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Comparison study of three kinds of AC-AC converters with high frequency link
CHEN Dao-lian，CHEN Yan-hui
(Power Electronics & Drives Research Institute, Fuzhou University, Fuzhou 350108, China)
Abstract: The circuit configuration and topology, control strategy, line power factor, reliability under load short-circuit, output capacity, magnetizing state of the high frequency transformer are proposed, and principle test results of Buck, Boost and Buck-Boost mode AC-AC converters with high frequency link are comparatively investigated in this paper, and important conclusions are obtained. The circuit configurations of AC-AC converters with high frequency link are constituted in the order of input filter, storage inductance (Boost mode), input cycloconverter, high frequency transformer or high frequency storage transformer, output cycloconverter, and output filter respectively. Research results have demonstrated that the three kinds of AC-AC converters with high frequency link have different technological performance, difficulty of engineering realization and application fields, and lay the key technical foundation on new type regulated sinusoidal AC power supply, AC regulators, electronic transformer and same frequency waveform conversion. 5 Refs. In Chinese.
Key words: AC-AC converter; high frequency link; Buck mode; Boost mode; Buck-Boost mode; performance comparison
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 1—4.
Improvement on DC bus structure of H-bridge unit based on PEEC model analysis
LI Fang-zheng, SUN Xu-dong, HUANG Li-pei
(State Key Lab of Power Systems, Dept. of Electrical Engineering, Tsinghua University, Beijing 100084, China)
Abstract: H-bridge unit is widely used in high capacity inverters. The DC power bus of the studied H-bridge unit was improved to the planar structure. The high frequency equivalent circuits of the two buses were constructed based on partial element equivalent circuit (PEEC) method. The total equivalent parameters of the PEEC model were defined and calculated. The total equivalent inductance of the improved bus is smaller than that of the original bus to about one twelfth, and the total equivalent resistance is decreased to about one eleventh. The equivalent capacitance between positive and negative bus increases for over 100 times. The circuit simulation based on PEEC model indicates that the peak value and rise rate of the spike voltage of the improved bus are attenuated about 50%. The experimental results confirm to the simulation. The bus improvement based on PEEC model analysis is effective. PEEC model of bus provides a way to improve or optimize the bus structure. 7 Refs. In Chinese.
Key words: DC power bus; electromagnetic interference (EMI); partial element equivalent circuit (PEEC); converter
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 5—8.
An implicit synchronization approach and its application in parallel computation of electro-magnetic transient
CHEN Lai-jun, CHEN Ying, MEI Sheng-wei
(State Key Lab of Power Systems, Dept. of Elec. Eng., Tsinghua University, Beijing 100084, China）
Abstract: A general time cost model for analyzing the efficiency of parallel electrical-magnetic transient simulation is built based on the computation scheme of most synchronous algorithms. Then, an implicit synchronization approach is proposed to reduce the time cost of synchronous operation in parallel electrical-magnetic transient simulations. The proposed approach enhances the parallelism of the simulations by two means such as utilizing synchronization waiting time to perform useful computations and assigning the computation loads to avoid the synchronous operation. The speed up effects of the proposed approach in different system partition result are analyzed and the most efficient system decomposition scheme is presented. Based on the proposed approach, an improved MATE algorithm for power system Electro-Magnetic transient simulation is also presented in this work. Test results prove that the implicit synchronization approach can improve the efficiency of the electrical-magnetic transient simulations effectively, as well as make the system decomposition scheme for parallel simulation more reasonable. 10 Refs. In Chinese.
Key words: synchronous algorithm, implicit synchronization, electro-magnetic transient, parallel computation
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 9—12.
New control strategy of electronic ballast for low-wattage MH lamps
LIN Guo-qing，ZHENG Yuan-yuan
(College of Electrical Engineering & Automation, Fuzhou University, Fuzhou 350002, China)
Abstract: A novel control strategy to match the dynamic characteristics of MH lamps is proposed in the paper, the required open-circuit voltage for MH lamps stand-up is obtained and the current control in stand-up process and the constant power control in steady operation are realized. Because of ZCS (Zero-current-switching) operation, the circuit can work in high switching frequency while achieving high efficiency. A differential amplifier is used to sample the lamp voltage and current signal, and to realize the common ground of the floating lamp signal and the drive circuit of half-bridge inverter. The circuit operation and control method are detailed and the main parameters are calculated. The experimental measurements are used to verify the theoretical prediction and analytical discussion. 11 Refs. In Chinese.
Key words: MH lamps; electronic ballast, control strategy; zero-current
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 13—16.
Interharmonic analysis based on TLS-ESPRIT algorithm and Adaline neural network
CHU Xian-wu
(School of Electrical & Information Engineering, Dalian Jiaotong University, Dalian 116028, China)
Abstract: An interharmonic parameter estimation method based on Total Least Squares Estimation of Signal Parameters via Rotational Invariance Techniques algorithm was proposed in this paper. The numbers and frequencies of harmonics and interharmonics in power network signals are estimated by TLS-ESPRIT algorithm, and then their amplitudes and phases are analyzed by applying adaline neural network. ESPRIT algorithm was proposed by Roy et al in 1986, which can be applied to a wide variety of problems including accurate detection and estimation of sinusoids and direction of arrival of noise. It exploits an underlying rotational invariance among signal subspace induced by an array of sensors with a translational invariance structure. The technique manifests significant performance and computational advantages over MUSIC algorithm. When Adaline neural network is used in harmonic analysis it need not train in advance and has the characteristics of simplicity and celerity. The simulation results showed the algorithm which needs no synchronous sampling data has high frequency resolution and strong anti-jamming capability, and the parameters estimation of harmonics and interharmonics is accurate. 10 Refs. In Chinese.
Key words: interharmonic; TLS-ESPRIT; Adaline; neural network; parameter estimation
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 17—20.
Study on resistivity-temperature characteristic of polyimide modified by voltage-sensitive additive
BAI Jing-jing, LI Liang-bin, ZHENG Xiao-quan
(State Key Lab of Power Equipment and Electrical Insulation, Xi’an Jiaotong University, Xi’an 710049, China)
Abstract: The space temperature environment for spacecraft operation is very complicated. The rapid transform between high and low temperature may eventually lead to the charge in the depth and surface of dielectric materials releasing multi-spectral impulsive discharge. And the high energy discharge pulse may result in abnormal work of sensitive electronic systems in spacecraft. The charge gathering degree in dielectric materials is closely related to its resistivity characteristic, so it is significant to research the resistivity-temperature characteristic of polyimide. In this paper，the resistivity-temperature characteristic of the polyimide composite modified by two kinds of μm grade voltage-sensitive inorganic additive in the temperature range -150℃ to 180 ℃ was studied. The research shows that the influence of the μm grade voltage-sensitive additive content for composite resistivity-temperature characteristic is significant: the modified materials presented negative temperature effect in low temperature. When the voltage-sensitive additive content was less than 5%, the resistivity of composite materials above 0℃ is increased. 4 Refs. In Chinese.
Key words：polyimide; voltage-sensitive additive; temperature; resistivity; space charge layer
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 21—24.
Design of damped LC filter for HT-SMES converter
ZHU Jia-hui1, YANG Bin1,2, CHENG Qiang1,2, FANG Jin2
(1. China Electric Power Research Institute, Beijing 100192, China;
2. School of Electric Engineering, Beijing Jiaotong University, Beijing 100044, China)
Abstract: To suppress the output voltage harmonics of the high-temperature superconducting magnetic energy storage system with voltage source converter, the damped LC low-pass filter of the SMES converter was designed. In this paper, the principles and the transmission characteristics of the LC filter were described, and the SPWM wave of the SMES converter was analyzed. By controlling the fundamental voltage decay of the filter, the parameters of the filter circuit were determined. At last, the damped LC filter was applied in the experiment of voltage compensation by using SMES. Experiment results show that the LC filter has gained favorable filtering effect in the SMES converter and improves the dynamic response and the steady-state performance of the SMES system.
Key words: high temperature superconducting magnetic energy storage (HT-SMES); voltage source converter; damped LC filter; voltage compensation
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 25—28.
A novel linear combination sampling SPWM technique
WANG Rong-sheng
(College of Electrical Engineering and Automation, Fuzhou University, Fuzhou 350108, China)
Abstract: The conventional asymmetric regular sampled PWM requires a large sampling number to be collected, and consequently consumes a large portion of microprocessor’s resources. This paper presents a novel linear combination sampling technique to address the above-mentioned issue. Through applying the linear combination sampling on the triangular carrier-wave peaks, the technique obtained another sample of the sinusoidal modulating wave from every carrier wave cycle. As a result, it reduced the sampling number by half. Harmonic calculation had validated that the minimization of total harmonic voltage distortion (THD) of the PWM voltage in the new technique was in agreement with that in the asymmetric regular sampling method, and it also maintained the linear relationship between the PWM fundamental waveform and the modulation index M. The software algorithm in the new technique was much simpler to generate PWM, and therefore, it will be applicable to real-time on-line microprocessor or DSP generation. The simulation results had validated the new technique. 7 Refs. In Chinese.
Key words: linear combination sampling; harmonic calculation; sampling number; asymmetric regular sampling
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 29—32.
Principles of adaptive resonance technology for contactless power transmission system
ZHAO Biao1, CHEN Xi-you2, YU Qing-guang1
(1.Dept. of Elec. Eng., Tsinghua University, Beijing 100084, China; 2.Dept. of Elec. Eng., Dalian University of Technology, Dalian 116024, China)
Abstract: In this paper, the coupled resonant circuit of the contactless power transmission system is analyzed, and the important role of the resonant state to improve the transmission power and transmission efficiency is discussed, also the control strategy of adaptive resonance technology is proposed. Through testing the phase difference between output voltage and current, the switching frequency of the converter is adjusted. After a period of transient process, the phase difference between output voltage and current becomes zero, then the feedback control of adaptive resonance is achieved. It is verified by simulation and experiment that the contactless power transmission system based on adaptive resonance technology can track and adjust parameter fluctuation of all elements, thus can ensure the transmission power and improve the transmission efficiency. 7 Refs. In Chinese.
Key words: contactless; adaptive; series resonance; phase-locked loop
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 33—37.
Reactive power optimization based on quantum-behaved particle swarm optimization with dimension mutation operator
WANG Xiu-yun, SONG Yun-feng, JIA Yan-bing, ZHU Hong-bo
(School of Electrical Engineering, Northeast Dianli University, Jinlin 132012, China)
Abstract: The question that PSO (Particle Swarm Optimization) can not converge to global optimal solution can be avoided by QPSO (Quantum-behaved Particle Swarm Optimization). QPSO considers that all particles have quantum-behavior and can be searched in the whole area of feasible solution. Ability of global search of QPSO is more excellent than PSO. Reactive power optimization is a complex problem. It is a problem involving discrete variables, nonlinear, discontinuous, multi-constraints and multi-variables. Incorporation with non-stationary assignment penalty function in solving reactive power optimization problem, the proposed QPSODMO (Quantum-behaved Particle Swarm Optimization with Dimension Mutation Operator) method is demonstrated and compared with QPSO approach, PSO approach and GA approach on the standard IEEE30-bus system. The investigations reveal that the proposed method is efficient in solving reactive power optimization problem. And by IEEE30 testing, reactive power optimization problem solved by QPSODMO can find better solution and have less loss than QPSO and the other PSO approach. Simulating algorithm shows feasibility and validity of the solution. 12 Refs. In Chinese.
Key words: quantum-behaved particle swarm optimization; global optimal solution; reactive power optimization;
non-stationary assignment penalty function
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 38—42.
Optimization and analysis of linear induction launcher
LI Xian1,2, WANG Qiu-liang1, LIU Jian-hua1,2
（1. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
2. Graduate University of the Chinese Academy of Sciences, Beijing 100190, China）
Abstract: In this paper, a two sections linear induction launcher was analyzed and optimized by using computer simulation. Firstly, according to the principles of the mesh-matrix method, a lumped parameter transient model for the analysis of the dynamic conditions was built. The simulation code was programmed by MATLAB. The flow chart for the computer simulation was drawn. Secondly, the effect of varying delay between phases for the 3-phase firing sequence in section 1 was studied and the best time intervals between the firing of the three phases were obtained. It also studied the initial position of sleeve in the first section which affected the muzzle velocity and the kinetic energy transfer efficiency. Finally, the effect of voltage changes in the first section was studied. The muzzle velocity and energy transfer ration was analyzed when the voltage in the second section increased. The computer simulation results have provided a theoretical guidance and experimental basis. 11 Refs. In Chinese.
Key words: linear induction launcher, simulation, muzzle velocity
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 43—47.
Study on rotor field oriented control system of bearingless PMSM based on SVPWM
WANG Cheng-bo, ZHU Huang-qiu, JI Yu-hui
(School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China)
Abstract: The bearingless PMSM is a strong-coupled complicated nonlinear system, establishing exact mathematical models of electromagnetic torque and radial suspension forces is premises condition for designing control system of bearingless PMSM, and the decoupling control of radial suspension force and electromagnetic torque is the base of stable operation of the motor. On the basis of introducing mechanical and electrical coordinates, the exact mathematical models of the motor are established. In order to realize decoupling control of bearingless PMSM, the rotor flux orientation control strategy based on SVPWM is adopted in the paper. On this basis, the diagram of control system and experimental platform are constructed and software structure of this control system is designed. Finally, the experimental results show the validity of the control method.
Key words: bearingless motor; mathematical models; decoupling control; SVPWM; software structure
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 48—52.
Harmonic current prediction method of universal power quality conditioner based on rapid block LMS algorithm
LI Sheng-qing, LUO Fei, CHEN Xing-guo
(Hunan University of Technology, Zhuzhou 412008, China)
Abstract: The paper presents a method of universal power quality conditioner harmonic current prediction based on rapid block LMS algorithm, which utilizes the FFT in LMS algorithm and overlapping storage. The filter updating weight value is obtained by means of block process. Each adjustable weight value is assigned with variable steps under generalized stationary and generalized non-stationary random process conditions. At moment t, the difference between the controlled and reference values is predicted, and the minimum value of the difference is obtained by choosing the t+1 moment control strategy and by using the rapid block LMS algorithm. The simulation results show that the method is correct and feasible.
Key words: universal power quality conditioner; fast Fourier transform; rapid block LMS algorithm; harmonics; prediction
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 53—56.
Fuzzy interval number based hierarchical analysis process for assessing black-start plans
LI Xiu-qing1，SHANG Jing-gang1，JIANG Shi-jin2，LIU Zi-jun2，SONG Yun-feng1
(1.School of Elec. Eng., Northeast Dianli University, Jilin 132012, China; 2.Jixi Electricity Power Bureau, Jixi 158100, China)
Abstract: Rational black-start plans are necessary for restoring the power system as soon as possible. A novel method for assessing black-start plans, namely fuzzy interval number based hierarchical analysis is proposed in this paper. First, the basic steps of hierarchical analysis process are introduced according to influencing factors to black-start plans. Secondly, considering the shortcomings of AHP, fuzzy interval number is introduced, which can be used to establish judgment matrix and to assign priority. Finally, the basic steps of this novel method are given. It is proved from an application of an actual power system that the method can provide dispatchers with more comprehensive and exact decision-making references. 7 Refs. In Chinese.
Key words: black-start; assess; analytic hierarchy process; fuzzy interval number
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 57—61.
Research on deceleration force of reluctance coilgun
ZHU Ying-wei1, YAN Zhong-ming2, XIE Xiao-fang1, DONG Liang2, WANG Yu1,2
(1.MOE. Key Lab of Maglev Technology and Vehicle, Southwest Jiaotong University, Chengdu 610031, China；
2. Superconductivity R&D Center (SRDC), Southwest Jiaotong University, Chengdu 610031, China)
Abstract: Reluctance coilgun could accelerate the ferromagnetic projectile by attraction force. This paper presents the theoretical analysis and computer simulation of projectile acceleration force. It is found that reluctance coilgun has serious eddy-current deceleration force when the projectile is at high initial speed or drivecoil has high magnetic field. The speed of projectile reduces instead of increase. The paper proposes that both decreasing the material conductivity of projectile and cutting notch on the projectile sleeve could reduce the eddy current deceleration force. Simulation results indicate both these methods are effective.
Key words: electromagnetic launcher; reluctance coilgun; eddy-current deceleration force; Ansoft maxwell
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 62—66.
Research on modeling of pulsed current sensor based on self-integrating Rogowski coil
KE Chun-jun, ZHANG Guo-gang, ZHAI Xiao-she, GENG Ying-san
(State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049, China)
Abstract: Self-integrating Rogowski coils are suitable and widely accepted for pulsed heavy current measurements due to their accuracy, bandwidth, wide range, and inherent electrical isolation. The high frequency circuit model of Rogowski coil provides an effective way to acquire its frequency characteristics and would be very helpful to design reliable and accurate Rogowski coil for measuring pulsed current. In this paper, the principle of Rogowski coil used to measure pulsed current is summarized, while some different high frequency models for self-integrating Rogowski coil are introduced. As a first approximation, the distributed parameter model of Rogowski coil has been made up as a transmission line circuit. With the inter-turn capacitance and mutual inductance of the coils omitted, the expressions of its output voltage and transfer impedance are deduced in the Laplace domain and the factors impacting on the frequency characteristics of the coil are analyzed. In order to obtain the distributed parameters of equivalent circuit, a three dimension FEM model of Rogowski coil have been founded in electromagnetic field, while the capacitances and inductances of Rogowski coil are calculated by finite element numerical analysis method. Then a distributed-element equivalent circuit is established. The simulation result of open-loop frequency characteristics is presented and transfer impedance of close-loop on the circuit is also calculated using the distributed parameter circuit. In addition, the method of how to select optimal parameters of damp resistance is discussed. Finally, in comparison with the simulation, the experimental results verified that the circuit model is appropriate and the distributed parameters calculated by FEM method are accurate.
Key words: Rogowski coil; pulsed current; distributed parameter model; frequency characteristics
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 67—71.
Test and analysis of 3D temperature distribution for induction motor stator winding
YANG Ming-fa, ZHANG Pei-ming
(College of Electrical Engineering & Automation, Fuzhou University, Fuzhou 350108, China)
Abstract: To improve the performance of motor temperature protection, this paper designed a temperature test system of totally enclosed fan cooled (TEFC) induction motor according to their structural characteristics. Three-dimensional temperature distribution of stator windings was measured. Measurement results show that because of the asymmetry of the structure and the heat dissipation conditions, temperature distribution of stator windings is asymmetric too. Temperature of end windings which located at the terminal box area is the highest. Based on the test results, the characteristics and reasons of stator windings temperature distribution were analyzed, based on which new ideas of motor protection and optimization design were put forward.
Key words: induction motor; temperature distribution; test; analysis; protection
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 72—76.
Corporate distribution network maintenance scheduling system based on improved genetic algorithm
HUANG Liang-liang, LUO An, LIU Qiu-ying, LI Qiang
(College of Electrical Information Engineering, Hunan University, Changsha 410082, China)
Abstract: The corporate distribution network maintenance scheduling is a combinational optimization problem with multi-objective and multi-constraint. Based on the actual situation of the corporate distribution network, the paper presents the maintenance scheduling mathematic model of the corporate distribution network in order to find the most economical and optimized maintenance schedule. According to line factor and the equipment parameters, the paper establishes different kinds of constraints, and adopts an improved genetic algorithm to optimize it and finally obtain the most optimization maintenance scheduling with the least loss of the line power, and also presents the corporate distribution network maintenance scheduling system model, which can improve the enterprise energy management level of the corporate distribution network so as to greatly improve the productive capability and keep the security and stability of the enterprises, and also greatly improve the energy management level of the corporate distribution network to get better economic and social benefits.
Key words: corporate distribution network; maintenance scheduling; improved genetic algorithm
// Adv. Tech. of Elec. Eng. & Energy, 2010, 29(2). 77—80.
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