Wyniki wyszukiwania - BazTech

1

Fault Diagnosis of Sensors for T-type Three-Level Inverter-fed Dual Three-Phase Permanent Magnet Synchronous Motor Drives

Wang Xueqing, Wang Zheng, Wang Wei, Cheng Ming

Power Electronics and Drives

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2019

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Vol. 4 (39)

165--176

EN

To improve the reliability of motor system, this paper investigates the sensor fault diagnosis methods for T-type inverter-fed dual three-phase permanent magnet synchronous motor (PMSM) drives. Generally, a T-type three-level inverter-fed dual three-phase motor drive utilizes four phase-current sensors, two direct current (DC)-link voltage sensors and one speed sensor. A series of diagnostic methods have been comprehensively proposed for the three types of sensor faults. Both the sudden error change and gradual error change of sensor faults are considered. Firstly, the diagnosis of speed sensor fault was achieved by monitoring the error between the rotating speed of stator flux and the value from speed sensor. Secondly, the large high-frequency voltage ripple of voltage difference between the estimated voltage and the reference voltage was used to identify the voltage sensor faults, and the faulty voltage sensor was determined according to the deviation of voltage difference. Thirdly, the abnormal current amplitude on harmonic subspace was adopted to identify the current sensor faults, and the faulty current sensor was located by distinguishing the current trajectory on harmonic subspace. The experiments have been taken on a laboratory prototype to verify the effectiveness of the proposed fault diagnosis schemes.

2

Kinematic-PPP using single/dual frequency observations from (GPS, GLONASS and GPS/GLONASS) constellations for hydrography

Farah Ashraf

Artificial Satellites : Journal of Planetary Geodesy

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2018

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Vol. 53, No. 1

37--46

EN

Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS’s contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.

3

Wykorzystanie czujnika ciśnienia świecy żarowej do kontroli procesu spalania

Szczurowski K., Walczak D., Zieliński Ł.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2014

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z. 3/99

139--144

PL

W pracy przedstawiono możliwości kontroli procesu spalania z wykorzystanie czujnika ciśnienia wbudowanego w najnowocześniejsze świece typu PSG (ang. Pressure Sensor Glow Plug). Świece te stosowane są w silnikach wysokoprężnych spełniających normy emisji spalin Euro 5 i Euro 6. Czujnik wbudowany w świecę, pozwala na kontrolę procesu spalania, poprzez bieżące monitorowanie ciśnienia panującego w komorze spalania. Ciśnienie to może być porównywane z ciśnieniem w innych cylindrach i odpowiednio korygowane poprzez zmianę dawki lub kąta wyprzedzenie wtrysku. Świeca ta może zastępować czujnik indykatorowy, używany powszechnie w badaniach silnikowych. Przedstawione wykresy pozwalają ocenić jakość i rozdzielczość.

EN

The paper presents the ability to control the combustion process with the use of a pressure sensor built into most modern type glow plug PSG (ang. Pressure Sensor Glow Plug). These glow plugs are used in diesel engines that meet emissions standards Euro 5 and Euro 6 sensor built into the glow plug, allows control the combustion process by monitoring the pressure in the combustion chamber. This pressure can be compared with the pressure in the other cylinders and adjusted by changing the dosage or the angle advance . This type of glow plug can replace an indicator sensor, commonly used in studies of internal combustion engines. The graphs allows to evaluate the quality and resolution.

4

On a study of double gai sequence space

Subramanian N., Misra U. K.

Journal of Mathematics and Applications

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2013

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Vol. 36

95--111

EN

Let χ2 denote the space of all prime sense double gai sequences and Λ2 the space of all prime sense double analytic sequences. This paper is devoted to the general properties of χ2.

5

Duals of homogeneous weighted sequence Besov spaces and applications

Huang P.-K., Wang K.

Journal of Applied Analysis

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2011

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Vol. 17, nr 2

181-205

EN

In this article, we study the duals of homogeneous weighted sequence Besov spaces b α,q p,w, where the weight w is non-negative and locally integrable. In particular, when 0 < p < 1, we find a type of new sequence spaces which characterize the duals of b α,q p,w. Also, we find the necessary and sufficient conditions for the boundedness of diagonal matrices acting on homogeneous weighted sequence Besov spaces. Using these results, we give some applications to characterize the boundedness of Fourier-Haar multipliers and paraproduct operators. In this situation, we need to require that the weight w is an Ap weight.

6

The double sequence space Γ2

Subramanian N., Tripathy B. C., Murugesan C.

Fasciculi Mathematici

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2008

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Nr 40

91-103

EN

Let Γ2 denote the space of all prime sense double entire sequences and Λ2 the space of all prime sense double analytic sequences. This paper is devoted to the general properties of Γ2.