Optimal Scheduling Strategy of Source-Load-Storage Based onWind Power Absorption Benefit

In recent years,the proportion of installed wind power in the three north regions where wind power bases are concentrated is increasing,but the peak regulation capacity of the power grid in the three north regions of China is limited,resulting in insufficient local wind power consumption capacity.Therefore,this paper proposes a two-layer optimal scheduling strategy based on wind power consumption benefits to improve the power grid’s wind power consumption capacity.The objective of the uppermodel is tominimize the peak-valley difference of the systemload,which ismainly to optimize the system load by using the demand response resources,and to reduce the peak-valley difference of the system load to improve the peak load regulation capacity of the grid.The lower scheduling model is aimed at maximizing the system operation benefit,and the scheduling model is selected based on the rolling schedulingmethod.The load-side schedulingmodel needs to reallocate the absorbed wind power according to the response speed,absorption benefit,and curtailment penalty cost of the two DR dispatching resources.Finally,the measured data of a power grid are simulated by MATLAB,and the results show that:the proposed strategy can improve the power grid’s wind power consumption capacity and get a large wind power consumption benefit.

Peak Shaving Strategy of Concentrating Solar Power Generation Based on Multi-Time-Scale and Considering Demand Response

According to the multi-time-scale characteristics of power generation and demand-side response(DR)resources,as well as the improvement of prediction accuracy along with the approaching operating point,a rolling peak shaving optimization model consisting of three different time scales has been proposed.The proposed peak shaving optimization model considers not only the generation resources of two different response speeds but also the two different DR resources and determines each unit combination,generation power,and demand response strategy on different time scales so as to participate in the peaking of the power system by taking full advantage of the fast response characteristics of the concentrating solar power(CSP).At the same time,in order to improve the accuracy of the scheduling results,the combination of the day-ahead peak shaving phase with scenario-based stochastic programming can further reduce the influence of wind power prediction errors on scheduling results.The testing results have shown that by optimizing the allocation of scheduling resources in each phase,it can effectively reduce the number of starts and stops of thermal power units and improve the economic efficiency of system operation.The spinning reserve capacity is reduced,and the effectiveness of the peak shaving strategy is verified.

基于相关性分析的电网非同步监测数据场景谐波责任划分

针对传统谐波责任划分方法需采用专门同步设备监测数据,且需基于等值电路模型划分谐波责任,工程应用较为复杂等不足,采用现有谐波监测装置非同步测量数据,提出一种综合考虑了数据非同步性、场景划分和数据相关性的谐波责任划分方法。首先,对原始非同步监测数据集采用分段聚合近似算法进行降噪预处理,利用形状动态时间规整算法(shape dynamic time warping,ShapeDTW)实现数据匹配对齐;然后,利用点排序识别聚类结构的聚类算法(ordering points to identify the clustering structure,OPTICS)划分场景以处理电力系统中因负荷投切和无功补偿装置切换等情况导致的谐波责任变化;最后,基于相关性分析构建场景谐波责任和总谐波责任指标,在指标构建的过程中引入了场景时长占比这一因素以得到更加科学合理的总谐波责任值。通过仿真验证和电网实例验证,该方法能基于现有非同步性监测数据实现各用户合理时间尺度动态谐波责任划分,可为工程上的快速谐波责任划分提供一定的新思路和新方法。

面向新型电力系统电力平衡的负荷响应管理综述

新能源占比逐渐提高的新型电力系统中,电力平衡压力凸显,利用规模庞大、响应灵活的负荷向系统提供调节资源能够有效提升系统平衡能力。因此,在全面梳理负荷响应具体进展的基础上,对负荷响应能力的进一步管理做出展望。概述新型电力系统中面对的电力平衡新问题,并对负荷响应新特征进行分析。围绕响应运营考虑、收益机制设计、关键响应技术和参与模式扩展4个层面,递进地对负荷响应管理进行综述。针对现阶段平衡过程中的实际挑战,提出对新型电力系统负荷响应管理能力深入挖掘的未来展望,包括跨区负荷响应研究、理性人视角下的负荷响应、有限信息和强随机性下的主体决策3个方面。

ANALYSIS FOR AIRCRAFT TAXIING AT VARIABLE VELOCITY ON UNEVENNESS RUNWAY BY THE POWER SPECTRAL DENSITY METHOD

In this paper a novel approach for the analysis of non stationary response of aircraft landing gear taxiing over an unevenness runway at variable velocity is explored, which is based on the power spectral density method. A concerned analytical landing gear model for simulating actual aircraft taxiing is formulated. The equivalent linearization results obtained by probabilistic method are inducted to treat landing gear non linear parameters such as shock absorber air spring force, hydraulic damping and Coulomb friction, tire stiffness and damping. The power spectral density for non stationary analysis is obtained via variable substitution and then Fourier transform. A representative response quantity, the overload of the aircraft gravity center, is analyzed. The frequency response function of the gravity overload is derived. The case study demonstrates that under the same reached velocity the root mean square of the gravity acceleration response from constant acceleration taxiing is smaller than that from constant velocity taxiing and the root mean square of the gravity acceleration response from lower acceleration taxiing is greater than that from higher acceleration.

SERF原子耦合磁强计抽运光功率误差分析

基于无自旋交换弛豫(Spin exchange relaxation-free,SERF)的原子自旋耦合磁强计同时具有敏感角速率和抑制环境磁场扰动的能力,是一种很有前途的长期导航应用工具.抽运光功率误差从标度因数和零偏稳定性两个方面限制了SERF耦合磁强计的长期稳定性,目前针对SERF惯性测量的抽运光误差分析均为分析标度因数误差,缺乏对零偏稳定性的分析.为了分析抽运光功率对系统的零偏稳定性影响,本文基于泰勒展开,将K–Rb–^(21)Ne耦合磁强计动力学系统由非线性系统简化为线性时不变系统,并基于状态空间方法推导了抽运光功率频率响应模型,最后在SERF耦合磁强计上对该模型进行了实验验证.理论和实验结果表明,耦合磁强计的磁光非正交将在光功率传递函数中引入微分环节,导致在耦合磁强计工作带宽里,耦合磁强计的输出信号与抽运光功率近似成比例环节.本文为分析SERF耦合磁强计中抽运光功率波动引起的惯性测量误差提供了精确的模型,为后续进行抽运光功率抑制提供了理论支持.

应用于空间系统的Power MOSFET辐射响应特性

为给金属氧化物半导体场效应功率管(PowerMOSFET)在航天系统中的应用提供辐照数据基础和依据。用60Co源对将应用于空间系统的两种PowerMOSFET进行了不同总剂量的辐照实验。从微观氧化物陷阱电荷和界面态的辐射感生角度,分析了PowerMOSFET器件在60Coγ射线辐射下的总剂量和剂量率效应以及辐照后70℃退火特性。试验表明与N沟道PowerMOSFET相比,P沟道PowerMOSFET可能更适合空间应用。

考虑源荷储联合调峰的日前-日内两阶段滚动优化调度

为了应对新能源大规模并网给电力系统带来的调峰压力,充分挖掘源荷储资源的调度潜力,建立了日前-日内两阶段滚动优化调度模型。首先,将柔性负荷通过需求响应机制纳入调度计划,分别对价格型需求响应和激励型需求响应行为进行建模。然后,建立计及机组寿命损耗和环境效益的火电机组调峰全过程成本模型。最后,考虑到风光出力预测误差呈现“近小远大”的特点,基于机会约束条件建立旋转备用约束,实现不同时间尺度下置信水平的配合。采用修改后的IEEE30节点系统作为算例,分析结果验证了本文所提模型的有效性,柔性负荷具有削峰填谷的作用,通过不同资源种类以及不同时间尺度上的协调优化,提高了新能源消纳水平,对电力系统的经济运行具有重要意义。

极端高温场景下计及需求响应的配电网动态重构

近年来,全球变暖导致极端高温事件频发,不仅电力需求显著增加,而且高比例可再生能源配电网发电能力急剧下降,给电力保供带来了巨大的压力。基于此,针对极端高温场景下的用户可靠用电问题,提出一种计及需求响应的配电网动态重构策略。首先,对极端高温场景下的光伏、风机出力以及负荷进行建模,利用场景集和场景缩减法模拟其不确定性。同时,构建考虑用户心理因素的申报量不确定性模型,针对用户需求响应积极性不高、实际响应量与日前申报量偏差过大的问题,提出比例型需求响应激励机制并建立满意度模型以衡量用户对需求响应的满意程度。其次,对负荷类型进行划分,基于不同类型用户可靠性需求,分析其停电损失影响,建立节点停电损失系数矩阵以衡量节点供电优先级。然后,以失负荷成本、需求响应补贴成本和开关动作成本最小为目标,建立了极端高温场景下计及需求响应的配电网动态重构模型。最后,在148节点算例上验证了所提方法的有效性,结果表明所提模型与方法有利于保障极端高温场景下用户的可靠用电。

高比例可再生能源电力系统的动态频率安全约束机组组合

随着高比例可再生能源的并网,电力系统的惯量响应和一次调频能力有所下降,因此在机组组合规划中需纳入动态频率安全约束条件。首先,提出了一种简单实用的动态频率安全约束建模方法,通过将频率响应分为两段,对备用容量不完全充足时的频率响应进行深入分析,充分考虑了惯量、备用容量以及单位调节功率对系统频率最小值的影响。其次,进一步将频率响应分为两种情况,以构建模频率最小值的安全约束模型。将所构建的动态频率安全约束应用在机组组合中,为使优化模型便于求解,对其中的非线性部分进行线性化变换。最后,通过算例验证了所提模型的有效性,结果表明该模型能够保证在发生最严重意外事件的任意时段内,均能确保故障后的频率响应符合频率安全要求。通过与无频率安全约束的机组组合对比,展示了频率安全约束的作用机理。与两种常用的频率安全约束对比,所提频率安全约束能在保证频率安全的情况下,找到相对更优的调频资源配置方案。

绿电交易场景下计及温控负荷的高铁站两阶段调度策略

考虑绿电交易场景下清洁能源出力的不确定性和负载的波动性,基于随机模型预测控制提出一种计及温控负荷的高铁站两阶段能量优化调度策略。首先,根据热功率平衡原理,建立符合高铁站特性的温控负荷模型,并引入此温控系统参与高铁站两阶段调度;其次,应用多元正态分布描述随机变量误差间的概率相关性,采用蒙特卡洛抽样和基于概率距离的场景快速削减方法生成高铁站日内绿电、光伏和负荷的典型场景,基于模型预测控制应用典型场景对日内高铁站用电系统进行滚动优化调度;最后以某高铁站为算例,分析典型季节下引入此温控模型的调度结果,验证所提模型在改善高铁站经济运行、新能源消纳等方面的优势及所提两阶段调度策略的鲁棒性。

数据驱动的火电机组二次调频特性建模方法

针对目前火电机组机理模型存在不能反映机组响应特性和模型参数难以准确获取等问题,提出一种数据驱动的火电机组二次调频特性模型构建方法。首先分析机组AGC(自动发电控制)调频响应特性,按调节强度划分机组工况,根据多组相近调节强度下火电机组二次调频响应曲线,采用最小二乘法提取二次调频响应特征。然后用二阶模型表征机组数学模型,在线修改模型阻尼系数以提高模型对调节强度变化的适应性,通过粒子群优化算法确定机组响应过程中3个响应阶段的自适应参数。最后设计算例验证了所提模型的有效性和优越性。

陕西镇安抽水蓄能电站地下厂房动力响应分析

抽水蓄能电站水头高,地下厂房结构振动问题突出,启停频繁,地下厂房动力响应分析作为厂房设计研究中的重点问题受到更多关注。以陕西镇安抽水蓄能电站为例,利用ANSYS有限元软件建立地下厂房实体模型,通过进行厂房自振特性及共振分析和对机组荷载及压力脉动作用下地下厂房动力响应进行研究,分析了不同工况下厂房整体、局部结构自振特性和动力响应。结果表明:镇安抽水蓄能电站厂房抗振设计基本合理,楼梯和立柱作为厂房薄弱环节需重点关注;电站在低水头运行时,厂房结构动力响应明显增大,在实际运行中应合理调度,尽量减少低水头运行时长。研究结果可为类似工程设计提供参考。

利用Power Builder7.0设计网络数据库的编程技巧

介绍了Power Builder 7.0的特点,提出了几种编程技巧,重点讨论了如何在Power Builder7.0编程中缩短响应时间、合理分配C/S的负载等问题,并对实施方法给出了具体说明,通过不同方法的响应时间的比较,证明了这些方法是可行的.

新型可控电网换相换流器故障特性及控制优化研究

基于可控电网换相型换流器(controllable line commutated converter,CLCC)的高压直流输电技术避免了常规直流换相失败问题,为高压直流馈入电网提供了崭新途径。文章揭示CLCC高压直流输电系统的故障响应机理,对比CLCC与电网换相型换流器、电压源型换流器等直流输电技术的功率特性差异。针对CLCC可控换流的技术特点,提出一种基于最大触发角提升的CLCC优化控制方法,改善了CLCC的故障响应特性,提升了受端电网交流电压的恢复速度。最后,基于PSD-PSModel电力系统仿真软件,建立送受端电网机电暂态和CLCC直流电磁暂态的混合仿真模型,验证理论分析的准确性和优化控制的有效性。

新能源电压型PWM变流器定频直接功率控制

在新能源电压型脉宽调制(PWM)变流器的控制中,空间矢量调制直接功率控制(DPC-SVM)成为研究的热点。传统DPC-SVM方法瞬时有功功率在变流器两侧的传输速度相差很大,当负载变化较大较快时,会引起直流电压产生过冲,对设备造成损害。本文对影响功率动态响应能力的因素进行了深入分析,推导了瞬时功率动态响应能力与变流器相关参数之间的关系,提出了利用动态过程中的瞬时无功功率加快能量在变流器两侧交换速度的一种控制方法。实验结果表明这种控制方法实现了快速功率响应控制,并且其稳态运行性能良好。该控制方法实现简单,具有一定的实用价值。

Power Flow Response Based Dynamic Topology Optimization of Bi-material Plate Structures

Work on dynamic topology optimization of engineering structures for vibration suppression has mainly addressed the maximization of eigenfrequencies and gaps between consecutive eigenfrequencies of free vibration, minimization of the dynamic compliance subject to forced vibration, and minimization of the structural frequency response. A dynamic topology optimization method of bi-material plate structures is presented based on power flow analysis. Topology optimization problems formulated directly with the design objective of minimizing the power flow response are dealt with. In comparison to the displacement or velocity response, the power flow response takes not only the amplitude of force and velocity into account, but also the phase relationship of the two vector quantities. The complex expression of power flow response is derived based on time-harmonic external mechanical loading and Rayleigh damping. The mathematical formulation of topology optimization is established based on power flow response and bi-material solid isotropic material with penalization(SIMP) model. Computational optimization procedure is developed by using adjoint design sensitivity analysis and the method of moving asymptotes(MMA). Several numerical examples are presented for bi-material plate structures with different loading frequencies, which verify the feasibility and effectiveness of this method. Additionally, optimum results between topological design of minimum power flow response and minimum dynamic compliance are compared, showing that the present method has strong adaptability for structural dynamic topology optimization problems. The proposed research provides a more accurate and effective approach for dynamic topology optimization of vibrating structures.

Experimental Study on Hydrodynamic Characteristics of Vertical-Axis Floating Tidal Current Energy Power Generation Device

To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device （VAFTCEPGD）, a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.

Optimization of Processing Parameters of Power Spinning for Bushing Based on Neural Network and Genetic Algorithms

A neural network model of key process parameters and forming quality is developed based on training samples which are obtained from the orthogonal experiment and the finite element numerical simulation. Optimization of the process parameters is conducted using the genetic algorithm (GA). The experimental results have shown that a surface model of the neural network can describe the nonlinear implicit relationship between the parameters of the power spinning process:the wall margin and amount of expansion. It has been found that the process of determining spinning technological parameters can be accelerated using the optimization method developed based on the BP neural network and the genetic algorithm used for the process parameters of power spinning formation. It is undoubtedly beneficial towards engineering applications.

Hydrodynamic Analysis of a Semi-submersible Wind-Tidal Combined Power Generation Device

Energy shortages and environmental pollution are becoming increasingly severe globally. The exploitation and utilization of renewable energy have become an effective way to alleviate these problems. To improve power production capacity, power output quality, and cost effectiveness, comprehensive marine energy utilization has become an inevitable trend in marine energy development. Based on a semi-submersible wind-tidal combined power generation device,a three-dimensional frequency domain potential flow theory is used to study the hydrodynamic performance of such a device. For this study, the RAOs and hydrodynamic coefficients of the floating carrier platform to the regular wave were obtained. The influence of the tidal turbine on the platform in terms of frequency domain was considered as added mass and damping. The direct load of the tidal turbine was obtained by CFX.FORTRAN software was used for the second development of adaptive query workload aware software, which can include the external force. The motion response of the platform to the irregular wave and the tension of the mooring line were calculated under the limiting condition(one mooring line breakage). The results showed that the motion response of the carrier to the surge and sway direction is more intense, but the swing amplitude is within the acceptable range. Even in the worst case scenario, the balance position of the platform was still in the positioning range, which met the requirements of the working sea area. The safety factor of the mooring line tension also complied with the requirements of the design specification. Therefore, it was found that the hydrodynamic performance and motion responses of a semi-submersible wind-tidal combined power generation device can meet the power generation requirements under all design conditions, and the device presents a reliable power generation system.