A development study for Chinese large scale renewable energy source base and technology. The renewable energy is an abundant, widely existing, and clean primary energy source. With the gradual exhaustion of the fossil fuel, its role in the sustainable energy development of the whole mankind will be higher and higher, and its percentage in the energy supply system will be ever increasing. During the first half of 21th century the readjustment process of energy structure has been starting. The main renewable energy besides the water energy will be solar, wind, biomass energies. A study of Chinese large scale renewable energy source base and technology with the participation of academicians and specialists concerned is organized by Chinese Academy of Sciences. Brief conclusion and propose of the study were included in this report. 6 Refs. In Chinese.
Key Words: renewable energy sources; solar energy; wind energy; biomass energy; energy source base
YAN Lu-guang (Chinese Academy of Sciences, Beijing 100864, China), XIA Xun-cheng, ZHOU Feng-qi, et al. // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 1—5.

DC-Modulated PFC Buck-Type AC/AC Converter for Light Dimming. Dimmers are very widely applied in theatres, cinemas, dancing-parties, auditoriums and signal systems. They are usually supplied by single-stage AC/AC converters in the past with voltage regulation technique with the disadvantages of high total harmonic distortion, low power factor and poor power transfer efficiency. This paper introduces a novel method - DC-modulation that implements DC/DC conversion technology into AC/AC converters. The DC-modulated single-stage PFC AC/AC converters effectively improved the power factor up to 0.999 and the power transfer efficiency up to 97.8 %. The experimental results verified our design and calculation. This technique will be widely used in light dimming and other industrial applications. 13 Refs. In English.
Key Words: power factor correction; DC-modulated AC/AC converters; light dimming; total harmonic distortion
Fang Lin LUO (1. EEE, Nanyang Technological University, Nanyang Avenue, Singapore 639798; 2. AnHui University of Technology, Ma’anshan 243002, Anhui, China), Hong YE // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 6—10.

High Performance Control of Matrix Converter Fed Induction Motor Drive System. Matrix converter fed motor drive is superior to pulse width modulation inverter drives since it not only provides bi-directional power flow, sinusoidal input/output currents, unity input power factor, but also allows a compact design due to the lack of dc-link capacitors for energy storage. In this paper, model and control of matrix converter fed induction motor drive system are analyzed. A combined control strategy is simplified and improved, which realizes space vector pulse width modulation of matrix converter and rotor flux oriented vector control technique for induction motor drive simultaneously. This control strategy combines the advantages of matrix converter with the good drive performance of vector control technique. Experimental results demonstrate the feasibility and effectiveness of the proposed control strategy. 13 Refs. In English.
Key Words: matrix converter; induction motor; space vector pulse width modulation; vector control
SUN Kai (Department of Electrical Engineering, Tsinghua University, Beijing 10080, China), HUANG Li-pei, MATSUSE Kouki // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 11—15.

Control of PMSM based on RBF neural network without position sensor. Firstly, the control strategy and the principle of control for PMSM without position sensor are analyzed. Then, a new control method for PMSM is proposed, which is based on radial basis function (RBF) neural network. There are no hidden units at the beginning, and the network has four inputs and two outputs. The inputs are the voltages and currents of stationary　 reference frame, and the outputs are the position angle and speed of rotor. Then according to an adaptive algorithm, the hidden units are increased or decreased during the process of off-line learning till the network is built with a much simpler and tighter structure. During on-line training, the network updates the network parameters using a gradient descending error algorithm. By mapping the voltages and currents of stationary　 reference frame to position angle and speed of rotor, the network can replace the traditional position sensors. The theory in this paper is verified by experimental results. 6 Refs. In Chinese.
Key Words: permanent magnet synchronous motor (PMSM); radial basis function (RBF); neural network; position sensorless control
SHI Ting-na (College of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China), WANG Xiang-chao, XIA Chang-liang // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 16—19.

Research of a new-style four coil double steady state permanent magnetic actuator. In order to solve the design problem of larger opening and closing start electric current and unsatisfied opening speed of permanent magnetic actuator with long stroke, the concept of four coil double steady state permanent magnetic actuator is suggested firstly in this paper. Theoretical analysis and tests indicate that this way is applicable. The key lies in that the turns of opening and closing trip coils must be suitable. The numbers of turns of opening and closing trip coils needed for different permanent magnetic actuators are different. In addition, a convenient control scheme of main electrical circuit of four coil double steady state permanent magnetic actuator is given. 6 Refs. In Chinese.
Key Words: permanent magnetic actuator; long stroke; four coils; trip coil; control
ZHANG Lai-fu (Shanxi Electric Power Research Institute, Taiyuan 030001, China), YANG Jie, HU Xiao-cen // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 20—23.

Study on the oil tank surface vibration characteristics for the running power transformer. Steady-state vibration recording recorded on the tank surface under on-line conditions provides essential information about fixation conditions both for windings and the magnetic core. Therefore, vibration signal analysis method is one of effective methods to monitor the condition of transformer windings and core. In this paper, the transformer vibration measurement system is set up and the vibration signals on the oil tank surface of running transformer in the field are measured. The influences of transformer type and sensor locations to the measured vibration signals are analyzed. The results show that, the vibration characteristics of the same type transformers are similar, and the vibration characteristics at the symmetrical positions on the upside and underside tank surface have little difference. Moreover, the vibration signals measured at other positions have no comparability. Finally, in this paper, the study about the change of vibration signal is carried on when the installed position of sensor is moved a little. It is presented that the installing position of sensor should be marked, and then if the next measurement is taken on, the installing position of sensor should be at the marked point or not exceed 5cm. The results presented in this paper can guide the application of vibration signal analysis method. 9 Refs. In Chinese.
Key Words: power transformer; oil tank; vibration; sensor
JI Sheng-chang (Xi’an Jiaotong University, Xi’an 710049, China), MEN Yang, LIU Yu-wen, et al. // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 24—28.

A new optimal power flow algorithm based on filter interior point method. A new OPF algorithm (FIPOPF) is proposed based on Filter Interior Point Method (FIPM), which can correct the iteration direction adaptively in face with the practical OPF problem. If there is no feasible solution, FIPOPF will converge to a stable point which will minimize the possibility of violation of “soft constraints” by solving an optimal problem which has only “hard constraints”. Numerical tests in five IEEE test systems and two actual systems show the robustness and high efficiency of the proposed method, which could satisfy the requirement of online optimal dispatch of the power system. 12 Refs. In Chinese.
Key Words: power system; optimal power flow; filter method; interior point method; online control
SUN Ying-yun (State Key Lab of Power Systems, Dept. of Elec. Eng., Tsinghua University, Beijing 100084, China), HE Guang-yu, MEI Sheng-wei // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 29—33.

Application of sensitivity analysis on the study of CM EMI of a three-phase inverter. The sensitivity analysis technique is applied on the investigation of common-mode conducted interference (CM EMI) of a three-phase PWM Inverter. It is proved that the Inverter-input-side parasitic parameters of the DC cable have trivial effects on CM EMI and the parasitic capacitors between the Inverter and the ground have significant effects on CM EMI as well as the parasitic capacitors between motor windings and motor shell. The result of sensitivity analysis is helpful to solve the problem of determining the spreading path of the CM EMI. And also it provides an useful guide for future handling of parasitic capacitors in the study of conducted interference of DC power supply. 6 Refs. In Chinese.
Key Words: sensitivity; inverter; conducted interference; parasitic parameters
YIN Ke-quan (College of Electrical and Information Engineering, Naval Univ. of Engineering, Wuhan 430033, China), XIAO Chang-han, SHAN Chao-long // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 34—38.

Analysis of transient voltage stability based on a novel transient stability index. Based on the quadratic approximation of the stability region boundary, this paper proposes a transient voltage stability margin index, and analyzes the transient voltage stability of a one-machine and one-load system including an electromechanical transient model of induction motor. Simulations show that the proposed index has the advantages of high accuracy, high engineering practicability and facility of computer-implementing, and can be applied to obtain the margin of the transient voltage stability, estimate the critical clearing time of transient voltage stability and rank the severity of the contingencies. Simulations show that, for the system of this paper, the heavier load and larger static portion of mechanical torque in the load are more inclined to lead to transient voltage instability. 23 Refs. In Chinese.
Key Words: transient voltage stability; stability margin; stability region boundary; quadratic approximation
WANG Yi-hong (State Key Lab of Power Systems, Dept. of Electrical Engineering, Tsinghua University, Beijing 100084, China), MEI Sheng-wei // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 39—44.

Effect of superconducting fault current limiters on power system protection and transient stability
XIA Yi1，LIU Jian-ming2
(1. China Electric Power Research Institute, Beijing 100085, China; 2. China Electric Power Information Center, Beijing 100761, China)
Abstract: The fast development of power system leads to sharp increase of the short circuit current. Until now, Superconducting Fault Current Limiter is considered the best limiting equipment. The power characteristics of the system installed with SFCLs are presented in details and the transient process of power systems is analyzed by using the equal area criterion. The explanation for the mechanism of SFCL’s influence on transient stability of power system is given. For the SFCL installed in the power system has impact on relaying protection, and the impact on the distance protection is especially distinct. The SFCl’s influence on the distance protection is analyzed in detail in the second half part of this paper. A new setting method is proposed. Finally the new method is tested using a simulation example.
Key words: SFCLs; power grid; transient stability; system protection
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 69—72.

Analysis of capacitor voltage of DC side on half-bridge three-level inverter with asymmetrical AC output
YAN Shi-chao, TANG Qing-quan, LIU Zheng-zhi
(Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China)
Abstract: Multilevel inverters which can provide more than two voltage levels and less distorted waveform offer many benefits for high voltage and large power applications. But neutral point potential will offset badly when the output current is not symmetrical. The object of this paper is to fast control power of Experimental Advanced Superconducting Tokamak. The power whose load is nearly a pure inductance is required to output an asymmetrical current. There are two respective diode rectifiers for the capacitors on the DC side. The main purpose of this paper is to analyze quantitative the change of the capacitor voltage on the DC side in different output condition to offer the power protection basis. At first, the paper analyses the theory of three-level inverter and the characteristic of diode rectification and explains four kinds of working modes about three-level PWM inverter. Then, based on the current charge method and energy conservation method, the paper analyses the change of the voltage of the capacitor on the DC side and gives out the formula of voltage change in unit cycle when a sine current with DC component passes through the inductive load. The two methods verified each other well and deduced to a consistent conclusion. The simulation and experiment verify further the rationality and correctness of two formulas.
Key words: asymmetrical alternating current; capacity voltage; three-level; PWM; diode rectification
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 69—72.

Modeling and parameter optimization of coilgun system with inductive energy storage supply
LI Jian-hui, LIU Xiu-cheng, WANG Chun-ming, WANG Zan-ji
(State Key Lab of Power System, Department of Electrical Engineering, Tsinghua University, Beijing100084)
Abstract: An equivalent circuit of coilgum system with inductive energy storage supply including the driving coil, the projectile and the electromagnetic coupling between driving coil and projectile was set up in this paper. The performance of the system was simulated with MATLAB, the effects of the system parameters on projectiles’ muzzle energy were analyzed and some important conclusions for the coilgun design were obtained. Based on the proposed model, some parameters were also optimized. A laboratory model of coilgun with inductive energy storage supply was set up and the testing results verified the correctness of the equivalent model and the simulations.
Key words: coilgun; inductive energy storage; pulsed power
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 69—72.

Magnet Science and Technology for Basic Research
at the High Field Laboratory for Superconducting Materials
WATANABE Kazuo
 (High Field Laboratory for Superconducting Materials,
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan)
Abstract: Since the first practical cryocooled superconducting magnet using a GM-cryocooler and high temperature superconducting current leads has been demonstrated successfully at the High Field Laboratory for Superconducting Materials (HFLSM), various kinds of cryocooled superconducting magnets in fields up to 15 T have been used to provide access for new research areas in fields of magneto-science. Recently, the HFLSM has succeeded in demonstrating a cryocooed 18 T high temperature superconducting magnet and a high field cryocooled 27.5 T hybrid magnet. Cryocooled magnet technology and basic research using high field magnets at the HFLSM are introduced.
Key words: cryocooled superconducting magnet; high magnetic field; magnet technology; GM-cryocooler
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 59-64.

Development of a dynamic characteristic testing device of rotational electrical apparatus with opto-electromechanical technology
CHEN De-wei, ZHANG Pei-ming
(Fuzhou University, Fuzhou 350002, China)
Abstract：This paper chiefly presents an optical electromechanical testing instrument for dynamic characteristics of rotational electrical apparatus with the combination of techniques from MSP430F449 model chip computer and CPLD. With this device, the switch-on and switch-off processes of rotational electrical apparatus can be detected dynamically. This device is taking part in the researching of intelligent electrical apparatus, which have achieved real-time dynamic process control, function optimization and is enhancing performance of electrical apparatus significantly.
Key words：rotational electrical apparatus; testing device; intelligent measuring
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 65-68.

Influence of different pulsed electric fields on HL-60 cell death. Pulsed electric field with different ramp slopes were used to irradiate the suspended HL-60 cells. The experiment settings are designed to produce pulsed electric field on sample with the intensity peak of 3.82MV/m within 100ns and 1μs, respectively. Cell death rates are assessed after electric irradiate according to the different field intensity, pulse number and recovery time between samples. Cell death rate increases for both ramp slopes when the field intensity or pulse number increases. Cell death increases faster after irradiated by 100ns pulsed electric field than that of 1μs. Cell death rates are recorded after stimulation with recovery time interval of 30 minutes. Cell death rate of 100ns pulsed electric field rises slowly and reaches its peak later than that of 1μs pulsed electric field. It means the 100ns pulsed electric field causes the death of cell in a more indirectly way contrasting with the 1μs pulsed electric field. 10 Refs. In Chinese.
Key Words: pulsed electric field; nanosecond; cell; apoptosis
XU Fei (Shanghai Dianji University, Shanghai 200240, China), HAN Qiang // Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 69—72.

High power electromagnetic pulse source based on transmission line charging technology
XU Jian-jun1,2, LIAO Cheng1, XIAO Kai-qi2 
(1. Electromagnetic Institute, Southwest Jiaotong University, Chengdu 610031, China;
2. Southwest Institute of Electronic Equipment, Chengdu 610036, China)
Abstract: In order to investigate the generation of high power electromagnetic pulse, a high power electromagnetic pulse radiation setup is developed in this paper. In the setup a high power pulse driving source with high output impedance based on Tesla transformer is utilized as charging source, and the subnanosecond pulse conditioning and radiation is realized by using transmission line charging technology and double ridged horn-shaped antenna connected with impedance transformer respectively. High power electromagnetic pulses with pulse repetition frequency (PRF) reached 100Hz and maximum field-range product equal to 294KV can be achieved by the setup. The spectrum of radiated pulse is concentrated in 0.4-1.0GHz.
Key words: high power; transmission line charging technology; subnanosecond pulse conditioning; double ridged horn
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 73-75.

Control and velocity measurement of multi-stage reconnection gun
ZHOU Zheng-yang, LIAO Min-fu, ZHAO Chun, ZOU Ji-yan
(Dept. of Electrical and Electronic Engineering, Dalian University of Technology, Dalian 116023, China)
Abstract: Reconnection gun is a type of electromagnetic launcher whose propulsive force is generated by the magnetic field line reconnection. The key point of multi-stage reconnection gun is the discharge of preserved energy in sequence at different stages. The principle of reconnection gun is introduced. A control project of multi-stage reconnection gun as well as the velocity measurement system are presented on the basis of a fabricated three-stage reconnection gun. The velocity data and its curve during the launch process are attained. A pill of 160 grams can be accelerated to 24.991m/s when the energy storage capacitor banks are charged to 3500V.
Key words: reconnection gun; control project; velocity measurement
// Adv. Tech. of Elec. Eng. & Energy, 2007, 26(2). 76-80.