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Offshore Drilling
Published in Sukumar Laik, Offshore Petroleum Drilling and Production, 2018
Two types of auxiliary brakes have been developed, a hydraulic brake and an electro-magnetic brake. The hydraulic brake utilises fluid friction to absorb some of the work done in lowering equipment into the hole. The hydraulic brake is designed to impel fluid in a direction opposite to the rotation of the drum, thus tending to slow the drum rotation. The electro-magnetic brake is essentially two opposed magnetic fields, the magnitude of which are determined by the speed of rotation of the drum and the amount of external current supplied. For either the hydraulic or electromagnetic brake to become effective, some movement of the drum is required. Therefore, neither of these types of brakes will bring the hoisting drum to a dead stop. It remains for the friction brake to effect complete stoppage. Some type of auxiliary brakes are standard equipment on most medium- and deep-drilling rigs.
Induction Machines
Published in Jacek F. Gieras, Electrical Machines, 2016
The torque-speed characteristic of an induction machine is plotted in Fig. 6.25, where it can be seen that the maximum torque Telmmax for a generator is higher than that for a machine in motor mode. The torque-slip characteristic is plotted in Fig. 6.26, where five modes of operation, i.e., Induction generator (s < 0),Synchronous machine (s = 0),Induction motor (0 < s < 1),Transformer (s = 1),Electromagnetic brake (s > 1)
Casting and Reheating of Steel
Published in Vladimir B. Ginzburg, Metallurgical Design of Flat Rolled Steels, 2020
Electromagnetic braking - In this process, a magnetic field is used to modify flow patterns of the mold within certain areas and to create desired flow in others. The electromagnetic brake system (EMBR) shown in Fig. 6.8 brakes the steel flow in a mold by applying a static magnetic field across the mold, perpendicular to the casting direction. The electric currents induced in the steel by the magnetic field produce a breaking force that is opposite to the movement of the steel. Subsequently, the velocity of cast steel reduces and its flow pattern modifies, resulting in better steel cleanliness [4,22].
Verification experiment of stocking and disposal tasks by automatic shelf and mobile single-arm manipulation robot
Published in Advanced Robotics, 2022
Junya Tanaka, Daisuke Yamamoto, Ryo Nakashima, Yuto Yamaji, Hiroshi Ohtsu, Keisuke Kamata, Kohei Nara, Tetsuya Asayama
As shown in Figure 8, the vertical movement mechanism is equipped with an electric motor with an electromagnetic brake, coupling, vertical movement ball screw (BSST2020-1000), and movable block. The electric motor with electromagnetic brake is connected to the vertical moving ball screw via a coupling. The movable block has an insertion hole through which the vertical-movement ball screw passes, and the inner wall of the insertion hole has a female screw that meshes with the vertical-movement ball screw. The vertical-movement ball screw is rotated by the driving force of an electric motor with an electromagnetic brake. As it rotates, the movable block attached to the up-and-down moving ball screw moves in the up-and-down direction. As a result, the entire five-tier shelf can be moved up and down by the movable block. The electromagnetic brake stops the rotation of the vertical-movement ball screw as necessary, preventing the entire five-stage shelf from lowering under its own weight.
Theoretical and experimental research on the port timing of a compressed air engine
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
During experiments, a 300 bar air compressor is the piston-type air equipment of this test bench and compressed air which is compressed by the air compressor is stored in a 200 L storage tank to provide a steady air source. A pressure reducing valve is used to adjust the compressed air to a lower pressure for the working of the CAE. After decompression, the pressure and airflow rate of the compressed air are monitored by a pressure meter and a flow counter. In this test bench, four high-frequency electromagnetic valves are installed on the top of four cylinder heads, respectively, which are used to control the supply of the compressed air. The rated voltage of the high-frequency electromagnetic valve is DC12V, the maximum working pressure is 3.5 MPa, the flow rate is 200 L/min, and the response time is less than 10 ms. During experiments, the spark plug of the original IC engine is replaced by an air nozzle, the compressed air goes through the air nozzle and supplies to the CAE. Four flow sensors and four pressure sensors are installed at the inlet pipes of the CAE to monitor the inlet airflow rates and the inlet pressures. The test bench includes a torque transducer combined with an electromagnetic brake to measure the power output from the test engine. Furthermore, all relevant data acquired are collected by a data acquisition unit for further research (Xu, Cai, and Shi 2014). Figure 3 shows a schematic diagram of test bench, Figure 4 shows a picture of the CAE system, and Figure 5 shows a picture of the experimental setup.
Design and implementation of an intelligent digital pitch controller for digital hydraulic pitch system hardware-in-the-loop simulator of wind turbine
Published in International Journal of Green Energy, 2021
V. Lakshmi Narayanan, R. Ramakrishnan
The DHPS-hardware is integrated with several sensors to measure its parameters. Angular Displacement (AD) encoder sensor will measure the generated pitch angle (βg) at HM. The AD encoder has a resolution of 1000 pulse per revolution and 4000 counts per revolution. The dynamic pitch load from the WECS is scaled down by 200 times. The scaled load is applied to Electromagnetic Brake (EB). The flow sensor is connected at port A & B of the HM. It monitors the proportional flow of DFCU. The measuring range of flow sensor varies from 3.4 × 10−6 m3/s to 8.5 × 10−4 m3/s. The flow sensor can withstand an operating pressure up to 25 MPa. The pressure transducers are connected at the port A & B of the HM. It has a range of 0 to 25 MPa and accuracy of ±0.1% FS. The pressure in the systems is monitored. All the sensors are connected to real-time I/O interface (NI-PXIe Hardware), as seen in Figure 6. The data can be acquired at a sampling speed of 2 Mega samples per second and transmitted with 16-bit accuracy. The NI-PXIe hardware is interfaced with the NI-VeriStand in machine learning computer. The NI-VeriStand application will communicate with the WECS model and the controllers developed in MATLAB/Simulink.