Safe operation method for voltage reduction arc suppression of ground fault phase of non-effective ground system

    公开(公告)号:US11368017B2

    公开(公告)日:2022-06-21

    申请号:US16616975

    申请日:2018-07-04

    Inventor: Xiangjun Zeng

    Abstract: The present invention discloses a safe operation method for voltage reduction arc suppression of a ground fault phase of a non-effective ground system, for use in ground fault safety operation of a neutral point non-effective ground generator or distribution network. When a single-phase ground fault occurs, an external voltage source is applied at a non-effective ground system side between a bus and the ground, or between a line and the ground, or between a neutral point and the ground, or between a shunting tap of a non-effective ground system side winding of a transformer and the ground, to reduce the fault phase voltage to be lower than the continuous burning voltage of a ground arc, thereby meeting the requirements of long-term non-stop safe operation. The operation means and control method effectively prevent power outages, and improve the reliability and security of power supply.

    Large-span bulk material conveying system

    公开(公告)号:US10994935B1

    公开(公告)日:2021-05-04

    申请号:US17139563

    申请日:2020-12-31

    Abstract: Disclosed a large-span bulk material conveying system, including a folding arm conveyor and a dike-striding elevation-type feeding conveying device. The folding arm conveyor is mainly composed of an undercarriage mounted on the ground of a stockyard, a tower body mounted on the undercarriage and provided with a gyration apparatus and a hopper, a balance arm provided with a balance trolley, a conveying arm provided with a portal frame I, a portal frame II and an unloading trolley, a tower top and other main components, wherein the balance arm, the conveying arm and the tower top are mounted on the tower body. The folding arm conveyor can rotate horizontally, and the conveying arm can be folded and retracted by controlling the wire rope by the windlass, so that the folding arm conveyor can be prevented from colliding with other devices or buildings during the rotation.

    Anti-agglomeration device using ultrasonic waves for a nanofluid

    公开(公告)号:US10994249B1

    公开(公告)日:2021-05-04

    申请号:US17088058

    申请日:2020-11-03

    Abstract: An anti-agglomeration device for a nanofluid includes a support module, a motion module, a photoacoustic conversion module and a control module. The support module includes a frame and screws and is configured to support the photoacoustic conversion module and the motion module. The photoacoustic conversion module includes a nanosecond laser, a first clamp, a lens, a silica optical fiber, a second clamp, gold nanoparticles and a container and is configured to realize photoacoustic conversion to generate ultrasonic waves. The motion module includes a servo motor, a dovetailed rail, a guide screw, a fixed plate, a slider and a deep groove ball bearing. The motion module is configured to support the photoacoustic conversion module and realize the combined motions of the photoacoustic conversion module. The control module includes a support plate and a CCD camera and is configured to control the motion module in real time.

    Method for selective detection of L-tryptophan using formaldehyde as medium

    公开(公告)号:US12130253B2

    公开(公告)日:2024-10-29

    申请号:US17271164

    申请日:2020-08-24

    Abstract: A method for a selective detection of L-tryptophan (L-Trp) using formaldehyde as a medium is disclosed. The method includes preparation of a copper sulfide nanosheets-chitosan/acidified functionalized multi-wall carbon nanotubes (CuS NS—CS/F-MWCNTs) composite material, preparation of a composite film-modified electrode CuS NS—CS/F-MWCNTs/GCE, and a detection of the L-Trp. Since oxidation peaks of L-Trp and L-tyrosine (L-Tyr) overlap and are difficult to separate, the present invention provides a method for a highly selective detection of L-Trp through the Pictet-Spengler reaction of formaldehyde (HCHO) with L-Trp, in which the oxidation peak potential of L-Trp is shifted to 0.82 V and the oxidation peak potential of L-Tyr is 0.63 V, thereby effectively avoiding the interference of L-Tyr. The CuS NS—CS/F-MWCNTs/GCE is applied to detect L-Trp in the formaldehyde medium without any interference from L-Tyr or other amino acids with 50-fold concentrations.

    Method for positioning rotor of switched reluctance motor with pulse number being self-adjustable along with speed

    公开(公告)号:US12057793B2

    公开(公告)日:2024-08-06

    申请号:US17918324

    申请日:2022-05-27

    Inventor: Hui Cai

    CPC classification number: H02P21/18 H02P25/08 H02P2203/01

    Abstract: The present invention discloses an all-speed-range estimation method for a rotor position of a switched reluctance motor. Under a low-speed working condition, a sector is selected for triggering according to comparison between a current response value and a current threshold, so as to determine the rotor position of the motor; under a medium-speed working condition, the rotor position of the motor is determined, according to a change of the number of injected pulses with the motor speed, by querying a preset data table; under a high-speed working condition, a capacitor charging loop is designed since there is a small number of injected pulses; a response current formed by during injection of a pulse voltage charges a capacitor; the capacitor is detected to measure a voltage; and the rotor position is determined by querying a preset voltage-rotor position data table according to a voltage value.

    Method for detecting compaction and shear strength characteristics of asphalt mixture during construction compaction

    公开(公告)号:US11221286B2

    公开(公告)日:2022-01-11

    申请号:US16880436

    申请日:2020-05-21

    Abstract: The present invention discloses a method for detecting compaction and shear strength characteristics of an asphalt mixture during construction compaction. The method mainly includes the following steps: using a device for detecting compaction and shear strength characteristics of the asphalt mixture; pressing a test claw into the asphalt mixture during construction; rotating the test claw slowly and uniformly to measure an internal temperature and a shear characteristic of the mixture during paving and subsequent compaction; calculating a corresponding compaction detection index based on the shear characteristic; and monitoring and guiding the construction quality and construction process accordingly based on the real-time detection index. The present invention measures the compaction detection index of the asphalt mixture during compaction simply, quickly and accurately. The present invention uses the compaction detection index together with a degree of compaction for dual control of asphalt pavement compaction.

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