Electrical performance of traction motors (direct current, series wound)

1928 ◽  
Keyword(s):  
Direct Current ◽  
Electrical Performance ◽  
Traction Motors ◽  
Current Series

scholarly journals Commutating Sparks of Direct Current Series Motors in a Transient State

TANSO ◽  
1961 ◽  
Vol 1961 (28) ◽  
pp. 7-11
Author(s):  
Tatsuo Yamamura ◽  
Shogo Yamazaki
Keyword(s):  
Direct Current ◽  
Transient State ◽  
Current Series

Prospects of improving technical and economic indicators of electric rolling stock

2020 ◽  
pp. 57-64
Author(s):  
Alexander Sergeevich Maznev ◽  
◽  
Alexander Alexandrovich Kiselev ◽  
Vladimir Аndreevich Usov ◽  
Аnnа Аndreevna Kalinina ◽  
...  
Keyword(s):  
Direct Current ◽  
Economic Indicators ◽  
Rolling Stock ◽  
Electric Locomotive ◽  
Traction Motors ◽  
Electric Rolling Stock ◽  
Instantaneous Values ◽  
Autonomous Voltage Inverter ◽  
Pulse Regulation ◽  
Technical And Economic Indicators

The paper considers methods of improving technical and economic indicators of direct current electric rolling stock. The authors propose a scheme of electric drive with pulse converters that are controlled by instantaneous values of armature and exciting currents. The scheme provides the realization of regenerative and resistance braking on almost the entire speed range. The paper also presents frequency characteristics of converters at speed from 5 to 100 km/h and proposes a scheme of direct current electric locomotive with pulse regulation of voltage on three connections of traction motors. Moreover, the authors discuss a structure of autonomous voltage inverter with group switching and reduced number of fully controlled semiconductor devices and present methods to prevent wheelspin through changing their load on rails and excitement of traction motors.

Commuter Rail Reelectrification: Is It Still Justified?

2003 ◽  
Vol 1838 (1) ◽  
pp. 11-18 ◽  
Author(s):  
John G. Allen ◽  
John P. Aurelius
Keyword(s):  
New Jersey ◽  
The Netherlands ◽  
High Voltage ◽  
Direct Current ◽  
North American ◽  
State Of The Art ◽  
Alternating Current ◽  
Dc System ◽  
Traction Motors ◽  
Commuter Rail

From the late 1960s through the mid-1990s, North American commuter railroads electrified with overhead wire moved toward high-voltage alternating current (AC) at commercial frequency so as to adopt state-of-the art technology. The extent and complexity of reelectrification have varied greatly, as projects in New Jersey, Connecticut, and Montreal, Canada, (and one planned for the Netherlands) show. Changes in the justification threshold for reelectrification are reviewed, along with a decision to retain a direct current (DC) system in Chicago. The recent development of onboard inverters, changing DC into AC for traction motors, has made it easier for electric rail operations to enjoy the benefits of AC propulsion without reelectrification costs.

scholarly journals Enhanced Thermal Conductivity and Dielectric Properties of h-BN/LDPE Composites

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4738
Author(s):  
Lijuan He ◽  
Junji Zeng ◽  
Yuewu Huang ◽  
Xiong Yang ◽  
Dawei Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Space Charge ◽  
Direct Current ◽  
Breakdown Strength ◽  
Hexagonal Boron Nitride ◽  
Electrical Equipment ◽  
Electrical Performance ◽  
Suppression Effect ◽  
Thermally Conductive ◽  
Ldpe Composites

Low-density polyethylene (LDPE), as an excellent dielectric insulating material, is widely used in electrical equipment insulation, whereas its low thermal conductivity limits its further development and application. Hexagonal boron nitride (h-BN) filler was introduced into LDPE to tailor the properties of LDPE to make it more suitable for high-voltage direct current (HVDC) cable insulation application. We employed melt blending to prepare h-BN/LDPE thermally conductive composite insulation materials with different contents. We focused on investigating the micromorphology and structure, thermal properties, and electrical properties of h-BN/LDPE composites, and explained the space charge characteristics. The scanning electron microscope (SEM) results indicate that the h-BN filler has good dispersibility in the LDPE at a low loading (less than 3 phr (3 g of micron h-BN particles filled in 100g of LDPE)), as well as no heterogeneous phase formation. The results of thermal conductivity analysis show that the introduction of h-BN filler can significantly improve the thermal conductivity of composites. The thermal conductivity of the composite samples with 10 phr h-BN particles is as high as 0.51 W/(m·K), which is 57% higher than that of pure LDPE. The electrical performance illustrates that h-BN filler doping can significantly inhibit space charge injection and reduce space charge accumulation in LDPE. The interface effect between h-BN and the substrate reduces the carrier mobility, thereby suppressing the injection of charges of the same polarity and increasing the direct-current (DC) breakdown strength. h-BN/LDPE composite doped with 3 phr h-BN particles has excellent space charge suppression effect and high DC breakdown strength, which is 14.3% higher than that of pure LDPE.

scholarly journals Detection of Typical Defects in Silicon Photovoltaic Modules and Application for Plants with Distributed MPPT Configuration

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4547 ◽  
Author(s):  
Jawad Ahmad ◽  
Alessandro Ciocia ◽  
Stefania Fichera ◽  
Ali Faisal Murtaza ◽  
Filippo Spertino
Keyword(s):  
Open Circuit ◽  
Electrical Performance ◽  
Shunt Resistance ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Current Series ◽  
Operational Life ◽  
Pv Modules ◽  
Power Point ◽  
Reference Parameters

During their operational life, photovoltaic (PV) modules may exhibit various defects for poor sorting of electrical performance during manufacturing, mishandling during transportation and installation, and severe thermo-mechanical stresses. Electroluminescence testing and infrared thermographic imaging are the most common tests for checking these defects, but they are only economically viable for large PV plants. The defects are also manifested as abnormal electrical properties of the affected PV modules. For defect diagnosis, the appropriate parameters on their I-V curves are open circuit voltage, photo-generated current, series resistance, and the shunt resistance. The health of PV modules can be assessed by calculating these values and comparing them with the reference parameters. If these defects are diagnosed in time, the power loss is avoided and safety hazards are mitigated. This paper first presents a review of common defects in PV modules and then a review of the methods used to find the above-mentioned parameters during the normal PV operation. A simple approach to determine the resistances of the equivalent circuit is discussed. Finally, through a modification in an ordinary maximum power point tracking (MPPT) algorithm, information about the state of health of PV modules is obtained. This method is effective, especially if applied to submodule-integrated MPPT architectures.

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