Applied Mechanics and Materials Vols. 556-562

Abstract: Femtocell is introduced to improve indoor coverage, which is beneficial for both users and operators. But it will also inevitably produce interference management issues in the heterogeneous network which consists of femtocells and macrocells. In this paper, a decentralized Q-learning-based power control strategy is proposed, comparing with homogenous power allocation and smart power control (SPC) algorithm. Simulation results have shown that Q-learning-based power control algorithm can implement the compromise of capacity between macrocells and femtocells, and greatly enhance energy efficiency of the whole network.

Abstract: A 24 GHz microstrip array antenna based on series and parallel combination feeding network is designed in this paper by theoretical and experimental study. The whole design process includes theoretical analysis, HFSS ( High Frequency Structure Simulator ) simulation and practical manufacture. The array antenna design mainly includes four parts, design of the microstrip patch element, determining the number of radiating patch elements, determining the distance between every two adjacent patch elements and design of feeding network. Then, the microstrip array antenna is simulated and optimized by HFSS. The simulation results show that the VSWR ( Voltage Standing Wave Ratio ) characteristics present good, the maximum gain reaches 21dB and E-plane together with H-plane half-power beamwidth is as small as about 11.8 o . Both of the first side lobe levels are about-14 dB reaching the design requirements. After practical manufacture, the testing results show that the various indicators coincide with the simulation results and the antenna is reliable with stable performance.

Abstract: Model creating and simulation of switching power circuit in this paper was accomplished with PSpice A/D module in CAPTURE CIS. Components in library or created could be used for circuit model. After setting the parameters, simulation could be processed and the result is shown in PROBE. For simulation analysis, this paper creates models for every part of the circuit firstly and then the whole.

Abstract: Wind speed of the time-varying bring many security hidden danger to the operation of the wind turbine, especially under the condition of the wind speed is too low or the wind speed is too large, wind turbine control device can make the wind machine stopped running, at this time on the stability of power grid and significant influence on the distribution of electric power system. Therefore, based on the simulation platform of PSCAD/EMTDC software was carried out on the wind turbine when suddenly stop running of power system modeling and simulation, research on power system transient changes at this moment.

Abstract: A new method to store the harmonic energy is proposed, by offering harmonic energy to DC load directly by combining the diode’s one-way electric conduction theory with the first-harmonic resonance theory. Using the PSCAD/EMTDC software to simulate the project in single phase and three phases. And it turn out that the theory is feasible.

Abstract: Recently, SVC and STATCOM have gotten a very quick development because they can be triggered dynamically and have feedback module so that they can inspects the vacancy of the Var and compensate it quickly and dynamically. In this paper, the stabilization of voltage in substation based on SVC in TCR and FC mode has been discussed.

Abstract: In this paper ,a main circuit mathematical model of Advanced Static Var Generator (ASVG) is established. a direct current control method for SVG is put forward based on d-q transformation, this method is also analyzed from theory and made simulation model, the simulation results show that this control method is reasonable and effective.

Abstract: With the circuit fabrication technology continues toward high-speed, high-density, low-power direction, modern circuit design techniques have changed radically. The speed improvement of digital system means rise and fall time of signals as short as possible, the improvement of frequency and edge rates will bring a series of high-speed design problems, these problems bring great challenges to the system hardware design, the correct design from logical point of view, if there is improper in the actual PCB design will lead to failure of the entire design. EMI radiation of PCB is analyzed, EMC simulation of PCB and optimizing improved are finished. The PCB electromagnetic compatibility is analyzed by using Protel 99SE and Ansoft Designer 2.2 software, and simulation result indicates optimizing design is correct and effective.

Abstract: This paper presents a method based on adaptive two-dimensional wavelet packet for three-phase power quality data. In this paper, we shall briefly introduce the method of dq0 transformation. First, the original data is converted by the method of dq0 transformation, its purpose may be to eliminate redundancy between the three-phases alternating data, then change the one-dimensional date converted into a two-dimensional matrix by the integral multiple of cycles, which aims to eliminate redundant between cycles. Finally, use the method of two-dimensional adaptive wavelet packet decomposition, image SPIHT coding and DEFLATE coding to compress the data. The simulation result shows that the algorithm effectively compress the three-phase power quality data, and it has a good compression effect.

Abstract: This paper presents a distributed power supply scheme for T/R assemblies which are the key pate of the active phased radar. Based on the analysis of the characteristics and design difficulties of T/R assemblies, the power supply uses the energy storage capacitor to provide the high peak current during the pulse, and uses the way of distributed power supply scheme to improve the reliability of power supply system. The power supply designed using this method can achieve load sharing for power supply Assemblies and effectively improve the accuracy of supply voltage.