scholarly journals Contribution To The Reduction Of The Ship’s Switchboard By Applying Sensor Technology

2021 ◽  
Vol 93 (6s) ◽  
pp. 235-249
Author(s):  
Nediljko Kaštelan ◽  
◽  
Marko Zubčić ◽  
Maja Krčum ◽  
Miro Petković ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Power Systems ◽  
Power System ◽  
High Voltage ◽  
New Technology ◽  
Voltage Divider ◽  
Rogowski Coil ◽  
Sensor Technology ◽  
Medium Voltage ◽  
Voltage Sensors

The paper discusses the contribution to energy efficiency by reducing the dimensions of the main switchboard (medium voltage or High Voltage – used on ship). Reducing the dimensions of the switchboards can be achieved by reducing the dimensions of the bus bars, while fully satisfying the conditions with regard to thermal and mechanical stresses. The same can be achieved by modifying some other components, such as the application of new technology for measuring current and voltage, using current and voltage sensors that fall into the category of completely new technological solutions. By replacing conventional measuring transformers (IT), compact and efficient sensor technology significantly contributes to reducing the dimensions and mass of switchboards, which ultimately contributes to energy efficiency. Previous applications, the possibility of improving existing solutions, especially in applications in marine power systems, and new technological solutions that contribute to the efficiency of the marine power system using the Rogowski coil sensor and voltage divider voltage sensors are also considered.

scholarly journals A REVIEW OF STUDY AND ANALYSIS OF PARTIAL DISCHARGE FOR DIFFERENT INSULATION MATERIALS WITH CAPACITANCE VALUE

2021 ◽  
Vol 7 (12) ◽  
pp. 64-66
Author(s):  
Neetu Baghelkar ◽  
Abhishek Dubey
Keyword(s):  
Power Systems ◽  
Power System ◽  
High Voltage ◽  
Electrical Power ◽  
Electrical Equipment ◽  
Electrical Power System ◽  
Insulation Materials ◽  
System A ◽  
Solid Liquid

In the high voltage (HV) electrical power system, a variety of solid, liquid and gaseous materials are used for insulation purposes to protect incipient faults within the HV power equipment. Among these, solid insulation is widely used for high voltage equipment in high voltage power systems. Most insulation materials are not perfect in all respects and always contain some impurities. In high voltage (HV) electrical equipment, the quality of the insulation plays a very important role. Continued growth in the power system has provided the opportunity to protect equipment for healthy operation throughout its useful life.

scholarly journals Modelling and simulation of online partial discharge measurement for medium voltage power cable

2020 ◽  
Vol 9 (2) ◽  
pp. 427-435
Author(s):  
A. Z. Abdullah ◽  
M. Isa ◽  
M. N. K. H. Rohani ◽  
H. A. Hamid ◽  
M. H. Amlus ◽  
...  
Keyword(s):  
High Voltage ◽  
Measurement System ◽  
Power Distribution ◽  
Complete Solution ◽  
Partial Discharge ◽  
Distribution Network ◽  
Rogowski Coil ◽  
Power Cable ◽  
Network Modelling ◽  
Medium Voltage

This paper presents the modelling of the online partial discharge (PD) measurement of the medium voltage (MV) power cable. Recently, PD monitoring trends are rapidly increasing due to high demand on reliable systems. Degradation are mainly due to the presence of PD in the high voltage power equipment used. PD measurement is therefore a highly recommended task to early detection of the degradation insulation for high voltage (HV) equipment in order to avoid breakdowns. Real network modelling is necessary to improvise system design in order to find the efficiency in a real power system network. In this paper, modelling focuses on a real distribution network by applying Rogowski coil (RC) as a detection sensor to trigger PD activity. The simulation is performed to determine the functionality and reliability of the system with the RC application in the network. The analysis is performed in the ATP-EMTP and MATLAB Simulink software environments. In addition, this paper contributed to justify the approach of a simplified PD sensor and measurement system. This PD measurement system provides a complete solution in the context of condition-oriented monitoring for the ability to apply the RC to trigger PD activity in the power distribution network. 

AC Cables Strengthening Railway Low Frequency AC Power Supply Systems

2017 ◽  
Author(s):  
Lars Abrahamsson ◽  
Daniel Serrano Jimenez ◽  
John Laury ◽  
Math Bollen
Keyword(s):  
Power Systems ◽  
Power System ◽  
High Voltage ◽  
Transmission Lines ◽  
Power Supply ◽  
Low Frequency ◽  
Hvdc Transmission ◽  
Reactive Compensation ◽  
Ac Transmission ◽  
Railway Power Systems

In present-day railway power supply systems using an AC frequency lower than the one in the public power system of 50/60 Hz, high voltage overhead transmission lines are used as one measure of strengthening the railway power supply system grids. This option may be economically beneficial, compared to strengthening the grid purely by increasing the density of converter stations or increasing the cross section areas of the overhead catenary wires. High voltage AC transmission lines in the railway power supply system allow larger distances between converter stations than would otherwise be possible for a given amount of train traffic. Moreover, the introduction of AC transmission lines implies reduced line losses and reduced voltage level fluctuations at the catenary for a given amount of train traffic. However, due to the increased public and government resistance for additional overhead high voltage AC transmission lines in general, different alternatives will be needed for the future improvements and strengthening of railway power systems. For a more sustainable transport sector, the share and amount of railway traffic needs to increase, in which case such a strengthening becomes inevitable. Earlier, usage of VSC-HVDC transmission cables has been proposed as one alternative to overhead AC transmission lines. One of the main benefits with VSC-HVDC transmission is that control of power flows in the railway power systems is easier and that less converter capacity may be needed. Technically, VSC-HVDC transmission for railway power systems is a competitive solution as it offers a large variety of control options. However, there might be other more economical alternatives reducing the overall impedance in the railway power system. In public power systems with the frequency of 50/60 Hz, an excess of reactive power production in lowly utilized cables imposes an obstacle in replacing overhead transmission lines with cables. In low frequency AC railway power system, the capacitive properties are less significant allowing longer cables compared to 50/60 Hz power systems. Moreover, in converter-fed railways, some kind of reactive compensation will automatically be applied during low-load. At each converter station, voltage control is already present following the railway operation tradition. Therefore, in this paper, we propose AC cables as a measure of strengthening low-frequency AC railway power systems. The paper compares the electrical performances of two alternative reinforcement cable solutions with the base case of no reinforcement. The options of disconnecting or toggling the cables at low load as well as the automatic reactive compensation by converter voltage control are considered. Losses and voltage levels are compared for the different solutions. Investment costs and other relevant issues are discussed.

scholarly journals Dynamic Voltage Stability Studies using a Modified IEEE 30-Bus System

2016 ◽  
Vol 1 (3) ◽  
pp. 9 ◽  
Author(s):  
Oluwafemi Emmanuel Oni ◽  
Kamati I Mbangula ◽  
Innocent Davidson E. Davidson
Keyword(s):  
Power Systems ◽  
Power System ◽  
High Voltage ◽  
Power System Stability ◽  
Electric Power System ◽  
System Stability ◽  
Stability Studies ◽  
Operating Life ◽  
Hvdc Line ◽  
Bus System

Power System stability is an essential study in the planning and operation of an efficient, economic, reliable and secure electric power system because it encompasses all the facet of power systems operations, from planning, to conceptual design stages of the project as well as during the systems operating life span. This paper presents different scenario of power system stability studies on a modified IEEE 30-bus system which is subjected to different faults conditions. A scenario whereby the longest high voltage alternating current (HVAC) line is replaced with a high voltage direct current (HVDC) line was implemented. The results obtained show that the HVDC line enhances system stability more compared to the contemporary HVAC line. Dynamic analysis using RMS simulation tool was used on DigSILENT PowerFactory.

scholarly journals Set up and characterization of a measuring system for PQ measurements in a MV site with PV generation

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 97
Author(s):  
Gabriella Crotti ◽  
Domenico Giordano
Keyword(s):  
Quality Measurement ◽  
Voltage Divider ◽  
Uncertainty Budget ◽  
Rogowski Coil ◽  
Measuring System ◽  
Measuring Instrument ◽  
Voltage Measurement ◽  
Medium Voltage ◽  
Set Up

The features of a Power Quality measurement system which includes both voltage and current transducers and a self-developed measuring instrument are described. The system is intended for measurements in substations at medium voltage level. A Rogowski coil and a voltage divider are the used transducers, whereas the measuring instrument is based on a Reconfigurable I/O-FPGA system with embedded software. Attention is focused on the procedures adopted for the characterization of the voltage and current sensors, which are carried out taking into account the expected on-site measurement conditions. An example of use of the systems for measurement of some PQ parameters in a private substation which connects an industrial load and two photo-voltaic generation plants to the public MV voltage network is presented, together with the associated voltage and current uncertainty budget. By making use of the results obtained in the characterization phase, the current and voltage measurement uncertainty can be reduced.

An Auxiliary Power Supply for Gate Drive of Medium Voltage SiC Devices in High Voltage Applications

2018 ◽  
Vol 924 ◽  
pp. 836-840
Author(s):  
Bo Xue Hu ◽  
He Li ◽  
Zhuo Wei ◽  
Ya Feng Wang ◽  
Diang Xing ◽  
...  
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Low Voltage ◽  
High Reliability ◽  
Voltage Divider ◽  
Input Voltage ◽  
Voltage Regulation ◽  
Multilevel Converters ◽  
Medium Voltage ◽  
Auxiliary Power

A high-reliability auxiliary power supply (APS) for gate drive circuits is crucial to utilization of emerging medium voltage (MV ≥ 10 kV) Silicon Carbide (SiC) devices in high voltage applications. This paper proposes an active voltage divider based APS with lower arm voltage regulation. The proposed APS circuit is targeting the application of MV SiC devices in modular multilevel converters (MMCs). It can harvest energy from a MV (≥ 7 kV) dc bus to provide an isolated low voltage output to gate drive circuits of MV SiC devices. Compared to existing APS solutions, it can achieve a high input voltage (≥ 7 kV) with simple circuit structure and control scheme. In this paper, the working principle of the proposed APS is presented and a circuit design example is shown. A circuit prototype with 7 kV input and 15 V/10 W output has been built and tested to verify the effectiveness of the proposed solution.

scholarly journals Development of Broadband Resistive–Capacitive Parallel–Connection Voltage Divider for Transient Voltage Monitoring

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 451
Author(s):  
Shijun Xie ◽  
Zhou Mu ◽  
Weidong Ding ◽  
Zhenbo Wan ◽  
Shaochun Su ◽  
...  
Keyword(s):  
Power Systems ◽  
High Voltage ◽  
Low Voltage ◽  
Influence Factors ◽  
Voltage Divider ◽  
Step Response ◽  
Internal Electric Field ◽  
Scale Factors ◽  
Different Temperatures ◽  
Transient Voltages

The on-site measurement of transient voltages is of great significance in analyzing the fault cause of power systems and optimizing the insulation coordination of power equipment. Conventional voltage transformers normally have a narrow bandwidth and are unable to accurately measure various transient voltages in power systems. In this paper, a wideband parallel resistive–capacitive voltage divider is developed, which can be used for online monitoring of transient voltages in a 220 kV power grid. The structures of the high-voltage and low-voltage arms were designed. The internal electric field distribution of the high-voltage arm was analyzed. The influence factors and improvement techniques of the upper frequency limit were studied. The parameters of the elements of the divider were determined. The voltage withstand performances and scale factors under lightning impulses and AC and DC voltages, the temperature stabilities of scale factors and the step response and bandwidth of the developed voltage divider were tested. The results show that the deviations of the scale factors under various voltage waveforms and different temperatures ranging from −20 to 40 °C are within 3%. The withstand voltage meets the relevant requirements specified in IEC60071-1-2011. The step response 10~90% rise time is approximately 29 ns, and the 3 dB bandwidth covers the range of DC to 10 MHz.

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