考虑直流侧电容存储能量的风电机组虚拟惯性控制策略

文章在传统转子动能虚拟惯性控制策略基础上,提出了一种考虑直流侧电容存储能量的风电机组虚拟惯性控制策略。该策略在建立转子动能和系统频率偏差关系的基础上,建立了风电变流器直流侧电容电压和系统频率偏差的函数关系,在频率事件下能够充分利用电容所存储的能量来增强电网的惯性,提高电网的频率调节能力。最后,通过PSCAD/EMTDC仿真验证了所提控制策略的有效性。     

风光互补发电系统的协调控制

通过对风光互补发电系统能量流动和运行特性的分析,归纳总结出系统的4种运行模式和15种工作状态,提出了一种包括最大功率跟踪控制、负载功率跟踪控制、蓄电池充放电控制和系统保护运行等控制策略的协调控制方案。该控制方案根据气象条件、负载和蓄电池工况,进行不同运行模式和工作状态之间的转换,并完成相应的控制策略,从而实现风光互补发电系统的优化及可靠运行。仿真结果验证了该文所论述协调控制方案的正确性和可行性。     

基于参考模型补偿的波浪发电功率优化控制

为提高不规则海况下直驱式波浪发电系统的功率捕获能力,利用流体仿真软件获取等效辐射阻尼力系数,建立波浪发电装置对应的非线性水动力模型,通过能量函数极值构造最优功率捕获下的反电磁力,基于磁场定向控制策略跟踪控制最优电磁力;针对实际模型失匹引起的状态误差和功率损失问题,设计自适应补偿控制律修正实际模型与理想模型间的偏差,补偿功率损耗。仿真结果表明：在同样波浪激励下,所提控制策略响应速度快,鲁棒性强,最高可提升系统约50%的输出功率并能补偿15%的功率损耗。     

基于模型预测控制的MPPT控制策略

提出一种新的基于模型预测控制(MPC)的最大功率点跟踪(MPPT)优化算法。该目标控制算法把基于电流的改进型电导增量法与模型预测控制算法相结合,完成对光伏阵列最大输出功率的快速跟踪。在算法执行过程中,通过建立系统性能指标函数,评价与估算出未来控制变量的动作,从而决定P-U曲线的跟踪方向。仿真结果表明:该控制策略有效地解决了传统电导增量法在外界环境激烈变化时所产生的误判现象,在提高系统稳定性的同时,大大地减少了最大功率点跟踪时间和系统的能量损耗。     

基于功率调节的微电网互联与配电网协调优化控制

多微电网互联结构可实现多个微电网间的能量协调,并形成能源互补优势。文章针对多微电网中各分布式电源在天气变化影响下产生的出力不确定性问题,以提高微电网互联系统电压稳定性为目标,研究基于微电网互联结构的微电网间功率协调控制方法。研究单个微电网内分布式电源出力波动特性及其与微电网互联系统、配电网系统之间的能量协调与功率支撑需求特性,建立基于功率平衡控制的微电网间互联控制策略;研究微电网互联系统内各微电网控制系统平衡计算,建立微电网互联系统与配电网间能量交换的控制模型与控制策略。以三机九节点拓扑模型建立微电网互联系统及接入网协调控制模型和算法进行验证,仿真结果表明,文章所提出的微电网协调优化控制方法能够有效减小微电网波动以及对配电网的影响。     

ISG电机对柴油机能量回收—存储—使用总能效率的调控作用

针对重型柴油机余热能的回收利用问题,提出了采用朗肯循环回收排气能量发电-蓄电池存储-电动冷却附件和起动发电一体机(integrated starter generator,ISG)电机协调用电的系统构型。通过调节ISG电机的功率,在实现产电和用电平衡的基础上,管理发动机及能量回收、储存及使用各环节的运行状态,以获得最大的总能效率。在基于GT-Suite的发动机及整车仿真平台上,研究了ISG电机发电/用电功率对发动机、朗肯循环、蓄电池及电动冷却附件的影响规律,揭示了系统间的耦合关系;然后从总能效率的角度,研究了ISG电机的作用规律,提出了ISG电机的优化控制策略。研究表明:ISG电机可在维持产电用电平衡同时,优化发动机及能量回收-储存-使用环节效率;该系统在道路工况下百公里油耗降低了9.8%~11.7%。     

Application and control of super capacitor in high-speed railway regenerative braking energy storage

针对高速列车在制动过程中产生的再生制动能量得不到有效利用的问题,提出一种基于超级电容（supercapacitor,SC）的高速铁路再生制动能量存储方案。该方案以铁路功率调节器（railway power conditioner,RPC）作为接口电路,将储能装置与牵引供电系统连接在一起,采用超级电容作为储能介质,通过双向DC/DC变流器与铁路功率调节器直流侧相连,从而实现能量存储与补偿负序电流的功能。在研究储能方案拓扑结构的基础上,分析了负序电流的补偿原理,并根据补偿原理研究了储能方案的控制策略,对RPC两变流器采用滞环控制的方法,对储能装置中的双向DC/DC变流器采用电流闭环的控制方法。仿真结果表明,所提出的存储方案能够有效回收利用高速列车产生的再生制动能,并对负序电流进行补偿,改善电网侧电能质量。     

基于fuzzy-PI双模控制的光伏发电系统最大功率点跟踪仿真研究

为了提高太阳电池阵列的工作效率和整个光伏发电系统的稳定性,在光伏发电系统中需要对光伏电池的最大功率点进行跟踪。为了消除常规模糊跟踪算法在最大功率点附近出现的振荡问题,在分析光伏电池伏安特性的基础上,提出了fuzzy-PI双模控制策略,分析了该控制算法的原理,并对控制系统做了设计。Matlab/Simulink仿真表明fuzzy-PI双模控制能够快速、准确地跟踪最大功率点,避免了最大功率点处的振荡,提高了系统稳定性和能量转换效率,从而使整个双模控制兼有了MPPT精确性与快速性。     

交流励磁变速恒频风力发电系统控制策略研究

本文分析了风力机传动系统动态特性和机电能量转换与传递原理，介绍了交流励磁变速恒频风力发电系统低风速时的转速控制策略和高风速时的功率控制策略，建立了直接转速控制策略和扰动调节控制策略的线性化数学模型，实验结果验证了数学模型的有效性。     

孤岛模式下光储交流微电网能量管理协调控制策略

针对光储交流微电网,考虑光伏阵列、蓄电池和负荷之间的多种能量供需情况,提出了一种孤岛运行模式下的能量管理协调控制策略。该控制策略采用主从控制方式,作为主源的蓄电池可以工作在充电或放电状态,保证为负载和光伏逆变器提供幅值和频率稳定的电压;作为从源的光伏系统可以根据微电网内部能量平衡关系,工作在最大功率跟踪或限功率负载匹配模式;负荷投切控制可以保证重要负荷持续供电以及避免蓄电池过放。通过不同工况下的仿真结果,验证了所提控制策略的正确性与有效性。     

风光互补电动汽车储能电站系统优化设计

通过对唐山市区太阳能和风能资源状况调查分析,对全年不同方位角和倾角上的太阳能辐射量进行模拟计算,得出南偏东9.8°方向、倾角为39.7°的倾斜面上接收的太阳能辐射量最大,其值为1.62×106Wh/m2。研究中对3kW风力发电机和1kW光伏发电系统的发电量进行了计算,并以1辆纯电动轿车为负载进行了容量配比优化,设计了风力发电系统、风光互补系统及光伏系统三种不同的方案,经过对各方案的经济性、可靠性及稳定性分析,得出最佳的设计方案为风光互补发电系统,该系统风力发电装机容量为3kW,光伏发电装机容量为8.96kW。     

Dynamic behavior of a stand-alone hybrid power generation system of wind turbine,microturbine, solar array and battery storage

This paper presents dynamic behavior and simulation results in a stand-alone hybrid power generation system of wind turbine, microturbine, solar array and battery storage. The hybrid system consists of a 195 kW wind turbine, an 85 kW solar array; a 230 kW microturbine and a 2.14 kAh lead acid battery pack optimized based on economic analysis using genetic algorithm (GA). At first, a developed Lyapunov model reference adaptive feedback linearization method accompanied by an indirect space vector control is applied for extraction of maximum energy from a variable speed wind power generation system. Then, a fuzzy logic controller is designed for the mentioned purpose and its performance is compared with the proposed adaptive controller. For meeting more load demands, the solar array is integrated with the wind turbine. In addition, the microturbine and the battery storage are combined with the wind and solar power generation system as a backup to satisfy the load demand under all conditions.A supervisory controller is designed in order to manage energy between the maximum energy captured from the wind turbine/solar arrays, and consumed energies of the load, dump load, battery state of charge (SOC), and generated energy by the microturbine. Dynamic modeling and simulation are accomplished using MATLAB Simulink? 7.2.     

Enhancing the operation of fuel cell-photovoltaic-battery-supercapacitor renewable system through a hybrid energy management strategy

It is necessary to have an energy management system based on one or more control strategies to sense, monitor, and control the behavior of the hybrid energy sources. In renewable hybrid power systems containing fuel cells and batteries, the hydrogen consumption reduction and battery state of charge (SOC) utilizing are the main objectives. These parameters are essential to get the maximum befits of cost reduction as well as battery and hydrogen storage lifetime increasing. In this paper, a novel hybrid energy management system (HEMS) was designed to achieve these objectives. A renewable hybrid power system combines: PV, PEMFC, SC, and Battery was designed to supply a predetermined load with its needed power. This (REHPS) depends on the PV power as a master source during the daylight. It uses the FC to support as a secondary source in the night or shading time. The battery is helping the FC when the load power is high. The supercapacitor (SC) is working at the load transient or load fast change. The proposed energy management system uses fuzzy logic and frequency decoupling and state machine control strategies working together as a hybrid strategy where the switching over between both strategies done automatically based on predetermined values to obtain the minimum value of hydrogen consumption and the maximum value of SOC at the same time. The proposed HEMS achieves 19.6% Hydrogen consumption saving and 5.4% increase in SOC value compared to the results of the same two strategies when working as a stand-alone. The load is designed to show a surplus power when the PV power is at its maximum value. This surplus power is used to charge the battery. To validate the system, the results were compared with the results of each strategy if working separately. The comparison confirms the achievement of the hybrid energy management system goal.     

Review on combined wind power generation and energy storage systems

储能系统由于能够实现电能的时空平移,具有响应速度快,规模化等优点,是改善风电波动性,提高其并网能力的有效手段,构建风储联合发电系统成为目前研究重点.简单介绍了风电并网对电力系统的影响及不同类型电池储能技术的发展现状,给出了部分国内外风储联合发电系统的示范工程,并分析了平滑风电功率波动,跟踪计划出力曲线和削峰填谷3种主要运行方式,重点阐述了目前风储联合发电系统控制策略和储能容量配置研究现状,对进一步开展风储联合发电系统的研究进行了展望,指出经济性仍然是制约储能技术应用的关键问题之一,提高包含储能单元的风储联合发电系统的经济性是今后的研究重点.     

Evaluation of distributed building thermal energy storage in conjunction with wind and solar electric power generation

Energy storage is often seen as necessary for the electric utility systems with large amounts of solar or wind power generation to compensate for the inability to schedule these facilities to match power demand. This study looks at the potential to use building thermal energy storage as a load shifting technology rather than traditional electric energy storage. Analyses are conducted using hourly electric load, temperature, wind speed, and solar radiation data for a 5-state central U.S. region in conjunction with simple computer simulations and economic models to evaluate the economic benefit of distributed building thermal energy storage (TES). The value of the TES is investigated as wind and solar power generation penetration increases. In addition, building side and smart grid enabled utility side storage management strategies are explored and compared. For a relative point of comparison, batteries are simulated and compared to TES. It is found that cooling TES value remains approximately constant as wind penetration increases, but generally decreases with increasing solar penetration. It is also clearly shown that the storage management strategy is vitally important to the economic value of TES; utility side operating methods perform with at least 75% greater value as compared to building side management strategies. In addition, TES compares fairly well against batteries, obtaining nearly 90% of the battery value in the base case; this result is significant considering TES can only impact building thermal loads, whereas batteries can impact any electrical load. Surprisingly, the value of energy storage does not increase substantially with increased wind and solar penetration and in some cases it decreases. This result is true for both TES and batteries and suggests that the tie between load shifting energy storage and renewable electric power generation may not be nearly as strong as typically thought.     

Supervisor control for a stand-alone hybrid generation system using wind and photovoltaic energy

A comprehensive supervisor control for a hybrid system that comprises wind and photovoltaic generation subsystems, a battery bank, and an ac load is developed in this paper. The objectives of the supervisor control are, primarily, to satisfy the load power demand and, second, to maintain the state of charge of the battery bank to prevent blackout and to extend the life of the batteries. For these purposes, the supervisor controller determines online the operation mode of both generation subsystems, switching from power regulation to maximum power conversion. Decision criteria for the supervisor based on measurable system variables are presented. Finally, the performance of the supervisor controller is extensively assessed through computer simulation using a comprehensive nonlinear model of the plant.     

Design and set up of a hybrid power system (PV-WT-URFC) for a stand-alone application in Mexico

The Mexican territory has a large potential for renewable energy development, such as geothermal, hydro, biofuels, wind and solar. Thus, a 2.5 kW hybrid power system (solar, wind and hydrogen) was designed and installed to meet the power demand for a stand-alone application at the University of Zacatecas. The hybrid unit integrates three power energy sources –a photovoltaic system (PV), a micro-wind turbine (WT), a prototype of a unitized regenerative fuel cell (URFC) and energy storage devices (batteries)– in addition to their interaction methodology. The main contribution of this work is the URFC integration to a hybrid power system for the production of H₂ (water electrolyzer mode) and energy (fuel cell mode). These three energy technologies were connected in parallel, synchronized to the energy storage system and finally coupled to a power conversion module. To achieve the best performance and energy management, an energy management and control strategy was developed to the properly operation of the power plant. A meteorological station that has wireless sensors for the temperature, the humidity, the solar radiation and the wind speed provides the necessary information (in real time) to the monitor and control software, which computes and executes the short and mid–term decisions about the energy management and the data storage for future analysis.     

Multicriteria Design of Hybrid Power Generation Systems Based on a Modified Particle Swarm Optimization Algorithm

Multisource hybrid power generation systems are a type of representative application of the renewables' technology. In this investigation, wind turbine generators, photovoltaic panels, and storage batteries are used to build hybrid generation systems that are optimal in terms of multiple criteria including cost, reliability, and emissions. Multicriteria design facilitates the decision maker to make more rational evaluations. In this study, an improved particle swarm optimization algorithm is developed to derive these nondominated solutions. Hybrid generation systems under different design scenarios are designed based on the proposed approach. First, a grid-linked hybrid system is designed without incoroprating system uncertainties. Then, adequacy evaluation is conducted based on probabilistic methods by accounting for equipment failures, time-dependent sources of energy, and stochastic generation/load variations. In particular, due to the unpredictability of wind speed and solar insolation as well as the random load variation, time-series models are adopted to reflect their stochastic characteristics. An adequacy evaluation procedure including time-dependent sources, is adopted. Sensitivity studies are also carried out to examine the impacts of different system parameters on the overall design performance.      

Modeling,control and simulation of a photovoltaic /hydrogen/ supercapacitor hybrid power generation system for grid-connected applications

Hybrid renewable energy systems (HRES) should be designed appropriately with an adequate combination of different renewable sources and various energy storage methods to overcome the problem of intermittency of renewable energy resources. Focusing on the inevitable impact on the grid caused by strong randomicity and apparent intermittency of photovoltaic (PV) generation system, modeling and control strategy of pure green and grid-friendly hybrid power generation system based on hydrogen energy storage and supercapacitor (SC) is proposed in this paper. Aiming at smoothing grid-connected power fluctuations of PV and meeting load demand, the alkaline electrolyzer (AE) and proton exchange membrane fuel cell (PEMFC) and SC are connected to DC bus of photovoltaic grid-connected generation system. Through coordinated control and power management of PV, AE, PEMFC and SC, hybrid power generation system friendliness and active grid-connection are realized. The validity and correctness of modeling and control strategies referred in this paper are verified through simulation results based on PSCAD/EMTDC software platform.     

储能电池在风光互补发电系统中的容量配置分析

储能电池是分布式发电系统的关键组件。增加储能电池的容量可以提高发电系统的可靠性,但会增加系统的投资和运行费用。基于上海地区全年8 760 h的气象数据,计算了风光互补发电系统在不同储能容量下的负荷缺电率和能量溢出率的变化。对于独立的风光互补发电系统,在满足能量溢出率小于0.3的情况下,如果系统缺电率维持在1%左右时,需要配置3天的储能容量;如果系统缺电率为0,则需要配置5天的储能容量。