In the paper a differential system is considered, which state is described by a parabolic initial boundary value problem with distributed parameters on a graph. Control action and observations occur simultaneously. Th...
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ISBN:
(纸本)9781467376983
In the paper a differential system is considered, which state is described by a parabolic initial boundary value problem with distributed parameters on a graph. Control action and observations occur simultaneously. The existence conditions of a unique control action and the controllability system are obtained.
The large dv/dt and di/dt outputs of power devices in DC-fed motor drive systems in electric vehicles (EVs) always introduce conducted electromagnetic interference (EMI) emissions and may lead to motor drive system en...
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The large dv/dt and di/dt outputs of power devices in DC-fed motor drive systems in electric vehicles (EVs) always introduce conducted electromagnetic interference (EMI) emissions and may lead to motor drive system energy transmission losses. The effect of distributed parameters on conducted EMI from the DC-fed high voltage motor drive systems in EVs is studied. A complete test for conducted EMI from the direct current fed(DC-fed) alternating current (AC) motor drive system in an electric vehicle (EV) under load conditions is set up to measure the conducted EMI of high voltage DC cables and the EMI noise peaks due to resonances in a frequency range of 150 kHz-108 MHz. The distributed parameters of the motor can induce bearing currents under low frequency sine wave operation. However the impedance of the distributed parameters of the motor is very high at resonance frequencies of 500 kHz and 30 MHz, and the effect of the bearing current can be ignored, so the research mainly focuses on the distributed parameters in inverters and cables at 500 kHz and 30 MHz, not the effect of distributed parameters of the motor on resonances. The corresponding equivalent circuits for differential mode (DM) and common mode (CM) EMI at resonance frequencies of 500 kHz and 30 MHz are established to determine the EMI propagation paths and analyze the effect of distributed parameters on conducted EMI. The dominant distributed parameters of elements responsible for the appearing resonances at 500 kHz and 30 MHz are determined. The effect of the dominant distributed parameters on conducted EMI are presented and verified by simulation and experiment. The conduced voltage at frequencies from 150 kHz to 108 MHz can be mitigated to below the limit level-3 of CISPR25 by changing the dominant distributed parameters.
The effect of distributed parameters on conducted EMI is investigated in its motor drive system under load conditions for an electric vehicle. A conducted EMI testing platform was constructed for the system. By testin...
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The effect of distributed parameters on conducted EMI is investigated in its motor drive system under load conditions for an electric vehicle. A conducted EMI testing platform was constructed for the system. By testing the conducted EMIs from the system under both load and idle conditions, the propagation paths of both high-and-low frequency differential-mode noise and common-mode interference were analyzed and the equivalent circuits were established. In frequency domain, the mechanism of the conducted EMIs was studied and the effect of distributed parameters on them was discussed. Tests show that high-frequency conducted EMI can be reduced by properly enlarging the distributed capacitances both between ground and power devices in the motor controller and between ground and dc-bus.
This paper develops a Bayesian approach to analysis of a generalized least squares (GLS) regression model for regional analyses of hydrologic data. The new approach allows computation of the posterior distributions of...
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This paper develops a Bayesian approach to analysis of a generalized least squares (GLS) regression model for regional analyses of hydrologic data. The new approach allows computation of the posterior distributions of the parameters and the model error variance using a quasi-analytic approach. Two regional skew estimation studies illustrate the value of the Bayesian GLS approach for regional statistical analysis of a shape parameter and demonstrate that regional skew models can be relatively precise with effective record lengths in excess of 60 years. With Bayesian GLS the marginal posterior distribution of the model error variance and the corresponding mean and variance of the parameters can be computed directly, thereby providing a simple but important extension of the regional GLS regression procedures popularized by Tasker and Stedinger ( 1989), which is sensitive to the likely values of the model error variance when it is small relative to the sampling error in the at-site estimator.
The paper presents some results on development and application of the method of vector Lyapunov functions to the nonlinear analysis of different dynamical properties of interconnected control systems with distributed ...
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The paper presents some results on development and application of the method of vector Lyapunov functions to the nonlinear analysis of different dynamical properties of interconnected control systems with distributed parameters. These results were obtained by the author and his coworkers at the Irkutsk Computing Centre of the Siberian Branch of the USSR Academy of Sciences.
This note seeks to extend the utility of size-biased distribution theory as applied to forestry through two relationships regarding the quadratic mean stand diameter. First, the quadratic mean stand diameter's rel...
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This note seeks to extend the utility of size-biased distribution theory as applied to forestry through two relationships regarding the quadratic mean stand diameter. First, the quadratic mean stand diameter's relationship to the harmonic mean basal area for horizontal point sampling, which has been known algebraically from early on, is proved under size-biased distribution theory. Second, a new result, which may prove most valuable in viewing the graphical representation of assumed distributions, is also derived. The results are also shown to apply to the basal area - size distribution, providing a unique duality between the two means.
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