The small-signal model of the photovoltaic generation system was built in a few references,and the sensitivity study of the dynamics process was performed.However,the dynamic model of the photovoltaic(PV)cells was not...The small-signal model of the photovoltaic generation system was built in a few references,and the sensitivity study of the dynamics process was performed.However,the dynamic model of the photovoltaic(PV)cells was not considered in these references,and the small-signal stability analysis and controllers'parameters design were not carried out using the proposed small-signal model.Therefore,a complete small-signal model of the photovoltaic generation system containing PV panels,inverters,controllers and power grid was built.The stability of the system after suffering a small disturbance was analyzed according to the eigenvalues.By means of eigenvalues participation factors analysis,the sensitivity of each mode to state variables was learnt,thereby the origin and characteristics of each mode was disclosed.Then,the eigenvalues traces were calculated,according to which controller's parameters were designed.A simulation model of the system based on Matlab/Simulink was presented.The simulation results show that the system is stable after suffering small disturbance of solar radiation intensity step,the design of the controller's parameters is proper,and the system dynamic responses are consistent with the result of small-signal analysis,which proved that the small-signal modeling and analysis in this paper are correct.展开更多
A compact high-voltage repetitive nanosecond pulse generator(HRNPG)was developed for studying the technology of repetitive nanosecond pulse technology and its related application.The HRNPG mainly consists of a repetit...A compact high-voltage repetitive nanosecond pulse generator(HRNPG)was developed for studying the technology of repetitive nanosecond pulse technology and its related application.The HRNPG mainly consists of a repetitive charging module,a Tesla transformer and a sharpening switch.With its voltage lower than 1 kV,the primary repetitive charging circuit comprises two fast thyristors as its low-voltage switches.The spiral Tesla transformer acts as the main step-up component,and its peak transformation ratio is designed to be more than 100.A self-breakdown spark switch,i.e.the sharpening switch,is used to sharpen the output of the transformer and to generate nanosecond pulses.The HRNPG prototype is capable of generating pulses of 100 kV in peak with rise time 30 ns and the maximum repetition rate of 500 Hz on a 6 k load.Experimental results show,without any magnetic core,the developed Tesla transformer prototype can easily output high voltage while keeping itself small in size and light in weight,which is of significance for the compactness and portability of the pulse generator.The N2-insulated spark switch operated well at voltage close to 100 kV and the repetition rate within several hundreds of hertz.展开更多
High energy density capacitor is a key device to power supply source for electromagnetic gun (EMG) system, and extending its lifetime is important for increasing the reliability of the power source. Working in high el...High energy density capacitor is a key device to power supply source for electromagnetic gun (EMG) system, and extending its lifetime is important for increasing the reliability of the power source. Working in high electric field could affect the capacitor lifetime, and this effect on metallized polypropylene film capacitors (MPPFCs) in pulsed-power applications is studied and presented. Experimental re- sults show that the lifetime of MPPFCs decreases with the increasing peak value of charged electric field, and this decrease could be described by function (L/L0) ∝ (E/E0)–m, where, m=7.32. The lifetime of MPPFCs also decreases with the increase of the reversal coeffi- cients in underdamped circuits, which could be described by (L/L0) ∝ (ln(1/K0)/(ln(1/K))–b, where, b=0.7. These results provide a basis for the lifetime prediction of MPPFCs in pulsed-power applications.展开更多
文摘The small-signal model of the photovoltaic generation system was built in a few references,and the sensitivity study of the dynamics process was performed.However,the dynamic model of the photovoltaic(PV)cells was not considered in these references,and the small-signal stability analysis and controllers'parameters design were not carried out using the proposed small-signal model.Therefore,a complete small-signal model of the photovoltaic generation system containing PV panels,inverters,controllers and power grid was built.The stability of the system after suffering a small disturbance was analyzed according to the eigenvalues.By means of eigenvalues participation factors analysis,the sensitivity of each mode to state variables was learnt,thereby the origin and characteristics of each mode was disclosed.Then,the eigenvalues traces were calculated,according to which controller's parameters were designed.A simulation model of the system based on Matlab/Simulink was presented.The simulation results show that the system is stable after suffering small disturbance of solar radiation intensity step,the design of the controller's parameters is proper,and the system dynamic responses are consistent with the result of small-signal analysis,which proved that the small-signal modeling and analysis in this paper are correct.
基金Project supported by National Natural Science Foundation of China （51107049）.
文摘A compact high-voltage repetitive nanosecond pulse generator(HRNPG)was developed for studying the technology of repetitive nanosecond pulse technology and its related application.The HRNPG mainly consists of a repetitive charging module,a Tesla transformer and a sharpening switch.With its voltage lower than 1 kV,the primary repetitive charging circuit comprises two fast thyristors as its low-voltage switches.The spiral Tesla transformer acts as the main step-up component,and its peak transformation ratio is designed to be more than 100.A self-breakdown spark switch,i.e.the sharpening switch,is used to sharpen the output of the transformer and to generate nanosecond pulses.The HRNPG prototype is capable of generating pulses of 100 kV in peak with rise time 30 ns and the maximum repetition rate of 500 Hz on a 6 k load.Experimental results show,without any magnetic core,the developed Tesla transformer prototype can easily output high voltage while keeping itself small in size and light in weight,which is of significance for the compactness and portability of the pulse generator.The N2-insulated spark switch operated well at voltage close to 100 kV and the repetition rate within several hundreds of hertz.
基金Project supported by Opening Foundation of National Engineering Laboratory for UltraHigh Voltage Engineering Technology (Kunming, Guangzhou, China)
文摘High energy density capacitor is a key device to power supply source for electromagnetic gun (EMG) system, and extending its lifetime is important for increasing the reliability of the power source. Working in high electric field could affect the capacitor lifetime, and this effect on metallized polypropylene film capacitors (MPPFCs) in pulsed-power applications is studied and presented. Experimental re- sults show that the lifetime of MPPFCs decreases with the increasing peak value of charged electric field, and this decrease could be described by function (L/L0) ∝ (E/E0)–m, where, m=7.32. The lifetime of MPPFCs also decreases with the increase of the reversal coeffi- cients in underdamped circuits, which could be described by (L/L0) ∝ (ln(1/K0)/(ln(1/K))–b, where, b=0.7. These results provide a basis for the lifetime prediction of MPPFCs in pulsed-power applications.
