Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control ...Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control method for its active-loop parameters is used to realize thewind-farmfrequency support,which has become the current research hotspot.Taking the ESVG with a supercapacitor on the DC side as the research object,the influence trend of the change of virtual rotation inertia and virtual damping coefficient on its virtual angular velocity and power angle is analyzed.Then,the constraint relationship between the equivalent virtual inertia time constant of the supercapacitor and the virtual rotation inertia of the ESVG is clarified.Then,combined with the second-order response characteristics of the ESVG power control loop,the selection principles of the frequency modulation coefficient,the virtual rotation inertia,and the virtual damping coefficient are determined.An ESVG adjustment control method,considering the adaptive adjustment of the active loop parameters of the supercapacitor equivalent inertia,is proposed.While ensuring the frequency support capability of the ESVG,the fluctuation degree of its output active power and the virtual angular velocity are suppressed,and the proposed adjustment method also improves the stability of the ESVG control system and the frequency support capability for the wind farm.Finally,the simulation verifies the correctness of the theoretical analysis and the effectiveness of the proposed strategy.展开更多
随着风电、光伏的不断接入,电网电压支撑能力不足等问题愈发严重,在新能源场站中配置静止无功发生器(static var generator,SVG)是解决上述问题的有效手段之一。传统跟网型SVG采用低带宽电压控制,难以满足宽频带下的电压支撑需求,而构网...随着风电、光伏的不断接入,电网电压支撑能力不足等问题愈发严重,在新能源场站中配置静止无功发生器(static var generator,SVG)是解决上述问题的有效手段之一。传统跟网型SVG采用低带宽电压控制,难以满足宽频带下的电压支撑需求,而构网型SVG具有理想的电压源特性,近年来受到广泛关注。然而,构网型SVG在模拟同步发电机同步特性的同时,存在大扰动下暂态功角失稳的风险。为此,在新能源联合送出系统控制结构的基础上,建立了基于直流电容动态方程的构网型SVG同步分析模型。其次,解析了新能源联合送出系统等效分析模型的功角特性,揭示了新能源动态影响下系统的暂态功角失稳机理。进一步,提出一种基于自适应功角补偿原理的稳定增强型自同步控制策略,可有效提升系统的暂态稳定性能。最后,通过数字仿真和RT-LAB硬件仿真验证了机理分析的正确性和稳定提升策略的有效性。展开更多
为提高风电场的低-高电压连续故障穿越能力,提出一种基于虚拟磁链的静止无功发生器(static var generator,SVG)控制策略。首先,分析双馈感应发电机、调相机和SVG对暂态电压的支撑效果;其次,建立同步调相机与SVG的暂态无功响应模型,明确...为提高风电场的低-高电压连续故障穿越能力,提出一种基于虚拟磁链的静止无功发生器(static var generator,SVG)控制策略。首先,分析双馈感应发电机、调相机和SVG对暂态电压的支撑效果;其次,建立同步调相机与SVG的暂态无功响应模型,明确磁链不突变是两者暂态电压支撑差异的关键因素;再次,将调相机磁链守恒性质叠加到SVG暂态响应特性中,提出基于虚拟磁链的SVG控制策略,并调整控制器参数,确保SVG的无功响应能力最大化;最后,通过仿真验证提出的SVG控制策略对暂态低电压的支撑和过电压的抑制都有良好效果,能够提高风电机组的故障穿越能力。展开更多
随着新能源占比的大幅提升以及发、输、用电各环节电力电子设备所占比重的不断提高,高比例新能源电网由于缺乏传统常规同步发电机等主动支撑型电压源,系统短路容量、转动惯量下降,频率、电压稳定问题频发,电网稳定性问题日益凸显。对此...随着新能源占比的大幅提升以及发、输、用电各环节电力电子设备所占比重的不断提高,高比例新能源电网由于缺乏传统常规同步发电机等主动支撑型电压源,系统短路容量、转动惯量下降,频率、电压稳定问题频发,电网稳定性问题日益凸显。对此,重点围绕构网型静止无功发生器(static var generator,SVG)进行研究。在构网型SVG仿真分析的基础上,开展新疆电网220 kV风电汇集站构网型SVG人工三相短路试验,系统性地验证了构网型SVG的同步电压支撑、暂态瞬时响应、3倍10 s的过载能力,并总结了计算值与实测值存在误差的影响因素。试验达到了预期的目的和效果,试验表明,构网SVG在短路故障期间,能保持一定的构网特性,具有良好的系统支撑能力。展开更多
The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
为了有效降低电能损耗,研究提出了基于SVG(Static Var Generator,静止无功发生器)的煤矿供电系统节能优化策略。该策略通过SVG无功补偿技术,实时监测并调整供电系统的无功功率,有效提升了系统的功率因数,从而降低了因无功功率流动而产...为了有效降低电能损耗,研究提出了基于SVG(Static Var Generator,静止无功发生器)的煤矿供电系统节能优化策略。该策略通过SVG无功补偿技术,实时监测并调整供电系统的无功功率,有效提升了系统的功率因数,从而降低了因无功功率流动而产生的电能损耗。最后通过实例验证了该策略在降低煤矿供电系统电能损耗方面的显著成效。展开更多
针对风电高电压穿越(high voltage ride through,HVRT)能力不足导致风电机组脱网的问题,详细阐述了直流故障引起并网点电压升高最终导致风电机组脱网的内在机理,分析了储能系统和静止无功补偿装置(static var generator,SVG)在HVRT期间...针对风电高电压穿越(high voltage ride through,HVRT)能力不足导致风电机组脱网的问题,详细阐述了直流故障引起并网点电压升高最终导致风电机组脱网的内在机理,分析了储能系统和静止无功补偿装置(static var generator,SVG)在HVRT期间的动态无功响应特性;通过对并网点电压进行实时监测,高电压穿越期间可将控制策略优先级分解为:风电场内部无功调节(储能系统和双馈异步风力发电机(doubly fed induction generator,DFIG)协同控制)、SVG无功调节。在此基础上,提出了一种储能系统、DFIG和SVG协同控制策略来提高风电场HVRT能力,同时对故障切除后存在的不利情况进行重新设置电压参考值环节,避免了不必要的无功流动。最后,基于MATLAB/Simulink平台搭建仿真模型,验证了理论分析与控制策略的正确性与有效性。研究结果对充分挖掘风电场自身无功调节能力,极大程度减轻SVG无功补偿负担提供了新思路。展开更多
This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic mo...This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.展开更多
This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hype...This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.展开更多
Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the s...Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the strong reliance on mathematical models seriously restrains its practical application.Therefore,improving the robustness of MPC has attained significant attentions in the last two decades,followed by which,model-free predictive control(MFPC)comes into existence.This article aims to reveal the current state of MFPC strategies for motor drives and give the categorization from the perspective of implementation.Based on this review,the principles of the reported MFPC strategies are introduced in detail,as well as the challenges encountered in technology realization.In addition,some of typical and important concepts are experimentally validated via case studies to evaluate the performance and highlight their features.Finally,the future trends of MFPC are discussed based on the current state and reported developments.展开更多
Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilizatio...Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilization of train adhesion within the total torque command,reduce the train skidding/sliding phenomenon and achieve optimal adhesion utilization for each axle,thus realizing the optimal allocation of the multi-motor electric locomotives.Design/methodology/approach–In this study,a model predictive control(MPC)-based cooperative maximum adhesion tracking control method for multi-motor electric locomotives is presented.Firstly,train traction system with multiple motors is constructed in accordance with Newton’s second law.These equations include the train dynamics equations,the axle dynamics equations,and the wheel-rail adhesion coefficient equations.Then,a new MPC-based multi-axle adhesion co-optimization method is put forward.This method calculates the optimal output torque through real-time iteration based on the known reference slip speed to achieve multi-axle co-optimization under different circumstances.Findings–This paper presents a MPC system designed for the cooperative control of multi-axle adhesion.The results indicate that the proposed control system is able to optimize the adhesion of multiple axles under numerous different conditions and achieve the optimal power distribution based on the reduction of train skidding/sliding.Originality/value–This study presents a novel cooperative adhesion tracking control scheme.It is designed for multi-motor electric locomotives,which has rarely been studied before.And simulations are carried out in different conditions,including variable surfaces and motor failing.展开更多
风电场站配置一定容量的无功补偿装置(如静止无功发生器(static var generator,SVG))可以提高风电外送能力。同时为了满足风电场站对于惯量和电压支撑的要求,SVG可以在直流侧集成功率型储能元件同时采用构网型控制。然而由于风电场出力...风电场站配置一定容量的无功补偿装置(如静止无功发生器(static var generator,SVG))可以提高风电外送能力。同时为了满足风电场站对于惯量和电压支撑的要求,SVG可以在直流侧集成功率型储能元件同时采用构网型控制。然而由于风电场出力的影响,构网型SVG存在着暂态同步失稳的风险。针对此问题,首先通过对构网型SVG接入风电场站的并网系统进行化简等效,得到构网型SVG的功角曲线。然后,利用等面积法则揭示风电场站中构网型SVG的失稳机理,并给出相应的稳定判据。进一步,提出一种基于惯量和阻尼系数协调自适应的暂态同步稳定性提升方法。在判断SVG发生暂态同步失稳时自适应改变惯量和阻尼系数,强迫SVG回到稳定平衡点。该方法可以提高构网型SVG的暂态同步稳定性,有利于风电外送能力的提升。最后在PSCAD/EMTDC中建立电磁暂态仿真模型,验证了构网型SVG失稳机理的正确性以及暂态同步稳定性提升方法的有效性。展开更多
Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these...Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.展开更多
This study examines the adaptive boundary control problem of flexible marine riser with internal flow coupling.The dynamic model of the flexible marine riser system with internal flow coupling is derived using the Ham...This study examines the adaptive boundary control problem of flexible marine riser with internal flow coupling.The dynamic model of the flexible marine riser system with internal flow coupling is derived using the Hamiltonian principle.An analysis of internal flow’s influence on the vibration characteristics of flexible marine risers is conducted.Then,for the uncertain environmental disturbance,the adaptive fuzzy logic system is introduced to dynamically approximate the boundary disturbance,and a robust adaptive fuzzy boundary control is proposed.The uniform boundedness of the closed-loop system is proved based on Lyapunov theory.The well-posedness of the closed-loop system is proved by operator semigroup theory.The proposed control’s effectiveness is validated through comparison with existing control methods.展开更多
基金funded by the Science and Technology Project of State Grid Corporation,grant number 5500-202329500A-3-2-ZN,funding data 2023.10–2025.12.
文摘Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator(ESVG),the adaptive adjustment control method for its active-loop parameters is used to realize thewind-farmfrequency support,which has become the current research hotspot.Taking the ESVG with a supercapacitor on the DC side as the research object,the influence trend of the change of virtual rotation inertia and virtual damping coefficient on its virtual angular velocity and power angle is analyzed.Then,the constraint relationship between the equivalent virtual inertia time constant of the supercapacitor and the virtual rotation inertia of the ESVG is clarified.Then,combined with the second-order response characteristics of the ESVG power control loop,the selection principles of the frequency modulation coefficient,the virtual rotation inertia,and the virtual damping coefficient are determined.An ESVG adjustment control method,considering the adaptive adjustment of the active loop parameters of the supercapacitor equivalent inertia,is proposed.While ensuring the frequency support capability of the ESVG,the fluctuation degree of its output active power and the virtual angular velocity are suppressed,and the proposed adjustment method also improves the stability of the ESVG control system and the frequency support capability for the wind farm.Finally,the simulation verifies the correctness of the theoretical analysis and the effectiveness of the proposed strategy.
文摘随着风电、光伏的不断接入,电网电压支撑能力不足等问题愈发严重,在新能源场站中配置静止无功发生器(static var generator,SVG)是解决上述问题的有效手段之一。传统跟网型SVG采用低带宽电压控制,难以满足宽频带下的电压支撑需求,而构网型SVG具有理想的电压源特性,近年来受到广泛关注。然而,构网型SVG在模拟同步发电机同步特性的同时,存在大扰动下暂态功角失稳的风险。为此,在新能源联合送出系统控制结构的基础上,建立了基于直流电容动态方程的构网型SVG同步分析模型。其次,解析了新能源联合送出系统等效分析模型的功角特性,揭示了新能源动态影响下系统的暂态功角失稳机理。进一步,提出一种基于自适应功角补偿原理的稳定增强型自同步控制策略,可有效提升系统的暂态稳定性能。最后,通过数字仿真和RT-LAB硬件仿真验证了机理分析的正确性和稳定提升策略的有效性。
文摘为提高风电场的低-高电压连续故障穿越能力,提出一种基于虚拟磁链的静止无功发生器(static var generator,SVG)控制策略。首先,分析双馈感应发电机、调相机和SVG对暂态电压的支撑效果;其次,建立同步调相机与SVG的暂态无功响应模型,明确磁链不突变是两者暂态电压支撑差异的关键因素;再次,将调相机磁链守恒性质叠加到SVG暂态响应特性中,提出基于虚拟磁链的SVG控制策略,并调整控制器参数,确保SVG的无功响应能力最大化;最后,通过仿真验证提出的SVG控制策略对暂态低电压的支撑和过电压的抑制都有良好效果,能够提高风电机组的故障穿越能力。
文摘随着新能源占比的大幅提升以及发、输、用电各环节电力电子设备所占比重的不断提高,高比例新能源电网由于缺乏传统常规同步发电机等主动支撑型电压源,系统短路容量、转动惯量下降,频率、电压稳定问题频发,电网稳定性问题日益凸显。对此,重点围绕构网型静止无功发生器(static var generator,SVG)进行研究。在构网型SVG仿真分析的基础上,开展新疆电网220 kV风电汇集站构网型SVG人工三相短路试验,系统性地验证了构网型SVG的同步电压支撑、暂态瞬时响应、3倍10 s的过载能力,并总结了计算值与实测值存在误差的影响因素。试验达到了预期的目的和效果,试验表明,构网SVG在短路故障期间,能保持一定的构网特性,具有良好的系统支撑能力。
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
文摘为了有效降低电能损耗,研究提出了基于SVG(Static Var Generator,静止无功发生器)的煤矿供电系统节能优化策略。该策略通过SVG无功补偿技术,实时监测并调整供电系统的无功功率,有效提升了系统的功率因数,从而降低了因无功功率流动而产生的电能损耗。最后通过实例验证了该策略在降低煤矿供电系统电能损耗方面的显著成效。
文摘针对风电高电压穿越(high voltage ride through,HVRT)能力不足导致风电机组脱网的问题,详细阐述了直流故障引起并网点电压升高最终导致风电机组脱网的内在机理,分析了储能系统和静止无功补偿装置(static var generator,SVG)在HVRT期间的动态无功响应特性;通过对并网点电压进行实时监测,高电压穿越期间可将控制策略优先级分解为:风电场内部无功调节(储能系统和双馈异步风力发电机(doubly fed induction generator,DFIG)协同控制)、SVG无功调节。在此基础上,提出了一种储能系统、DFIG和SVG协同控制策略来提高风电场HVRT能力,同时对故障切除后存在的不利情况进行重新设置电压参考值环节,避免了不必要的无功流动。最后,基于MATLAB/Simulink平台搭建仿真模型,验证了理论分析与控制策略的正确性与有效性。研究结果对充分挖掘风电场自身无功调节能力,极大程度减轻SVG无功补偿负担提供了新思路。
基金supported by the National Natural Science Foundation of China(Nos.62103052 and No.52175214)。
文摘This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.
基金supported by the National Natural Science Foundation of China(12072090).
文摘This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.
基金supported in part by the National Natural Science Foundation of China under Grant 52077002。
文摘Model predictive control(MPC)has been deemed as an attractive control method in motor drives by virtue of its simple structure,convenient multi-objective optimization,and satisfactory dynamic performance.However,the strong reliance on mathematical models seriously restrains its practical application.Therefore,improving the robustness of MPC has attained significant attentions in the last two decades,followed by which,model-free predictive control(MFPC)comes into existence.This article aims to reveal the current state of MFPC strategies for motor drives and give the categorization from the perspective of implementation.Based on this review,the principles of the reported MFPC strategies are introduced in detail,as well as the challenges encountered in technology realization.In addition,some of typical and important concepts are experimentally validated via case studies to evaluate the performance and highlight their features.Finally,the future trends of MFPC are discussed based on the current state and reported developments.
基金supported by Scientific Research Projects of China Association of Metros(CAMET-KY-2022039)State Key Laboratory of Traction and Control System of EMU and Locomotive(2023YJ386).
文摘Purpose–This study aims to propose a cooperative adhesion control method for trains with multiple motors electric locomotives.The method is intended to optimize the output torque of each motor,maximize the utilization of train adhesion within the total torque command,reduce the train skidding/sliding phenomenon and achieve optimal adhesion utilization for each axle,thus realizing the optimal allocation of the multi-motor electric locomotives.Design/methodology/approach–In this study,a model predictive control(MPC)-based cooperative maximum adhesion tracking control method for multi-motor electric locomotives is presented.Firstly,train traction system with multiple motors is constructed in accordance with Newton’s second law.These equations include the train dynamics equations,the axle dynamics equations,and the wheel-rail adhesion coefficient equations.Then,a new MPC-based multi-axle adhesion co-optimization method is put forward.This method calculates the optimal output torque through real-time iteration based on the known reference slip speed to achieve multi-axle co-optimization under different circumstances.Findings–This paper presents a MPC system designed for the cooperative control of multi-axle adhesion.The results indicate that the proposed control system is able to optimize the adhesion of multiple axles under numerous different conditions and achieve the optimal power distribution based on the reduction of train skidding/sliding.Originality/value–This study presents a novel cooperative adhesion tracking control scheme.It is designed for multi-motor electric locomotives,which has rarely been studied before.And simulations are carried out in different conditions,including variable surfaces and motor failing.
文摘风电场站配置一定容量的无功补偿装置(如静止无功发生器(static var generator,SVG))可以提高风电外送能力。同时为了满足风电场站对于惯量和电压支撑的要求,SVG可以在直流侧集成功率型储能元件同时采用构网型控制。然而由于风电场出力的影响,构网型SVG存在着暂态同步失稳的风险。针对此问题,首先通过对构网型SVG接入风电场站的并网系统进行化简等效,得到构网型SVG的功角曲线。然后,利用等面积法则揭示风电场站中构网型SVG的失稳机理,并给出相应的稳定判据。进一步,提出一种基于惯量和阻尼系数协调自适应的暂态同步稳定性提升方法。在判断SVG发生暂态同步失稳时自适应改变惯量和阻尼系数,强迫SVG回到稳定平衡点。该方法可以提高构网型SVG的暂态同步稳定性,有利于风电外送能力的提升。最后在PSCAD/EMTDC中建立电磁暂态仿真模型,验证了构网型SVG失稳机理的正确性以及暂态同步稳定性提升方法的有效性。
基金supported by the Fundamental Research Funds for Central Public Welfare Research Institute,No.2020CZ-5(to WS and GS)the National Natural Science Foundation of China,No.31970970(to JSR)Fundamental Research Funds for the Central Universities,No.YWF-23-YG-QB-010(to JSR)。
文摘Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.
基金financially supported by Sichuan Science and Technology Program(Grant No.2023NSFSC1980).
文摘This study examines the adaptive boundary control problem of flexible marine riser with internal flow coupling.The dynamic model of the flexible marine riser system with internal flow coupling is derived using the Hamiltonian principle.An analysis of internal flow’s influence on the vibration characteristics of flexible marine risers is conducted.Then,for the uncertain environmental disturbance,the adaptive fuzzy logic system is introduced to dynamically approximate the boundary disturbance,and a robust adaptive fuzzy boundary control is proposed.The uniform boundedness of the closed-loop system is proved based on Lyapunov theory.The well-posedness of the closed-loop system is proved by operator semigroup theory.The proposed control’s effectiveness is validated through comparison with existing control methods.
