Quality improvement of shunt active power filter with direct instantaneous power estimator based on Virtual Flux

This paper presents a new control strategy which is based on a switching table applied for Virtual Flux Direct Power Control (VF-DPC) of voltage source inverter based shunt active power filter (SAPF). This control method is applied to eliminate harmonic pollution and compensate the reactive power in the presence of nonlinear loads and unbalanced sources. Its main goal is to select switching states of the SAPF converter appropriately based on a look-up table established by hysteresis controllers acting on the instantaneous error between the commanded and VF-estimated values of active and reactive power. Our method aims to improve the electrical quantity behavior in steady and dynamic states while reducing the installing cost of the filter through eliminating the AC line voltage sensors. Facing to disturbances affecting the electrical network, a phase locked loop (PLL) has been integrated.The control strategy proposed for the active filter has been tested in the Matlab/Simulink environment.     

电能质量数据采集策略的研究与实现

电能质量数据采集主要指PQDIF（Power Quality Data Interchange Format）文件的采集,通过对PQDIF文件的来源以及电能质量智能信息系统数据需求的研究,给出一种高效可靠的数据采集策略。该策略对PQDIF文件的采集主要包括自动和手动两种方式。通过对传统多线程FTP技术的改进,可以实现采集特定时间段内创建的PQDIF文件,为电能质量智能信息系统的运行提供实时可靠的基础数据来源。     

Optimal reactive power dispatch for real power loss minimization and voltage stability enhancement using Artificial Bee Colony Algorithm

Reactive Power Dispatch (RPD) plays important role in power system reliability and security. This paper proposes the Optimal Reactive Power Dispatch (ORPD) for real power loss minimization, voltage deviation minimization and voltage stability enhancement using Artificial Bee Colony (ABC) Algorithm. ORPD is a mixed integer nonlinear optimization problem which includes both continuous and discrete control variables. The ABC algorithm is used to find the setting of control variables such as generator voltage magnitude, tap position of tap changing transformer and reactive power output of the compensation devices. The proposed algorithm is tested on IEEE 30 and 57 bus systems, Simulation results show that the proposed approach converges to better solutions and much faster than the earlier reported approaches in the literature. The optimization strategy is general and can be used to solve other power system optimization problems.     

多能源电动汽车中的功率比较控制策略及仿真

在多能源电动汽车的模型基础上，针对能量管理系统(EMS)该文提出了一种功率比较控制策略。EMS的功率比较控制策略是通过比较实际所需功率和能量存储元件的最大提供和吸收功率来达到分配功率的目的。同时提出了最大提供功率和吸收功率的确定方法。仿真结果表明：功率比较控制策略比简单查表控制策略在续驶里程、燃料经济性和效率等方面均有所改善。     

基于概率的自适应学习预测策略

动态电源管理技术降低系统功耗的主要办法是根据工作负载的变化动态地切换目标设备工作模式。针对自适应学习树模型的缺陷,提出基于概率的自适应学习预测策略,通过概率描述设备行为,能够提高预测正确率,从而达到系统功耗与性能之间的优化平衡。基于概率的自适应学习预测策略是一种集预测、控制、反馈为一体的预测策略。实验结果表明,该预测策略具有较好的稳定性,与其他预测策略相比可以进一步降低系统的功耗。     

An Adaptive Wireless Power Sharing Control for Multiterminal HVDC

Power sharing among multiterminal high voltage direct current terminals (MT-HVDC) is mainly developed based on a priority or sequential manners, which uses to prevent the problem of overloading due to a predefined controller coefficient. Furthermore, fixed power sharing control also suffers from an inability to identify power availability at a rectification station. There is a need for a controller that ensures an efficient power sharing among the MT-HVDC terminals, prevents the possibility of overloading, and utilizes the available power sharing. A new adaptive wireless control for active power sharing among multiterminal (MT-HVDC) systems, including power availability and power management policy, is proposed in this paper. The proposed control strategy solves these issues and, this proposed controller strategy is a generic method that can be applied for unlimited number of converter stations. The rational of this proposed controller is to increase the system reliability by avoiding the necessity of fast communication links. The test system in this paper consists of four converter stations based on three phase-two AC voltage levels. The proposed control strategy for a multiterminal HVDC system is conducted in the power systems computer aided design/electromagnetic transient design and control (PSCAD/EMTDC) simulation environment. The simulation results significantly show the flexibility and usefulness of the proposed power sharing control provided by the new adaptive wireless method.     

基于NOMA系统的用户分组和功率分配策略

针对非正交多址接入（NOMA）系统的最优用户分组和功率分配方案的高复杂度问题,提出一种改进的用户分组和功率分配策略。首先,对用户进行分组,由信道增益值确定每个子信道的第一个用户,再由贪婪匹配方法分配剩余用户;然后,对用户的功率进行分配,将该功率分配问题分成子信道间和子信道内两部分,对于子信道间采用线性注水算法分配功率,对于子信道内则采用所提的迭代功率分配算法分配功率;最后,构造拉格朗日函数以实现在最大发射功率以及保证每个用户最低数据速率的约束下系统吞吐量的最大化。仿真结果表明,在多用户的情况下,与线性注水的分数阶功率分配（LWF-FTPA）算法和等分数阶功率分配（EQ-FTPA）算法相比,系统吞吐量分别提高了8%和20%,所提策略优于传统算法。     

Power quality analysis using Discrete Orthogonal S-transform (DOST)

Power quality is one of the major issues in the modern electrical power world. The widespread usage of power electronic devices and non-linear loads make the power system more vulnerable to the power quality disturbances. As the power grids are expanding more and more because of the renewable sources, it necessitates responsive detection and accurate classification of power quality disturbances for corrective measures. This paper presents a new approach for power quality analysis using an orthogonal time–frequency representation of S-transform called Discrete Orthogonal S-transform (DOST). These power quality disturbances are generated on EHV transmission line under different fault and load condition. Different power quality disturbances have been analyzed using the short time Fourier transform (STFT), discrete wavelet transform (DWT), S-transform (ST) and DOST. Different case studies validate the superiority of DOST over other transforms in a more efficient way to monitor the power quality disturbances.     

可再生能源分布式微网电源规划方法及应用

近年来, 可再生能源分布式发电微网技术研究引起国内外广泛关注. 本论文将遗传算法应用到风–光–柴–蓄组成的可再生能源分布式微网电源规划中, 建立微网电源规划模型及相关约束条件, 以满足能量平衡控制、费效率等为最优原则, 给出了算法的实现流程. 最后, 结合案例说明了算法的应用.     

Power management for a DC MicroGrid integrating renewables and storages

A power management controller for a DC MicroGrid containing renewable energy sources, storage elements and loads is presented. The controller ensures power balance and grid stability even when some devices are not controllable in terms of their power output, and environmental conditions and load vary in time. Power balance and desired voltage level for the DC MicroGrid are considered as constraints for the controller. Simulations and an experimental setup are implemented to show the effectiveness of the proposed control action.     

Development of optimum scheduling strategies for test facilities

An optimum scheduling strategy for scheduling test facilities at an Air Force research facility is presented in the paper. The objective is to reduce both the electric power and labor costs at the research facility. Power rates for both on-peak and off-peak periods are considered. The developed strategy is computerized to facilitate application by the user. The program is written in Turbo Pascal. Using this strategy it is found that substantial cost savings could be achieved.     

新型双DSP结构混合有源电力滤波器控制系统

有源电力滤波器是近年发展起来的治理谐波和无功补偿的一种有效的技术。有源电力滤波器主要包括拓扑结构和控制系统两部分,而控制系统是APF的核心部分,决定了APF的性能指标和补偿效果。介绍了一种全数字控制双DSP结构混合有源电力滤波器控制系统,详细分析了全数字控制系统的新型控制算法、硬件电路和软件流程。搭建了一个20 KVA的样机进行了实验研究,实验结果表明该装置滤波和无功补偿效果较好,这种HAPF的性能价格比较高,具有良好的工程推广应用价值。     

Robust constrained predictive feedback linearization controller in a solar desalination plant collector field

This paper proposes a feedback linearization strategy for a solar collector field, which is a constrained non-linear processes. The benefits of input–output feedback linearization are improved by a filtered Smith predictor-based model predictive control algorithm with embedded variable constraint mapping to take advantage of: (i) linear control without losing the intrinsic non-linearities typical of thermal power plants; (ii) including input amplitude constraint handling capabilities due to control signal saturations induced, for example, by strong irradiance disturbances or plant start-up; and (iii) avoiding unstable or highly oscillatory responses caused by plant-model mismatch. Simulation studies are first presented to analyze robustness and constraint-mapping features, and real experimental tests of this technique in the AQUASOL desalination plant solar field have been included to demonstrate the advantages of its implementation, especially for reference tracking despite disturbances.     

FPGA based substantial power evolution controlling strategy for solar and wind forecasting grid connected system

The solar and wind are both the most promising renewable and clean energy sources, the solar stable energy progress and environmental protection have been increasingly noticeable. In this regard, an accurate solar and wind energy prediction is extremely important to avoid large voltage changes to the power grid and to provide a mechanism for the system to optimally manage the generated energy. Wind energy forecasting is widely practiced among modest power systems for high levels of windmills. This paper aims to develop a new hybrid system for wind and solar energy prediction. The proposed hybrid (wind & solar) energy prediction model is based on a Substantial Power Evolution Strategy (SPES) dedicated to short-term forecasting. The proposed forecasting system SPES is implemented using MATLAB. This paper implements the short-term and hybrid power forecasting using Substantial Power Evolution Strategy based on Prediction Intervals (PIs). This feature is one of the major innovations in the proposed hybrid renewable energy forecasting system. The accuracy of the proposed system will be revealed by comparing the results of the corresponding values of the independent forecasting models called persistence models. The designed device presents a real-time application of predicting daily total solar and wind power using any geographic location and environmental conditions using FPGA. Finally, fully developed system packages can be commercialized and/or utilized for further research projects, and researchers can analyze, validate and visualize their models for related fields.     

一种基于虚拟IP的PLCSN组网路由算法

针对传统基于逻辑拓扑的低压电力载波网络不可靠不稳定的问题,提出了一种基于虚拟IP的组网路由算法。该算法按深度优先遍历策略搜索全网,结合可变功率方法探测未知节点,根据节点间的信号衰减得出基于物理拓扑的网络平等簇结构,采用反映拓扑结构的虚拟IP进行网络编址,从而实现节点定位及高效路由。     

SoC处理器的电源管理系统设计

从软硬件角度探讨SoC处理器电源管理系统的设计,分析SoC处理器PMU的特征,根据其应用需求讨论有关PMIC的设计问题,包括：电源IC内部结构及选型原则,数字PMIC与传统电源IC相比所做的改进,一种新的电源管理总线——PMBus和一种高度整合的PMIC应用。从嵌入式操作系统的角度分析了动态电源管理系统的设计。     

基于混沌PSO算法的求解电力公司最优报价策略研究

电力公司报价策略是一个两层优化问题,其中第一层ISO模型是为保证社会公共效益最大化而制定的市场清除价模型,确定参与发电的电力公司;第二层是发电公司期望利润最大的模型。采用启发式算法求解简单易行,具有全局最优解,且与初始点选择无关。本文运用改进后的混沌粒子群优化算法(PSO)求解电力公司利润最大的优化问题,并与确定性方法和基本粒子群的计算结果进行了比较。此方法在IEEE30节点6机系统验证了有效性。     

Pacing strategies during a cycling time trial with simulated headwinds and tailwinds

The aims of this study were to examine the effects of one self-selected and two enforced pacing strategies (constant and variable power output) on cycling performance during a time trial in which variable wind conditions were simulated. Seven male cyclists rode their own bicycles on a Computrainer cycle ergometer, which was programmed to simulate a 16.1 km time trial on a flat course with a 8.05 km h(-1) headwind in the first half of the race and a 8.05 km h(-1) tailwind in the second half of the race. Subjects rode an initial time trial (ITT) at a self-selected pace to the best of their ability. The mean power output from this trial was then used to calculate the pacing strategies in the subsequent two trials: Constant (C)--riders rode the whole time trial at this mean power output; and Variable (V)--riders rode the first headwind section at a power output 5% higher than the mean and then reduced the power output in the last 8.05 km so that the mean power output was the same as in the initial time trial and in trial C. Power output, heart rate and ratings of perceived exertion (RPE) were recorded every 1.61 km. Finish times, 8.05 km split times and blood lactate levels, pre- and post-exercise (to calculate delta lactate), were also recorded in each trial. In the ITT, riders chose a mean +/- SD power output of 267 +/- 56 W in the first 1.61 km which was 14% higher than the overall race mean +/- SD of 235 +/- 41 W. Power outputs then dropped to below the race mean after the first few kilometres. Mean +/- SD finish times in the C and V time trials were 1661 +/- 130 and 1659 +/- 135 s, respectively. These were significantly faster than the 1671 +/- 131 s recorded in the initial time trial (p = 0.009), even though overall mean power outputs were similar (234 - 235 W) between all trials (p = 0.26). Overall mean RPE and delta lactate were lowest in trial V (p < 0.05). Perceived exertion showed a pacing strategy by race split interaction (p < 0.0001), but it was not increased significantly during the first 8.05 km of the V condition when power outputs were 5% higher than in condition C. Heart rate showed no main effect of pacing strategy (p = 0.80) and the interaction between strategy and race split did not reach statistical significance (p = 0.07). These results suggest that in a 16.1 km time trial with equal 8.05 km headwind and tailwind sections, riders habitually set off too fast in the first few kilometres and will benefit (10 s improvement) from a constant pacing strategy and, to a slightly greater degree (12 s improvement), from a variable (5% +/- mean) pacing strategy in line with the variations in wind direction during the race. Riders should choose a constant power when external conditions are constant, but when there are hilly or variable wind sections in the race, a variable power strategy should be planned. This strategy would be best monitored with 'power-measuring devices' rather than heart rate or subjective feelings as the sensitivity of these variables to small but meaningful changes in power during a race is low.     

矩阵变换器励磁控制的无刷双馈风力发电系统

应用在双馈风力发电系统中的功率变换器必须具有功率双向流动的能力, 交直交循环变流器和交交矩阵变换器都可满足功率的双向流动要求. 而矩阵变换器能同时提供正弦的输入电流和输出电压, 输入电流可调节为超前、滞后或同相于输入电压, 输出电压可实现幅值、频率和网侧功率因数的独立控制. 利用矩阵变换器, 通过控制无刷双馈电机控制绕组的电压幅值、频率, 为风力发电系统提供励磁. 压频比控制器采用模型参考模糊自适应控制策略, 对电机的转速和功率因数进行控制. 采用DSP,CPLD构建了基于四步换流方案的矩阵变换器实验励磁系统, 仿真和实验结果验证了系统设计的正确性、可行性和稳定性, 为矩阵式变换器的实际应用提供了实验基础.     

基于MATLAB的有源功率因数校正系统的建模与仿真

有源功率因数校正器(简称APFC)现在广泛地使用在交—直电源变换电路中,以消除电力系统的谐波,提高功率因数。而在校正器中采用新的控制算法或技术,可以更好地达到消除电力系统的谐波、提高功率因数的目的。通过MATLAB/SIMULINK对所研究对象的模型进行功能仿真、验证,将验证通过的控制器模型直接自动生成微处理器目标代码,并下载到目标微处理器中进行实际控制效果的评估。这样,可以大大提高开发新的控制算法的效率。本文主要介绍基于MATLAB的有源功率因数校正系统的功能仿真、验证,从而对下一步将控制思想移植到数字信号处理器(DSP)中做好充分准备。