Intelligent Fractional-Order Controller for SMES Systems in Renewable Energy-Based Microgrid

An autonomous microgrid that runs on renewable energy sources is presented in this article.It has a supercon-ducting magnetic energy storage(SMES)device,wind energy-producing devices,and an energy storage battery.However,because such microgrids are nonlinear and the energy they create varies with time,controlling and managing the energy inside them is a difficult issue.Fractional-order proportional integral(FOPI)controller is recommended for the current research to enhance a standalone microgrid’s energy management and performance.The suggested dedicated control for the SMES comprises two loops:the outer loop,which uses the FOPI to regulate the DC-link voltage,and the inner loop,responsible for regulating the SMES current,is constructed using the intelligent FOPI(iFOPI).The FOPI+iFOPI parameters are best developed using the dandelion optimizer(DO)approach to achieve the optimum performance.The suggested FOPI+iFOPI controller’s performance is contrasted with a conventional PI controller for variations in wind speed and microgrid load.The optimal FOPI+iFOPI controller manages the voltage and frequency of the load.The behavior of the microgrid as a reaction to step changes in load and wind speed was measured using the proposed controller.MATLAB simulations were used to evaluate the recommended system’s performance.The results of the simulations showed that throughout all interruptions,the recommended microgrid provided the load with AC power with a constant amplitude and frequency.In addition,the required load demand was accurately reduced.Furthermore,the microgrid functioned incredibly well despite SMES and varying wind speeds.Results obtained under identical conditions were compared with and without the best FOPI+iFOPI controller.When utilizing the optimal FOPI+iFOPI controller with SMES,it was found that the microgrid performed better than the microgrid without SMES.

Bias Momentum Attitude Control System Using Energy/Momentum Wheels

The integrated power and attitude control for a bias momentum attitudecontrol system is investigated. A pair of counter-spinning wheels is used to provide the biasangular momentum and store/ discharge energy for power requirement of the devices on the spacecraft.The roll/yaw motion is controlled by pitch magnetic dipole moment. The torque-based control law ofthe wheels is designed, so that the desired pitch control torque is provided and the operation ofcharging/discharging energy is carried out based on the given power. System singularity in thecontrol law of wheels is fully avoided by keeping the wheels counter-spinning. A power managementscheme using kinetic energy feedback is proposed to keep energy balance, which can avoid wheelsaturation caused by superfluous energy. The minimum moment of inertia of the wheels is limited bythe maximum bias angular momentum and the minimum energy, such constrains are analyzed incombination with the geometrical method. Numerical simulation results are presented to demonstratethe effectiveness of the control scheme.

Spacecraft Attitude Tracking and Energy Storage Using Flywheels

The control law of the flywheel in an integrated power and attitude control system （IPACS） for a spacecraft is investigated. The flywheels are used as attitude control actuators as well as energy storage device. A feedback control law for attitude tracking is firstly developed by using Lyapunov approach, and then a torque based control law of the flywheel is studied. The control torque vector of the flywheel is decomposed into three parts which are orthogonal to one another by using the method of singularity value decomposition （SVD）. One part is used to provide the attitude control torque, another part is used to store energy with given power, and the last part is used to accomplish wheel speed equalization to avoid wheel saturation caused by large difference among the wheel spin rates. A management scheme for energy storage power using kinetic energy feedback is proposed to keep energy balance, which can avoid wheel saturation caused by superfluous energy. Numerical simulation results demonstrate the effectiveness of the control scheme.

An Interactive Operating Demand Response Approach for Hybrid Power Systems Integrating Renewable Energy Sources

The increased deployment of renewable energy in existing power networks has jeopardized rotational inertia,resulting in system degradation and insta-bility.To address the issue,this paper proposes a demand response strategy for ensuring the future reliability of the electrical power system.In addition,a modified fuzzy logic control topology-based two-degree-of-freedom(fractional order proportional integral)-tilt derivative controller is designed to regulate the frequency within a demand response framework of a hybrid two-area deregulated power system.The test system includes thermal power plants,renewable energy sources(such as wind,parabolic trough solar thermal plant,biogas),and electric vehicle assets.To adaptively tune the controller’s coefficients,a quasi-opposition-based harris hawks optimization(QOHHO)algorithm is developed.The effectiveness of this algorithm is compared to other optimization algorithms,and the stability of the system is evaluated.The results demonstrate that the designed control algorithm significantly enhances system frequency stability in various scenarios,including uncertainties,physical constraints,and high penetration of renewables,compared to existing work.Additionally,an experimental assessment through OPAL-RT is conducted to verify the practicality of the proposed strategy,considering source and load intermittencies.

New Strategy of IPACS Design and Energy Management for Spacecrafts

The design problem of an integrated power and attitude control system （IPACS） for spacecrafts is investigated. A Lyapunov-typed IPACS controller is designed for a spacecraft equipped with 4 flywheels （3 orthogonal ＋ 1 skew）. This controller keeps in the nonlinear properties of original systems, so the control result can be more precise. A control law of the flywheels is also proposed to accomplish the attitude control and energy storage simultaneously. Aiming at the limitations existing in the power conversion characteristic and the wheel＇s motor, a new strategy of energy management is proposed. The strategy can not only make the charged/discharged energy reaching balance in each orbital period, but also sufficiently utilize the power provided by the solar arrays. Therefore, the size and mass of solar arrays can be decreased, and the cost of spacecraft can be economized. A simulation example illustrates the validity of the designed IPACS.

Model Predictive Control Strategy for Residential Battery Energy Storage System in Volatile Electricity Market with Uncertain Daily Cycling Load

This paper presents a control strategy for residential battery energy storage systems,which is aware of volatile electricity markets and uncertain daily cycling loads.The economic benefits of energy trading for prosumers are achieved through a novel modification of a conventional model predictive control(MPC).The proposed control strategy guarantees an optimal global solution for the applied control action.A new cost function is introduced to model the effects of volatility on customer benefits more effectively.Specifically,the newly presented cost function models a probabilistic relation between the power exchanged with the grid,the net load,and the electricity market.The probabilistic calculation of the cost function shows the dependence on the mathematical expectation of market price and net load.Computational techniques for calculating this value are presented.The proposed strategy differs from the stochastic and robust MPC in that the cost is calculated across the market price and net load variations rather than across model constraints and parameter variations.

Energy Management and Operational Control Methods for Grid Battery Energy Storage Systems

Energy storage is one of the key means for improving the flexibility,economy and security of power system.It is also important in promoting new energy consumption and the energy Internet.Therefore,energy storage is expected to support distributed power and the micro-grid,promote open sharing and flexible trading of energy production and consumption,and realize multi-functional coordination.In recent years,with the rapid development of the battery energy storage industry,its technology has shown the characteristics and trends for large-scale integration and distributed applications with multi-objective collaboration.As a grid-level application,energy management systems(EMS)of a battery energy storage system(BESS)were deployed in real time at utility control centers as an important component of power grid management.Based on the analysis of the development status of a BESS,this paper introduced application scenarios,such as reduction of power output fluctuations,agreement to the output plan at the renewable energy generation side,power grid frequency adjustment,power flow optimization at the power transmission side,and a distributed and niohile energy storage system at the power distribution side.The studies and application status of a BESS in recent years were reviewed.The energy management,operation control methods,and application scenes of large-scale BESSs were also examined in the study.

耦合相变储能的火电机组集成系统控制策略优化及效果分析

提升火电机组调峰调频能力是构建新型电力系统的重要举措。该文从锅炉-汽轮机能流解耦角度出发,设计抽取部分中压缸排汽进行储热的相变储能系统,与火电机组耦合后形成机-炉-储集成系统,提出重构机-炉-储三主体负荷指令的控制策略,并以某660 MW(P_(e0)=660 MW)超超临界机组为例进行效果评估。考虑中压缸排汽参数后,选取融化温度为117.7℃的赤藓糖醇为储能材料,研究抽汽比例对机组降负荷性能的影响。结果表明:当中压缸排汽的抽汽比例由0.00变为0.85时,机组等效降负荷速率由2.00%P_(e0)/min提升至5.13%P_(e0)/min,柔性明显增强;储能系统中储热量最大为118.73 GJ,储(火用)量最大为28.97 GJ;负荷指令重构后,系统瞬态过程中热效率增加,最大增加了1.85%,(火用)效率降低,最大降低了2.23%。

基于三端柔性直流的光热储能站与新能源场站功率协同控制策略

新能源基地大多经传统交流方式接入高压交流或直流外送通道,为解决大规模新能源经交流接入方式下并网容量小、损耗大,以及功率波动对电网稳定性影响等问题,构建了一个基于柔性直流输电并网的风电和光伏、光热储能及电网三端柔性直流系统。基于直流电压-有功功率特性,提出一种适用于该系统的站间协调控制策略,根据柔性直流输电系统的直流电压波动情况,调整光热储能机组的出力,以平抑风、光功率波动,降低其对电网的影响。针对光热储能侧换流站,采用直流电压裕度下垂混合控制策略,通过控制器参数配置,抑制控制模式切换过程中的暂态过电压,提高系统响应速度。最后,在PSCAD/EMTDC中搭建三端柔性直流系统仿真模型,验证所提控制策略的有效性。

风电场配套储能的自适应虚拟惯性——阻尼控制

提出了一种面向风储系统并网点频率稳定性提升的储能自适应虚拟惯性-阻尼控制策略。首先,通过分析推导,在储能控制策略中引入惯量控制参数与阻尼控制参数的调整系数,实现控制参数的自适应调整;其次,通过小信号分析整定,给出惯量控制参数与阻尼控制参数的取值范围;最后,基于所搭建的风储联合系统,对本文所提控制方法面对不同类型故障时的有效性进行了验证。结果证明,相比于传统虚拟同步控制方法,本文所提方法能够显著提升并网点频率稳定性,并且实现惯性和阻尼的自适应平滑调节。

电池储能温度-功率特性建模及其在综合能源系统中的应用

针对综合能源系统(IES)中电池储能在极端高温、低温下寿命衰减快、性能差的问题,该文提出含温度-功率特性的电池储能运行模型及含电池储能温度控制的IES低碳经济调度方法。通过电池特性实验和软件仿真,构建电池电热耦合模型,并提出相应的电热耦合模型凸化方法;根据凸化电池电热耦合模型估算电池温度并构建含温度-功率特性的电池储能运行模型,分析电、气、冷、热多能流耦合特性,构建IES低碳经济运行模型;结合电池储能运行模型及其温度控制,以最小化IES总运行成本为目标,构建混合整数规划模型,制定IES经济调度策略。为验证所提方法的效果,该文根据不同季节运行场景,构建仿真模型,将所提方法与不包含电池储能温度控制的方法进行对比。对比结果表明,所提方法可以有效提升电池储能运行的使用寿命、热安全性及利用率,降低IES运行成本与碳排放量。

集成储能挖掘机动臂液压缸运动特性优化

集成储能液压缸是一种多腔液压缸,由差动缸和柱塞缸组合形成。其储能腔与蓄能器直接连接,形成储能回路,用于回收再利用动臂势能,具有高效的势能再生利用和广泛适用性,但蓄能器的引入使其难以实现高精度运行。为了解决上述问题,提出了一种主回路和储能回路协同控制的方案,在储能回路中引入比例阀,并与主回路阀协同控制,以改善挖掘机动臂的运动特性。通过在SimulationX软件环境中建立挖掘机的联合仿真模型,分析并对比采用该方案与采用传统控制方案下的动臂运动特性。结果表明,该方案可以降低蓄能器对动臂运动特性的影响,并提升集成储能液压缸的速度和位移控制精度。

基于三道防御的新型储能一体舱火灾防控

近年来,电化学储能技术在各个领域广泛应用。对于大容量储能系统电池簇集中式布置导致的热失控问题,目前已形成一种系统安全性高的分布式模块化储能方案,其最小集成单元为储能电池与储能变流器(PCS)一体舱。针对该应用场景,借鉴电网安全运行的成熟经验,提出一种基于三道防御方案的消防控制策略。此方案概念清晰、逻辑严谨且易于操作实施,对于新型储能一体舱的火灾防控具有一定的参考作用。

基于模糊控制的并网风储一体化系统多目标优化配置

在“双碳”背景下,含混合储能系统(hybrid energy storage system,HESS)的风电场对系统配置优化能力的要求不断提高。为提升系统配置优化协同性,实现风电波动平抑,综合考虑经济性、平抑效果和使用寿命,提出了一种基于模糊控制的并网风储一体化系统多目标优化配置方法。首先,为了使储能功率与风电场的性能特征相匹配,应用快速傅里叶变换(fast Fourier transform,FFT)作为分频方法,实现了自适应小波包平滑策略下的HESS功率分配。然后,基于经济性和平抑效果建立多目标优化模型,确定了最优的HESS配置方案。最后,设计优化储能使用寿命的模糊控制策略,改善了高功率存储(high power storage,HPS)的充放电水平,有效优化了HPS的荷电状态(state of charge,SOC)。

大规模构网型储能集中接入对短路电流的影响分析

随着技术性能提升和成本降低,构网型储能集中并网规模不断扩大,其对系统短路电流的影响不容忽视。基于构网型储能的机电暂态仿真模型,分析不同限幅策略下设备的短路电流幅相特性,并通过算例仿真不同储能接入规模、过流能力、并网电压等级及运行工况下近区母线短路电流的变化情况,从多个角度揭示储能并网对近区母线短路电流的影响规律,量化构网型储能对并网母线短路电流的贡献幅值,并针对考虑短路电流提升效果的构网型储能容量配置及布点提出相关建议。

储能辅助机组AGC调频一体化协调控制系统方案研究

近年来我国电力领域清洁能源发展迅猛,国内电网电源结构发生了巨大变化,对火力发电机组灵活性要求逐步提高。储能参与常规火力发电机组AGC辅助调频,可以提高发电机组辅助服务水平、增强电网调频能力、增加电厂收益。以西北某电厂储能辅助火电机组AGC调频项目为例,提出了储能辅助机组AGC调频的一体化协调控制系统方案,该系统通过与火电机组多个系统的协调控制,实现对储能辅助火电机组AGC调频系统的集中协调、快速功率控制,从而改善火电机组AGC调节能力,提升发电机组综合调频性能指标K值,提升发电机组AGC调频性能和市场竞争性,以期给类似工程提供参考。

光伏发电系统与储能技术的集成与优化

探讨光伏发电系统与储能技术的集成与优化,以提高能源利用效率和系统稳定性。阐述光伏发电系统和储能技术的基本原理与特点,并分析其集成方法,包括性能优化、能量管理与调度策略以及智能控制与监测系统的设计应用。通过对某光伏发电站与储能系统的集成优化方案进行实例分析,并对实施效果进行评估与分析,验证集成优化的有效性和实用性,为光伏发电系统与储能技术的进一步发展提供重要参考。

基于光储充放一体化的电气自动化智能控制系统设计研究

在当今世界能源短缺、环境恶化的背景下,可再生能源已经成为世界各国关注的焦点。其中,光储充放一体化是一种新型的可再生能源开发模式,已引起人们的广泛关注。开展光储充放一体化智能配电系统的设计研究,通过对光伏、储能、能源管理和充电设施的综合设计,实现对电能的高效智能使用和管理。从光存储、充电和放电等方面进行了研究,并对其设计思想和工程应用进行论述。

灵活性资源参与的电热综合能源系统低碳优化

针对可再生能源的消纳问题,研究可控负荷机制与电-热耦合网中的储能调控策略,构建综合灵活性资源模型优化系统的低碳运行。首先分析区域电网中差异化布局的工业负荷调控机制,基于城市能源网架电热耦合建立可控负荷及电-热储能调控模型;然后以经济成本、风光消纳及碳排放为指标构建综合效益模型,提出碳排放流动拓扑,描述依附于能量流的碳排放流信息;最后对IEEE 33节点电网和45节点热网耦合能源系统进行仿真,分析多元灵活性资源响应对系统综合效益的改善效果,并通过拓扑直观显示典型场景中电-热碳排放流动过程。结果表明发掘灵活性资源能够提升电热综合能源系统对风光能源的消纳裕度,验证了所提方法的合理性和有效性。

新能源应用安全风险防控战略框架研究

新能源大规模应用是实现“双碳”战略目标的主要途径,开展新能源应用安全风险防控战略研究有助于新能源应用安全监管、风险防控与保障体系建设,推动新能源相关产业高质量发展。当前我国新能源应用涉及的新兴基础设施类型多样,面临着安全事故成因复杂、安全风险认知仍不充分、安全防控技术体系不完备、安全监管制度建设滞后等现实问题。本文从我国新能源应用发展现状与安全形势分析出发,剖析了充/换电站、储能站、加氢站、综合能源站等新能源应用基础设施面临的安全风险防控问题,总结了国外相关安全风险防控的现状与经验启示;围绕建立新能源应用安全事故前、中、后立体防控与保障体系,加强各利益相关方的安全风险管理与监管能力两大防控目标,构建了新能源应用安全风险防控战略框架,明确了管理与技术两个维度的重点任务以及中长期工程科技支撑项目。进一步提出了顶层设计、治理标准、监管平台、技术研发、人才培养、共建生态等发展建议,以增强新能源应用安全的研究与应用水平。