Propulsion Motor Research Articles

ПАРАЛЛЕЛЬНАЯ РАБОТА ДИЗЕЛЬ-ГЕНЕРАТОРНЫХ УСТАНОВОК ПОСТОЯННОЙ И ПЕРЕМЕННОЙ ЧАСТОТЫ ВРАЩЕНИЯ

The paper focuses on the operation of the ship's single power station with a common link of direct current and a diesel generator of variable speed are considered. It is shown that the operation of a diesel generator set at a constant (nominal) rotational speed, but variable load is characterized by a nonoptimal (overrated) specific fuel consumption. At the same time, forced regulation of the internal combustion engine rotation speed in accordance with the electric load of the generator make it possible to provide energy-efficient mode of generating electricity. One way to improve the energy performance of the ship single power station is to convert one of the parallel operating diesel generators into a variable speed mode. In this case, the load between the parallel operating diesel generators is distributed in proportion to their rotation frequencies, regardless of the individual loading of the propulsion motors. To stabilize voltage of the diesel generators operating in the variable speed mode, a power semiconductor converter is used. Functional scheme and mathematical simulation model of the ship single power station, graphs of transient processes with load changes in the channel of electric propulsion system of the vessel are presented.

VIP is involved in peripheral CRF-induced stimulation of propulsive colonic motor function and diarrhea in male rats.

We investigated whether vasoactive intestinal peptide (VIP) and/or prostaglandins contribute to peripheral corticotropin-releasing factor (CRF)-induced CRF1 receptor-mediated stimulation of colonic motor function and diarrhea in rats. The VIP antagonist, [4Cl-D-Phe6, Leu17]VIP injected intraperitoneally completely prevented CRF (10 µg/kg ip)-induced fecal output and diarrhea occurring within the first hour after injection, whereas pretreatment with the prostaglandins synthesis inhibitor, indomethacin, had no effect. In submucosal plexus neurons, CRF induced significant c-Fos expression most prominently in the terminal ileum compared with duodenum and jejunum, whereas no c-Fos was observed in the proximal colon. c-Fos expression in ileal submucosa was colocalized in 93.4% of VIP-positive neurons and 31.1% of non-VIP-labeled neurons. CRF1 receptor immunoreactivity was found on the VIP neurons. In myenteric neurons, CRF induced only a few c-Fos-positive neurons in the ileum and a robust expression in the proximal colon (17.5 ± 2.4 vs. 0.4 ± 0.3 cells/ganglion in vehicle). The VIP antagonist prevented intraperitoneal CRF-induced c-Fos induction in the ileal submucosal plexus and proximal colon myenteric plexus. At 60 min after injection, CRF decreased VIP levels in the terminal ileum compared with saline (0.8 ± 0.3 vs. 2.5 ± 0.7 ng/g), whereas VIP mRNA level detected by qPCR was not changed. These data indicate that intraperitoneal CRF activates intestinal submucosal VIP neurons most prominently in the ileum and myenteric neurons in the colon. It also implicates VIP signaling as part of underlying mechanisms driving the acute colonic secretomotor response to a peripheral injection of CRF, whereas prostaglandins do not play a role. NEW & NOTEWORTHY Corticotropin-releasing factor (CRF) in the gut plays a physiological role in the stimulation of lower gut secretomotor function induced by stress. We showed that vasoactive intestinal peptide (VIP)-immunoreactive neurons in the ileal submucosal plexus expressed CRF1 receptor and were prominently activated by CRF, unlike colonic submucosal neurons. VIP antagonist abrogated CRF-induced ileal submucosal and colonic myenteric activation along with functional responses (defecation and diarrhea). These data point to VIP signaling in ileum and colon as downstream effectors of CRF.

Simultaneous optimization of topology, control and size for multi-mode hybrid tracked vehicles

Hybrid tracked vehicles have become increasingly popular for off-road applications due to their better fuel economy and higher output power. Currently, the most popular in the production of tracked vehicles are the series hybrid, because of the simple powertrain designs. However, they suffer from high energy conversion losses and large propulsion motors. To overcome these issues, multi-mode hybrid tracked vehicles are employed since they have high efficiency and excellent overall performance. The proposed multi-mode hybrid powertrain can realize straight driving, turning, and driving backwards without any additional steering mechanism. To systematically explore all the possible designs of multi-mode hybrid designs with planetary gears, a topology-control-size-integrated optimization approach is presented. A novel near-optimal energy management strategy, Efficiency Evaluation Real-time Control Strategy (EERCS), is proposed to rapidly calculate near-optimal control rules for design candidates. The EERCS is confirmed to achieve results similar to those of Dynamic Programming (DP), yet the computation time is over 50 times less. With the help of EERCS, the optimal design together with its parameters is computed using multi-objective optimization based on a meta-heuristic algorithm. Results of a case study show that the optimized design with downsized components produces improved drivability and fuel economy compared to the series hybrid benchmark.

Energy Management in Current Fed Switched Inverter Based Propulsion Motor for Marine Application

In this paper the super capacitor and battery based current fed switched converter produce high voltage gain and the performance of motor is improved. The fuel based renewable energy produce the less dynamic performance of the motor and life time is reduced so the proposed paper use the super capacitor based energy production. The permanent magnet synchronous based motor has high performance. The permanent magnet synchronous motor vector control strategy is adopted. The proposed method the inverter and motor are interconnected. The motor functioning is used in the marine based electric device. The proposed method use the space vector control method is used. The possibility of the system and the control methods are established by MATLAB/ simulink environment.

Analysis of superconducting linear synchronous motor for electromagnetic propulsion

There is a high demand for electromagnetic launchers in applications such as electromagnetic catapults and launch-assist systems for spacecraft, owing to their advantages in terms of controllability and reusability. This work proposes a double-sided superconducting-magnet linear synchronous motor capable of large thrust densities that can satisfy the demands of high-load launcher systems. Ring windings and narrow-toothed structures were applied to increase the density of the armature winding and reduce cogging-torque-induced fluctuations, and superconducting magnet with iron-core was first proposed to produce a strong air gap magnetic field. Numerical simulations are used to construct a simulation model of the motor, which is then used to study the relationships between the thrust characteristics of the motor and the dimensions of its armature and air-gap length. The results of this analysis provide information on the optimal thrust characteristics of linear motors in electromagnetic launcher systems.

Comparison between two models of BLDC motor, simulation and data acquisition

Alternative propulsion motors have been studied to increase the performance/consumption ratio in vehicles. A solution is the HEVs (hybrid electric vehicles), which are becoming important to the automotive industry. The electric motor BLDC (Brushless Direct Current) has been chosen to integrate the HEVs because of its characteristics, such as silent operation and high efficiency. Therefore, the motor operating principle is important to develop studies and research in automotive industries. The aim of this study is to develop a BLDC mathematical model to obtain the physical dimensions, such as current, voltage and torque through the comparison of the simulation time between existing models in the literature and experimental tests to integrate a virtual vehicle model. Two models are studied in this article, a simple one that approximates the three phases of BDLC motor to one single phase, as in a brushed DC motor, and a model that considers all phases and their commutation. Both models are compared in terms of computational effort and accuracy of the results, and the DC motor was the one that best integrated the vehicle model. Furthermore, an experimental measurement is performed to calibrate the model and it is integrally acquired by an Arduino UNO board, an inexpensive board. All models are implemented in the software Matlab/SimulinkTM where the voltage is the required input and several variables, such as phase current, speed, friction, and torque, can be the output.

Brain and Gut CRF Signaling: Biological Actions and Role in the Gastrointestinal Tract.

Corticotropin-releasing factor (CRF) pathways coordinate behavioral, endocrine, autonomic and visceral responses to stress. Convergent anatomical, molecular, pharmacological and functional experimental evidence supports a key role of brain CRF receptor (CRF-R) signaling in stress-related alterations of gastrointestinal functions. These include the inhibition of gastric acid secretion and gastric-small intestinal transit, stimulation of colonic enteric nervous system and secretorymotor function, increase intestinal permeability, and visceral hypersensitivity. Brain sites of CRF actions to alter gut motility encompass the paraventricular nucleus of the hypothalamus, locus coeruleus complex and the dorsal motor nucleus while those modulating visceral pain are localized in the hippocampus and central amygdala. Brain CRF actions are mediated through the autonomic nervous system (decreased gastric vagal and increased sacral parasympathetic and sympathetic activities). The activation of brain CRF-R2 subtype inhibits gastric motor function while CRF-R1 stimulates colonic secretomotor function and induces visceral hypersensitivity. CRF signaling is also located within the gut where CRF-R1 activates colonic myenteric neurons, mucosal cells secreting serotonin, mucus, prostaglandin E2, induces mast cell degranulation, enhances mucosal permeability and propulsive motor functions and induces visceral hyperalgesia in animals and humans. CRF-R1 antagonists prevent CRF- and stressrelated gut alterations in rodents while not influencing basal state. These preclinical studies contrast with the limited clinical positive outcome of CRF-R1 antagonists to alleviate stress-sensitive functional bowel diseases such as irritable bowel syndrome. The translational potential of CRF-R1 antagonists in gut diseases will require additional studies directed to novel anti-CRF therapies and the neurobiology of brain-gut interactions under chronic stress.

On-line Overshoot Suppression Method for EV Propulsion Motor Considering Cross Coupled Inductance

The effects of cross-coupled inductance are significant in high power density motors. It is observed here that the cross-coupled inductance causes current and voltage overshoots in the high-speed region. As the required voltage exceeds the voltage limit, the system becomes unstable. Here, the current dynamics are analyzed with a reduced model that incorporates a cross-coupled inductance, $L_{qd}$ . Further, it is shown that $L_{qd}$ makes an uncanceled zero in the current transfer function, which invokes the overshoot. It can be compensated with an estimate $\hat{L}_{qd}$ . However, it is not easy to obtain correct estimates of $L_{qd}$ in a wide current range. In this paper, an online overshoot suppression algorithm is proposed by using a high-pass filter. The simulation and experimental results provide some evidence for the effectiveness of the proposed algorithm. Finally, it is shown experimentally that the proposed algorithm cured the vehicle hunting problem after tapping off the gas pedal in a high-speed operation.

Comparative of Feasibility Study Between Diesel Mechanical Propulsion System and Combination of Diesel Engine and Electric Motor Propulsion System on Offshore Patrol Vessel (OPV) 80 m

The modern offshore patrol vessel is designed to carry out various missions in the management of economic exclusion zones, thus having some speed of service. For example, the speed for slow patrol is 10 knots, regular patrols 18 knots and chasing 22 knots. This condition requires a flexible propulsion system, which is combination of mechanical and electrical propulsion system. The application of this propulsion system to the OPV can increase the load factor of the propulsion system, resulting in lower fuel consumption than when using a mechanical propulsion system. Based on feasibility analysis results, the choice of combination of mechanical and electrical propulsion system is more advantageous than mechanical propulsion system, although investment and maintenance cost is higher. Therefore, patrol boats should use combination of mechanical and electrical propulsion system.

Optimal Design of a Novel Hybrid Electric Powertrain for Tracked Vehicles

Tracked vehicles have been widely used in construction, agriculture, and the military. Major problems facing the industry, however, are high emissions and fuel consumption. Hybrid electric tracked vehicles have thus become increasingly popular because of their improved fuel economy and reduced emissions. While the series hybrid system has drawn the most attention and has been applied in most cases, the low efficiency caused by energy conversion losses and large propulsion motors has limited its development. A novel multi-mode powertrain with two output shafts controlling each side of the track independently is first proposed. The powertrain is a three-planetary-gear power-split system with one engine, three motors, and an ultracapacitor pack. Compared with the existing technologies, the proposed powertrain can realize skid steering without an extra steering mechanism, and significantly improve the overall efficiency. To demonstrate the advantages of the novel powertrain, a topology-control-size integrated optimization problem is solved based on drivability, fuel economy, and cost. Final simulation results show that the optimized design with downsized components can produce about a 30% improvement in drivability and a 15% improvement in fuel economy compared with the commonly used series hybrid benchmark. Moreover, the optimized design is verified to be much more economical taking cumulative cost into account, which is very attractive for potential industrial applications in the future.

Load Test of 3-MW HTS Motor for Ship Propulsion

This paper describes the test facility and load test program for a 3-MW high-temperature superconducting (HTS) motor for ship propulsion. The test facility was used to conduct a constant-load test and a variable-load test. The program consisted of the constant-load test, the variable-load test, and the inspection after tests. During the constant-load test, the motor efficiency was measured at various rotor speeds and torques, and the 100-h cumulative endurance test at 3 MW was completed successful. The variable-load test is composed of three different modes that simulated an emergency maneuver of full astern to stop the ship and avoid a collision, and they have been verified. After the series of tests, the HTS motor was taken apart and an inspection confirmed that there was no problem with the HTS field coils or other main parts. This program demonstrated the reliability of the 3-MW HTS motor for ship propulsion.

High Torque Flux Switching Permanent Magnet Machine in Segmented Outer Rotor using Appropriate Split Ratio for Electric Scooter Propulsion

<span>Recently, permanent magnet synchronous machine (PMSM) having the diameter of 11inches was successfully developed and installed in electric scooter vehicle (ESV) for propulsion. It consists of segmented stators of 24 armature slots and 100 pieces of permanent magnet of 2 kg weight mounted on rotating rotor. Upon the huge amount of materials and permanent magnet used, PMSM produced 110Nm only. Looking at the size, this torque is low and could not sustain acceleration for long distance travels. To overcome the challenge of low torque, this paper presents a new machine type, flux switching motor (FSM) with 1 kg weight of permanent magnet flux source employing segmented outer rotor. Six ranges of split ratio of 0.80-0.85 for outer rotor 24slot-14pole FSPM motor configurations were designed and compared. The 2D-FEA by JMAG software version 14 is used to examine its performance in term of flux linkage, cogging torque, back-emf and average torque which the structure with split ratio of 0.85 took lead by securing highest torque profile of 209Nm. It also achieved low cogging torque to operate in safe region. In conclusion, appropriate split ratio significantly enhances high torque capability of permanent magnet flux switching motor for electric scooter propulsion.</span>

Optimization analysis of propulsion motor control efficiency

Optimization analysis of propulsion motor control efficiency

Coupled Cryogenic Thermal and Electrical Models for Transient Analysis of Superconducting Power Devices with Integrated Cryogenic Systems

Benefits of an integrated high temperature superconducting (HTS) power system and the associated cryogenic systems on board an electric ship or aircraft are discussed. A versatile modelling methodology developed to assess the cryogenic thermal behavior of the integrated system with multiple HTS devices and the various potential configurations are introduced. The utility and effectiveness of the developed modelling methodology is demonstrated using a case study involving a hypothetical system including an HTS propulsion motor, an HTS generator and an HTS power cable cooled by an integrated cryogenic helium circulation system. Using the methodology, multiple configurations are studied. The required total cooling power and the ability to maintain each HTS device at the required operating temperatures are considered for each configuration and the trade-offs are discussed for each configuration. Transient analysis of temperature evolution in the cryogenic helium circulation loop in case of a system failure is carried out to arrive at the required critical response time. The analysis was also performed for a similar liquid nitrogen circulation for an isobaric condition and the cooling capacity ratio is used to compare the relative merits of the two cryogens.

A CALCULATION METHOD OF TRANSIENT MODES OF ELECTRIC SHIPS’ PROPELLING ELECTRIC PLANTS

The purpose of the work is to develop the method for calculating the transient modes of electric ships’ propelling electric plants during maneuver. This will allow us to evaluate and improve the maneuverability of vessels with electric motion. Methodology. The solution to the problems is proposed to be carried out on the basis of mathematical modeling of maneuvering modes. The duration of transient modes in an electric power plant at electric ships’ maneuvers is commensurable with the transient operation modes of the vessel itself. Therefore, the analysis of the electric power plants’ maneuvering modes should be made in unity with all the components of the ship’s propulsion complex. Results. A specified mathematical model of transient regimes of electric ship’s propulsion complex, including thermal motors, synchronous generators, electric power converters, propulsion motors, propellers, rudder, ship’s hull is developed. The model is universal. It covers the vast majority of modern and promising electric ships with a traditional type of propulsors. It allows calculating the current values of the basic mode indicators and assessing the quality indicators of maneuvering. The model is made in relative units. Dimensionless parameters of the complex are obtained. These parameters influence the main indicators of the quality of maneuvering. The adequacy of the suggested specified mathematical model and the developed computation method based on it were confirmed. To do this, the results of mathematical modeling for a real electric ship were compared with the data obtained in the course of field experiments conducted by other researchers. Originality. The mathematical description of a generator unit, as an integral part of an indivisible ship’s propulsion complex, makes it possible to calculate the dynamic operation modes of electric power sources during electric vessels’ maneuvering. There is an opportunity to design the electric ships’ propulsion power plant according to the final result – according to the indicators characterizing the vessel and its maneuvering properties. The use of a system of dimensionless units provides a generality to the results obtained. Electric ships with equal values of dimensionless parameters will have correspondingly the same values (in relative units) of maneuvering quality indicators. Practical value. The developed mathematical model and the research method constructed on its basis allow calculating the current values of the basic regime parameters of all the components of the ship’s propulsion complex. A mathematical apparatus for estimating the main indicators of the quality of electric ships’ maneuvering is proposed. There is an opportunity to improve the electric ships’ maneuvering characteristics by optimizing the operation of propulsion motors.

Neural pathways for colorectal control, relevance to spinal cord injury and treatment: a narrative review.

Narrative review. The purpose is to review the organisation of the nerve pathways that control defecation and to relate this knowledge to the deficits in colorectal function after SCI. A literature review was conducted to identify salient features of defecation control pathways and the functional consequences of damage to these pathways in SCI. The control pathways for defecation have separate pontine centres under cortical control that influence defecation. The pontine centres connect, separately, with autonomic preganglionic neurons of the spinal defecation centres and somatic motor neurons of Onuf's nucleus in the sacral spinal cord. Organised propulsive motor patterns can be generated by stimulation of the spinal defecation centres. Activation of the somatic neurons contracts the external sphincter. The analysis aids in interpreting the consequences of SCI and predicts therapeutic strategies. Analysis of the bowel control circuits identifies sites at which bowel function may be modulated after SCI. Colokinetic drugs that elicit propulsive contractions of the colorectum may provide valuable augmentation of non-pharmacological bowel management procedures.

Analysis and Experimental Evaluation of Normal Force of Linear Induction Motor for Maglev Vehicle

This paper presents the analysis and experimental of the effective normal force and power consumption in a maglev vehicle. A maglev vehicle employs the electromagnets as suspension and linear motors for propulsion. These components give the higher ride comfort but suffered from energy efficiency. Therefore, a vector control-based algorithm and various air gaps are employed to increase the propulsion efficiency and lower the system energy consumption. The effective levitation load according to the levitation gap and normal force of a linear induction motor is calculated by power consumption in a levitation system and compared with finite-element analysis results. The experiment is carried out with the full-scaled train in test line and the efficiency of a propulsion system is also presented.

Investigation on a Power Coupling Steering System for Dual-Motor Drive Tracked Vehicles Based on Speed Control

Double-motor drive tracked vehicles (2MDTV) are widely used in the tracked vehicle industry due to the development of electric vehicle drive systems. The aim of this paper is to solve the problem of insufficient propulsion motor torque in low-speed, small-radius steering and insufficient power in high-speed large-radius steering. In order to do this a new type of steering system with a coupling device is designed and a closed-loop control strategy based on speed is adopted to improve the lateral stability of the vehicle. The work done entails modeling and simulating the 2MDTV and the proposed control strategy in RecurDyn and Matlab/Simulink. The simulation results show that the 2MDTV with the coupling device outputs more torque and power in both steering cases compared to the 2MDTV without the coupling device, and the steering stability of the vehicle is improved by using the strategy based on speed.

Hydrogen sulphide as a signalling molecule regulating physiopathological processes in gastrointestinal motility.

The biology of H2 S is a still developing area of research and several biological functions have been recently attributed to this gaseous molecule in many physiological systems, including the cardiovascular, urogenital, respiratory, digestive and central nervous system (CNS). H2 S exerts anti-inflammatory effects and can be considered an endogenous mediator with potential effects on gastrointestinal motility. During the last few years, we have investigated the role of H2 S as a regulator of gastrointestinal motility using both animal and human tissues. The aim of the present work is to review published data regarding the potential role of H2 S as a signalling molecule regulating physiopathological processes in gastrointestinal motor function. H2 S is endogenously produced by defined enzymic pathways in different cell types of the intestinal wall including neurons and smooth muscle. Inhibition of H2 S biosynthesis increases motility and H2 S donors cause smooth muscle relaxation and inhibition of propulsive motor patterns. Impaired H2 S production has been described in animal models with gastrointestinal motor dysfunction. The mechanism(s) of action underlying these effects may include several ion channels, although no specific receptor has been identified. At this time, even though there is much experimental evidence for H2 S as a modulator of gastrointestinal motility, we still do not have conclusive experimental evidence to definitively propose H2 S as an inhibitory neurotransmitter in the gastrointestinal tract, causing nerve-mediated relaxation.

Analysis and Control of Electromagnetic Coupling Effect of Levitation and Guidance Systems for Semi-High-Speed Maglev Train Considering Current Direction

A semi-high-speed magnetic levitation (maglev) train with a maximum speed of 200 km/h is being developed in Korea. It utilizes linear induction motors for propulsion and adopts electromagnetic suspension for levitation. For high-speed operation, guidance systems should be adopted to stabilize the train especially on curved tracks. For compatibility of the rail with previously developed urban maglev trains, the installation of the guidance electromagnet has to be restricted to be placed near the levitation electromagnet. Owing to the spatial closeness, mutual magnetic flux by the levitation and guidance electromagnets is produced at an overlapping portion of the rail. For stable control of the two systems, the coupling effects must be analyzed, because the levitation and guidance electromagnets are not operated independently. This paper aims to analyze the coupling effects by considering the magnetic field and a magnetic equivalent circuit. This paper suggests levitation and guidance systems for the semi-high-speed maglev train by considering each electromagnetic characteristic depending on the current direction.