Preparation and Properties of Lateral Contact Structure SiC Photoconductive Semiconductor Switches

Background: Traditional thyristor-based three-phase soft starters of induction motor often suffer from high starting current and heavy harmonics. Moreover, both the trigger pulse generation and driving circuit design are usually complicated. Methods: To address these issues, we propose a novel soft starter structure using fully controlled IGBTs in this paper. Compared to approaches of traditional design, this structure only uses twophase as the input, and each phase is controlled by a power module that is composed of one IGBT and four diodes. Results: Consequently, both driving circuit and control design are greatly simplified due to the requirement of fewer controlled power semiconductor switches, which leads to the reduction of the total cost. Conclusion: Both Matlab/Simulink simulation results and experimental results on a prototype demonstrate that the proposed soft starter can achieve better performances than traditional thyristorbased soft starters for Starting Current (RMS) and harmonics.

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Autonomous Geometrical Mechanics

10.1093/oso/9780198822370.003.0022 ◽

2018 ◽

Author(s):

Peter Mann

Keyword(s):

Phase Space ◽

Contact Structure ◽

Invariant Tori ◽

Time Dependent ◽

Contact Structures ◽

Natural Setting ◽

Adiabatic Invariance ◽

Jet Bundle ◽

Integrability Theorem ◽

Extended Phase

This chapter examines the structure of the phase space of an integrable system as being constructed from invariant tori using the Arnold–Liouville integrability theorem, and periodic flow and ergodic flow are investigated using action-angle theory. Time-dependent mechanics is formulated by extending the symplectic structure to a contact structure in an extended phase space before it is shown that mechanics has a natural setting on a jet bundle. The chapter then describes phase space of integrable systems and how tori behave when time-dependent dynamics occurs. Adiabatic invariance is discussed, as well as slow and fast Hamiltonian systems, the Hannay angle and counter adiabatic terms. In addition, the chapter discusses foliation, resonant tori, non-resonant tori, contact structures, Pfaffian forms, jet manifolds and Stokes’s theorem.

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Quaternionic contact 4n + 3-manifolds and their 4n-quotients

Annals of Global Analysis and Geometry ◽

10.1007/s10455-021-09758-5 ◽

2021 ◽

Author(s):

Yoshinobu Kamishima

Keyword(s):

Scalar Curvature ◽

Lie Group ◽

Contact Structure ◽

Einstein Manifolds ◽

Hermitian Metrics ◽

Kähler Metric ◽

Formula One ◽

Quaternion Space ◽

Kahler Metric ◽

Do So

AbstractWe study some types of qc-Einstein manifolds with zero qc-scalar curvature introduced by S. Ivanov and D. Vassilev. Secondly, we shall construct a family of quaternionic Hermitian metrics $$(g_a,\{J_\alpha \}_{\alpha =1}^3)$$ ( g a , { J α } α = 1 3 ) on the domain Y of the standard quaternion space $${\mathbb {H}}^n$$ H n one of which, say $$(g_a,J_1)$$ ( g a , J 1 ) is a Bochner flat Kähler metric. To do so, we deform conformally the standard quaternionic contact structure on the domain X of the quaternionic Heisenberg Lie group$${{\mathcal {M}}}$$ M to obtain quaternionic Hermitian metrics on the quotient Y of X by $${\mathbb {R}}^3$$ R 3 .

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Rise time and recovery of GaAs photoconductive semiconductor switches

10.1117/12.25062 ◽

1991 ◽

Cited By ~ 3

Author(s):

Fred J. Zutavern ◽

Guillermo M. Loubriel ◽

Marty W. O'Malley ◽

Dan L. McLaughlin ◽

Wesley D. Helgeson

Keyword(s):

Rise Time ◽

Semiconductor Switches

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The Legendrian knot complement problem

Journal of Knot Theory and Its Ramifications ◽

10.1142/s0218216518500670 ◽

2018 ◽

Vol 27 (14) ◽

pp. 1850067 ◽

Cited By ~ 1

Author(s):

Marc Kegel

Keyword(s):

Contact Structure ◽

Legendrian Knot ◽

Tight Contact ◽

Legendrian Links ◽

User Friendly ◽

The Way

We prove that every Legendrian knot in the tight contact structure of the [Formula: see text]-sphere is determined by the contactomorphism type of its exterior. Moreover, by giving counterexamples we show this to be not true for Legendrian links in the tight [Formula: see text]-sphere. On the way a new user-friendly formula for computing the Thurston–Bennequin invariant of a Legendrian knot in a surgery diagram is given.

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