Great promotion of development of large scale integrative energy base in Xinjiang
YAN Lu-guang¹, XIA Xun-cheng², LV Shao-qin³, WU Jia-chun⁴, LIN Min³, HUANG Chang-gang¹
(1.Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; 2. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumchi 830011, China; 3. Xinjiang New Energy Research Institute, Urumchi 830011, China; 4. Coal Industry Management Bureau of Xinjiang, Urumchi 830000, China)
Abstract: Xinjiang is affluent in energy resources and occupies a special geography position. It has an important stratagic meaning on energy repertory, energy supply, energy security and energy channels. In this paper the main content of development of integrative energy base, its constructing supposition, also main suggestion to push development of large scale integrative energy base in Xinjiang were described. 6 Refs. In Chinese.
Key words: Xinjiang; sustainable energy; integrative energy base
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 1—4.

Novel sensorless speed and position detection for permanent magnet linear synchronous motor drive system
LU Hua-cai, JIANG Ming, CHEN Qi-gong
(Anhui Polytechnic University, Anhui Provincial Key Laboratory of Electric and Control, Wuhu 241000, China)
Abstract: In order to implement sensorless control for permanent magnet linear synchronous motor (PMLSM), speed and position of the motor must be estimated without mechanical sensors. In this paper, a novel sensorless position and speed detection algorithm is designed for PMLSM by only measuring terminal voltages and currents. This algorithm is developed from the dq estimating model of the motor, which is Park change from the three-phase voltage model of the motor. Then two q-axis current derivatives are calculated by the estimated model and the measuring current signal respectively. The loop observer is done using the difference between the two current derivatives and the position is obtained by integrating the speed. Further, the algorithm is simple to implement. Experimental results show that the algorithm can estimate speed and position of the motor and its accuracy can satisfy the servo requirement. 13 Refs. In Chinese.
Key words: sensorless; permanent magnet linear synchronous motor; loop observer
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 5—8.

Analysis and optimization on power transmission characteristics for voltage-fed ICPT system
SUN Yue, XIA Chen-yang, ZHAO Zhi-bin, ZHAI Yuan, YANG Fang-xun 
(College of Automation, Chongqing University, Chongqing 400030, China)
Abstract: In order to optimize the power transfer capability and efficiency of the inductively coupled power transfer (ICPT) system, the power transmission capability and efficiency of the voltage-fed ICPT system were analyzed. It is generally believed that the power transmission capability can be improved by increasing the resonant frequency. But through this study we found that for the use of SS topology ICPT system, there is an optimized selection for the resonant frequency, while for the use of SP topology ICPT system, at a certain frequency band, the increase of the resonant frequency has no effect on its transmission power and efficiency, and the number of secondary winding of the voltage-fed ICPT system was optimized. Finally, the theoretical research was justified via an experiment. 9 Refs. In Chinese.
Key words: inductively coupled power transfer (ICPT); voltage-fed; transmission power; efficiency; optimize 
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 9—12.

Small signal modeling of active clamp forward converter with magnetic integration
CHEN Wei, LU Zeng-yi
(College of Electrical Engineering and Automation of Fuzhou University, Fuzhou 350108, China)
Abstract: Integration of transformer and the output inductor can effectively reduce the output current ripple and improve the output quality in forward converter. On purpose of the systematic investigation, a general method to build small signal model is proposed. The control to output transfer function of active clamp forward converter with magnetic integration is emphasized. In terms of the windings’ coupling between transformer and the output inductor, the dynamic zeroes and poles are additionally introduced. Moreover, the right half plane zero emerges in condition of zero output current ripple. 12 Refs. In Chinese.
Key words: magnetic integration; small signal modeling; right half plane zero; zero ripple
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 13—17.

Constructing stable nodes to suppress common-mode EMI for power converters
HUANG Hua-gao, CHEN Wei, CHEN Heng-lin, QIAN Zhao-ming
(Zhejiang University, Hangzhou 310027, China)
Abstract: In this paper, a simple approach to suppress common mode conducted electromagnetic interference (EMI) is proposed. The method is explained in detail with Boost converter adopted as a typical example. Most of common mode conducted EMI due to the high dv/dt nodes in the converter can be suppressed by constructing stable potential nodes (dv/dt almost zero) in the circuit, which is implemented by changing placement of the boost inductor and using the common-anode diode instead of the common-cathode one. It is verified by theoretical analysis and experimental results that this method is effective and applicable without much added cost. Also, this method can be easily transferred and used in other converters, such as buck, buck-boost, flyback and PFC circuits etc. 8 Refs. In Chinese.
Key words: power converter; common mode interference; suppression technique; stable nodes
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 18—20.

Algorithm of electric power online analysis and measurement based on Q format calibration method
YANG Fu-gang
(School of Information and Electronics, Shandong Institute of Business and Technology, Yantai 264005, China)
Abstract: Using TMS320F2812 DSP as core processor, combined with Q format calibration method and IQmath library provided by TI, an algorithm which can meter and analyze electric power online was presented. First, hardware phase-locked loop technology was used to achieve synchronous sampling of the power control signal. Then the designed FIR low-pass digital anti-aliasing filter was employed to filter out noise, harmonics and other high-order interference signal. Finally, the modified FFT algorithm was used in the separation of power grid voltage, current fundamental and the high-order harmonic components to carry out high-precision measurement and analysis of the relevant energy parameters. In the process of the algorithm implementation, using a Q format calibration method to accomplish high-speed floating-point operations in the fixed-point processor, the use of properties of real DFT can greatly reduce computational complexity and improve computing speed. The testing results show the proposed algorithm can achieve high accuracy of power analysis and measurement.
Key words: DSP; Q format calibration method; power on-line analysis; IQmath library

A network harmonics and reactive power parameters on-line monitoring analysis and control simulation system
ZHANG Shuang, LUO An, ZHAO Wei, CHEN Qiong
(Hunan University, Changsha 410082, China)
Abstract: This paper presents a network harmonics and reactive power parameters on-line monitoring analysis and control simulation system. It detects and analyzes harmonic and reactive parameter quickly and accurately by the base-12 FFT algorithms. Power quality monitoring system based on Web Services can achieve network-based on-line monitoring. At the same time, a power quality simulation model based on a power plant was established in this paper. The paper presents the harmonic suppression and reactive power compensation scheme with Injected Hybrid Active Power Filter (IHAPF), and control is achieved by parameter fuzzy self-tuning PI control so as to obtain the optical control effect. The test results show that the system is highly effective and accurate.
Key words: Harmonics and reactive power; parameters of fuzzy self-tuning PI control; real-time simulation

Contrast of simulation technique and experiment research of single-stage induction coil-launcher
LI Feng-ceng, LEI Bin, LI Zhi-yuan
(Dept. of Ammunition Engineering, Ordnance Engineering College, Shijiazhuang 050003, China)
Abstract: As one kind of electromagnetism launcher, induction coil-launcher has wide application perspective in the military affairs domain. Based on the current filament model of the single-stage induction coil-launcher, we have compiled the dynamic emulator using the software MATLAB. We also have simulated the dynamic performance of the launcher using FEM software ANSOFT. At last we carried out the launch experiment of the single-stage induction coil-launcher. Using the experiment, we validate the launch performance of the launcher. We also compare the current filament model with the finite element model of the single-stage induction coil-launcher by contrasting the simulation results with the experiment results. At last, we acquire the conclusion that both models have their advantages and disadvantages, but both of them can describe the launch performance of the coil-launcher accurately. 8 Refs. In Chinese.
Key words: single-stage induction coil-launcher; dynamic simulation; current filament model; finite element model; experiment research
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 31—34.

Extraction of parasitic capacitance of integrated LC component for planar EMI filter
WU Li-fang, WANG Shi-shan, ZHOU Xiao-lin
(Nanjing University of Aeronautics and Astronautic, Nanjing 210016, China)
Abstract: Aiming at predicting and analyzing the high frequency performance of EMI filter efficiently, the effect of parasitic capacitance of planar inductor must be considered. In this paper, the 2D and 3D electrostatic FE model of the integrated LC component for planar EMI filter is firstly presented respectively, through calculating the parasitic capacitance among the windings, the lumped circuit model for N-turns planar winding consisted of PCB inductor is derived, then the equivalent parallel capacitor of planar winding could be given out. By analyzing the effects of permittivity and fringing effect on parasitic capacitance, the calculated result is to be verified by comparison with measurement. The method of extraction for parasitic capacitance can be used to design the planar winding and the integrated LC structure. 8 Refs. In Chinese.
Key words: integrated LC component；parasitic capacitance；FE model；planar winding
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 35—39.

Research on relation between two approaches of power flow tracing
LIU Yao-nian¹, LIU Peng-fei¹, LI Li²，ZHANG Wei-min¹，LAI Bin³
(1. Elec. Eng. College, Northeast Dianli University, Jilin 132012, China; 2. Liuzhou Power Generation Co. Ltd., Liuzhou 545002, China; 3. 93 branches in Power Company of Heilongjiang, Heihe 161441, China)
Abstract: There are two main algorithms for power flow tracing, one is based on the solution of simultaneous linear equations, the other is based on the graph theory. In this paper，the upstream and downstream tracing distribution matrices are researched in the form of matrix power series in order to prove the relation between the two approaches. It proves not only the realtion between the two approaches in mathematics, but also provides an additional insight into the tracing methodology. The example with a 4-bus system is given to demonstrate the accuracy of the proposed conclusion
Key words: electricity market; power flow tracing; matrix power series; directed graph; link between algorithms

Research on SVPWM based fuzzy sliding mode DTC system
REN Zhi-ling，XIAO Rui
(Institute of Electrical and Control Engineering, Liaoning Technical University, Huludao 125105, China)
Abstract：In view of large torque ripple in conventional direct torque control (DTC)，the paper presents a program with combination of fuzzy sliding mode control and space vector pulse width modulation (SVPWM) technique for direct torque control system. The system uses fuzzy sliding mode controller instead of the conventional flux and torque hysteresis controllers, and using SVPWM technology to achieve system control. Through analysis of the stationary two-phase asynchronous motor coordinate system of the mathematical model, the paper constructs the MATLAB simulation model of discrete systems and simulation. On this basis, the paper designs a control systems based on DSP experimental platform. Design of DSP based direct torque control system includes two aspects: hardware and software design. Experimental results show that the control scheme is feasible and effective. However, by comparing the experimental and simulation results, it can be seen that there is large difference between them. It is believed that with further improvement of experimental platform, better control effect can be achieved.
Key words: direct torque control; fuzzy control; sliding mode; space vector pulse width modulation; simulation

Optimum operation of underground power cables buried in non-homogeneous soil
LU Zhi-wei¹, XU Yan¹, WANG Yan-heng², WANG Heng³
(1.Technological School of Transmission and Transformation, Northeast Dianli University, Jilin 132012, China; 2. Datang Changchun Second Thermoelectric Co.,Ltd., Changchun 130031, China; 3. Dongbei Electric Power Design Institute, Changchun 130021, China)
Abstract: In densely populated areas, electricity is usually transported and distributed through buried cables in cluster laying. One of the most important needs in power cable engineering and operation is to have information about maximum current carrying capacity. When uniform maximum current is conducted in power cables, the current carrying capacity of buried cables in cluster laying is not effectively utilized. In order to improve the current carrying capacity of power cables, based on finite difference method and artificial fish swarm algorithm, a method and associated computer program that calculate the maximum current loadings of underground cables are developed. The maximum sum of total current is taken as an objective function. The temperature of any cables lower than maximum permissible temperature is the constraint condition. The optimum current of each cable buried in backfill soil is determined. The results show that the total current can be increased effectively when the thermal resistivity of the backfill soil is great.
Key words：power cables；current carrying capacity；finite difference method；artificial fish swarm algorithm

Low voltage ride through technology for variable-speed constant-frequency direct-drive wind power systems
MENG Ming, JING Yan, LI He-ming
(School of Electrical and Electronic Engineering, North China Electric Power University, Baoding 071003, China)
Abstract：With the rapid increase of the variable-speed constant-frequency wind power in the transmission system, the grid codes are strict with grid-connected wind power system and demand that wind power system should keep connecting with the grid when the grid goes out of order，especially the grid voltage sags. And the direct-drive permanent magnetic wind power system with full power converter has been demonstrated to have excellent operating characteristics under low voltage. So this paper presents the research of LVRT technology for VSCF direct-drive wind power system. The adverse effects of grid voltage sags on direct-drive wind power system are analyzed firstly. Then combined with existing related standards, the control requirements are proposed to make sure that direct-drive wind power system will succeed in low voltage ride through. Further, other types of low voltage ride-through technology suitable for direct-drive wind power system are summarized, analyzed and compared fully. Finally, the latest progress and the development trend of LVRT technology are given. 13 Refs. In Chinese.
Key words: direct-drive wind power system; variable-speed constant-frequency(VSCF); grid voltage sags; low voltage ride through(LVRT); crowbar circuit; reactive power compensation
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 53—58.

Design and application of emergency response system of Shenzhen power grid
LI Rui, CHEN Ying, SHEN Chen, MEI Sheng-wei
(Department of Electrical Engineering, Tsinghua University, Beijing 100084, China)
Abstract: For the stability and security of the Sourthern Chinese power system, it is very important to build up a practical and effective emergency response system of the Shenzhen power grid. In this work, the structure of the emergency response system of the Shenzhen power grid is introduced throughly, which is constructed by four critical parts such as the organizations, procedures, work-flows, and contingency plans. Moreover, to support the functions and applications of the proposed emergency response system, an advanced information platform is also proposed. Three key techniques of this information system are discussed in detail, including multi-level prediction and early warning models of contigencies, digital contigency planning and online smart control plans. The successful citywide anti-blackout practices and the anti-disaster daily works of the Shenzhen power grid prove the feasibility and effectiveness of the proposed emergency response system. 22 Refs. In Chinese.
Key words: urban power grid; great blackout; emergency response
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 59—65.

Feasibility of ultrasonic wireless power transmission
ZHANG Jian-hua, HUANG Xue-liang，ZOU Yu-wei, BAI Yang
(School of Electrical Engineering, Southeast University, Nanjing 210096, China)
Abstract: Wireless power transmission (WPT) has attracted extensive attention from scholars at home and abroad in recent years, but ultrasonic has not yet received sufficient attention as a power transmission medium. Ultrasonic WPT has several advantages, such as strong directional transmission, its energy easily to be focused, with far enough distance and so on. This paper proposed an electric circuit model of ultrasonic WPT. When piezoelectric materials used as ultrasonic transducers, we obtained the equivalent circuit diagram of ultrasonic WPT through electromechanical equivalent circuit diagram of piezoelectric materials. And two types of ultrasonic transducers were analysed which were applicable to ultrasound-based WPT. Also the efficiency of ultrasonic WPT was estimated. 9 Refs. In Chinese.
Key words: ultrasonic; WPT; piezoelectric effect; ultrasonic transducer
// Adv. Tech. of Elec. Eng. & Energy, 2011, 30(2). 66—69.

A novel transfer capability enhancement approach based on optimal location of series capacitor
KANG Jian¹, WANG Lei-ming², PAN Shu-jie²
(1. Shandong Electric Power Engineering Consulting Institute Corr.Ltd., Jinan 250013, China;
2. State Nuclear Electric Power Planning Design & Research Institute, Beijing 100094, China)
 
Abstract: Determination of location where series capacitor should be installed is important for enhancement of transfer capability. The strategy for selecting the optimal location of series capacitor is developed in this paper. It is known that the influence of constraints such as voltage limits, branch power limits and other electrical equipments limits and voltage collapse limits are critical for transfer capability. Considering some kinds of limits, transfer capability is estimated by continuation power flow method. A formula for the first order sensitivity of the transfer capability with respect to transmission line’s reactance is deduced at the binding limit. The sensitivity formula is applied as an index for selecting the optimal location of series capacitor. The available condition that the index used for selecting the series capacitor optimal placement is also presented in this paper. Simulation results of IEEE 30-bus system and IEEE 118-bus system prove that the proposed method is effective and of practical value.
Key words: transfer capability; series capacitor; sensitivity; optimal location; continuation power flow method

A simple high accuracy phase locked loop method
GENG Pan¹, WU Wei-min¹, CHEN Jian-ming¹, YE Yin-zhong², LIU Yi-jian¹
(1. The Research Institute of Electronic Automation of Shanghai Maritime University, Shanghai 200135, China;
2. Shanghai Institute of Technology, Shanghai 200235, China)
Abstract: This paper proposes a simple high accuracy inner-synchronization phase locked loop method used for digital control. This method is very easy to be realized. When the system works under normal condition, it could track the grid synchronized signal in high accuracy. When the system losses the grid synchronized signal, it could keep stable operation under the former frequency and phase position, and it is more suitable for the systems which need to switch between grid-tied and stand-alone mode. In this paper, the working principle of the phase locked loop with inner-synchronized program is analyzed at first. The accuracy using this phase locked loop method is derived. Finally, experimental results on a 1kW prototype prove the validity of the proposed method.
Key words: digital control; inner-synchronization; phase locked loop; synchronized signal

Discharge status evaluation on external insulation of insulator based on results of ultra-violet radiation measurement and fuzzy reasoning
WANG Jin-gang¹, ZHANG Zuo-peng², LONG Zhen-ze¹, REN Zhi-chang², DENG Xu-dong², HE Wei¹, YANG Fan¹
(1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China; 2. EVH Bureau of Chongqing Electric Power Company, Chongqing 400039, China)
Abstract: In this paper, a method based on the fuzzy theory and ultra-violet (UV) radiation measurement to access the discharge status of external insulation of the insulator is presented. In this method, the amount of UV pulses generated by corona discharge of insulator is measured firstly, while collecting temperature of environment and humidity information, and then the relationship between the inputs is confirmed by analyzing online monitoring data, a series of fuzzy sets for fuzzy reasoning is set up, and the membership function is derived, fuzzy inference rules are established. Then the fuzzy reasoning is carried out to estimate the discharge status of external insulation. Finally, the validity of this method is verified by simulating and analyzing the data detected from the tests of connecting to grid in Simulink.
Key words: corona discharges; ultra-violet pulse; discharge status of external insulation; fuzzy reasoning; Simulink

Modeling of photovoltaic-array based on BP neural networks improved by particle swarm optimization algorithm
GUO Liang^1,2, CHEN Wei-rong², JIA Jun-bo^2,3, HAN Ming², LIU Yong-hao²
(1. School of Elec. Eng., Southwest Jiaotong University, Chengdu 610031, China; 2. School of Eng., Temasek Polytechnic, Singapore 529757; 3. School of Electrical ＆ Electronic Eng., Nan yang Technological University, Singapore 639798)
Abstract: In view of serious complexity and nonlinearity of photovoltaic array, its modeling is very difficult, therefore a Back Propagation (BP) Neural Network model based on Particle Swarm Optimization (PSO) algorithm is proposed. Neural Network has excellent nonlinear fitting ability, but it also has some shortcomings, such as low convergence speed, easy to fall into local optimal value, and low accuracy, etc. PSO algorithm is used to optimize the inner connection weights of Neural Network; therefore the performance of Neural Network is promoted. Modeling of photovoltaic array is based on this improved Neural Network. Test and simulation results showed the high identification accuracy and high convergence speed of this model.
Key words: photovoltaic array; neural network; particle swarm optimization algorithm