Analysis of Renewable Energy Absorption and Economic Feasibility in Multi-Energy Complementary Systems under Spot Market Conditions

As the power system transitions to a new green and low-carbon paradigm,the penetration of renewable energy in China’s power system is gradually increasing.However,the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration.This paper first constructs a wind-solar-thermalmulti-energy complementary system,analyzes its external game relationships,and develops a bi-level market optimization model.Then,it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system.Finally,simulation studies using the IEEE 30-bus system demonstrate that the multi-energy complementary system stabilizes nodal outputs,enhances the profitability of market participants,and promotes the market-based integration of renewable energy.

Design of the Multi-Energy Complementary Distributed Energy System for Towns

The multi-energy complementary distributed energy system (MCDES) covers a variety of energy forms, involves complex operation modes, and contains a wealth of control equipment and coupling links. It can realize the complementary and efficient use of different types of energy, which is the basic component of the physical layer of the Energy Internet. In this paper, aiming at the demand of the energy application for towns, a distributed energy system based on multi-energy complementary is constructed. Firstly, the supply condition of the distributed energy for the demonstration project is analyzed, and the architecture of the multi-energy complementary distributed energy system is established. Then the regulation strategy of the multi-energy complementary distributed energy system is proposed. Finally, an overall system scheme for the multi-energy complementary distributed energy system suitable for towns is developed, which provides a solid foundation for the development and promotion of the multi-energy complementary distributed energy system.

Design and Implementation on the Wind and Light Complementary LED Lighting Controller based on Novel Base Board Packaging Technology

In this paper, we conduct theoretical research on design and implementation on wind and light complementary LED lighting controller based on the novel base board packaging technology. LED, as a kind of device can convert electric power into visible light directly the homomorphism of semiconductor devices, with high efficiency and small energy consumption, good light quality, use safety, long service life, green environmental protection, flexible control as this is common lamps and lanterns is incomparable advantage. Therefore, it is considered to be 21 century of a new generation of lighting source. Based on the superiority of LED, it is widely applied in many fields of lighting. To enhance the traditional solar based pure LED system, we enhance it with the combination of the wind power and the optimized controller that holds specific meaning.

微型燃气轮机的动态建模与优化控制研究

微型燃气轮机因其灵活性和快速响应能力,可作为综合能源系统中的灵活调度资源,填补因气象条件的随机性和间歇性带来的能量缺口,也可为分布式可再生能源电站的并网提供支撑。为解决微型燃气轮机在复杂系统中的控制问题,同时适应微燃机自身的强耦合、非线性和时变性特点,该文基于MATLAB/SIMULINK平台,搭建燃机动态模型,并提出一种自适应模型预测控制算法,通过引入模型在线修正、PI静差控制等方法,以解决线性模型难以准确调控非线性系统和全局控制问题。结果表明,构建的燃机模型在孤网模式和并网模式下的平均相对误差分别为0.08%和0.52%。提出的自适应模型预测控制算法在响应多能互补系统调度时平均相对误差相较比例积分微分(proportional-integral-derivative,PID)控制和模型预测控制(model predictive control,MPC)分别降低了36.67%和88.05%,在响应速度和控制精度方面均优于其他算法,具有优秀的控制性能,且展现出与调度算法很好的适配性,有较好的发展潜能。

光储一体化变流器改进滑模自抗扰控制

由于光照强度等不可控因素的影响,光伏模块输出功率具有较大的随机性,容易降低光储并网系统的暂态性能。为此,该文在光储一体化变流器中提出了一种改进滑模自抗扰控制(SM-ADRC)策略以降低暂态时的直流母线电压波动并加快功率响应速度。首先,针对传统扩张状态观测器(ESO)对状态变量和扰动观测精度不足的问题,引入新的误差作为ESO的调节依据以提升跟踪能力;其次,将反步设计和互补滑模控制相结合运用到状态误差反馈律中,以提升控制系统的鲁棒性,并通过改进指数趋近律减小滑模固有的抖振现象;再次,从理论上证明了基于改进指数趋近律的反步互补滑模(BCSMC)和改进ESO的稳定性以及改进ESO的误差范围;最后,通过仿真和StarSim实验平台对比在不同工况下的直流母线波动情况和功率响应速度,验证了所提改进SM-ADRC策略相比于传统SM-ADRC策略和PI控制策略的优越性和可行性。

基于高效目标的多能互补能源站运行策略研究

以北京市海淀区某大型会议中心为例,采用DeST建立建筑能耗模型,进行了全年逐时负荷计算,依据项目所在地政策要求、资源禀赋及场地条件,确定采用地源热泵+空气源热泵的复合式系统,地源热泵制冷装机占比30.11%,制热装机占比32.21%,可再生能源制冷制热装机占比均为100%。通过对多能互补能源站中地源热泵机组、空气源热泵机组及循环水泵等设备的运行特性分析,提出了基于高效目标的机组最优能效加载+水泵变压差变流量控制策略,并与常规控制系统设定的机组顺次加载+水泵定压差变流量控制策略进行了全年运行能耗比较。结果显示:基于高效目标下的能源站控制策略供暖综合能效为3.36,较常规控制策略节能4.25%,能效提升4.44%;制冷综合能效为4.77,较常规控制策略节能11.03%,能效提升12.40%。该控制策略节能效果显著,可为类似多能互补能源站节能控制策略制定提供借鉴。

Real-time Feed-forward Force Compensation for Active Magnetic Bearings System Based on H∞ Controller

There are two kinds of unbalance vibrations—force vibration and displacement vibration due to the existence of unbalance excitation in active magnetic bearings（AMB） system. And two unbalance compensation methods—closed-loop feedback and open loop feed-forward are presented to reduce the force vibration. The transfer function order of the control system directly influencing the system stability will be increased when the closed-loop method is adopted, which makes the real-time compensation not easily achieved. While the open loop method would not increase the primary transfer function order, it provides conditions for real-time compensation. But the real-time compensation signals are not easy to be obtained in the open loop method. To implement real-time force compensation, a new method is proposed to reduce the force vibration caused by the rotor unbalance on the basis of AMB active control. The method realizes real-time and on-line force auto-compensation based on H∞ controller and one novel feed-forward compensation controller, which makes the rotor rotate around its inertia axis. The time-variable feed-forward compensatory signal is provided by a modified adaptive variable step-size least mean square（VSLMS） algorithm. And the relevant least mean square（LMS） algorithm parameters are used to solve the H∞ controller weighting functions. The simulation of the new method to compensate some frequency-variable and sinusoidal signals is completed by MATLAB programming, and real-time compensation is implemented in the actual AMB experimental system. The simulation and experiment results show that the compensation scheme can improve the robust stability and the anti-interference ability of the whole AMB system by using H∞ controller to achieve close-loop control, and then real-time force unbalance compensation is implemented. The proposed research provides a new control strategy containing real-time algorithm and H∞ controller for the force compensation of AMB system. And the stability of the control system is finally improved.

State feedback control for Lurie networked control systems

The problem of the stability analysis and controller design which the network-induced delays and data dropout problems network-induced delays are assumed to be time-varying and bounded, for Lurie networked control systems （NCSs） is investigated, in are simultaneously considered. By considering that the and analyzing the relationship between the delay and its upper bound, employing a Lyapunov-Krasovskii function and an integral inequality approach, an improved stability criterion for NCSs is proposed. Furthermore, the resulting condition is extended to design a less conservative state feedback controller by employing an improved cone complementary linearization （ICCL） algorithm. Numerical examples are provided to show the effectiveness of the method.

Why meta-analyses are important for complementary and alternative medicine research

Complementary and alternative medicine(CAM) is defined as a group of interventions that are not generally considered part of conventional medicine. This definition already implies that CAM interventions are often not systematically studied; and the research evidence from single trials on CAM is often limited by small sample sizes, unclear methodology, and inadequate statistics. As a result, both, significant and insignificant results are oftenhard to interpret based on single trials. Summarizing the evidence from single CAM trials, qualitative systematic reviews still have to deal with the same problems as individual trials as they can only rely on the original reports. Thus, effects of CAM interventions are often underestimated or overestimated based on single trials or qualitative systematic reviews. While meta-analyses still are limited by the methodological shortcomings of the included studies, a well-conducted meta-analysis can deal with two common problems of CAM trials: inadequate statistics that rely on within-group comparisons and small underpowered sample sizes. Although large and high quality trials are urgently needed for most CAM interventions, funding often is limited. Until higher quality research is available, meta-analyses provide a useful tool to investigate the actual level of evidence of currently published CAM trials. This editorial presents examples of meta-analyses in the field of CAM and discusses how they contribute to the consolidation of evidence.

Efficacy and safety of mild-warm moxibustion in treating diarrhea-predominant irritable bowel syndrome(spleen deficiency and dampness excess syndrome):a study protocol for a randomized controlled trial

1Background:Irritable bowel syndrome(IBS)is a disorder of bowel function,and diarrhea-predominant irritable bowel syndrome(IBS-D)is the most common.The current treatment for IBS-D is focused on improving patients’gastrointestinal-related symptoms,but there are limitations such as unstable effects and adverse drug reactions.Acupuncture and moxibustion exerts advantages in treating IBS-D.They include several forms,of which moxibustion is one of the most commonly used.And moxibustion is a common way used in treating IBS-D,but there is a lack of relevant evidence-based medical research data.This protocol aims to compare the efficacy of moxibustion(mild-warm moxibustion)in treating IBS-D(spleen deficiency and dampness excess syndrome)with the first-line treatment.Methods:In this prospective,parallel,randomized controlled trial(RCT)protocol,patients will be randomly allocated for 4-week treatment or control therapies and then 4-week follow-up in both groups.We will use Irritable Bowel Syndrome-Symptom Severity Scale(IBS-SSS)score,Irritable Bowel Syndrome-Quality of Life(IBS-QOL)score,serum brain-gut peptide levels,and traditional Chinese medicine(TCM)syndrome scale score to produce more evidence on IBS-D treatment with moxibustion.Finally,we will use SPSS 22.0 software to statistically analyze the data.Discussion:Mild-warm moxibustion is a complementary alternative therapy that fits with the pathogenesis of IBS-D.We hope to see more clinical evidence for mild-warm moxibustion against IBS-D that this RCT supported.

考虑非汛期库水位动态控制的水-光互补中短期调度研究

为解决大规模水-光互补系统在非汛期的多时间尺度耦合调度难题,阐明了库水位动态控制调度模式下的水-光中短期互补的基本原理,分别构建了考虑非汛期库水位动态控制的水-光互补中期和短期多目标优化调度数学模型,并以青海省黄河上游班多水-光互补系统为例验证模型有效性。结果表明,与传统调度模式相比,库水位动态控制调度模式下水库非汛期日初库水位平均增高0.94~1.17 m,水电日均发电水头平均提高0.06%~0.80%;非汛期水-光互补系统发电量提高0.221%,弃光电量降低0.025%。因此,非汛期库水位动态控制调度可提高水-光中短期互补性能。

垂直起降系统的互补滑模与情感神经网络控制

针对具有未知扰动的垂直起降机双闭环控制系统,提出一种基于连续径向基情感神经网络的互补积分滑模控制策略。建立了包含未知扰动项的垂直起降机的数学模型,为系统内外环分别设计滑模控制器和互补积分滑模控制器,基于对系统鲁棒性的考量,利用连续径向基情感神经网络逼近系统未知扰动项,给出神经网络权重的自适应律,形成一套新型的复合控制策略,利用Lyapunov方法分析了系统的稳定性。通过对垂直起降机的仿真实验与实物实验进行分析对比,证明了所设计的控制器具有更快的收敛速度、更高的跟踪精度和更佳的鲁棒性。

基于滑模自抗扰的储能变流器控制策略

为了提高储能变流器(PCS)的动态性能,设计基于降阶级联扩张状态观测器(ESO)和互补滑模控制(CSMC)的改进自抗扰控制(ADRC)策略,将改进ADRC策略应用于PCS的双向DC/AC变流器电压外环.改进ESO为降阶级联ESO以提高状态变量和系统总扰动的估计速度,增加扰动估计能力;更改PD控制为CSMC以设计状态误差反馈律,提升PCS的系统鲁棒性;设计改进指数趋近律以抑制抖振现象.为了证明改进ADRC策略相较于PI控制和传统ADRC的优越性,建立仿真模型并搭建相关实验平台.仿真与实验结果表明,改进ADRC策略减小了PCS暂态时直流母线电压波动,提高了PCS交流侧功率响应速度,改善了交流侧的输出电能质量.

多智能体系统固定时间一致性的多永磁同步电机转速协同控制

为了提高多电机转速协同控制精度,该文提出一种多智能体系统固定时间一致性的多永磁同步电机转速协同控制新思想。首先,将多永磁同步电机调速系统视为一个多智能体系统,设计了基于无向通信拓扑图的固定时间一致性协议;同时,设计了固定时间滑模观测器估计扰动并在一致性协议中引入前馈补偿,从而得到期望的q轴电流。然后,在矢量控制调速系统的框架下设计了固定时间互补滑模电流控制器,用于跟踪q轴参考电流。利用李雅普诺夫函数分别证明了控制器和观测器可以在与系统初始状态无关的情况下实现固定时间内收敛。最后,在三台永磁同步电机调速系统实验平台上与传统偏差耦合控制算法进行了对比实验验证,证明了所提控制算法的可行性和鲁棒性。

水电高占比下风电接入对系统稳定性影响

随着绿色清洁高效能源基地的构建,以水电为主体的水风互补成为我国西南能源开发的重要特征。为研究在典型水电系统中接入风电对系统稳定性带来的影响,首先,针对水风互补系统以转矩分析法分析了风电接入对系统频率和功角稳定性的影响,并通过算例和Prony分析验证了风速与风电渗透率对系统稳定性的影响。结果表明,风电的接入在一定程度上可以削弱传统水电系统的超低频振荡,而风电接入互联送端系统会导致区域等值惯量的下降,进而使系统区域间低频振荡风险加剧。其次,考虑风电的接入会诱发区域间低频振荡,在风电系统中引入风电的附加综合虚拟惯性与阻尼控制。算例与Prony分析验证了该控制策略能有效提高系统稳定性。最后,在区域间大规模风电接入场景下,利用改进的鲸鱼算法对风电的附加控制器参数进行了优化;结果表明,参数的整定有效提高了系统的频率以及功角稳定性。

基于45 nm CMOS SOI工艺的毫米波双频段低相噪压控振荡器设计

本文基于45 nm互补金属氧化物半导体绝缘体上硅工艺(Complementary Metal Oxide Semiconductor Silicon On Insulator,CMOS SOI)设计了一款支持5G毫米波24.25~27.5 GHz和37~43.5 GHz双频段的低相位噪声压控振荡器(Voltage Controlled Oscillator,VCO).基于CMOS SOI工艺良好的晶体管开关特性,结合开关电容阵列及开关电感方案,提高宽带调谐电容、电感Q值,扩展VCO工作频段,降低相位噪声.同时,输出匹配网络也采用开关电容切换方式,实现了5G毫米波双频段良好阻抗匹配及稳定功率输出.流片测试结果表明该VCO可以完整覆盖5G毫米波双频段24.25~27.5 GHz和37~43.5 GHz,低频段输出功率-4.8~0 dBm,高频段输出功率-6.4~-2.3 dBm.在24.482 GHz载频,1 MHz频偏处的相位噪声为-105.1 dBc/Hz;在43.308 GHz载频,1 MHz频偏处的相位噪声为-95.3 dBc/Hz.VCO核心直流功耗15.3~18.5 mW,电路核心面积为0.198 mm^(2).低频段(高频段)的FoM(Figure of Merit)及FoMT优值分别达到-181.3 dBc/Hz(-175.4 dBc/Hz)、-194.3 dBc/Hz(-188.3 dBc/Hz).

CVaR-based Reserve Optimization for Isolated Multi-energy Complementary Generation Systems in Mixed Time Scale

With the rapid growth of photovoltaic integration,the volatility and uncertainty of intermittent photovoltaic injection will dramatically reduce system operation reliability from the generation side.The system operator may face certain financial risks brought by unexpected power failure under low operation reliability.Therefore,maintaining sufficient power reserve to meet system operation reliability and reduce risk,especially in an isolated system,is essential.However,the traditional reserve preparation strategy fails to consider the uncertainties of the power generation under the high penetration levels of emerging renewable energy resources.A novel reserve preparation strategy for an isolated system is developed in this paper using a twostage model.In the first stage,the optimal hourly scheduling of an isolated system is determined.In the second stage,a minute level conditional value-at-risk(CVaR)based model is established where the uncertainty of the reserve requirement is introduced with the chance constraint.The proposed discretized step transformation(DST)and subtraction type convolution(STC)methods are utilized to convert the model into mixedinteger linear programming,and finally solved by applying the CPLEX solver.The IEEE 39-bus system is used as the test case to validate the feasibility and effectiveness of the proposed two-stage model.

Comprehensive evaluation of multi-energy complementary ecosystem based on improved multicriteria decision-making method

The multi-energy complementary ecosystem is an important form of the modern energy system.However,standardized evaluation criteria and the corresponding method framework have not yet been formed,resulting in unclear standards and irregular processes of its construction.To cope with this issue,a novel comprehensive evaluation framework for multi-energy complementary ecosystems is proposed in this study.First,a 5D comprehensive evaluation criteria system,including environment,economy,technology,safety and systematicness,is constructed.Then,a novel multicriteria decision-making model integrating an analytic network process,entropy and preference-ranking organization method for enrichment evaluation under an intuitional fuzzy environment is proposed.Finally,four practical cases are used for model testing and empirical analysis.The results of the research show that the unit cost of the energy supply and the internal rate of return indexes have the highest weights of 0.142 and 0.010,respectively.It means that they are the focus in the construction of a multi-energy complementary ecosystem.The net flows of four cases are 0.015,0.123,-0.132 and-0.005,indicating that cases with a variety of energy supply forms and using intelligent management and control platforms to achieve cold,heat and electrical coupling have more advantages.

水风光互补系统一次调频方案研究

为解决新能源并网后产生的频率问题,提出一种考虑水风光互补的调频策略。首先,建立含风、水、光、荷的简单系统数学模型;其次,结合水轮机、风电机组、光伏及其调频策略所对应的代数微分方程和基于直流潮流的系统网络方程,推导出负荷扰动时水轮机、风电机组、光伏并网节点频率响应的频域解析式;最后根据解析式分析调频死区和调频控制参数等对系统频率的影响,提出一种水风光互补系统联合调频方案。在仿真软件PSD-BPA中搭建四机系统及实际电网的仿真模型,对调频方案的有效性和可行性进行验证,多场景下仿真结果表明该方法可提高系统一次调频能力。

含储能的多能互补系统功率控制方案

为实现对含储能的多能互补系统中多种能源输出功率的安全高效控制,本文提出一种功率控制方案。首先,给出含储能的多能功率控制系统的硬件和软件架构;然后,提出一种三轮功率分配方案并给出具体流程,第一轮是储能与其他能源之间的功率分配,第二轮是其他能源电站之间的功率分配,第三轮是各类型电站内部发电设备之间的功率分配;最后,在百兆瓦级光储项目中进行实际验证,结果证明了所提方案的有效性。