investigate the effect of three machines and two combinations thereof to control two model weeds seeded directly in the crop row of soya bean. Reduction of the soil cover (%) in the crop row was evaluated after the means were applied and compared to the control treatment (hoeing between the crop rows). Results of two experiments conducted in 2007 and 2008 show that soil cover of companion plants within the crop row can be reduced up to 70 % when compared to the control treatment. Before best treatments can be recommended for the farmers, large-scale tests have to be conducted in order to improve the use of these means to keep the impact on the main crop as low as possible

Eignung von neuen Sommerölleinsorten für den Ökolandbau im Schweizer Mittelland

Oil flax was cropped in Switzerland in former times but seldom today. To investigate new varieties with respect to their agronomic performance and suitability for the production of cold-pressed oil, 15 varieties of spring flax were tested in the years 2005-2007 at one site. They were sown in small plots with four replicates and managed according the rules of Swiss organic farming. Averaged over the years, seed yield of the varieties ranged from 1.4 - 1.9 t/ha. Pressure of pests and diseases were generally low and weeds were controlled successfully by mechanical means. In order to recommend flax varieties for the production of oil, oil quality aspects need to be considered and investigated carefully

Reliability-Oriented Design of Vehicle Electric Propulsion System Based on the Multilevel Hierarchical Reliability Model

This chapter describes a methodology of evaluation of the various sustainability indicators, such as reliability, availability, fault tolerance, and reliability-associated cost of the electric propulsion systems, based on a multilevel hierarchical reliability model (MLHRM) of the life cycles of electric vehicles. Considering that the vehicle propulsion systems are safety-critical systems, to each of their components, the strict requirements on reliability indices are imposed. The practical application of the proposed technique for reliability-oriented development of the icebreaking ship’s electric propulsion system and the results of computation are presented. The opportunities of improvement of reliability and fault tolerance are investigated. The results of the study, allowing creating highly reliable electric vehicles and choosing the most appropriate traction electric drive design, are discussed

Degree of Fault Tolerance as a Comprehensive Parameter for Reliability Evaluation of Fault Tolerant Electric Traction Drives

This paper describes a new approach and methodology of quantitative assessment of the fault tolerance of electric power drive consisting of the multi-phase traction electric motor and multilevel electric inverter. It is suggested to consider such traction drive as a system with several degraded states. As a comprehensive parameter for evaluating of the fault tolerance, it is proposed to use the criterion of degree of the fault tolerance. For the approbation of the proposed method, the authors carried out research and obtained results of its practical application for evaluating the fault tolerance of the power train of an electrical helicopter

Passive Filter Design Algorithm for Transient Stabilization of Automotive Power Systems

The automotive power system is being increasingly expanded by adding high-dynamic power electronics. These components can potentially cause malfunction or failure of safety-relevant low-voltage components. The susceptibility to disturbances is often reduced by usage of oversized passive input electronics. This paper introduces an alternative means of disturbance suppression by the introduction of system integrated adaptive passive filters. A proposed methodology is presented for examining the suitability of potential access points within complex networks. An algorithmic procedure for the parametrization of several switchable bandpass filter stages is explained. The in-vehicle measurement demonstrates the effectiveness of the dimensioned filter being able to reduce disturbances at 70 kHz by more than 75 %.Passive Filter Design Algorithm for Transient Stabilization of Automotive Power SystemsacceptedVersio