Surveyor ejecta detector model ML 256-1 and 185-1 and Surveyor ejecta detector ground support equipment model ML 260-1 Final engineering report

Engineering analyses on Surveyor lunar dust particle detector instrumentation, and ground support equipmen

Performance and Power Factor Improvement of Indirect Vector Controlled Cage Induction Generator in Wind Power Application

Wind energy is one of the most important and promising source of renewable energy all over the world, mainly because it is considered to be nonpolluting and economically viable. At the same time there has been a rapid development of related wind energy technology. The control and estimation of wind energy conversion system constitute a vast subject and are more complex than those of dc drives. Induction generators with cage type rotors have been used extensively in wind power generation systems for the variable speed applications in a wide power range. Generally, variable speed wind energy conversion system with Induction generators require both wide operating range of speed and fast torque response, regardless of any disturbances and uncertainties (turbine torque variation, parameters variation and un-modeled dynamics). This leads to more advanced control methods to meet the real demand. The recent advances in the area of field-oriented control along with the rapid development and cost reduction of power electronics devices and microprocessors have made variable speed wind energy conversion system an economical alternative for wind power applications. The complexity of wind energy conversion system increases substantially if high performances are demanded. The main reasons for this complexity are the need of variable frequency, harmonically optimum converter power supplies, the complex dynamics of ac machines, machine parameter variations etc. Various control techniques have been developed in the recent days for the control of cage induction generators. In this work a hybrid controller is developed for performance improvement of a cage induction generator used for wind power applications. The wind power generation system employs an indirect vector controlled cage induction machine as the generator. The induction generator system is evaluated separately with conventional PI-controllers, fuzzy controllers, self tuned fuzzy controllers and hybrid controllers and the performances are compared for each case. Power factor of the overall system is improved through control of grid side converter. Control circuits for PWM converter inverter system are also fabricated and tested

The giant acoustic atom --- a single quantum system with a deterministic time delay

We investigate the quantum dynamics of a single transmon qubit coupled to surface acoustic waves (SAWs) via two distant connection points. Since the acoustic speed is five orders of magnitude slower than the speed of light, the travelling time between the two connection points needs to be taken into account. Therefore, we treat the transmon qubit as a giant atom with a deterministic time delay. We find that the spontaneous emission of the system, formed by the giant atom and the SAWs between its connection points, initially decays polynomially in the form of pulses instead of a continuous exponential decay behaviour, as would be the case for a small atom. We obtain exact analytical results for the scattering properties of the giant atom up to two-phonon processes by using a diagrammatic approach. We find that two peaks appear in the inelastic (incoherent) power spectrum of the giant atom, a phenomenon which does not exist for a small atom. The time delay also gives rise to novel features in the reflectance, transmittance, and second-order correlation functions of the system. Furthermore, we find the short-time dynamics of the giant atom for arbitrary drive strength by a numerically exact method for open quantum systems with a finite-time-delay feedback loop.Comment: To be published on Physical Review

SIRU development. Volume 1: System development

A complete description of the development and initial evaluation of the Strapdown Inertial Reference Unit (SIRU) system is reported. System development documents the system mechanization with the analytic formulation for fault detection and isolation processing structure; the hardware redundancy design and the individual modularity features; the computational structure and facilities; and the initial subsystem evaluation results

Analysis of electric propulsion electrical power conditioning component technology. Volume 1 - Data bank Final report

Analysis of electric propulsion electric power conditioning component technology - data revie

Index to NASA Tech Briefs, 1972

Abstracts of 1972 NASA Tech Briefs are presented. Four indexes are included: subject, personal author, originating center, and Tech Brief number

A Computer Aided Optimization Technique for Digital Systems Timing

Computer-aided optimization using Monte Carlo techniques for digital systems timin

Modeling and Analysis of Power Processing Systems

The feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems is investigated. It is shown that a digital computer may be used in an interactive mode for the design, modeling, analysis, and comparison of power processing systems