Energy-efficient data transmission with non-ideal circuit power for downlink cellular networks

The downlink energy-efficient transmission schedule with non-ideal circuit power over Wreless networks involving a single transmitter and multiple receivers was investigated. According to the special structure of the problem, a novel algorithm called OOSCPMR （the optimal offine scheduling with non-ideal circuit power for multi-receivers） is proposed, and the optimal offine solutions to optimize the energy- efficient transmission policy are found. The packets to be transmitted can be divided into two types where one type of packet is determined to be transmitted using the enrgy- efficient tansmission time, and the other type of packet is determined by the ID moveright algorithm. Finally, an energy-efficient online schedule is developed based on te proposed OOSCPMR algoriAm. Simulation results show that the optima offline transmission schedule provides te lower bound performance for the online tansmission schedule. The proposed optimal offline and online policy is more energy efficient than the existing schemes tat assume ideal circuit power.

Fault Diagnosis of Power Electronic Circuits Based on Adaptive Simulated Annealing Particle Swarm Optimization

In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its internal components affects the performance of the system.The stability and reliability of an energy system can be improved by studying the fault diagnosis of power electronic circuits.Therefore,an algorithm based on adaptive simulated annealing particle swarm optimization(ASAPSO)was used in the present study to optimize a backpropagation(BP)neural network employed for the online fault diagnosis of a power electronic circuit.We built a circuit simulation model in MATLAB to obtain its DC output voltage.Using Fourier analysis,we extracted fault features.These were normalized as training samples and input to an unoptimized BP neural network and BP neural networks optimized by particle swarm optimization(PSO)and the ASAPSO algorithm.The accuracy of fault diagnosis was compared for the three networks.The simulation results demonstrate that a BP neural network optimized with the ASAPSO algorithm has higher fault diagnosis accuracy,better reliability,and adaptability and can more effectively diagnose and locate faults in power electronic circuits.

Incidence Colorings of Powers of Circuits

The incidence chromatic number of G is the least number of colors such that G has an incidence coloring. It is proved that the incidence chromatic number of Cn^p, the p-th power of the circuit graph, is 2p ＋ 1 if and only if n = k（2p ＋ 1）, for other cases： its incidence chromatic number is at most 2p ＋ [r/k] ＋ 2, where n = k（p ＋ 1） ＋ r, k is a positive integer. This upper bound is tight for some cases.

Allocation of synchronous condensers for restoration of system short-circuit power

Modern power systems,employing an increasing number of converter-based renewable energy sources(RES)and decreasing the usage of conventional power plants,are leading to lower levels of short-circuit power and rotational inertia.A solution to this is the employment of synchronous condensers in the grid,in order to provide sufficient short-circuit power.This results in the increase of the short-circuit ratio(SCR)at transmission system busbars serving as points of interconnection(POI)to renewable generation.Evaluation of the required capacity and grid-location of the synchronous condensers,is inherently a mixed integer nonlinear optimization problem,which could not be done on manual basis considering each type of machine and all bus-bars.This study therefore proposes a method of optimal allocation of synchronous condensers in a hypothetic future scenario of a transmission system fed by renewable generation.Total cost of synchronous condenser installations in the system is minimized and the SCRs at the POIs of central renewable power plants are strengthened.The method has potential for application on larger grids,aiding grid-integration of RES.

Low power consumption 4-channel variable optical attenuator array based on planar lightwave circuit technique

The power consumption of a variable optical attenuator（VOA） array based on a silica planar lightwave circuit was investigated. The thermal field profile of the device was optimized using the finite-element analysis. The simulation results showed that the power consumption reduces as the depth of the heat-insulating grooves is deeper, the up-cladding is thinner,the down-cladding is thicker, and the width of the cladding ridge is narrower. The materials component and thickness of the electrodes were also optimized to guarantee the driving voltage under 5 V. The power consumption was successfully reduced to as low as 155 mW at an attenuation of 30 dB in the experiment.

Investigation on Flow Accelerated Corrosion Mitigation for Secondary Circuit Piping of the Third Qinshan Nuclear Power Plant

Flow accelerated corrosion（FAC） is the main failure cause of the secondary circuit carbon steel piping in nuclear power plants.The piping failures caused by FAC have resulted in numerous unplanned outages and tragic fatalities.The existing researches focus on the main factors contributing to FAC,which include metallurgical factors,environmental factors and hydrodynamic factors. Some effective FAC management methods and programs with long term monitoring and inspection data analysis are recommended.But a comprehensive FAC management system should be developed in order to mitigate and manage FAC systematically.In this paper,the FAC influencing factors are analyzed in combination with the operating conditions of the secondary circuit piping in the Third Qinshan Nuclear Power Plant（TQNPP）,China（Third Qinshan Nuclear Power Company Limited,China）.A comprehensive FAC mitigation and management system is developed for TQNPP secondary circuit piping.The system is composed of five processes,viz.materials substitution,water chemical optimization,long-term monitor strategy for the susceptible piping,integrity evaluation of the local thinning defects,and repair or replacement.With the implementation of the five processes,the material of FAC sensitive pipe fittings are modified from carbon steel to stainless steel,N_2H_4 and NH_3 are finally selected as the water chemical regulator of secondary circuit,the secondary circuit pips are classified according to FAC susceptibility in order to conduct long term monitoring strategy,and an integrity evaluation flow for local thinning caused by FAC in carbon steel piping is developed.If the component with local thinning defects is not fit-for-service,corresponding repair or replacement should be conducted.The comprehensive FAC mitigation and management system with five interrelated processes would be a cost-effective method of increasing personnel safety,plant safety and availability.

Power Management Integrated Circuit with 90Plus Efficiency Used in AC/DC Converter

Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of-art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specific suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.

Study on High-power LED Heat Dissipation Based on Printed Circuit Board

In order to study the role of printed circuit board(PCB)in high-power LED heat dissipation,a simple model of high-power LED lamp was designed.According to this lamp model,some thermal performances such as thermal resistances of four types of PCB and the changes of LED junction temperature were tested under three different working currents.The obtained results indicate that LED junction temperature can not be lowered significantly with the decreasing thermal resistance of PCB.However,PCB with low thermal resistance can be matched with smaller volume heat sink,so it is hopeful to reduce the size,weight and cost of LED lamp.

SYNCHRONOUS DERIVED CLOCK AND SYNTHESIS OF LOW POWER SEQUENTIAL CIRCUITS

Based on analyzing significance of controlling clock in design of low power sequential circuits, this paper proposes a technique that the gating signal is derived from the master latch in a flip-flop to make the derived clock having no glitch and no skew. The design of a decimal counter with half-frequency division shows that by using the synchronous derived clock the counter has lower power dissipation as well as simpler combinational logic. Computer simulation shows 20% power saving.

Simulation realization of skip cycle mode integrated control circuit in the switching power supply with low standby loss

This paper explores and proposes a design solution of an integrated skip cycle mode （SCM） control circuit with a simple structure. The design is simulated and implemented with XD10H-1.0μm modular DIMOS 650 V process. In order to meet the requirement of a wide temperature range and high yields of products, the schematic extracted from the layout is simulated with five process corners at 27℃ and 90℃. Simulation results demonstrate that the proposed integrated circuit is immune to noise and achieves skipping cycle control when switching mode power supply （SMPS） works with low load or without load.

集成电路和功率器件抗辐射工艺加固技术研究综述

随着我国空间装备的高速发展,尤其是深空探测器,微电子器件抗辐射性能得到广泛关注。抗辐射工艺加固是实现器件抗辐射性能提升的重要途径之一。本文围绕空间总剂量效应和单粒子效应,对近年来集成电路和功率器件辐射效应机理和工艺加固技术的研究进展进行了介绍和总结,为抗辐射工艺加固技术的发展与应用提供了有益参考。

A Parallel Circuit Simulator for Iterative Power Grids Optimization System

This paper discusses a high efficient parallel circuit simulator for iterative power grid optimization. The simulator is implemented by FPGA. We focus particularly on the following points: 1) Selection of the analysis method for power grid optimization, the proposed simulator introduces hardware-oriented fixed point arithmetic instead of floating point arithmetic. It accomplishes the high accuracy by selecting appropriate time step of the simulation;2) The simulator achieves high speed simulation by developing dedicated hardware and adopting parallel processing. Experiments prove that the proposed simulator using 80 MHz FPGA and eight parallel processing achieves 35 times faster simulation than software processing with 2.8 GHz CPU while maintaining almost same accuracy in comparison with SPICE simulation.

一种支持SoC数字电路老化及寿命的评估方法

使用Spice可靠性仿真技术和高温稳态寿命(HTOL)实验相结合的方法,研究不同的MOSFET器件组成的环振电路在持续翻转状态下,不同应力时间和应力电压对其寿命退化的影响。依据仿真结果和Power-Law模型建立数字电路的寿命预测理论模型。通过HTOL实验验证模型的准确性。结果表明,随着时间的增加,器件的寿命退化率逐渐增加,且随着时间的推移,寿命的变化率越来越小。随着应力电压的增加,器件的寿命退化率更快趋向于稳定。器件退化符合R-D模型,仿真结果与试验结果高度,进一步证实了本模型对SoC数字电路寿命预测的准确性。通过这种组合仿真和实验的方法,可以更加准确地评估数字电路的寿命,为芯片制造过程中的可靠性设计提供参考。

面向高比例新能源电网短路计算的机电-电磁融合电源模型

为解决新型电力系统计算与分析中传统电源模型难以继续适用的问题,提出一种面向高比例新能源电网短路计算的机电-电磁融合电源模型。一方面,考虑新能源电源通用控制策略作用下的外部输出特性,采用单一压控电流源等效电源侧海量新能源电源的整体输出;另一方面,根据短路电流故障的时间划分尺度,保留传统发电机工频基波意义下的外部输出特性,并采用3个大小不一且衰减速度不同的电压源等效电源侧所有发电机的整体输出。进而采用3个电压源和1个压控电流源并联的形式作为融合电源模型的结构,并采用内点法对融合电源模型参数进行在线辨识。通过短路仿真数据和电网实测故障录波数据验证了融合电源模型的适用性。

Calculation of Eddy Current Loss and Short-circuit Force in SSZ11-50000/110 Power Transformer

The ?method is used in this paper to calculate the leakage magnetic field of SSZ11-50000/110 Power transformer, and by which the structures’ influences to the main leakage flux are analyzed. Through the combination of the product and TEAM Problem 21B, the surface impedance method shows its great advantage in the calculation of eddy current loss.

Ultra-Low Power Pipeline Structure Exploiting Noncritical Stage with Circuit-Level Timing Speculation

With the increase of the clock frequency and silicon integration, power aware computing has become a critical concern in the design of the embedded processor and system-on-chip （SoC）. Dynamic voltage scaling （DVS） is an effective method for low-power designs. However, traditional DVS methods have two deficiencies. First, they have a conservative safety margin which is not necessary for most of the time. Second, they are exclusively concerned with the critical stage and ignore the significant potential free slack time of the noncritical stage. These factors lead to a large amount of power waste. In this paper, a novel pipeline structure with ultra-low power consumption is proposed. It cuts off the safety margin and takes use of the noncritical stages at the same time. A prototype pipeline is designed in 0.13 μm technology and analyzed. The result shows that a large amount of energy can be saved by using this structure. Compared with the fixed voltage case, 50% of the energy can be saved, and with respect to the traditional adaptive voltage scaling design, 37.8% of the energy can be saved.

一种双电容换流型混合式直流断路器

混合式直流断路器可以快速、准确隔离线路故障,在直流电网故障清除难题中发挥重要作用。为解决直流断路器开断能力要求高、限流能力弱、制造成本大、故障隔离速度慢等问题,提出一种双电容换流型混合式直流断路器(Double capacitor commutated hybrid DC circuit breaker,D-C-DCCB)拓扑。构建断路器时,巧妙利用自充电通路实现电容预充电及反向充电后电容能量的耗散。通过电容反向充电与阻感限流支路降低故障电流上升速率及峰值,利用限流电阻与二极管组实现限流电感,完成限流工作后被短路及储存能量耗散,加快故障隔离速度的同时,有效减少了避雷器吸收能量。对所提断路器的拓扑结构及工作原理进行分析及推导,在PSCAD/EMTDC中对所提断路器拓扑进行了四端直流电网仿真验证,与现有的直流电网故障清除拓扑在性能及经济性方面进行了对比,证明了所提断路器具有性能好、经济性高的优点。

磁感定义与复磁路相量分析

该文以变压器为例,分别建立并联和串联两种形式的等效正弦交变复磁路模型,相应地给出两种磁感的不同定义和物理意义,并比较各自的优劣势。首先,以相量图的形式分析不同负载性质等效复磁路中各物理量的相位关系,并在磁感定义的基础上完善磁路与电路的类比关系;其次,推导任意负载下等效电路有功和无功功率与类比复磁路中等效电路中虚拟有功和无功功率的数值关系;然后,以同步发电机为例,利用基于磁感的等效复磁路分析交流电机中定转子磁场的相互作用,分别基于等效复磁路和有限元方法分析一个变压器算例,验证理论分析的正确性;最后,给出研究结论,并据此客观地分析基于磁感的复磁路的作用。

基于LMMHD波浪能发电机特性的高效实时输出功率控制系统

针对目前液态金属磁流体(LMMHD)波浪能发电机输出功率控制系统响应慢、精度差、变换效率低、低压下不能可靠换向的问题,在LMMHD波浪能发电机输出特性分析的基础上,提出一种通过实时调节LMMHD发电机等效负载来控制发电机输出功率的控制策略,该控制策略快速准确且多模块并联时不存在并联均流问题。通过对考虑寄生参数影响的主电路效率的理论分析,得到了所提输出功率控制策略下主电路效率的变化规律,进而提出了多模块并联的方案,提高了系统效率,降低了单模块的设计难度。并提出了一种滚动时域判断和双模块独立驱动的换向驱动方法,在实现低压下可靠换向的同时避免了电流从体二极管流通,降低了导通损耗。仿真和样机实验结果验证了所提策略的有效性。

高压大功率SiC MOSFETs短路保护方法

碳化硅(SiC)MOSFETs短路承受能力弱,研究其短路保护方法成为保障电力电子设备安全运行的重要课题。现有方法大多围绕低压小功率SiC MOSFETs,然而随着电压和功率等级的提升,器件特性有所差异,直接套用以往设计难以实现高压大功率SiC MOSFETs的快速、可靠保护。该文首先详细研究了几种常用短路检测方法;其次基于高压大功率SiC MOSFETs器件特性,深入对比分析了不同短路检测方法的适用性,提出一种阻容式漏源极电压检测和栅极电荷检测相结合的短路保护方法;最后搭建了实验平台验证所提方法的可行性。结果表明,提出的方法在硬开关短路故障(hard switching fault,HSF)下,保护响应时间缩短了1.4μs,短路能量降低了62.5%;且能可靠识别负载短路故障(fault under load,FUL)。