避雷线调谐抽能的研究

本文首次提出利用绝缘避雷线进行调谐抽能,论述了调谐抽能的原理、条件、等值电路和计算方法,用研制的5KVA变压器抽能装置进行模拟试验,理论计算和试验结果比较接近。     

串联调谐装置的调谐分析

介绍了变压器工频耐压试验的串联调谐装置，对其性能和特性进行了分析，给出了结论。     

调匝式自动补偿消弧装置调谐测量原理研究

针对调匝式自动补偿消弧装置现有调谐方法测量精度差、不能适应在牵手变电站中并联运行等问题,提出了利用谐振法结合曲线拟合法测量系统电容电流的方法。该方法测量精度高,调档数目少,能自动并联,无需相互通信,适合在各种场合并联运行。模拟电网试验和现场运行试验结果令人满意。     

调匝式自动补偿消弧装置调谐测量原理研究

针对调匝式自动补偿消弧装置现有调谐方法测量精度差、不能适应在牵手变电站中并联运行等问题,提出了利用谐振法结合曲线拟合法测量系统电容电流的方法.该方法测量精度高,调档数目少,能自动并联,无需相互通信,适合在各种场合并联运行.模拟电网试验和现场运行试验结果令人满意.     

交流调谐滤波器的进展

论述了交流调谐滤波器的工作原理和固有缺点,说明滤波器参数变化所引起的失谐是导致滤波性能恶化的主要原因。介绍了新型自动连续调谐滤波器的原理结构及其关键部件,指出用有源技术增强LC调谐滤波器对参数变化的自适应能力是滤波装置今后的一个发展方向。     

半波长交流输电柔性调谐技术

为支撑和加快全球能源互联网建设,半波长输电技术作为一种点对点、超远距离的大容量输电技术方案,是支撑跨国、跨洲输电的有效途径之一,具有较强的优势。半波长输电要求线路为3 000 km(50Hz),实际线路很少能满足这个要求。当线路长度不足或过长时,可以采用人工技术将实际线路调谐成半波长。针对常规无源调谐网络对系统频率变化适应性较差、容易因失谐而失去半波特性及无源调谐适应范围窄等问题,提出了柔性调谐技术。柔性调谐技术通过变频式柔性调谐装置或同步补偿式柔性调谐装置来实现。柔性调谐避免了现有半波长输电无源调谐网络对系统频率变化和双回线适应性较差,容易因失谐而失去半波特性及无源调谐网络内部发生短路故障时引发过电压问题,且同时适用于电气距离大于或小于半波长的线路,具有良好的性能。     

调谐型无功补偿装置选型计算

谐波污染会使传统的无功补偿方式——并联电力电容器无法正常投入使用。调谐型无功补偿方式可有效应用于谐波污染严重的电网。调谐型无功补偿装置采用电容器串联电抗器的方法,使该回路的调谐频率低于网络中产生的最低次谐波的频率。补偿装置的调谐频率及补偿容量由电容器和电抗器的特征参数共同决定。文章详细介绍了调谐型补偿装置的调谐频率确定原则,即选型计算,电容器电容值、设计电压、设计容量的计算方法及电抗器的选择,并以施耐德电气公司产品为例说明此选型过程。     

谐振与调谐变压器

调谐变压器可以降低试验电源的输入电流及输入容量,以满足大容量发电机工频耐压试验的要求。本文认椁调谐变压器的工作原理和特点,分析了漏磁电感对调谐变压器性能的影响。     

半波长交流输电柔性调谐的控制策略与仿真分析

半波长交流输电要求线路送受端的电气距离接近半个工频波长。当线路的电气长度不足半个波长时,需要进行人工调谐以确保线路呈现半波长特性。针对现有无源型调谐网络的不足,本文提出了π型半波长输电柔性调谐装置,包括两组并联调谐器和一组串联调谐器。结合并联调谐器和串联调谐器的主电路结构及工作原理,设计了适用于半波长柔性调谐的控制策略,并通过仿真验证了π型柔性调谐装置的可行性。通过适当的控制策略,柔性调谐装置可实现功率因数补偿这一附加功能,仿真结果表明,在实施功率因数补偿后,避免了无功功率经过半波长线路,减小了半波长线路沿线电压、电流的波动。     

磁共振式无线电能传输相控电容调谐新方法

研究了磁共振式无线电能传输的传输效率,指出获得高传输效率的关键在于提高谐振电路的品质因数;针对高品质因数谐振电路的易失谐性,提出一种基于相控电容的谐振电路调谐方法:通过改变相控电容的相位角,等效形成一个可变电容,用此可变电容对谐振电路进行调谐,从而稳定传输效率和功率。分析相控电容调谐原理,设计相控电容调谐电路,给出相位与等效电容之间的对应关系,并采用仿真和实验的方法对其调谐特性进行了验证。结果表明:相控电容调谐具有一定的可行性,可使磁共振式无线电能传输在耦合改变时,通过谐振补偿来维持电能传输的稳定性,因而对其推广应用具有重要意义。     

A procedure for tuning automatic controllers with determining a second-order plant model with time delay from two points of a complex frequency response

The problem of obtaining the mathematical model of a plant in the course of adaptively tuning the operating automatic closed-loop control systems is considered. A new method is proposed for calculating the parameters of a model with four free coefficients represented by two inertial sections with a time delay. The model parameters are calculated from the data of experiments on determining two points of a plant??s complex frequency response. The results from checking the performance of the method in combination with obtaining information on the plant dynamics by applying the Fourier transform to the impulse transient response of the system are presented. The PID controller is tuned using a parameter scanning algorithm with directly checking the amplitude-frequency response of the closed-loop system, using which the stability margin can be calculated and different quality criteria can be applied.     

Power system stabilization control based on the wide area phasor measurement

This paper presents a method of tuning power system stabilizers (PSS) in order to damp low‐frequency oscillations in a multimachine power system based on wide area phasor measurements. The authors have developed a method for detecting interarea low‐frequency modes from measured small oscillations associated with load fluctuations by approximating the oscillations as a coupled vibration model. In this paper, the coupled vibration model is extended to include the effect of PSS. PSS are tuned directly by using the extended model, since the model includes parameters of PSS. The advantage of this method is that steady state phasor fluctuations are available for tuning PSS and assessing the effect of the tuning control. That is, a large disturbance like a line fault is not necessary since the stability of major modes can be investigated directly by using eigenvalues of the extended model. The identification process does not require information on the input to the system for perturbation. Some numerical analyses demonstrate the effectiveness of the method by using phasor dynamical data obtained by a power system simulation package. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 163(1): 16–24, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20640     

Simultaneous tuning of power system damping controllers usinggenetic algorithms

This paper presents a method that simultaneously tune multiple power system damping controllers using genetic algorithms (GAs). Damping controller structures are assumed to be fixed consisting basically of lead-lag filters. The tuning method takes robustness into consideration as it guarantees system stabilization over a prespecified set of operating conditions. Modified GA operators are used in the simultaneous optimization of both phase compensations and gain settings for the stabilizers. The method is applied for global PSS tuning to the well-known New England system and to the coordinated tuning of 22 PSSs in a 1762-bus modified equivalent South-Southeastern Brazilian system     

基于PWM整流器的无功补偿容量整定方法

为了充分利用PWM整流器的容量,实现对电网无功功率的调节及电网电压的稳定控制,深入分析了一种基于PWM整流器的无功补偿容量整定方法。重载情况下,PWM整流器在其容量范围内向电网不补偿或少量补偿无功功率,无功功率补偿量由PWM整流器的额定容量和直流负载功率共同决定;轻载情况下,PWM整流器能够补偿电网所缺的所有无功功率。文章还详细分析了直流电容参数的选取方法。最后通过MATLAB/Simulink仿真进行了验证,仿真结果表明该整定方法能够实现无功功率的动态补偿。     

Data‐Driven Controller Tuning for Nonminimum Phase Plants with Stability Constraints

This paper addresses the model reference control problem, which is a typical control problem found in data‐driven controller tuning methods. For nonminimum phase plants, the unstable zeros of the plant should be included in the reference to avoid destabilization of the resulting closed‐loop system and improve tracking performance. First, we propose a data‐driven controller tuning method with closed‐loop stability taken into consideration and with the tuned controller parameters in the time domain. If the plant has unstable zero(s), the proposed method would not lead to destabilizing controller in the worst case. Closed‐loop stability is checked using linear inequalities described with input/output data. This contributes to reducing computation in the proposed method. Moreover, this paper proposes a data‐driven controller tuning method for nonminimum phase plants estimating the unstable zero(s) using a flexible reference model at each parameter update and reflecting them into the resulting reference model. The effectiveness of the proposed method is confirmed through numerical experiments.     

基于调相法的消弧线圈自动跟踪补偿的测量方法

提出了一种基于调相法的消弧线圈自动跟踪补偿测量方法。对于消弧线圈并阻尼电阻接地的配电网,通过投切并联在消弧线圈两端的阻尼电阻以增加系统的阻尼率,同时调节消弧线圈的电感量,保证调节前后零序电压的相位互差90°,即可根据已知信息计算出系统的对地电容和对地电导的精确值。通过在Matlab中建立仿真模型并进行仿真实验,验证了所提出的新型调谐方法的正确性。这种调谐新方法操作简单,易于实现,并且在预调式和随调式消弧线圈中均可使用。     

非接触电能传输系统的频率稳定性研究

分析了非接触电能传输系统主电路的频率稳定性问题,提出了利用相控电感电路动态调谐以提高系统工作频率稳定性的方法,保证最大功率传输和系统正常工作,并对动态调谐的工作原理进行了分析和仿真研究.     

基于遗传算法的有源电力滤波器直流母线电压控制

随着电力电子装置的普遍应用,其非线性特征而引起的电网电压和电流畸变越来越引起人们的重视,有源电力滤波器(APF)是一种较好的谐波滤除装置,但存在直流侧电压不稳的问题。分析了影响APF直流侧电压稳定的几个因素,推导了电压源型有源电力滤波器的数学模型,结合遗传算法辅助优化计算了该系统中APF的PI调节系数,MATLAB/simulink仿真验证了该方法的可行性,为遗传算法在PI整定方面的研究提供了借鉴。     

Diode-pumped tunable Yb:YAG miniature lasers at room temperature:modeling and experiment

We present a simple design rule for diode-laser pumped quasi-three-level lasers by using the M² factor. The validity of this model was demonstrated by diode-pumped Yb:YAG laser experiments. The maximum output power of 1.33 W and optical slope efficiency of 63% were obtained in a 400-μm Yb:YAG chip miniature laser. Using a 200-μm Yb:YAG chip, a 70% optical slope efficiency was reached. In a coupled-cavity configuration, with a quartz birefringent tuning filter, 8.2 THz (29 nm) of tuning was obtained at room temperature. By changing to a calcite birefringent filter, single-axial-mode oscillation with an output power of 500 mW was observed