采用定制电力技术解决配电侧电能质量问题

基于电能质量定义,介绍了当前新的研究领域———定制电力技术,着重分析了统一电能质量控制器(UPQC)的产生背景。在此基础上通过对小型定制电力工业园区模型的介绍和分析,表明采用定制电力技术将成为解决配电侧电能质量问题的关键。     

Optimal tracking secondary voltage control for the DFIG wind turbines and compensator devices

The optimal tracking secondary voltage control (OTSVC) is a new developed voltage control scheme for wind park based Doubly Fed Induction Generator (DFIG). The proposed controller is developed to achieve efficient voltage regulation and provided optimal reactive power compensation to the interconnected power system. The performance of the controller for enhancing the network voltage profile is compared with secondary voltage control, primary voltage control and optimal voltage profile obtained from the optimal power flow analysis. Furthermore, the OTSVC is employed for controlling wind park based DFIG and other sources of reactive power such as static var compensator (svc). The dynamic performance of the controller for multiple sources of reactive power is tested for steady state operation and in response of system contingencies with considering the impact of communication time delays. Simulation results are presented and the capability of the controller in providing the desired reactive power compensation and voltage support for the power system are verified.     

电能质量调节器的研究

针对电力系统中存在大量的非线性负荷,介绍了一种综合解决电能质量问题的电能质量调节器.分析了电能质量调节器的结构和工作原理;介绍了基于同步旋转Park变换的d-q检测方法以及用三角波作为载波的PWM控制方式;最后介绍了用于解决电压跌落和浪涌的动态调节三角载波的控制方式.     

优质电力园区多DFACTS设备协调控制策略

优质电力园区利用多种DFACTS设备为园区内不同等级的负荷提供相应等级的电能,是一种解决电能质量问题的重要手段。由于多种DFACTS设备可能同时动作,需要对它们进行协调控制。文章依托南京青奥会优质电力园区配套工程,提出基于电能质量监控中心的多DFACTS设备协调控制策略,PSCAD/EMTDC的仿真结果验证了该方法的正确性和有效性。     

优质电力园区供电电源和定制电力装置协调性分析

优质电力园区(PPP)是定制电力技术应用的重要方面。本文主要从应用案例和研究现状两方面来对供电电源和电能质量装置协调性进行分析。首先分析了两种典型PPP应用案例中的协调问题;然后分析了实现不同电能质量等级供电和提高整体供电可靠性这两种不同研究方向PPP的协调问题,重点分析了前者,并给出了协调流程图。最后针对今后建设和研究方向的PPP,指出了如何实现供电电源和PQDs协调。     

动态电压恢复器研究综述

动态电压恢复器（DVR）作为一种重要的用户电力装置，受到国内外研究者的广泛关注。首先介绍DVR的工作原理和基本结构，然后从拓扑结构、补偿策略以及控制方法几个方面对现有文献进行综述。最后对DVR的研究发展进行了探讨。     

现代电能质量的主要问题及其对策

阐述了电能质量的概念，分析了产生电能质量问题的原因及其分类。指出电压暂降是现代电能质量的主要问题。介绍了几种具有代表性的解决电压暂降问题的用户电力设备(如DVR，UPQC等)的工作原理和特性。     

基于预测电流控制的配电网无功补偿器研究

配电网静止无功补偿器(DSTATCOM)是用户电力技术的重要装置之一.提出基于预测电流控制的双环控制方法,利用DSTATCOM来抑制电压波动、跌落和平衡三相不对称负载.实验结果表明所设计的DSTATCOM具有良好的性能,能够有效地解决电能质量问题.     

优质电力园区应用案例与拓扑结构研究综述

优质电力园区(Premium Power Park,PPP)作为定制电力技术应用的一个重要方面,无论在传统的工业领域,还是在现代的金融、IT行业都得到了应用。文中首先分析了国内外两个典型的PPP——特拉华PPP和仙台市多级电能质量供电系统示范基地的运行情况,并简要地介绍了国内外其它PPP的应用情况;然后从供电方式、所供应负荷类型以及采用定制电力装置的补偿能力等方面对PPP拓扑结构的发展状况进行了分析;最后对PPP今后的研究和发展方向作了总体分析,为今后PPP的规划和建设提供可选方案。     

UPQC直流储能单元的APFC控制技术

统一电能质量控制器(UPQC)是用户电力技术中的新兴装置,它能统一实现多重电能质量调节功能。系统地介绍了UPQC的综合补偿功能,并给出了一种典型的UPQC拓扑结构。为了进一步提高UPQC的性能,将有源功率因数校正(APFC)技术引入UPQC直流储能单元的直流电容电压控制,详细阐述了其工作原理,并给出了仿真实验结果。APFC技术用于UPQC的直流储能单元中是完全可行的,它使UPQC的性能更完善。     

配电网动态电能质量问题及其解决方案

针对目前动态电能质量存在的问题尤其是电压跌落产生的原因,介绍了动态电能质量问题的分析方法和控制技术。应用合理的分析方法准确快速的提取电能质量的动态特性参数,正确的控制技术是调节装置良好动态特性的保证。由于定制电力技术作为面向用户电能质量的技术,在解决动态电能质量上有突出的作用,又分析了定制电力技术的调节装置的基本原理和功能,并对各种方案进行了比较。     

电能质量问题的研究和技术进展(一)--电能质量一般概念

解释电能质量、电磁兼容等基本术语，从供电质量与用户需求的角度分析了质量指标的影响，用区域分割式的解决方案隔离电能质量扰动源与特殊电力用户，提出基于用户电力技术的电能质量辅助服务的建议。     

不同系统联结方式下通用电能质量控制器的功率分析

探讨了通用电能质量控制器的工作原理及其基本的系统联结方式,结合稳定直流侧电容电压调节器的控制策略,分析了在相同的电网和负载条件下,不同系统联结方式的通用电能质量控制器功率情况,包括电网和串联控制器、并联控制器、负载等输出和吸收的瞬时功率脉动分量、直流分量及其构成和作用.获得的结论能为UPQC系统联结方式的确定和容量估算及工程应用提供参考.     

Experimental evaluation of active power factor correction techniques in a single-phase AC-DC boost converter

The increasing need to improve power quality with the reduction of the harmonic content of current and voltage waveforms has been intensively analyzed in several studies, thus motivating the proposal of many high power factor rectifiers based on the classic converters such as boost and buck-boost. Moreover, distinct control techniques have also been proposed due to the commercial availability of integrated circuits (ICs) dedicated to impose sinusoidal input currents in switch-mode power supplies (SMPSs). The boost converter operating in continuous conduction mode (CCM) is by far the most traditional choice for this purpose due to circuit simplicity and low electromagnetic interference (EMI) levels. Within this context, this work analyzes some of the most important control techniques used in power factor correction (PFC). The performance of a single-phase boost converter using peak current mode control (PCMC), average current mode control (ACMC), and one cycle control (OCC) is evaluated experimentally in detail. A comprehensive analysis of key aspects such as the input current waveform and respective harmonic content, dc output voltage, and dynamic response of the converter is also presented.     

A Comparative Performance Evaluation of Extended AANF with Different Parameter Estimation Techniques for Renewable Energy Integration

This paper presents real time performance evaluation of three phase extension of an amplitude adaptive notch filter (AANF) for online estimation of frequency, amplitude, and sequence components of the input grid voltage signal. The performance of an extended AANF is compared with conventional synchronous reference frame-phase lock loop (SRF-PLL), enhanced phase lock loop (EPLL), and existing adaptive notch filter (ANF). Comparative analysis has been carried out based on their ability in extracting frequency and amplitude of input grid voltage signal under balanced and unbalanced voltage sag/swell, frequency shift and distorted grid condition. Three phase AANF method provides high degree of accuracy than SRF-PLL, EPLL, and ANF in extracting appropriate signal information for unbalanced and harmonically distorted grid condition. The important feature of this method is its amplitude adaptability, which improves its speed of response and accuracy when grid signal is of variable amplitude. OPAL-RT’s (OP4500) real time controller with an in-built Xilinx Kintex-7 FPGA processor is used for real time implementation. Experimental results validate fast and accurate performance of an extended AANF in extracting frequency, amplitude, and sequence components of the utility grid voltage signal, which can be further used for performance improvement of grid connected renewable energy systems, custom power devices, and flexible ac transmission systems (FACTS) devices.     

New control approach for capacitor supported DSTATCOM in three-phase four wire distribution system under non-ideal supply voltage conditions based on synchronous reference frame theory

A large number of single-phase linear and non-linear loads may be supplied from three phase ac mains with neutral conductor. They cause excessive neutral current, harmonics and reactive power burden and unbalance. A four wire DSTATCOM (distribution static compensator) is used for neutral current compensation along with reactive power compensation, harmonics elimination and load balancing. A novel control approach is proposed for the control of four wire DSTATCOM under non-ideal supply voltage conditions. A four-leg voltage-source converter (VSC) with a dc capacitor is used as a four wire DSTATCOM. The proposed control approach is based on synchronous reference frame (SRF) theory and an indirect current control technique. The switching signals for the voltage-source converter (VSC) of the DSTATCOM are derived from the estimated reference supply currents. The load balancing, harmonics elimination and the neutral current compensation are demonstrated along with unity power factor (UPF) and zero voltage regulation (ZVR) modes of operation. Simulation results based on MATLAB software with its Simulink and power system blockset (PSB) toolboxes are presented to validate the control strategy. The DSTATCOM is able to maintain the self-supported dc bus under various disturbances.     

面向智能电网的新一代电能质量管理平台

总结了电能质量监测系统发展趋势,提出建立基于现有电能质量监测系统的电能质量管理平台。在电能质量评估功能基础上,加入了分级电能质量预警、谐波潮流计算、薄弱环节/扰动源识别、电能质量趋势预测、综合管理措施和动态仿真功能。采用异常数据挖掘技术,实现电能质量预警模块中超标和异常检测,并依据阈值设定的不同,提出了稳态和暂态电能质量指标的4级预警策略,并建立了相应预警特征事件库。平台引入电能质量水平趋势预测和动态仿真模块校核管理措施的策略。最后,提出将功能集成化的平台应用于优质供电园区电能质量管理和控制中的构想。该平台电能质量评估和预警模块已投入电网实际应用。     

三相串联电能质量控制器补偿电压的优化

串联型电能质量控制器(SPQC)通过向系统电压中串联一个电压源来调节用户侧电压质量。在系统电压出现跌落，浪涌，不平衡等现象的情况下，使用SPQC进行补偿可以获得更高的效率。本文对系统电压不平衡条件下SPQC注入电压的特性进行了分析。在这个基础上对三相三线制和三相四线制三相不平衡电压跌落的优化补偿进行了研究，分别就三相四线制系统和三相三线制系统提出了优化补偿电压的算法并进行了仿真。仿真结果很好的证明了理论分析的正确性。     

一种基于智能改进算法的定制电力设备优化配置策略

为了更好地治理配电网谐波污染、低功率因数以及电力系统电压波动所带来的敏感负荷不能正常工作问题,研究了配电网多种定制电力设备的优化配置。综合考虑电能质量治理目标以及投资费用建立了优化配置数学模型,并提出一种将遗传算法与内点法有机结合的混合优化策略用于多种定制电力设备的优化配置。该混合策略利用遗传算法锁定各装置的最优安装位置并求得近似最优安装容量,将近似容量设为内点法初值寻找更加精确更优的安装容量。此外,分别基于约束越限和预判自适应对遗传算法和内点法做出改进,提高了寻优速度。理论分析和仿真结果表明,该混合算法比单独的遗传算法稳定性更高、寻优结果更加精确。     

Extended Reactive Capability of DFIG Wind Parks for Enhanced System Performance

This paper discusses the impact of utilizing the capability curve of a doubly fed induction generator (DFIG) based wind park on steady state and dynamic power system operation. The interconnection requirements set forth by FERC in order 661-A mandate the operation of wind parks within a power factor range of 0.95 leading and lagging. This operation drastically underutilized the reactive output of the machine. The results presented demonstrate that committing the full reactive capability of a DFIG park for generation dispatch produce a significant reduction in system losses. This additional reactive support was also found to improve post-fault voltage profiles by damping oscillations and preventing overshoots immediately after being subjected to a disturbance. This utilization of extended reactive limits in voltage control may prevent system collapse.