基于约束因子限幅控制的双馈感应发电机有功功率平滑控制

在分析双馈感应发电机（doubly-fed induction generator,DFIG）运行特性和传统最大风能追踪控制（maximum power point tracking,MPPT）策略的基础上,给出一种基于约束因子限幅控制的DFIG有功功率平滑控制策略,提出功率输出限幅值可调的控制思想,结合发电机转速控制和风力机变桨距控制来实现输出功率保持在任意给定值。给出了约束因子的表达式和取值规则。在Matlab／Simulink仿真平台上采用所提平滑控制策略,对一个9MW风电场的有功功率输出特性进行研究,计算了2种控制策略下输出功率的平滑性能指标和方差值。实验结果表明,与传统最大风能追踪控制策略相比,所提出的平滑控制策略能显著减小发电机输出功率的波动,优化了系统的电能质量。     

Robust control of an isolated hybrid wind-diesel power system using Linear Quadratic Gaussian approach

This paper presents the application of the Linear Quadratic Gaussian (LQG) controller for voltage and frequency regulation of an isolated hybrid wind-diesel scheme. The scheme essentially consists of a vertical axis wind turbine driving a self-excited induction generator connected via an asynchronous (AC-DC-AC) link to a synchronous generator driven by a diesel engine. The synchronous generator is equipped with a voltage regulator and a static exciter. The wind generator and the synchronous generator together cater for the local load and power requirement. However, the load bus voltage and frequency are governed by the synchronous generator. The control objective aims to regulate the load voltage and frequency. This is accomplished via controlling the field voltage and rotational speed of the synchronous generator. The complete nonlinear dynamic model of the system has been described and linearized around an operating point. The standard Kalman filter technique has been employed to estimate the full states of the system. The computational burden has been minimized to a great extent by computing the optimal state feedback gains and the Kalman state space model off-line. The proposed controller has the advantages of robustness, fast response and good performance. The hybrid wind diesel energy scheme with the proposed controller has been tested through a step change in both wind speed and load impedance. Simulation results show that accurate tracking performance of the proposed hybrid wind diesel energy system has been achieved.     

Comparative evaluation of sliding mode fuzzy controller and PID controller for a boost converter

Nonlinear controllers such as fuzzy controllers and sliding mode controllers have been applied to boost converters because of their nonlinear properties. Although both fuzzy and sliding mode controllers have desirable characteristics, they have disadvantages in practice when applied individually. A sliding mode fuzzy controller is proposed to control boost converters. The sliding mode fuzzy controller combines the advantages of both fuzzy controllers and sliding mode controllers. It also has advantages of its own that are well suited for digital control design and implementation. A sliding mode fuzzy controller is designed and verified with experimental results using a prototype boost converter with a DSP-based digital controller. Experimental results of the boost converter using sliding mode fuzzy control are evaluated in comparison with experimental results using a linear PID and PI controller. The comparison indicates that the sliding mode fuzzy controller is able to obtain the desired transient response under varying operating points without chattering. The startup response using sliding mode fuzzy control is superior to the response using PID and PI control, while the load transient response shows no obvious advantage.     

补偿电压暂降的超级电容器储能系统控制研究

介绍了电压暂降的危害及其抑制措施,并在分析超级电容器储能系统对电压暂降的补偿原理的基础上,设计了该储能系统的控制系统及其参数。仿真结果表明,设计的控制系统能实时有效地控制电压、抑制电压暂降。     

LCL滤波型风电并网变流器的研究

介绍了LCL滤波型风电并网变流器的主电路拓扑结构和数学模型,提出了采用电网电流反馈闭环控制,实现电网侧电流闭环的有功、无功功率解耦的控制策略;采用MATLAB(R2010a)建立了系统仿真模型.仿真结果及试验结果表明,采用该控制策略,对LCL滤波型风电并网变流器进行控制的有效性.     

空间双通道电机噪声有源控制系统研究

针对实验室一台直流电动机-同步发电机机组运行噪声的频谱特点,提出空间双通道有源噪声控制系统降低电机运行噪声。采用四种双通道控制算法(Ⅰ)FxLMS算法,(Ⅱ)FuRLMS算法,(Ⅲ)HFxLMS算法以及(Ⅳ)FBFxLMS算法进行电机运行噪声有源控制实验,对于电机运行转速分别为1300 r/min、1400 r/min和1500 r/min时,噪声控制区域内水平平面和垂直平面上平均声压级降低量均大于10 dB,水平平面上最大声压级降低量分别为17.92 dB、13.28 dB和17.88 dB,垂直平面上最大声压级降低量分别为16.73 dB、16.36 dB和16.99 dB,降噪效果表明本文提出的空间双通道有源控制系统能有效地降低电机运行噪声。     

基于微网平衡的港口桥吊电机控制系统

分析了洋山港桥吊电机冲击性负荷和在生产过程中频繁起停产生的电压波动和电网运行不稳定等问题.从系统角度分析桥吊电机频繁起停与微网供配电系统的特点,提出对桥吊电机进行系统综合控制和单元分组控制相结合的递阶控制策略,并进一步提出超级电容储能器对桥吊电机预起动电能补偿的控制方案,可有效减小桥吊电机对电网的冲击,降低电能损耗和对环境的影响.同时,该方案可以为其他领域微网系统提供借鉴作用.     

省级电力公司门户升级改造风险管控研究

为了适应国家电网公司信息化建设工作的不断开展,深入提升门户实用化水平,确保甘肃省电力公司企业门户系统更好地为公司员工日常工作服务,甘肃省电力公司决心全面启动升级改造工作.针对门户系统升级改造过程中可能出现的风险,甘肃省电力公司从管理体制和技术手段2方面提供了管控措施:一方面成立专门的风险管控小组,对门户升级改造过程实行分阶段管控,对整个门户系统风险管控流程进行预先规划;另一方面采取相应的备份措施,对升级脚码进行事前演练,对门户升级过程中可能出现的问题进行预先评估并制定相应的处理措施.最终确保了整个门户的无间断升级,并保证了整个门户系统升级改造过程在时间和风险上的可控性.     

SCS-200A频率电压紧急控制装置组态式软件的设计与实现

通过对频率电压紧急控制装置软件的研究,根据软件模块化、分层抽象和隔离数据与程序逻辑的原则,提出了功能设定、数据采集与处理、定值管理、出口控制等组态配置实现的方法。在SCS-200A频率电压紧急控制装置中开发了使用该方法的组态式工程软件,完成了型式试验。使用该软件,有利于频率电压紧急控制装置配置的标准化,有利于频率电压紧急控制装置生产、维护和升级改造的灵活性,有利于提高频率电压紧急控制装置的可靠性。     

永磁曳引机结构及控制分析

对比分析永磁曳引机三种常用转子结构。在两种不同的控制方式下,采用磁场分析软件分别计算曳引机在额定工况下的输出转矩,并结合转子结构特点提出最佳控制方式。