The 6 MW/4.6 GHz lower hybrid current drive (LHCD) system will be set up on the experimental advanced superconducting tokamak (EAST) for achieving a steady-state op- eration. The high power and continuous wave (C...The 6 MW/4.6 GHz lower hybrid current drive (LHCD) system will be set up on the experimental advanced superconducting tokamak (EAST) for achieving a steady-state op- eration. The high power and continuous wave (CW) mode microwave test bench operating at 250 kW/4.6 GHz has already been finished, which can be used to simulate different kinds of high power microwave environments to test microwave components and units for the new LHCD sys- tem. The power control and data acquisition system on the test bench composed of power control, high reflected power protection and data acquisition function is described here in detail. Long- term operation of the test bench showed that the power control and data acquisition system is very stable and reliable.展开更多
The power communication network is a separate network from the power grid whose primary purpose is to ensure the power grid's safe operation.This paper expounds the composition of the comprehensive network managem...The power communication network is a separate network from the power grid whose primary purpose is to ensure the power grid's safe operation.This paper expounds the composition of the comprehensive network management architecture of the power communication data network and the implementation of the data acquisition module in the network management system through theoretical analysis,for the reference of relevant personnel,in order to better promote the collection of power grid communication network data.展开更多
The energy of a radio wave is reduced through the dispersion, the refraction and the absorption because the medium transferring the vibration of a radio wave is the seawater. In the end the reduced energy of a radio w...The energy of a radio wave is reduced through the dispersion, the refraction and the absorption because the medium transferring the vibration of a radio wave is the seawater. In the end the reduced energy of a radio wave causes the reduced transmitting length for communication, the long postponed communication and the frequent error. The subsea communication for the marine environment monitoring which must overcome the weak points of the RF wave and the most practical method for the marine sensor network realization is to use the acoustic wave method, but the energy consumption rate of the acoustic wave communication method is about 100 times greater than the one of the RF wave method. So, the power supply of the sensor node in the marine sensor network system is the most important interest field. In this study, the sample which consists of an acrylic elastomer(VHB4905 film from 3M), conductible carbon grease(from MG chemical) and electric wire for the basic study of an energy harvesting strategy and technique using EAP actuator was fabricated, and the conductible carbon grease was used for an electrode. The characteristics of the fabricated sample were analyzed through the experiment. We also mixed carbon grease with aluminum powder for conductibility improvement, and the effect of the mixed electrode was confirmed through the conductivity measurement.展开更多
In order to provide power quality monitoring activities with metrological certification, a DAS (data acquisition system) has been designed, realized and characterized. The system allows acquisition on tri-phases plu...In order to provide power quality monitoring activities with metrological certification, a DAS (data acquisition system) has been designed, realized and characterized. The system allows acquisition on tri-phases plus neutral lines picking up 499 samples per period of the fundamental at 50 Hz. To ensure certified measurements, the system gets external certified time and voltage references. The system uses a FTDI Virtual Com Port Driver to communicate data over High Speed RS232 virtual interface and it does not need any advanced programming skill. The choice to use a virtual serial communication makes the data acquisition software portable over many platforms, regardless by the development environment and by the programming language. To test the proposed device some custom software have been written in many programming language (C^#, VB6, LabView, MatLab), moreover in order to characterize the device the most common ADC (analog to digital converter) performing test have been applied.展开更多
This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, ...This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, it has a higher sampling rate and an improved simultaneity performance. It also improves the data collection method and sensor design for the measurement of Faraday voltages and Faraday currents. The system has been successfully used in many regular MHD generator tests. It provides an excellent base for the future research and development of the Coal fired MHD electrical power generation.展开更多
In this paper the authors explore the Global Positioning System (GPS) signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the perf...In this paper the authors explore the Global Positioning System (GPS) signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the performance of a software GPS receiver in terms of its speed. A trade-off study is done to seek a good balance between the acquisition accuracy and the processing time. The frequency-domain acquisition method by circular correlation, used in a software GPS receiver, has been improved by studying the power spectrum of the Coarse Acquisition (C/A) code alone. The analysis of C/A code reveals that its power spectrum is symmetrical; hence only half the points are required to perform circular correlation. Besides, either half of the spectrum is asymmetrical where a larger amount of power is concentrated in almost one-quarter of the spectrum on its either sides. This further reduces the number of points used to perform correlation. Comparative results of MATLAB simulation of full-size, half-size and quarter-size circular correlation done on actual data stored on hard disk are provided, and they agree with those obtained using GPS receiver. Further reduction in acquisition time has been achieved by investigating the effect of length of the noncoherent pre-integration period. The improved acquisition methods pave way for further development of new algorithms to enhance software GPS receiver performance.展开更多
The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiment...The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.展开更多
In this paper, the measurement method of calorimetric power for an electron cyclotron resonance heating(ECRH) system for EAST is presented. This method requires measurements of the water flow through the cooling cir...In this paper, the measurement method of calorimetric power for an electron cyclotron resonance heating(ECRH) system for EAST is presented. This method requires measurements of the water flow through the cooling circuits and the input and output water temperatures in each cooling circuit. Usually, the inlet water temperature stability is controlled to obtain more accurate results.The influence of the inlet water temperature change on the measurement results is analyzed for the first time in this paper. Also, a novel temperature calibration method is proposed. This kind of calibration method is accurate and effective, and can be easily implemented.展开更多
For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the r...For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the remote assets. The primary objective of this paper is to develop a communication link for monitoring and controlling a grid-connected inverter in a remote location. Furthermore, the paper presents developments that have been incorporated to improve the communication link. The literature survey indicates that LoRa is superior compared to other technologies, but has some security and reliability issues. This paper also presents an encryption algorithm to improve the security of the LoRa link. Local data storage added to the system before transmitting data increases the system reliability. A display at the transmission end is added to improve the user-friendliness of the communication link. A Powerline Communication link is parallelly added to the LoRa link to improve the reliability. Finally, tests are conducted with an actual inverter and the results are presented. The tests show that the developed communication link has improved security and reliability, while its open nature makes it highly scalable and adaptable for employment in other smart grid applications.展开更多
Through the comparison of various acquisition technology and related technology theory of the existing scheme, the paper analyze and design the power battery testing platform of the data acquisition system, and give t...Through the comparison of various acquisition technology and related technology theory of the existing scheme, the paper analyze and design the power battery testing platform of the data acquisition system, and give the research design scheme of the utility model through the design of the software on PC and CAN bus, which makes the full synchronization requirements acquisition unit; improve the linearity and stability of total voltage and current acquisition by the integrated circuit, and improve the system sampling rate, effectively complete the corresponding index. Finally, through experimental verification, to ensure the completion of the technical indicators.展开更多
To improve the heat dissipation of high-power light-emitting diodes (LEDs), a cooling system with a fan is proposed. In the experiment, the LEDs array of 18 W composed of 6 LEDs of 3 W is used and the room temperature...To improve the heat dissipation of high-power light-emitting diodes (LEDs), a cooling system with a fan is proposed. In the experiment, the LEDs array of 18 W composed of 6 LEDs of 3 W is used and the room temperature is 26oC. Results show that the temperature of the substrate of LEDs reaches 62oC without the fan, however, it reaches only 32oC when the best cooling condition appears. The temperature of the LEDs decreases by 30oC since the heat produced by LEDs is transferred rapidly by the fan. The experiment demonstrates that the cooling system with the fan has good performance.展开更多
基金supported by National Magnetic Confinement Fusion Science Program of China(No.2010GB105001)
文摘The 6 MW/4.6 GHz lower hybrid current drive (LHCD) system will be set up on the experimental advanced superconducting tokamak (EAST) for achieving a steady-state op- eration. The high power and continuous wave (CW) mode microwave test bench operating at 250 kW/4.6 GHz has already been finished, which can be used to simulate different kinds of high power microwave environments to test microwave components and units for the new LHCD sys- tem. The power control and data acquisition system on the test bench composed of power control, high reflected power protection and data acquisition function is described here in detail. Long- term operation of the test bench showed that the power control and data acquisition system is very stable and reliable.
文摘The power communication network is a separate network from the power grid whose primary purpose is to ensure the power grid's safe operation.This paper expounds the composition of the comprehensive network management architecture of the power communication data network and the implementation of the data acquisition module in the network management system through theoretical analysis,for the reference of relevant personnel,in order to better promote the collection of power grid communication network data.
文摘The energy of a radio wave is reduced through the dispersion, the refraction and the absorption because the medium transferring the vibration of a radio wave is the seawater. In the end the reduced energy of a radio wave causes the reduced transmitting length for communication, the long postponed communication and the frequent error. The subsea communication for the marine environment monitoring which must overcome the weak points of the RF wave and the most practical method for the marine sensor network realization is to use the acoustic wave method, but the energy consumption rate of the acoustic wave communication method is about 100 times greater than the one of the RF wave method. So, the power supply of the sensor node in the marine sensor network system is the most important interest field. In this study, the sample which consists of an acrylic elastomer(VHB4905 film from 3M), conductible carbon grease(from MG chemical) and electric wire for the basic study of an energy harvesting strategy and technique using EAP actuator was fabricated, and the conductible carbon grease was used for an electrode. The characteristics of the fabricated sample were analyzed through the experiment. We also mixed carbon grease with aluminum powder for conductibility improvement, and the effect of the mixed electrode was confirmed through the conductivity measurement.
文摘In order to provide power quality monitoring activities with metrological certification, a DAS (data acquisition system) has been designed, realized and characterized. The system allows acquisition on tri-phases plus neutral lines picking up 499 samples per period of the fundamental at 50 Hz. To ensure certified measurements, the system gets external certified time and voltage references. The system uses a FTDI Virtual Com Port Driver to communicate data over High Speed RS232 virtual interface and it does not need any advanced programming skill. The choice to use a virtual serial communication makes the data acquisition software portable over many platforms, regardless by the development environment and by the programming language. To test the proposed device some custom software have been written in many programming language (C^#, VB6, LabView, MatLab), moreover in order to characterize the device the most common ADC (analog to digital converter) performing test have been applied.
文摘This paper introduces the design and development of a new computerized data acquisition system for the coal fired magnetohydrodynamical (MHD) electrical power generation experiments. Compared to the previous system, it has a higher sampling rate and an improved simultaneity performance. It also improves the data collection method and sensor design for the measurement of Faraday voltages and Faraday currents. The system has been successfully used in many regular MHD generator tests. It provides an excellent base for the future research and development of the Coal fired MHD electrical power generation.
文摘In this paper the authors explore the Global Positioning System (GPS) signal acquisition and tracking algorithms used in software GPS receiver. Acquisition time is the most important parameter in evaluating the performance of a software GPS receiver in terms of its speed. A trade-off study is done to seek a good balance between the acquisition accuracy and the processing time. The frequency-domain acquisition method by circular correlation, used in a software GPS receiver, has been improved by studying the power spectrum of the Coarse Acquisition (C/A) code alone. The analysis of C/A code reveals that its power spectrum is symmetrical; hence only half the points are required to perform circular correlation. Besides, either half of the spectrum is asymmetrical where a larger amount of power is concentrated in almost one-quarter of the spectrum on its either sides. This further reduces the number of points used to perform correlation. Comparative results of MATLAB simulation of full-size, half-size and quarter-size circular correlation done on actual data stored on hard disk are provided, and they agree with those obtained using GPS receiver. Further reduction in acquisition time has been achieved by investigating the effect of length of the noncoherent pre-integration period. The improved acquisition methods pave way for further development of new algorithms to enhance software GPS receiver performance.
基金The project supported by the Chinese Academy of Sciences (No. SYKXD04)
文摘The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.
基金supported by the National Magnetic Confinement Fusion Science Program of China (Grant Nos.2011GB102000, 2015GB103000)
文摘In this paper, the measurement method of calorimetric power for an electron cyclotron resonance heating(ECRH) system for EAST is presented. This method requires measurements of the water flow through the cooling circuits and the input and output water temperatures in each cooling circuit. Usually, the inlet water temperature stability is controlled to obtain more accurate results.The influence of the inlet water temperature change on the measurement results is analyzed for the first time in this paper. Also, a novel temperature calibration method is proposed. This kind of calibration method is accurate and effective, and can be easily implemented.
文摘For decades, the power system was highly centralized. With the growing integration of distributed generations into the system, there is a necessity for bi-directional communication methods to monitor and control the remote assets. The primary objective of this paper is to develop a communication link for monitoring and controlling a grid-connected inverter in a remote location. Furthermore, the paper presents developments that have been incorporated to improve the communication link. The literature survey indicates that LoRa is superior compared to other technologies, but has some security and reliability issues. This paper also presents an encryption algorithm to improve the security of the LoRa link. Local data storage added to the system before transmitting data increases the system reliability. A display at the transmission end is added to improve the user-friendliness of the communication link. A Powerline Communication link is parallelly added to the LoRa link to improve the reliability. Finally, tests are conducted with an actual inverter and the results are presented. The tests show that the developed communication link has improved security and reliability, while its open nature makes it highly scalable and adaptable for employment in other smart grid applications.
文摘Through the comparison of various acquisition technology and related technology theory of the existing scheme, the paper analyze and design the power battery testing platform of the data acquisition system, and give the research design scheme of the utility model through the design of the software on PC and CAN bus, which makes the full synchronization requirements acquisition unit; improve the linearity and stability of total voltage and current acquisition by the integrated circuit, and improve the system sampling rate, effectively complete the corresponding index. Finally, through experimental verification, to ensure the completion of the technical indicators.
文摘To improve the heat dissipation of high-power light-emitting diodes (LEDs), a cooling system with a fan is proposed. In the experiment, the LEDs array of 18 W composed of 6 LEDs of 3 W is used and the room temperature is 26oC. Results show that the temperature of the substrate of LEDs reaches 62oC without the fan, however, it reaches only 32oC when the best cooling condition appears. The temperature of the LEDs decreases by 30oC since the heat produced by LEDs is transferred rapidly by the fan. The experiment demonstrates that the cooling system with the fan has good performance.