共查询到20条相似文献，搜索用时 250 毫秒
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基于电压源换流器(VSC)的高压直流输电(VSC-HVDC)是一种新型的电力传输技术。该技术与传统高压直流输电相比具有更加灵活的控制策略和简单的工作模式。本文采用一个电流前馈解耦控制策略,通过使用该控制策略,VSC-HVDC系统不仅可以实现独立的控制有功功率和无功功率,而且可以缩短动态响应时间。为了改善直流电压控制的性能,交流工作电流用来补偿直流电压。结果得到该控制策略在发生交流单相故障时具有反应速度快,稳定性强的特点。 相似文献
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从提高小电流接地电网供电可靠性的角度出发,论证了低压侧母线采用双母线、双母线带旁路母线或单母线分段接线方式且母线联络开关在正常运行方式下处于合闸状态的一次变电站多台手动调节消弧线圈协同优化补偿整定计算中需要先行判断接地线路所连接母线的必要性和运行方式安排的原则。按照本文所述方法,可以提高小电流接地电网供电可靠性、减少操作次数、缩短电网异常处理时间和降低由电网异常发展为电网事故的风险。 相似文献
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分析了二极管箝位型三电平静止无功发生器主电路原理,讨论了三电平空间矢量脉宽调制技术中小矢量、中矢量、大矢量对直流侧两个电容电压的影响。在此基础上,结合SVG自身控制的要求与特点,提出了基于直流侧两个电容的电压差值和SVG交流侧瞬时三相电流的方向来调整矢量作用序列中等效的正、负小矢量作用时间的比例,从而使直流侧中点电压达到平衡的控制策略,该控制策略不需增加SVG系统的检测电路。最后,通过仿真验证了文章所提出的中点电位控制策略可以有效地抑制三电平SVG直流电容电压不平衡程度,实现算法简单,在工程实践上具有一定的实用性。 相似文献
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针对传统中高压智能配电网中的电力电子均衡控制器稳定性不佳、电流质量差、工作效率低的问题。对电力电子均衡控制器进行优化设计,分析电力电子均衡控制器进行直流转换的工作原理,在此基础上,设计三相式电力电子均衡控制器电路拓扑,采用MMC将高压侧三相交流电压转换为高压直流电压,通过DC-DC转换器完成高压侧和低压侧的电气隔离。并采用恒定电压值控制控制器负载侧输出,确保获取准确负载电压值;设计了控制器软件关键代码,并设计了均衡控制器进行高压交流侧MMC的控制策略、ISOP隔离型DC-DC变换器的控制策略和低压侧三相四桥臂逆变器控制策略,最终完成电力电子的均衡控制。实验分析了均衡控制器在空载、带载时的运作状态,证明设计的均衡控制器对电容、电流和电压的转换效果良好,响应速度快,设计的控制策略准确有效。 相似文献
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PWM整流器的直接电流控制策略和控制器的设计 总被引：1，自引：0，他引：1
本文对PWM整流器的控制策略进行了概述,并对各种控制策略做了相应的比较,并指出了各自的优缺点。其中重点介绍了直接电流控制技术的原理、PWM整流器d-q模型的建立及控制器设计,最后通过仿真验证了原理的正确性。 相似文献
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本文主要设计了三相PWM整流器及其控制电路的主要参数,并对三相PWM整流电路进行仿真.着重对基于空间电压矢量的PWM整流电路电流解耦控制策略进行研究.通过仿真验证PWM整流器可以实现单位功率因数,且直流电压稳定,动态响应较快. 相似文献
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This paper presents a multi objective differential evolution (MODE) based voltage security enhancement through combined preventive-corrective control strategy. Load shedding, generation rescheduling and optimal utilization of FACTS devices are considered for security enhancement. Maximum l-index of load buses is taken as the indicator of voltage stability. Minimization of cost of FACTS devices, minimization of amount of load shedding along with improvement in voltage stability are the objectives of this multi objective optimization problem. The optimal location of FACTS devices are selected using modal analysis technique. The buses for load shedding are selected based on the minimum eigen value of load flow Jacobian. The proposed MODE algorithm employs DE/randSF/1/bin strategy scheme with self tuned parameter which employs binomial crossover and difference vector based mutation. A fuzzy based decision making algorithm is employed to get the best compromise solution from the non dominated solutions. The proposed MODE is also tested with statistical performance metrices. The proposed methodology is implemented on IEEE 30 bus and IEEE 57 bus test systems. The proposed MODE method provides better solutions in the pareto optimal front than the other optimization techniques such as MOGA and NSGA II under combined preventive–corrective control approach. In IEEE 30 bus system, the amount of load shedding is reduced by 40% and voltage stability is improved by 15% and in IEEE 57 bus system, the amount of load shedding is reduced by 15.4% and voltage stability is improved by 13% by the proposed approach. Hence the simulation results show that the proposed approach provides considerable reduction in the amount of load shedding and enhancement of voltage stability by including generation rescheduling and utilization of FACTS devices. 相似文献
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This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dc-dc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the d-q reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller. 相似文献
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系统基于公交优先智能控制策略,采用内嵌ARM9内核的三星S3C2410处理器,整合了GPS(全球定位系统)、GPRS(通用无线分组业务)以及多数据流传感器,实现对公交车辆位置、温度、人数等数据的采集、传输及反馈,提高了公交系统调度效率和增强了安全性,实现了公交优先的智能控制。介绍了系统的构成,并给出软硬件的设计方案。 相似文献
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系统基于公交优先智能控制策略,采用内嵌ARM9内核的三星S3C2410处理器,整合了GPS(全球定位系统)、GPRS(通用无线分组业务)以及多数据流传感器,实现对公交车辆位置、温度、人数等数据的采集、传输及反馈,提高了公交系统调度效率和增强了安全性,实现了公交优先的智能控制。介绍了系统的构成,并给出软硬件的设计方案。 相似文献
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新型动态电压恢复器在双馈风力发电机中的应用 总被引：1，自引：0，他引：1
在不对称电网故障下,采用基于同相位补偿法改进控制策略的新型动态电压恢复器（DVR）,提高双馈风力发电机（DFIG）的低电压穿越能力。通过两个改进的正负序检测器分别对网侧和机侧电压分量进行分解,消除不平衡故障下的负序分量的影响;利用四个PI控制器分别调节每一相序,注入串联电压,保证双馈风力发电机电压可以达到正常值;通过旋转这个串联电压,注入无功功率到电网中,保证系统的稳定运行,仿真结果证明了所提控制策略的有效性。 相似文献
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Dezhi Xu Yuchen Dai Chengshun Yang Xinggang Yan 《Journal of The Franklin Institute》2019,356(4):1880-1898
This study focuses on the control of islanded photovoltaic (PV) microgrid and design of a controller for PV system. Because the system operates in islanded mode, the reference voltage and frequency of AC bus are provided by the energy storage system. We mainly designed the controller for PV system in this study, and the control objective is to control the DC bus voltage and output current of PV system. First, a mathematical model of the PV system was set up. In the design of PV system controller, command-filtered backstepping control method was used to construct the virtual controller, and the final controller was designed by using sliding mode control. Considering the uncertainty of circuit parameters in the mathematical model and the unmodeled part of PV system, we have integrated adaptive control in the controller to achieve the on-line identification of component parameters of PV system. Moreover, fuzzy control was used to approximate the unmodeled part of the system. In addition, the projection operator guarantees the boundedness of adaptive estimation. Finally, the control effect of designed controller was verified by MATLAB/Simulink software. By comparing with the control results of proportion-integral (PI) and other controllers, the advanced design of controller was verified. 相似文献
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针对高压电机起动过程中的电网电压凹陷,以及电网枢纽点的母线电压波动等电能质量问题,提出了一种基于PLC调控自给直流励磁磁阀式可控电抗器的新型高压电机软起动方式。该方法克服了传统软起动方式装置体积大,谐波较大,对环境要求高,可靠性低,价格昂贵等缺点。结合自励式磁控软起动器基于恒流起动的控制策略,开发出基于16位单片机（Intel 80C196KC）和可编程逻辑控制器（PLC,Siemens S7-200）相结合的软起动器控制装置。 相似文献
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Tousif Khan Nizami Arghya Chakravarty Chitralekha Mahanta 《Journal of The Franklin Institute》2018,355(12):4996-5017
In this paper, the issue of output voltage regulation in buck type dc-dc converters is addressed using a current sensorless control technique. The proposed strategy integrates a finite time current observer with an adaptive backstepping control scheme to yield a cost-effective and robust control mechanism. The overall controller stability in the sense of Lyapunov is proved. Applicability of the proposed control is verified experimentally on a buck converter in the laboratory. The control scheme is implemented on dSPACE DS1103 platform based on DSP TM320F240 processor. To examine the efficacy of the proposed method, the buck converter is subjected to a wide change in input voltage, load resistance and reference voltage. For comparison purpose, a conventional adaptive backstepping control scheme is evaluated under identical conditions of experimental study to examine the merit of the proposed control. The results obtained reveal that the proposed control is prompt in rejecting perturbations and achieves a smooth, reliable and satisfactory output voltage regulation with faithful and time bound estimation of inductor current. Thereby, this investigation demonstrates the validity of the proposed control in maintaining a stringent output voltage regulation in buck converters. 相似文献
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本文在传统变频装置的基础之上,采用三相电压型PWM整流器代替原有的电力二极管不控整流,从根本上解决了变频器整流单元对电网的污染问题。实现了电能回馈电网,以实现理想的四象限变频传动。利用TI公司的TMS320LF2407ADSP设计了双侧PWM电压源变换器硬件实现原理图,并给出了系统的软件实现。 相似文献
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采用单相电流型多电平变流器作为光伏并网发电系统的电路接口,可以降低开关器件的开关频率和电流应力,同时可以使电网侧电流获得更好的谐波特性。为获取更好的谐波性能,电流型多电平逆变器部分采用POD-PWM调制,并通过直流侧电流反馈实现分流电感电流的均衡控制。最后,通过锁相环控制,使多电平逆变器输出的电流跟踪电网电压,实现并网。基于PSIM仿真环境,设计了单相五电平电流型光伏并网逆变系统,对上述方案的正确性和可行性进行了验证。 相似文献