Damping controller design based on FO-PID-EMA in VSC HVDC system to improve stability of hybrid power system

Wind energy sources have different structures and functions from conventional power plants in the power system.These resources can affect the exchange of active and reactive power of the network.Therefore,power system stability will be affected by the performance of wind power plants,especially in the event of a fault.In this paper,the improvement of the dynamic stability in power system equipped by wind farm is examined through the supplementary controller design in the high voltage direct current(HVDC)based on voltage source converter(VSC)transmission system.In this regard,impacts of the VSC HVDC system and wind farm on the improvement of system stability are considered.Also,an algorithm based on controllability(observability)concept is proposed to select most appropriate and effective coupling between inputs-outputs(IO)signals of system in different work conditions.The selected coupling is used to apply damping controller signal.Finally,a fractional order PID controller(FO-PID)based on exchange market algorithm(EMA)is designed as damping controller.The analysis of the results shows that the wind farm does not directly contribute to the improvement of the dynamic stability of power system.However,it can increase the controllability of the oscillatory mode and improve the performance of the supplementary controller.

MULTI-LAYER PIEZOELECTRIC ACTUATOR AND ITS APPLICATION IN CONTROLLABLE CONSTRAINED DAMPING TREATMENT

A kind of novel multi-layer piezoelectric actuator is proposed and integrated with controllable constrained damping treatment to perform hybrid vibration control. The governing equation of the system is derived based on the constitutive equations of elastic, viscoelastic and piezoelectric materials, which shows that the magnitude of control force exerted by multi-layer piezoelectric actuator is the quadratic function of the number of piezoelectric laminates used but in direct proportion to control voltage. This means that the multi-layer actuator can produce greater actuating force than that by piezoelectric laminate actuator with the same area under the identical control voltage. The optimal location placement of the multi-layer piezoelectric actuator is also discussed. As an example, the hybrid vibration control of a cantilever rectangular thin-plate is numerically simulated and carried out experimentally. The simulated and experimental results validate the power of multi-layer piezoelectric actuator and indicate that the present hybrid damping technique can effectively suppress the low frequency modal vibration of the experimental thin-plate structure.

Fuzzy Hybrid Control of Vibration Attitude of Full Car via Magneto-rheological Suspensions

A magneto-rheological（MR） semi-active suspension system with the controllable damping forces has received more attention in reducing the vibration of a vehicle. However, many control strategies only discussed one or two vibration states of the vehicle based on a quarter-car model or a half vehicle model via MR suspensions. They cannot provide a satisfying whole-vehicle performance on a road test. Hence, a full car vibration model via an MR suspension system is proposed. To reduce the heave, pitch and roll motion of the vehicle body and the vertical vibration of four wheels, a fuzzy hybrid controller for vibration attitude of full car via MR suspensions is proposed. First, a skyhook-fuzzy control scheme is designed to reduce the heave, roll and pitch motion of the vehicle body. Second, a revised ground hook control strategy is adopted to decrease the vertical vibration of the wheels. Finally, a hybrid control scheme based on a fuzzy reasoning method is proposed to tune the hybrid damping parameter, which is suitable for coordination the attitude of the vehicle body and the wheels. A test and control system for the vibration attitude of full car is set up. It is implemented on a car equipped with four MR suspensions. The results on random highway and rough road indicate that the fuzzy hybrid controller can decrease the vibration accelerations of the vehicle body and the wheels to 65%-80% and 80%-90%, respectively. It reduces the automotive vibrations of heave, roll and pitch more effectively than a passive suspension and an MR suspension with a traditional hybrid control scheme so that it achieves better ride comfort and road holding concurrently. This paper proposes a new fuzzy hybrid control（FHC） method for reducing vibration attitude of full car via MR suspensions and develops a road test to evaluate the FHC.

Test and numerical simulation of a new type of hybrid control technique

In this paper, a new hybrid control technique, based on a combination of base-isolation and semi-active variable stiffness/damping in a superstructure, is presented. To illustrate the efficiency of the proposed control system, model tests on a mini-electromagnetic shaking table and a numerical simulation were performed. The test and numerical calculation results indicate that this new hybrid control mode with additional damping and smaller additional stiffness can achieve a better control efficiency.

融合主动减振的增程混动系统动力域控制器开发

针对增程混动系统的扭转振动问题,开发了一种基于多核单片机的动力域控制器,集成了整车控制、APU系统控制、发动机控制和电机控制的软硬件,在多核任务分配和核间协调的基础上,通过电机相位和发动机相位同步算法,利用矩形波进行扭矩补偿,实现了主动减振功能。试验结果表明:利用该控制器,恒转速倒拖工况发动机转速波动范围可以减少79.7%;倒拖起动工况和自由停机工况共振时,第一阶次频率分量的幅值降幅约42.9%。

铁路悬索桥车致纵向运动混合阻尼减振研究

针对铁路悬索桥在列车过桥时梁端纵向运动响应控制问题,提出了一种创新的混合阻尼减振方案,采用多种类型的阻尼器控制梁端位移,以满足不同的减振需求.以某在建大跨铁路悬索桥为工程背景,建立了空间桁架精细模型和等效单梁简化模型,系统研究了混合阻尼减振方案不同阻尼器参数对减振效果的影响.该方案将低指数黏滞阻尼器纵向安装于桥塔与加劲梁之间,同时在桥台与加劲梁之间纵向安装电涡流阻尼器.鉴于桥台结构的特殊性,电涡流阻尼器被设计为仅能承受压力的装置,并通过样机试验进行了验证.为了进一步提升减振性能,电涡流阻尼器还配备了摩擦耗能元件.该混合阻尼减振方案能够有效控制列车过桥时梁端的纵向运动响应,显著提高桥梁结构的安全性和耐久性,在类似工程中具有重要的参考价值和借鉴意义.

基于主动式阻尼的混合式步进电机转速振荡抑制控制

混合式步进电机因其特殊的机械结构导致自身阻尼极小,在实际运行过程中会发生振荡过大,甚至失步的问题。为提高混合式步进电机的控制品质,提出一种基于主动式阻尼的步进电机转速振荡抑制方法。首先,将电机模型转化至同步旋转dq坐标系,将电流i_d控制恒为额定电流,利用位置误差和速度误差调节电流i_q生成瞬时转矩,抑制电机运行时存在的振荡现象。其次,为实现电机闭环反馈控制,提出一种将同步频率提取滤波器(SFF)与三阶锁相环(PLL~3rd)相结合的无传感器控制方法。SFF可以滤除反电动势信号中的高次谐波,PLL~3rd能消除转速变化过程中的稳态误差。实验证明,该方法有效抑制了步进电机运行过程中的振荡现象,提升了电机的运行品质。

基于ESMO-DPLL的混合式步进电机主动式阻尼控制

针对混合式步进电机阻尼系数较小引起的振荡以及失步问题,提出一种主动式阻尼闭环控制方法提高步进电机的控制品质。首先,该方法基于同步旋转dq坐标系下的电机模型,将电流id控制恒为额定电流,利用转速误差调节电流iq生成瞬时转矩,改善电机运行时存在的振荡现象。其次,为实现转速闭环,提出一种扩展滑模反电动势观测器(ESMO)与双锁相环(DPLL)相结合的无传感器控制方法,ESMO改善了传统滑模观测器的抖振问题,DPLL能消除加减速过程中的稳态误差。最后,通过实验验证了所提方法的有效性。

基于多类型换流设备的受端电网耦合鲁棒阻尼控制策略

针对混合级联直流馈入与柔性输电设备密集接入的受端电网,为增强其特定振荡模式的阻尼,利用不同换流设备控制回路间的相互作用,提出了一种基于多输入多输出系统模型的耦合鲁棒阻尼控制器设计方法。根据主模比指标选取振荡抑制效果最佳的反馈信号作为控制器输入信号;利用总体最小二乘-旋转不变技术识别系统的振荡模式并辨识系统降阶模型;采用混合H_(2)/H_(∞)方法设计耦合鲁棒控制阻尼器。控制器采用平衡截断法进行降阶,兼具鲁棒性能与实际工程应用。混合级联直流与受端江苏电网互联系统的时域仿真结果表明,相比于传统超前-滞后控制器,耦合鲁棒阻尼控制器在多种扰动和故障下均能有效抑制低频振荡,使系统快速恢复稳定运行。

Interconnection and damping assignment and Euler-Lagrange passivity-based control of photovoltaic/battery hybrid power source for stand-alone applications

A DC hybrid power source composed of photovoltaic cells as the main power source,Li-ion battery storage as the secondary power source,and power electronic interface,is modeled based on port-controlled Hamiltonian systems and Euler-Lagrange framework.Subsequently,passivity-based controllers are synthesized.Local asymptotic stability is ensured as well.In addition,a power management system is designed to manage power flow between components.Modeling and simulation of the proposed hybrid power source is accomplished using MATLAB/Simulink.Our interest is focused on the comparison of the two passivity-based control methods and their use in hybrid power systems.

混合多端直流输电系统直流侧阻抗建模及谐振抑制

混合多端直流(hybrid multi-terminal HVDC,H-MTDC)输电系统直流场设备的自然等效电阻较小,在控制系统无法提供足够大阻尼的情况下易导致系统直流侧的谐振振荡。首先推导了换相换流站(line commuted converter,LCC)和模块化多电平换流站(modular multilevel converter,MMC)直流侧输出阻抗,在MATLAB中建立了H-MTDC系统的阻抗模型并给出了基于环路增益的稳定判据。其次,通过计算环路增益对各控制参数的频域灵敏度定量地分析了参数变化对环路增益曲线的影响,明确了影响系统谐振特性的主导因素,并结合稳定判据制定了参数调整方案。再次,通过反馈换流站输出的直流电流,将LCC站原定直流电流控制器改进为电流阻尼控制器并设计了控制器参数。最后,通过PSCAD/EMTDC时域仿真验证了所提谐振抑制策略的有效性。

机械臂与环境交互的位置/力切换抑制振动方法

当机械臂执行位置/力的混合跟踪任务时,位置控制一般用于机械臂的自由运动阶段,力控制一般用于约束运动阶段。这种位置/力切换的控制结构既能实现与环境接触前对机械臂位置的精确控制,也能保证接触后对期望控制力的准确跟踪。由于开关系统本身存在的切换不稳定性,机械臂在以一定的速度与环境接触时,机械臂执行器会在环境表面振动甚至弹跳。针对此问题,提出了一种半主动阻尼阻抗学习方法,该方法主要包含两部分:基于位置/力切换控制的半主动阻尼控制器;基于一种逆秩拟牛顿法(broyden fletcher goldfarb shanno,简称BFGS)的阻抗学习算法,根据学习到的环境参数调节半主动阻尼,实现机械臂在接触面的振动抑制和平稳过渡。在仿真及实验中,应用提出的方法让机械臂与不同环境交互,结果表明:该方法能很好地抑制接触过渡阶段的超调力,并防止机械臂在切换过程中的振动,实现了柔顺接触和平稳过渡。

基于挤压-阀混合式磁流变脂悬置动态实验研究

传统的磁流变悬置只采用单一的工作模式(如挤压式或阀式),并且在较短的行程所能提供的可控阻尼有限,很难适应大功率动力装置的隔振需求。挤压-阀混合悬置装置则充分利用了磁流变材料的挤压模式和具有径向流动的阀模式,在较小位移下能够产生大阻尼力,具有性能稳定可靠并且在有限的工作行程能够产生较大阻尼力的优点。文中对挤压阀悬置动态实验进行研究,通过动态实验分析了对隔振性能有重要影响的可控阻尼和刚度特性。结果表明,新型悬置的动刚度随着频率的增加先快速增大,随后逐渐趋于平缓,而等效阻尼随着频率的增加而快速减小,在20 Hz降低幅度逐渐趋于平缓。

混合型有源电力滤波器双闭环控制

混合型有源滤波器(HAPF)是一种改善电能质量的装置,针对其无源器件容易造成直流侧电压难以控制以及系统谐振的问题,提出一种变流器输出电流和电感电压反馈的双闭环控制器。首先建立变流器输出电压和无源支路上电感电压的数学模型,但模型中存在大量耦合项,为了实现无静差控制,采用变量前馈的解耦方式消除耦合量。然后对系统控制进行设计,电感电压作为外环保证跟踪精度;选用变流器输出电流作为内环,加入系统有源阻尼,抑制系统谐振尖峰。最后仿真和实验结果表明,该控制策略提高了直流侧电压控制的动态响应速度和稳态精度,同时降低了谐振尖峰对系统稳定性的影响。

SHAPF的电流控制策略及参数设计

为了实现并联混合型有源电力滤波器(SHAPF)高补偿性能的要求,提出一种SHAPF电流双闭环控制策略。利用基波电流环为谐波电流环控制器提供阻尼项,实现有源阻尼的同时减少一组传感器,降低系统复杂度。分析了SHAPF的滤波特性,并给出了SHAPF系统配置的参数设计方法。分析了电流双闭环控制器在离散系统中的稳定性条件,并给出了控制器参数设计方法。搭建了SHAPF的仿真模型与实验样机。结果表明SHAPF具备良好的谐波补偿性能,验证了电流双闭环控制策略及参数设计的合理性。

Review of sub-synchronous interaction in wind integrated power systems: classification, challenges, and mitigation techniques

Emerging sub-synchronous interactions(SSI)in wind-integrated power systems have added intense attention after numerous incidents in the US and China due to the involvement of series compensated transmission lines and power electronics devices.SSI phenomenon occurs when two power system elements exchange energy below the synchro-nous frequency.SSI phenomenon related to wind power plants is one of the most significant challenges to main-taining stability,while SSI phenomenon in practical wind farms,which has been observed recently,has not yet been described on the source of conventional SSI literature.This paper first explains the traditional development of SSI and its classification as given by the IEEE,and then it proposes a classification of SSI according to the current research status,reviews several mitigation techniques and challenges,and discusses analysis techniques for SSI.The paper also describes the effect of the active damping controllers,control scheme parameters,degree of series compensation,and various techniques used in wind power plants(WPPs).In particular,a supplementary damping controller with converter controllers in Doubly Fed Induction Generator based WPPs is briefly pronounced.This paper provides a real-istic viewpoint and a potential outlook for the readers to properly deal with SSI and its mitigation techniques,which can help power engineers for the planning,economical operation,and future expansion of sustainable development.

适用于混合级联直流输电系统的柔直换流器直流侧控制方法

针对高低阀级联组成的特高压混合直流输电系统,提出一种适用于柔直换流器的直流电压控制方法。在选取单个柔直换流器作为定直流电压控制模式的基础上,其余定功率控制换流器加入分级辅助电压控制,稳态时精准控制直流功率,动态时针对不同电压波动,分级投入电压辅助控制,快速平抑直流过电压、欠电压和长时振荡问题。在此基础上,级联结构中的多柔直换流器直流侧不经平波电抗而直接并联,为避免多换流器间振荡,加入直流阻尼控制方法。最后利用实时数字仿真(RTDS)系统搭建级联直流系统仿真模型,仿真结果验证了所提方法的正确性和有效性。

变阻尼混合质量阻尼器动力仿真及减振机理研究

针对混合质量阻尼器(Hybrid Mass Damper,HMD)在结构减振控制中控制力输出和质量块冲程过大的问题,提出变阻尼混合质量阻尼器(Variable Damping Hybrid Mass Damper,VD-HMD)控制系统,在不降低控制效果的情况下减小控制力输出和降低质量块的冲程,并获得更好的控制效果。首先,建立VD-HMD控制系统的力学模型和运动方程;然后,利用一个设置有VD-HMD的单自由度模型作为研究对象,并将磁流变阻尼器作为变阻尼单元,进行数值分析;最后,论述VD-HMD控制系统的减振机理。仿真结果表明:VD-HMD系统有效解决控制装置的控制力输出和质量块的冲程过大的问题,并进一步提升控制效果,降低结构响应的效果更为优异。

基于IHF-PLL^(3)rd的混合式步进电机主动式阻尼控制

混合式步进电机本身阻尼极小,在实际运行过程中经常会发生振荡过大、甚至失步的问题。为提高步进电机的控制品质,提出一种基于三阶锁相环(third-orderphaselocked loop,PLL^(3)rd)-积分谐波滤波器(integral harmonic filter,IHF)的步进电机主动式阻尼控制方法。首先,主动式阻尼控制是利用同步d-q坐标系调节定子电流,其中控制id恒定为额定电流,调节iq生成瞬时转矩以抑制振荡。其次,为实现转速闭环达到增加电机阻尼的目的,提出一种PLL^(3)rd与IHF相结合的转速观测方法。其中,PLL^(3)rd可消除电机加减速过程中的稳态误差,而IHF可以有效滤除电机反电势中的高次谐波分量,该方法解决了传统微步控制中只减小了振荡幅度但是没有改变控制系统阻尼大小的问题。最后,通过实验验证所提方案的有效性。