计及价格型需求响应负荷响应量与风电出力相关性的含风电电力系统优化调度研究

文章建立了计及风电场出力与价格型需求响应负荷响应量相关性的含风电电力系统优化调度模型。首先应用Copula函数建立风电场出力与需求响应负荷响应量的联合概率分布模型;然后提出两种满意度指标来衡量用户在电力系统优化调度中的参与程度和用户获利情况,并计入优化调度模型的约束条件;最后以电网调度运行总成本最小为目标函数建立优化调度模型。以10机系统标准算例为例,分析验证了所建模型的合理性和准确性。结果表明,风电出力与价格型需求响应负荷响应量具有一定的负相关性,并且计及相关性后可以降低系统运行成本,提高系统调度的经济性。     

考虑源荷不确定性和N-1安全约束的电力系统优化调度

大规模风电并网增加了系统运行的不确定因素,文章利用快速可调资源平抑风电和负荷波动引发的功率不平衡,并考虑备用调用过程减少对系统潮流的影响。首先分析了风电和负荷预测误差的概率分布模型;然后,建立含N-1网络安全机会约束和旋转备用机会约束的电力系统优化调度模型,以系统调度总成本最小为目标优化机组出力;最后,基于起作用整数变量的识别方法的Benders分解法处理N-1网络安全约束,提高求解效率。利用修正的IEEE30节点系统,验证了所提模型能够保障系统备用可用性、经济性和安全性,充分挖掘抽水蓄能的快速可调能力。     

考虑多时间尺度灵活性的含大规模风电电力系统机组组合研究

考虑机组多时间尺度启停约束,建立系统多时间尺度灵活性供给模型;考虑风电预测误差分布时变性,建立多时间尺度灵活性需求分析模型;基于混合整数线性规划方法,提出考虑多时间尺度灵活性的含大规模风电电力系统机组组合模型.模型能够充分反映含大规模风电电力系统多时间尺度灵活性供需平衡关系,在保证灵活性和安全性的前提下,提高运行经济性...     

基于风速Weibull分布的电力系统备用容量优化模型

为了解决风电功率的随机波动和预测精度不高对风电并网的影响,引入风速Weibull概率分布函数和风功率概率分布函数,建立了基于风速概率分布的长期经济调度模型。该模型考虑长期调度和风电功率概率分布,在计算备用时不需考虑风电功率的时序性,这样使得模型得到了简化。最后通过算例仿真,讨论了该模型对系统备用容量和风电场成本的影响,同时验证了该模型的可行性。     

智能化含风电配电网多目标协同调度模型

由于风电场的随机不可控变量较多,难以达到理想调度效果,提出了智能化含风电配电网多目标协同调度模型。将经济性指标和电压偏差作为目标函数,确定机组潮流、响应速度、传输线路、出力以及爬坡指标的约束条件;在考虑风电场波动情况的基础上,利用PLSPP算法预测风电场的负荷及出力值,修正误差,制定不同时段下的机组出力计划,结合MIPSO算法得到协调度最高值,实现智能化协同调度模型的构建。仿真测试结果表明,所构建模型风电场预测曲线的拟合程度为99.6%,其最低日均费用为3.914 8 万元、日均电压偏差仅为23.514 7 pu,由此证明该模型可以在花费最低成本的前提下实现高效、精准的调度。     

含风电的电力系统区间调度问题求解

在含风电的电力系统中,风电功率的预测结果和实际值之间的误差影响了电力系统的优化调度及实用性。文章研究了含风电的电力系统的区间调度问题,并利用辅助模型将区间调度转化为一般调度,求解得出决策变量的区间解和相应的目标函数区间值,并将场景削减方法应用到区间调度中。最后,算例仿真辅助模型证明文章所提出的区间调度的实用性,场景削减方法对调度区间具有良好效果。     

含电池储能风电场的发电系统风险评估

考虑风电机组的功率特性和故障率等因素建立单个风机的停运模型,结合风速的自回归滑动平均模型和风电场尾流效应的影响建立风电场的可靠性模型;考虑电池储能的充放电约束、容量约束和故障率建立电池储能系统的可靠性模型,在此基础上,结合风电场不同调度策略建立含电池储能风电场的可靠性模型。考虑常规机组的随机故障和负荷的随机波动,基于序贯蒙特卡洛方法建立含电池储能风电场的发电系统风险评估模型,并给出评估指标。在Matlab中编写相关评估程序,通过对IEEE-RTS 79算例进行仿真,从风险管控方面给出能降低系统风险的电池储能充放电约束、电池储能电量和风电场调度策略,为风电场用电池储能系统的设计和风能调度策略的选取提供重要参考。     

计及含蓄热机组快速爬坡能力的风火联合电力系统调度

为提高电网中的风电利用率,一个可能途径是通过利用火电机组的蓄热能力,使之获得较快的爬坡速率去响应具有波动性和间歇性的风电出力。本文针对含风电与火电的电力系统经济调度问题,提出一个包含机组蓄热利用决策的优化模型。含蓄热的火电机组与传统火电机组不同,其爬坡能力是动态变化且具有记忆性的,因此需要针对此类机组建立新的爬坡率约束。文中将上述约束转化为等价的线性形式,并采用混合整数规划方法求解。仿真算例结果表明:含蓄热机组所提供的额外爬坡能力使系统中的风电利用率得到了显著提高。     

基于IBSO-SDT的风电爬坡事件检测方法

为提升风电爬坡事件的检测效果，针对含电池储能的风电场，提出基于改进天牛群优化旋转门算法的爬坡事件检测方法。首先，对天牛群搜索算法进行改进，利用其搜索旋转门算法的最优门宽，并据此提取风电功率的特征数据点；然后，对特征数据点进行处理以消除“凸起”现象，进而连接相邻两个数据点形成一个风电特征时段，将风电特征时段进行分类，结合爬坡方向对其进行编码，并依据编码结果进行合并；接着，结合给出的含电池储能风电场爬坡事件定义，对合并后的风电特征时段进行爬坡事件检测；最后，利用某风电场实际运行数据对检测方法进行仿真，并与多种爬坡事件检测方法进行对比，验证了所提方法的有效性。     

不同时间尺度的风功率建模及LOLP算法研究

风功率与时间的紧密相关性,使得风电有别于常规机组,因此,必须建立能够反映风功率时间特性的模型。大规模风电的接入对电力系统的可靠运行带来威胁,采用随机生产模拟以及序列运算等方法可以评估电源的可靠性,LOLP和LOLE则是其中的核心指标。文章利用每10 min风功率的测量数据,建立在时间序列上的风功率多状态模型,并采用随机生产模拟的方法,提出了含风电场的电力系统长期LOLP算法;建立在时间断面上的风功率马尔可夫链模型和状态转移矩阵;采用序列运算的方法,提出了含风电场的电力系统短期LOLP算法;最后,在IEEE-RTS 79模型中实现了上述算法,得到了相关结论。文章的研究对于含风电场的电力系统电源规划、运行规划以及可靠性评估等具有重要意义。     

风电系统的无功功率与电网电压稳定

论述了风电容量在占局部电网相当比例时,风电机组的无功功率调整与电网电压之间的关系,对于定速和变速风电机组的运行特性做了分析,提出了在需要做无功功率调整时风电机组应能满足的特殊要求。     

New energy power generation-wind power generation

This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field（VSCF）, program implementation included Alternating Current （AC）-Direct Current （DC）-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale.     

Output power control for large wind power penetration in small power system

Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives of output power leveling and acquisition power increase are achieved. In this control approach, WTG is given output power command by fuzzy reasoning which has three inputs for average wind speed, variance of wind speed, and absolute average of frequency deviation. Since fuzzy reasoning is used, it is possible to define output power command corresponding to wind speed condition and changing capacity of power system momentarily. Moreover, high performance pitch angle control based on output power command is achieved by generalized predictive control (GPC). The simulation results by using actual detailed model for wind power system show the effectiveness of the proposed method.     

Output power variations with solar power satellites

The first comprehensive evaluation of output power variations expected from Solar Power Satellites is presented. The various factors are classified in a two tier manner as: deterministic (either periodic or non-periodic) and statistical (either constant with system life or changing with life). The largest variations are due to seasonal periodic factors, namely variations in the solar constant (± 3.3 per cent) and a solar illumination variation with the photovoltaic array held perpendicular to the orbit plane (± 4.2 per cent). Other key factors delineated which are being quantified presently include power reductions due to microwave power tube failure and silicon solar cell radiation damage, while multiple shadowing of adjacent power stations in geosynchronous orbit and rectenna structural factors and combining efficiency variations are representative of areas that need further study.     

Microthermophotovoltaic power generator with high power density

A promising energy source for portable MEMS devices, microthermophotovoltaic (micro-TPV) power generator, is described in this paper. The system mainly consists of a micro SiC combustor, and a GaSb photovoltaic (PV) cell array and a simple nine-layer dielectric filter, with a volume of about 3.1 cm³. When the flow rate of H₂ is 4.2 g/h, and H₂/O₂ ratio is 0.7, the system is able to deliver 3.06 W electrical power, the open-circuit voltage and short-circuit current are 2.31 V and 1.74 A, respectively, the result is a power density of about 1.0 W/cm³ (1 MW/m³). The effect of all kinds of factors on the performance of the micro-TPV system is also discussed in this paper.     

A hybrid power source for pulse power applications

Portable 12 V power supplies are used extensively for communications and power tool applications. These devices demand fast response times of the power supply. Fuel cells are generally best suited to continuous power applications and require an initial warm-up period, although they offer the prospect of increased operational duration over a battery for a given weight of portable system. This paper investigates the combination of specific energy performance from the fuel cell system with the specific power and response time of the battery. Two separate hybrid systems have been developed and tested; a planar, 20-cell, polymer electrolyte membrane fuel cell (PEMFC) stack together with either a lead–acid or nickel/cadmium battery; and a conventional 20-cell, bipolar, PEMFC stack. Both systems have been tested under pulse-load conditions at temperatures between −20°C and +40°C, and for comparison, the individual components have undergone similar tests. The hybrid systems have successfully operated continuously for several weeks under load profiles that the fuel cell alone could not sustain.     

Wind power and market power in competitive markets

Average market prices for intermittent generation technologies are lower than for conventional generation. This has a technical reason but can be exaggerated in the presence of market power. When there is much wind smaller amounts of conventional generation technologies are required, and prices are lower, while at times of little wind prices are higher. This effect reflects the value of different generation technologies to the system. But under conditions of market power, conventional generators with market power can further depress the prices if they have to buy back energy at times of large wind output and can increase prices if they have to sell additional power at times of little wind output. This greatly exaggerates the effect. Forward contracting does not reduce the effect. An important consequence is that allowing market power profit margins as a support mechanism for generation capacity investment is not a technologically neutral policy.     

Got power? [power engineers recruitment]

This paper discusses the different factors that can help to ensure that the future demand for power engineers will be met. These factors include the articulation of a compelling mission, development of a comprehensive strategy, execution of supporting tactics, and demonstration of leadership.     

Modeling market power in Korea's emerging power market

The Korean power market is being formed from the unbundled generation, transmission and distribution assets of Korea Electric Power Corporation. The KEPCO generation has been allocated to six independent gencos with a combined generating capacity of 46,629 MW in 2002. This gave an 11% margin over the peak load that year (41,921 MW).